The JI
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
 QUICK SEARCH:   [advanced]


     
 


This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Request Permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Rossi, M.
Right arrow Articles by Young, J. W.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Rossi, M.
Right arrow Articles by Young, J. W.
The Journal of Immunology, 2005, 175: 1373-1381.
Copyright © 2005 by The American Association of Immunologists


BRIEF REVIEWS

Human Dendritic Cells: Potent Antigen-Presenting Cells at the Crossroads of Innate and Adaptive Immunity1

Marco Rossi*,{ddagger},§ and James W. Young2,*,{dagger},{ddagger},§

* Laboratory of Cellular Immunobiology, {dagger} Allogeneic Bone Marrows Transplantation and Clinical Immunology Services, {ddagger} Division of Hematologic Oncology, Department of Medicine, § Memorial Sloan-Kettering Cancer Center, and Weill Medical College of Cornell University, New York, NY 10021


    Abstract
 Top
 Abstract
 Introduction
 Human DCs: distinct subsets...
 Blood moDCs
 Plasmacytoid DCs
 LCs and DDC-IDCs derived...
 Terminal activation and...
 Further distinctions in...
 Ag uptake, processing, and...
 Roles of Toll-like and...
 Fc{gamma} receptors for uptake...
 CD34+ HPC-derived LCs are...
 moDCs are superior stimulators...
 Regulatory T cells (Tregs)...
 Clinical applications of human...
 Conclusions
 References
 
Dendritic cells (DCs) are specialized, bone marrow-derived leukocytes that are critical to the development of immunity. Investigators have emphasized the role of DCs in initiating adaptive or acquired MHC-restricted, Ag-specific T cell responses. More recent evidence supports important roles for DCs in the onset of innate immunity and peripheral tolerance. Progress in the generation of DCs from defined hemopoietic precursors in vitro has revealed the heterogeneity of these APCs and their attendant divisions of labor. This review will address these developments in an attempt to integrate the activities of different DCs in coordinating innate and adaptive immunity.


    Introduction
 Top
 Abstract
 Introduction
 Human DCs: distinct subsets...
 Blood moDCs
 Plasmacytoid DCs
 LCs and DDC-IDCs derived...
 Terminal activation and...
 Further distinctions in...
 Ag uptake, processing, and...
 Roles of Toll-like and...
 Fc{gamma} receptors for uptake...
 CD34+ HPC-derived LCs are...
 moDCs are superior stimulators...
 Regulatory T cells (Tregs)...
 Clinical applications of human...
 Conclusions
 References
 
Paul Langerhans first described dendritic cells (DCs)3 in human skin but thought these were cutaneous nerve cells (1). Steinman and Cohn (2) discovered these cells almost a century later in mouse spleen and applied the term "dendritic cells" based on their unique morphology. For almost two decades, however, proving the specialized properties of these cells for initiating immunity required depletion of other cells like monocytes, macrophages, and B cells that also presented Ag. Potent immunostimulatory activity was enriched in the remaining DCs. The paradigm emerged that Ag capture segregated to immature, peripherally distributed DCs, with Ag presentation and lymphocyte stimulation being an acquired property of mature DCs in secondary lymphoid organs. The essential and pivotal role of DCs in the onset of immunity was thus established.


    Human DCs: distinct subsets and hemopoietic precursors
 Top
 Abstract
 Introduction
 Human DCs: distinct subsets...
 Blood moDCs
 Plasmacytoid DCs
 LCs and DDC-IDCs derived...
 Terminal activation and...
 Further distinctions in...
 Ag uptake, processing, and...
 Roles of Toll-like and...
 Fc{gamma} receptors for uptake...
 CD34+ HPC-derived LCs are...
 moDCs are superior stimulators...
 Regulatory T cells (Tregs)...
 Clinical applications of human...
 Conclusions
 References
 
Progress in the study of DC biology exploded in the 1990s. Investigators developed cytokine-driven methods for expanding and differentiating DCs ex vivo in both mouse and human systems (3, 4, 5, 6, 7, 8, 9, 10), and further refinements continue to emerge (11, 12, 13, 14, 15). For the first time, sufficient numbers of DCs became accessible for large-scale study and applications.

DCs are the single most central player in all immune responses, both innate and adaptive. DCs are exceptionally potent immunogens under inflammatory conditions, yet are also critical to the induction and maintenance of self-tolerance in the steady state (16, 17, 18). The heterogeneity of DCs and their activation states afford investigators more opportunities to define and manipulate the immune response using these specialized leukocytes.

Human DCs are all bone marrow-derived leukocytes (19). They are distinct from follicular DCs, which are not leukocytes and of stromal origin. Follicular DCs interact with B cells in the germinal center, but they have no role in T cell, NK cell, or NKT cell immunity as do conventional or plasmacytoid DCs (20).

Human DCs comprise at least four types defined under cytokine-driven conditions in vitro (Fig. 1). These include conventional or "myeloid" DCs (5, 6, 8, 10, 12, 14, 15, 21, 22): 1) CD14+ blood monocyte-derived DCs (moDCs); 2) dermal DCs or interstitial DCs (DDC-IDCs); 3) Langerhans cells (LCs); and 4) plasmacytoid DCs (23). A trace population of DCs also circulates in human blood. Those DCs are lineage negative, CD11c+, CD86+, and HLA-DRbright and express CD83 after activation by brief overnight culture (24). Although not identical, they share many phenotypic and immunostimulatory features with cytokine-generated conventional DCs in vitro.



View larger version (34K):
[in this window]
[in a new window]
 
FIGURE 1. Development of human DC subsets. Precursors in blood and bone marrow (left section) can give rise to four types of DCs under cytokine-driven conditions ex vivo. Resident populations of immature, nonactivated DCs (middle section) are normally found in the steady state in the periphery and/or the circulation. Semimature DCs continuously present self-Ags, and probably harmless non-self-Ags, in secondary lymphoid organs to maintain peripheral tolerance and anergy. Counterparts for these various DC types develop in vitro in the presence of the indicated cytokines. Harmful pathogens or other dangerous insults to the steady state can lead to inflammation with full maturation and activation of each DC subset (right section). Physiologically, this stimulus is usually provided by a microbial pathogen or product, often signaling through TLRs, or by activated CD4+ T cells expressing CD40L. One can approximate this situation by supplying inflammatory cytokines in vitro, but different maturation stimuli do not affect all aspects of DC immunogenicity uniformly. Terminal maturation and activation are necessary for DCs to exert optimal immunogenicity. FL, Flt-3 ligand; GM, GM-CSF; KL: c-kit ligand; TGF, TGF-{beta}; TNF, TNF-{alpha}.

 
DCs are also a major component of lymphoid tissues, particularly the T cell areas. In the case of lymph nodes, DCs access these areas via afferent lymphatics. Investigators now know that most DCs in lymphoid organs are immature or semimature in the steady state and efficiently process self-Ags to induce and maintain tolerance (16, 18, 25). Under inflammatory conditions, however, DCs undergo a complex maturation process. The specifics of maturation vary with the stimulus, but the result is stimulation of innate and adaptive immunity. DCs in lymphoid tissues include populations termed "conventional" or myeloid, as well as "plasmacytoid", the latter named because of their morphological resemblance to plasma cells (23). This review will focus on human DCs generated in vitro with cytokines, because these have yielded ample numbers and purity for experimental and clinical evaluations.

The precursors of DC progeny generated in vitro with cytokines should approximate resident populations of DCs that exist in vivo under steady-state conditions. The cytokine-driven DC progeny are induced populations and hence would not be found in vivo except under inflammatory conditions. Manipulation of immunity using DCs generated in vitro should therefore exploit the less mature and nonactivated forms to promote tolerance and the activated and mature forms to break tolerance and promote immunity.


    Blood moDCs
 Top
 Abstract
 Introduction
 Human DCs: distinct subsets...
 Blood moDCs
 Plasmacytoid DCs
 LCs and DDC-IDCs derived...
 Terminal activation and...
 Further distinctions in...
 Ag uptake, processing, and...
 Roles of Toll-like and...
 Fc{gamma} receptors for uptake...
 CD34+ HPC-derived LCs are...
 moDCs are superior stimulators...
 Regulatory T cells (Tregs)...
 Clinical applications of human...
 Conclusions
 References
 
The most accessible DC precursor is the CD14+ monocyte in peripheral blood, which differentiates into CD14neg, CD11c+, CD83++, HLA-DRbright, moDCs under the influence of GM-CSF and IL-4 (5, 6, 12, 26) (Fig. 1 and Table I). Blood monocytes also exhibit a sensitivity to ambient cytokines that can drive their differentiation to DCs resembling either activated LCs or DDC-IDCs (27, 28, 29, 30, 31). This may provide biologic flexibility to monocyte precursors and moDCs as first responders to pathogens, allergens, and other causes of inflammation.


View this table:
[in this window]
[in a new window]
 
Table I. Epitopes that distinguish human DC types

 

    Plasmacytoid DCs
 Top
 Abstract
 Introduction
 Human DCs: distinct subsets...
 Blood moDCs
 Plasmacytoid DCs
 LCs and DDC-IDCs derived...
 Terminal activation and...
 Further distinctions in...
 Ag uptake, processing, and...
 Roles of Toll-like and...
 Fc{gamma} receptors for uptake...
 CD34+ HPC-derived LCs are...
 moDCs are superior stimulators...
 Regulatory T cells (Tregs)...
 Clinical applications of human...
 Conclusions
 References
 
Plasmacytoid DC precursors comprise another population identifiable in the circulation as lineage negative, HLA-DRbright, BDCA-2+, BDCA-4+, and CD123bright cells (23, 32) (Fig. 1 and Table I). Human plasmacytoid DCs lack myeloid markers CD11c and CD33. In contrast, the mouse counterpart expresses low levels of CD11c along with B220 and Gr1 and expresses CD123 only after fms-like tyrosine kinase 3 ligand (Flt3-L) treatment (33, 34, 35). Conventional DCs in humans also express the CD123 receptor for IL-3, but less than plasmacytoid DCs (36). IL-3 supports plasmacytoid DC viability, and it is partially interchangeable with GM-CSF for conventional DCs because of a common {beta}-chain shared by receptors for both cytokines (37).

G-CSF mobilizes increased proportions of plasmacytoid DCs from the bone marrow (38, 39), but Flt3-L is the main cytokine for development of plasmacytoid DCs from hemopoietic stem cells (40, 41). Thrombopoietin in combination with Flt-3L supports the generation of human plasmacytoid DCs in vitro from CD34+ hemopoietic progenitor cells (HPCs) (42), but it has proven more difficult to achieve large yields in comparison to those of conventional DCs generated in vitro with cytokines (3, 4, 7, 8, 9, 10, 12, 13, 14, 15).

Freshly isolated plasmacytoid DCs express much lower levels of MHC and costimulatory molecules than their conventional DC counterparts (23, 43). They also capture, process, and load Ags onto MHC molecules less effectively. These nonactivated plasmacytoid DCs are therefore poor stimulators of T lymphocytes. IL-3 in combination with CD40 ligand (CD40L) or microbial products leads to full plasmacytoid DC activation and more potent lymphocyte stimulation (44, 45, 46, 47, 48, 49).


    LCs and DDC-IDCs derived from CD34+ hemopoietic progenitors (HPCs)
 Top
 Abstract
 Introduction
 Human DCs: distinct subsets...
 Blood moDCs
 Plasmacytoid DCs
 LCs and DDC-IDCs derived...
 Terminal activation and...
 Further distinctions in...
 Ag uptake, processing, and...
 Roles of Toll-like and...
 Fc{gamma} receptors for uptake...
 CD34+ HPC-derived LCs are...
 moDCs are superior stimulators...
 Regulatory T cells (Tregs)...
 Clinical applications of human...
 Conclusions
 References
 
In addition to circulating blood DCs and moDCs, the conventional or nonplasmacytoid DCs include LCs and DDC-IDCs. These two resident populations of DCs are distributed throughout the body where the immune system first encounters Ag. Thus, LCs localize to epithelial surfaces of skin and mucosa, and the DDC-IDCs localize to the subepithelial tissues of the dermis in skin and the interstitia of solid organs. That LCs are bone marrow-derived leukocytes was first established in 1979 (19), and that LCs are cutaneous DCs was determined several years later (50).

These DCs develop in vitro from CD34+ HPCs under the aegis of defined cytokines that include GM-CSF and TNF-{alpha} (4, 7, 9) (Fig. 1 and Table I). c-kit-ligand (7, 9) and Flt-3-L (41) are also critical to expansion of the clonogenic DC progenitors but do not affect DC differentiation. TGF-{beta}, especially under serum-free conditions, supports LC differentiation (10, 14, 15, 51). These LCs have Birbeck granules and express Langerin and e-cadherin, which are down-regulated with activation (15, 52, 53).

Human LCs do not express CD11b, an epitope found on moDCs and DDC-IDCs (15). DDC-IDCs develop through a CD14+ intermediate (8, 21, 22), for which the alternative macrophage differentiation pathway is suppressed by IL-4 (26), just as with moDCs. LCs do not develop through a CD14+ intermediate (21), although some investigators have reported differentiation of Langerhans-like DCs from CD14+ blood monocytes (28, 29). All conventional DCs express CD1a, which is not limited to LCs. DDC-IDCs and moDCs, but not LCs, express the other CD1 isoforms, including CD1d (15), which presents glycolipid Ags (see Table I).


    Terminal activation and maturation of DCs
 Top
 Abstract
 Introduction
 Human DCs: distinct subsets...
 Blood moDCs
 Plasmacytoid DCs
 LCs and DDC-IDCs derived...
 Terminal activation and...
 Further distinctions in...
 Ag uptake, processing, and...
 Roles of Toll-like and...
 Fc{gamma} receptors for uptake...
 CD34+ HPC-derived LCs are...
 moDCs are superior stimulators...
 Regulatory T cells (Tregs)...
 Clinical applications of human...
 Conclusions
 References
 
All DCs require some form of terminal maturation to become fully immunogenic. We now know that there are many different environmental stimuli that can mature DCs in different ways. All of the various lymphocyte responses require activation by mature DCs, so that DC maturation is a pivotal event in the control of innate and adaptive immunity. Maturation also ensures that DCs do not revert to a less mature and less immunogenic form. Microbial products constitute a physiologic activation stimulus via TLRs on both plasmacytoid and conventional DCs (47, 48). CD40L (CD154), either expressed by activated T cells or as a multimeric recombinant protein, can also mature DCs (54, 55). A combination of inflammatory cytokines that includes IL-1-{beta}, TNF-{alpha}, IL-6, and PGE2 (11) is often used to mature DCs for study in vitro and for use in clinical vaccine trials.

Terminal activation down-regulates certain chemokine receptors like CCR1 and CCR5, adhesion molecules like e-cadherin on LCs, and Ag uptake. Maturation up-regulates numerous other properties of immunogenic DCs, many expressed with distinct kinetics, including inducible costimulatory molecules, cytokine secretion, and Ag presentation. Mature DCs also increase CCR7 expression, which mediates trafficking into lymph nodes after vaccination (56, 57, 58). A theoretical disadvantage is the lower IL-12p70 secretion after exposure to PGE2 (59) compared with CD40L. Data in vitro (15) and in vivo (60), however, demonstrate ample Th1 and CTL responses after stimulation by DCs matured in the presence of PGE2, regardless of any effect on IL-12p70.


    Further distinctions in nomenclature and function
 Top
 Abstract
 Introduction
 Human DCs: distinct subsets...
 Blood moDCs
 Plasmacytoid DCs
 LCs and DDC-IDCs derived...
 Terminal activation and...
 Further distinctions in...
 Ag uptake, processing, and...
 Roles of Toll-like and...
 Fc{gamma} receptors for uptake...
 CD34+ HPC-derived LCs are...
 moDCs are superior stimulators...
 Regulatory T cells (Tregs)...
 Clinical applications of human...
 Conclusions
 References
 
moDCs and plasmacytoid DCs have been, respectively, labeled DC1 and DC2 because of their propensity to stimulate Th1- vs Th2-type responses. This oversimplification, however, neglects stimulation of more varied T cell responses. The label DC1 also fails to incorporate any consideration of LCs or DDC-IDCs as conventional DCs. Skewing toward Th2 responses by plasmacytoid DCs in the presence of IL-3 led to their being termed DC2. This has no bearing, however, on their role as tolerogenic DCs in inducing CD4+ and CD8+ regulatory T cells (61, 62). It also overlooks the major physiologic role of plasmacytoid DCs as the most abundant source of type I IFNs after activation by viruses (44, 45, 46, 47, 48, 49, 63). DDC-IDCs and moDCs have been considered homologous, because both develop from a postproliferative, CD14+ precursor. More recent phenotypic and functional data, however, indicate that these two types of DCs are distinct (15, 64, 65). The specific descriptive term for each type of DC is therefore more useful than nomenclature like DC1 vs DC2, or myeloid vs lymphoid DCs.


    Ag uptake, processing, and presentation: DCs as cross-presenters
 Top
 Abstract
 Introduction
 Human DCs: distinct subsets...
 Blood moDCs
 Plasmacytoid DCs
 LCs and DDC-IDCs derived...
 Terminal activation and...
 Further distinctions in...
 Ag uptake, processing, and...
 Roles of Toll-like and...
 Fc{gamma} receptors for uptake...
 CD34+ HPC-derived LCs are...
 moDCs are superior stimulators...
 Regulatory T cells (Tregs)...
 Clinical applications of human...
 Conclusions
 References
 
DCs use phagocytosis, endocytosis, pinocytosis, and specific receptors to capture microbial pathogens, dead or dying cells, immune complexes, and other Ags for immune presentation. DCs share most features of Ag processing and presentation on class I and II MHC molecules with other APCs. Ags acquired from the extracellular environment are typically processed onto class II MHC molecules, whereas class I MHC molecules bear Ags synthesized in the cytosolic compartment. DCs are endowed, however, with the capacity to cross-present exogenous Ags on class I MHC complexes (66, 67, 68, 69, 70, 71, 72).

Cross-presentation entails processing and presentation of exogenous Ag on the DC’s own MHC molecules, including class I, to autologous MHC-restricted T cells, regardless of the MHC alleles expressed by the Ag source. Investigators have emphasized moDCs in studies of cross-presentation because of their ready availability in vitro and high phagocytic activity. Phagocytosis is only one means of Ag uptake, however, and the alternative fate of phagocytosed Ag is sequestration and degradation rather than processing and MHC-restricted presentation. In fact, cytokine-induced, CD34+ HPC-derived LCs are much less phagocytic than moDCs, yet elicit more potent T cell responses by cross-presentation (15). The specific receptors involved on these induced LCs have not yet been defined. LCs in situ, however, do express low levels of DEC-205 (CD205), one of the C-type lectin receptors, and even up-regulate this receptor with maturation in skin explant cultures (73).

Much has also been made of the distinction between apoptotic and necrotic cell death as a source of cross-presented Ag (74). Whether Ag remains intact or denatured during apoptosis or necrosis, as well as any association with additional danger signals, are the greater determinants of effective cross-presentation and a tolerant or immune outcome (75).


    Roles of Toll-like and C-type lectin receptors in DC-based immunity
 Top
 Abstract
 Introduction
 Human DCs: distinct subsets...
 Blood moDCs
 Plasmacytoid DCs
 LCs and DDC-IDCs derived...
 Terminal activation and...
 Further distinctions in...
 Ag uptake, processing, and...
 Roles of Toll-like and...
 Fc{gamma} receptors for uptake...
 CD34+ HPC-derived LCs are...
 moDCs are superior stimulators...
 Regulatory T cells (Tregs)...
 Clinical applications of human...
 Conclusions
 References
 
The early phases of infection elucidate how DCs first encounter, respond, and limit an inflammatory insult to the steady state. DCs express pattern recognition receptors that bind pathogen-associated molecular patterns expressed by microbial products or molecules from damaged host tissues. These pattern recognition receptors include TLRs, most of which signal through MyD88.

Examples of TLR-ligand interactions include peptidoglycan binding of TLR2, viral dsRNA binding of TLR3 (mimicked by synthetic dsRNA, e.g., poly(I:C)), LPS binding of TLR4, viral ssRNA binding of TLR7, and unmethylated bacterial CpG DNA motif binding of TLR9. Conventional DCs express several of TLRs1–6 and 8, depending on the subset and activation state (14, 48, 76). Plasmacytoid DCs are the only DCs that express TLR7 and 9, although blood monocytes express TLR7 and B cells express TLR9 (48, 76).

Ligand binding of TLRs up-regulates CD83, costimulatory molecules, and CCR7, which drives DC migration to T cell areas of draining lymph nodes (46, 48). TLR activation also leads to the secretion of huge amounts of IFN-{alpha} by plasmacytoid DCs (44, 45, 48, 49, 76) or IL-6, IL-10, TNF, and/or IL-12 by conventional DCs, depending on the subset and particular stimulus (48, 76).

These early activated DCs thus play an important role in the bystander activation of other DCs and the recruitment of NK, NK T, and CD8+ T cells, which then secrete IFN-{gamma} and other inflammatory cytokines that support the ensuing adaptive immune response (49, 63) (Fig. 2). Appropriate stimulation of TLRs on DCs by their respective ligands can thus initiate the entire spectrum of innate and, in turn, acquired immunity. The inflammatory cytokine combinations (11) used in vitro for terminal DC maturation and activation mimic the sequelae of physiologic TLR ligand binding.



View larger version (24K):
[in this window]
[in a new window]
 
FIGURE 2. Inflammatory perturbations of the steady state led to DC stimulation of innate and adaptive immune responses. Shown on the left are the principal cellular components of innate immunity as they pertain to the currently understood role of human DCs. moDCs as well as circulating conventional and plasmacytoid DCs can directly activate resting NK cells. Plasmacytoid DCs are activated by TLR ligands, mainly viruses or bacterial CpG DNA, and secrete type I IFNs that powerfully enhance the activation of moDCs and NK and NKT cells (as well as CD4+ T cells, data not shown). Type I IFNs may also activate other conventional DCs, but this has not yet been well documented. NK cells possess activating ligands for DCs, both NK and NKT cells secrete inflammatory cytokines, and NKT cells may also express CD40L, all of which promote activation and maturation of conventional and plasmacytoid DCs. Shown on the right are the principal cellular components of acquired or adaptive immunity as they pertain to human DCs. Under inflammatory conditions, Ag capture segregates to immature DCs (shown at top on the right), with Ag presentation and immunogenic lymphocyte stimulation being an acquired property of mature DCs (shown at bottom on the right). During this process, other inflammatory cytokines, TLR ligands, and CD40L expressed by already activated T cells can participate in DC maturation. This results in Ag-specific, MHC-restricted T and B cell responses that underlie adaptive immunity and the development of immunologic memory. DCs seem unique among APCs in their ability to stimulate B cells and CD8+ T cells directly, but involvement of CD4+ helper T cells optimizes these immune responses. Mature DCs can in turn activate NK and NKT cells as again shown on the left. Not shown is the steady-state condition in the absence of inflammation, where most DCs in lymphoid organs are immature or semimature and process and present self-Ags to induce or maintain tolerance. CD40L (CD154); type I IFN: IFN A and B; IFN-{gamma}.

 
Another group of pattern recognition receptors expressed by DCs are the C-type lectin receptors, which bind the carbohydrate moieties of glycoprotein self-Ags and pathogens for processing and presentation on MHC molecules. Resident or nonactivated forms of DCs express these receptors, which are specialized for Ag capture and processing. Expression by immature moDCs includes among others, the macrophage mannose receptor (MMR: CD206), DEC-205 (CD205), DC-specific intercellular adhesion molecule-grabbing nonintegrin (DC-SIGN) (CD209), BDCA-2, and dectin-1. LCs express DEC-205, and DDC-IDCs express DEC-205 and DC-SIGN (73). LCs also express Langerin (CD207), which is an endocytic receptor that induces the formation of Birbeck granules (53). With the exception of DEC-205 (73, 77), DC activation and maturation down-regulate expression of C-type lectin receptors, as DC function changes from Ag uptake to Ag presentation.

TLRs and C-type lectin receptors work in concert to balance immune tolerance with activation. DCs use C-type lectin receptors to sample and present self-Ags and harmless environmental Ags in the steady state, thereby maintaining peripheral tolerance (16, 18). Some pathogens also exploit these receptors to evade immune activation, e.g., HIV and DC-SIGN (78, 79, 80). Perturbation of the steady state by concomitant exposure to an activating stimulus like TLR-binding ligands or CD40L can override any tolerizing function of C-type lectin receptors and lead to immune activation (77, 81).


    Fc{gamma} receptors for uptake of immune complexes or opsonized Ag by DCs
 Top
 Abstract
 Introduction
 Human DCs: distinct subsets...
 Blood moDCs
 Plasmacytoid DCs
 LCs and DDC-IDCs derived...
 Terminal activation and...
 Further distinctions in...
 Ag uptake, processing, and...
 Roles of Toll-like and...
 Fc{gamma} receptors for uptake...
 CD34+ HPC-derived LCs are...
 moDCs are superior stimulators...
 Regulatory T cells (Tregs)...
 Clinical applications of human...
 Conclusions
 References
 
Resident populations of mouse and human DCs and their precursors express some combination of activating (CD16 (mouse; human monocyte precursor subset), CD32a (human only), and CD64 (mouse and human)) and inhibitory (CD32b (mouse and human)) Fc{gamma} receptors (19, 82, 83, 84, 85, 86). Among cultured and cytokine-induced human DCs, only circulating blood DCs and moDCs maintain expression of Fc{gamma} receptors (84, 87). These are not passive uptake receptors but signal the cell using immunoreceptor tyrosine-based inhibitory and immunoreceptor tyrosine-based activation motifs (82). The balance of activating and inhibitory Fc{gamma} receptors; the binding avidity of allelic receptor isoforms; the species, subclass, and density of the opsonizing IgG Ab; and the size of the immune complex all determine the outcome of these receptor-ligand interactions (87, 88, 89, 90, 91). Targeting tumor Ags to Fc{gamma} receptors on DCs increases the efficiency of Ag cross-presentation (91, 92, 93). Activating Fc{gamma} receptors also promote DC maturation and activation (87), which may be unrelated to effects on Ag processing (91). CD32b opposes signaling through activating Fc{gamma} receptors and may exert a separate inhibitory effect as well (87, 88, 92).


    CD34+ HPC-derived LCs are superior stimulators of class I MHC-restricted cytolytic T lymphocytes (CTL) in vitro
 Top
 Abstract
 Introduction
 Human DCs: distinct subsets...
 Blood moDCs
 Plasmacytoid DCs
 LCs and DDC-IDCs derived...
 Terminal activation and...
 Further distinctions in...
 Ag uptake, processing, and...
 Roles of Toll-like and...
 Fc{gamma} receptors for uptake...
 CD34+ HPC-derived LCs are...
 moDCs are superior stimulators...
 Regulatory T cells (Tregs)...
 Clinical applications of human...
 Conclusions
 References
 
Investigators have found distinct cytokine profiles, chemokine responsiveness, and functional segregation of LC and DDC-IDC émigrés to discrete T cell or B cell predominant areas of secondary lymphoid organs (94, 95, 96). Putative counterparts of cytokine-induced moDCs have also been identified in vivo (97, 98).

Direct comparisons of these three subtypes of conventional DCs in vitro have shown that all express comparable maturation phenotypes and stimulatory function in allogeneic MLRs. Cytokine-induced, CD34+ HPC-derived LCs, however, are superior stimulators of CTL, at least against a recall viral Ag (15). LCs do this in the complete absence of bioactive IL-12p70, even after an optimal stimulus delivered by recombinant human CD40L-trimer (15, 55, 99). Mature LC and DDC émigrés from human skin also do not secrete IL-12p70 (99).

IL-12 has long been considered essential for generating Th1 and CTL responses, but perhaps overemphasized due to inadvertent measurement of inactive IL-12p40 homodimers (100). IL-12p70 supports stimulation of Th1 and CTL, but it may do so by first stimulating NK cells to secrete IFN-{gamma}, which conditions DCs and Th1 responses (101, 102). Both LCs and DDC-IDCs secrete ample IL-12p40, suggesting that other heterodimeric cytokines with activity similar to IL-12 and incorporating the p40 chain, e.g., IL-23, merit further consideration (100, 103).


    moDCs are superior stimulators of NK and NKT cells in vitro
 Top
 Abstract
 Introduction
 Human DCs: distinct subsets...
 Blood moDCs
 Plasmacytoid DCs
 LCs and DDC-IDCs derived...
 Terminal activation and...
 Further distinctions in...
 Ag uptake, processing, and...
 Roles of Toll-like and...
 Fc{gamma} receptors for uptake...
 CD34+ HPC-derived LCs are...
 moDCs are superior stimulators...
 Regulatory T cells (Tregs)...
 Clinical applications of human...
 Conclusions
 References
 
Recent data have established an important role for DCs in innate immune responses by NK and (65, 104, 105, 106) and NKT cells (107, 108, 109, 110). DCs enhance the reactivity of resting NK cells, which otherwise respond to the aggregate of activating and inhibitory signals on their targets. Among conventional DCs, human moDCs are the most potent stimulators of NK cell proliferation and cytotoxicity (65). LCs lack sufficient IL-12p70 secretion to induce NK cell activation but provide unidentified factors that sustain NK cell proliferation and survival after activation by moDCs (65).

NKT cells are a trace population of T cells sharing some features of NK cells, which express an invariant TCR {alpha}-chain and respond to glycolipid Ags presented on CD1d (111, 112). Autologous tissues provide self-glycolipid ligands such that NKT cells are in a chronic state of low level activation with suppressor function mediated by IL-4. Tumors like melanoma provide glycolipid ligands like GD3 (113), and the drug {alpha}-galactosylceramide is an artificial ligand. The presentation of glycolipid ligand by CD1d-expressing DCs (107, 108, 110), however, or the simultaneous delivery of a microbial stimulus to DCs resulting in high IL-12p70 secretion (114), leads in either case to robust activation of NKT cells and IFN-{gamma} secretion. The critical operative is the need for DCs to convert NKT cells from suppressor to effector function. Among conventional DCs, only moDCs and DDC-IDCs express CD1d and only moDCs secrete IL-12p70 (15). Therefore, it would seem that only moDCs could mediate NKT cell activation.

In either setting, both DC-stimulated NK and NKT cell innate immune effectors become potent sources of IFN-{gamma} and other inflammatory cytokines. This can support the innate maturation of resident populations of DCs through a reciprocal activating interaction and expand the ensuing adaptive Th1 response mediated by cytotoxic effectors (101, 106, 115) (Fig. 2).


    Regulatory T cells (Tregs) induced by DCs and the role of indoleamine 2,3-dioxygenase (IDO)
 Top
 Abstract
 Introduction
 Human DCs: distinct subsets...
 Blood moDCs
 Plasmacytoid DCs
 LCs and DDC-IDCs derived...
 Terminal activation and...
 Further distinctions in...
 Ag uptake, processing, and...
 Roles of Toll-like and...
 Fc{gamma} receptors for uptake...
 CD34+ HPC-derived LCs are...
 moDCs are superior stimulators...
 Regulatory T cells (Tregs)...
 Clinical applications of human...
 Conclusions
 References
 
Constitutive CD4+CD25+Foxp3+ Tregs are not as phenotypically discrete in humans as in the mouse. Immature DCs, interacting with constitutive Tregs in a contact-dependent manner, secrete immunosuppressive IL-10. This induces regulatory or suppressor T cells, Tr1 and Th3, which exert their effects in a contact-independent manner by the respective secretion of IL-10 or TGF-{beta} (116, 117, 118). CD4+ (61) and CD8+ (62) regulatory T cells can develop from primary stimulation by plasmacytoid DCs.

IDO is an immunosuppressive enzyme because it limits T cell proliferation by degrading the rare but essential amino acid tryptophan, which also generates kynurenine and other potentially toxic metabolites (119, 120, 121, 122, 123, 124, 125, 126). Constitutive Tregs express CTLA4, which can condition DCs to become regulatory with an associated increase in IDO activity. Activated T cells also increase expression of CTLA4, which turns off the adaptive T cell immune response and may work through IDO.

Investigators have proposed a subset of regulatory CD123(IL-3R)+ DCs that functions through increased IDO activity and tryptophan depletion (120). All human DCs express CD123, but plasmacytoid DCs express much higher levels. It is not clear whether IDO halts T cell responsiveness by tryptophan starvation only or if it can also induce regulatory T cells like Tr1 or Th3. IDO is not active in immature DCs, except in LCs (M. Rossi, C. Antczack, D. H. Munn, and J. W. Young, unpublished data). Therefore, immature DCs should not stimulate inducible Tregs by this mechanism as well as mature DCs. Mature, activated moDCs, LCs, and DDC-IDCs all exert IDO enzymatic activity (M. Rossi, C. Antczack, D. H. Munn, and J. W. Young, unpublished data), which therefore merits investigation as a negative feedback mechanism against otherwise unchecked immune responses.


    Clinical applications of human DCs for active immunotherapy
 Top
 Abstract
 Introduction
 Human DCs: distinct subsets...
 Blood moDCs
 Plasmacytoid DCs
 LCs and DDC-IDCs derived...
 Terminal activation and...
 Further distinctions in...
 Ag uptake, processing, and...
 Roles of Toll-like and...
 Fc{gamma} receptors for uptake...
 CD34+ HPC-derived LCs are...
 moDCs are superior stimulators...
 Regulatory T cells (Tregs)...
 Clinical applications of human...
 Conclusions
 References
 
There is great interest in altering the cytokine milieu that drives DC immunogenicity (127) or in using DCs to expand Tregs for the control of autoimmunity (128, 129). Most current clinical studies, however, use DCs for active immunotherapy trials in cancer. Most tumor Ags are poor immunogens because they are self-Ags or self-differentiation Ags, to which there is considerable tolerance. DCs provide a potential solution to this challenge by coupling tumor Ag with all of the requisite costimulatory ligands, cytokines, and chemokine-directed migration to secondary lymphoid organs. There they can stimulate incoming T cells to exit via efferent lymph into the periphery as cytolytic and helper T cell effectors.

Challenges to designing the optimal DC vaccine include the choice of DC subset or combination of subsets. For example, whether the functional distinctions between conventional DC subsets in vitro (15) have physiologic relevance in vivo is the subject of an ongoing vaccine trial in melanoma at our institution. The presumptive advantage of LCs has been the rationale for other investigators to include CD34+ HPC-derived DCs, which comprise LCs among the progeny, in vaccine preparations (130). The malleability of moDC precursors under certain cytokine conditions might also yield moDC progeny that function more like LCs (28, 29). Other unknowns include optimal Ag-loading strategies like peptide pulsing, overlapping polypeptide pulsing, cross-presentation of dying tumor cells, fused tumor-DC heterokaryons, DNA or RNA transfection with or without a vector construct, frequency and route of immunization, and cell dose. One issue that seems finally laid to rest is the need for activated and terminally mature DCs to avoid any reversion to immature DCs that may be inactive or even generate suppressive Tregs (131, 132).

The first human DC vaccine trial used the rare circulating DCs isolated ex vivo from steady-state pheresis products and loaded with tumor-specific idiotypes to treat patients with follicular lymphoma (133). This approach is not selective for any one of several DC subsets in blood, and the yields are low. The advent of the cytokine-generated DC era has supported large-scale clinical evaluations, and a number of trials have followed suit (Refs.130 and 134 , among others). In the aggregate, these studies have shown that DC vaccinations are safe and that tumor-specific T cell responses can be generated by DC vaccination using standard immunologic assays in vitro. Although patients eligible for these early phase clinical trials have advanced disease, clinical responses have been achieved in some instances (130, 133, 134, 135). Major challenges remain in terms of harnessing the capacity of DCs for simultaneous presentation of multiple tumor Ags tailored to their own MHC molecules, rather than presentation of only a few peptides with defined MHC restrictions. Migration of DCs to draining lymph nodes also requires optimization after vaccination.


    Conclusions
 Top
 Abstract
 Introduction
 Human DCs: distinct subsets...
 Blood moDCs
 Plasmacytoid DCs
 LCs and DDC-IDCs derived...
 Terminal activation and...
 Further distinctions in...
 Ag uptake, processing, and...
 Roles of Toll-like and...
 Fc{gamma} receptors for uptake...
 CD34+ HPC-derived LCs are...
 moDCs are superior stimulators...
 Regulatory T cells (Tregs)...
 Clinical applications of human...
 Conclusions
 References
 
We propose that the division of labor among distinct human DC subtypes achieves the most effective balance between steady-state tolerance and the induction of innate and adaptive immunity against pathogens, tumors, and other harmful insults. Maintenance of tolerance in the steady state is an active process involving resting or semimature plasmacytoid and conventional DCs. Breakdowns in this homeostasis can result in autoimmunity. Perturbation of the steady state by harmful Ags should first lead to the onset of innate immunity mediated by rapid responders in the form of plasmacytoid and moDC stimulators and NK and NKT cell effectors (Fig. 2). These innate effectors in turn provide abundant inflammatory cytokines, notably IFN-{gamma}, which along with other inflammatory cytokines support the activation and maturation of resident and circulating populations of DCs (Fig. 2). These are critical to the onset and expansion of adaptive immunity. IDO activity exerted by mature DCs may dampen T cell responses by mechanisms to be defined and provide a clue to the unsolved riddle of how DCs turn off otherwise unchecked immune stimulation. Interference with such regulatory mechanisms should be useful in sustaining desirable immune responses. The use of DC subtypes as vaccines to stimulate both innate and adaptive immunity, either in combination or in a prime-boost sequence, may prove most useful clinically by harnessing two valuable effector cell compartments.


    Acknowledgments
 
We appreciate the contributions of all present and former members of our laboratory, as well as many important collaborators and colleagues whose work has helped to advance the field of DC immunology. We thank Drs. Adam Boruchov, Christian Munz, and Ralph Steinman for helpful review of this manuscript.


    Footnotes
 
The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

1 Our laboratory has been supported by Grants P01 CA59350, P01 CA23766, R01 CA83070, R21 CA97714, and R21 CA105718 from the National Cancer Institute, National Institutes of Health (Bethesda, MD) and by William H. Goodwin and Alice Goodwin of the Commonwealth Cancer Foundation for Research and the Experimental Therapeutics Center of Memorial Sloan-Kettering Cancer Center. Back

2 Address correspondence and reprint requests to Dr. James W. Young, Department of Medicine, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10021. E-mail address: youngjw{at}mskcc.org Back

3 Abbreviations used in this paper: DC, dendritic; moDC, monocyte-derived DC; DDC-IDC, dermal DC-interstitial DC; LC, Langerhans cell; HPC, hemopoietic progenitor cell; CD40L, CD40 ligand; Treg, regulatory T cell; IDO, indoleamine 2,3-dioxygenase. Flt3-L, fms-like tytosine kinase 3 ligand; DC-SIGN, DC-specific intercellular adhesion molecule-grabbing nonintegrin. Back

Received for publication May 4, 2005. Accepted for publication June 2, 2005.


    References
 Top
 Abstract
 Introduction
 Human DCs: distinct subsets...
 Blood moDCs
 Plasmacytoid DCs
 LCs and DDC-IDCs derived...
 Terminal activation and...
 Further distinctions in...
 Ag uptake, processing, and...
 Roles of Toll-like and...
 Fc{gamma} receptors for uptake...
 CD34+ HPC-derived LCs are...
 moDCs are superior stimulators...
 Regulatory T cells (Tregs)...
 Clinical applications of human...
 Conclusions
 References
 

  1. Langerhans, P.. 1868. Ueber die Nerven der menschlichen Haut. Archiv für pathologische Anatomie und Physiologie, und für Klinische Medicin. Berlin. 44: 325-337.
  2. Steinman, R. M., Z. A. Cohn. 1973. Identification of a novel cell type in peripheral lymphoid organs of mice. I. Morphology, quantitation, tissue distribution. J. Exp. Med. 137: 1142-1162.[Abstract]
  3. Inaba, K., M. Inaba, N. Romani, H. Aya, M. Deguchi, S. Ikehara, S. Muramatsu, R. M. Steinman. 1992. Generation of large numbers of dendritic cells from mouse bone marrow cultures supplemented with granulocyte/macrophage colony-stimulating factor. J. Exp. Med. 176: 1693-1702.[Abstract/Free Full Text]
  4. Caux, C., C. Dezutter-Dambuyant, D. Schmitt, J. Banchereau. 1992. GM-CSF and TNF-{alpha} cooperate in the generation of dendritic Langerhans cells. Nature 360: 258-261.[Medline]
  5. Sallusto, F., A. Lanzavecchia. 1994. Efficient presentation of soluble antigen by cultured human dendritic cells is maintained by granulocyte/macrophage colony-stimulating factor plus interleukin 4 and downregulated by tumor necrosis factor {alpha}. J. Exp. Med. 179: 1109-1118.[Abstract/Free Full Text]
  6. Romani, N., S. Gruner, D. Brang, E. Kampgen, A. Lenz, B. Trockenbacher, G. Konwalinka, P. O. Fritsch, R. M. Steinman, G. Schuler. 1994. Proliferating [sic] dendritic cell progenitors in human blood. J. Exp. Med. 180: 83-93.[Abstract/Free Full Text]
  7. Szabolcs, P., M. A. S. Moore, J. W. Young. 1995. Expansion of immunostimulatory dendritic cells among the myeloid progeny of human CD34+ bone marrow precursors cultured with c-kit ligand, granulocyte-macrophage colony-stimulating factor, and TNF-{alpha}. J. Immunol. 154: 5851-5861.[Abstract]
  8. Szabolcs, P., D. Avigan, S. Gezelter, D. H. Ciocon, M. A. S. Moore, R. M. Steinman, J. W. Young. 1996. Dendritic cells and macrophages can mature independently from a human bone marrow-derived, post-CFU intermediate. Blood 87: 4520-4530.[Abstract/Free Full Text]
  9. Young, J. W., P. Szabolcs, M. A. S. Moore. 1995. Identification of dendritic cell colony-forming units among normal CD34+ bone marrow progenitors that are expanded by c-kit-ligand and yield pure dendritic cell colonies in the presence of granulocyte/macrophage colony-stimulating factor and tumor necrosis factor a. J. Exp. Med. 182: 1111-1119.[Abstract/Free Full Text]
  10. Strobl, H., E. Riedl, C. Scheinecker, C. Bello-Fernandez, W. F. Pickl, K. Rappersberger, O. Majdic, W. Knapp. 1996. TGF-{beta}1 promotes in vitro development of dendritic cells from CD34+ hemopoietic progenitors. J. Immunol. 157: 1499-1507.[Abstract]
  11. Jonuleit, H., U. Kuhn, G. Muller, K. Steinbrink, L. Paragnik, E. Schmitt, J. Knop, A. H. Enk. 1997. Pro-inflammatory cytokines and prostaglandins induce maturation of potent immunostimulatory dendritic cells under fetal calf serum-free conditions. Eur. J. Immunol. 27: 3135-3142.[Medline]
  12. Thurner, B., C. Roder, D. Dieckmann, M. Heuer, M. Kruse, A. Glaser, P. Keikavoussi, E. Kampgen, A. Bender, G. Schuler. 1999. Generation of large numbers of fully mature and stable dendritic cells from leukapheresis products for clinical application. J. Immunol. Methods 223: 1-15.[Medline]
  13. Lutz, M. B., N. Kukutsch, A. L. J. Ogilvie, S. RoBner, F. Koch, N. Romani, G. Schuler. 1999. An advanced culture method for generating large quantities of highly pure dendritic cells from mouse bone marrow. J. Immunol. Methods 223: 77-92.[Medline]
  14. Gatti, E., M. A. Velleca, B. C. Biedermann, W. Ma, J. Unternaehrer, M. W. Ebersold, R. Medzhitov, J. S. Pober, I. Mellman. 2000. Large-scale culture and selective maturation of human Langerhans cells from granulocyte colony-stimulating factor-mobilized CD34+ progenitors. J. Immunol. 164: 3600-3607.[Abstract/Free Full Text]
  15. Ratzinger, G., J. Baggers, M. A. de Cos, J. Yuan, T. Dao, J. L. Reagan, C. Munz, G. Heller, J. W. Young. 2004. Mature human Langerhans cells derived from CD34+ hematopoietic progenitors stimulate greater cytolytic T lymphocyte activity in the absence of bioactive IL-12p70, by either single peptide presentation or cross-priming, than do dermal-interstitial or monocyte-derived dendritic cells. J. Immunol. 173: 2780-2791.[Abstract/Free Full Text]
  16. Hawiger, D., K. Inaba, Y. Dorsett, M. Guo, K. Mahnke, M. Rivera, J. V. Ravetch, R. M. Steinman, M. C. Nussenzweig. 2001. Dendritic cells induce peripheral T cell unresponsiveness under steady state conditions in vivo. J. Exp. Med. 194: 769-779.[Abstract/Free Full Text]
  17. Liu, K., T. Iyoda, M. Saternus, Y. Kimura, K. Inaba, R. M. Steinman. 2002. Immune tolerance after delivery of dying cells to dendritic cells in situ. J. Exp. Med. 196: 1091-1097.[Abstract/Free Full Text]
  18. Bonifaz, L., D. Bonnyay, K. Mahnke, M. Rivera, M. C. Nussenzweig, R. M. Steinman. 2002. Efficient targeting of protein antigen to the dendritic cell receptor DEC-205 in the steady state leads to antigen presentation on major histocompatibility complex class I products and peripheral CD8+ T cell tolerance. J. Exp. Med. 196: 1627-1638.[Abstract/Free Full Text]
  19. Katz, S. I., K. Tamaki, D. H. Sachs. 1979. Epidermal Langerhans cells are derived from cells originating in bone marrow. Nature 282: 324-326.[Medline]
  20. Tew, J. G., J. Wu, M. Fakher, A. K. Szakal, D. Qin. 2001. Follicular dendritic cells: beyond the necessity of T-cell help. Trends Immunol. 22: 361-367.[Medline]
  21. Caux, C., B. Vanbervliet, C. Massacrier, C. Dezutter-Dambuyant, B. de Saint-Vis, C. Jacquet, K. Yoneda, S. Imamura, D. Schmitt, J. Banchereau. 1996. CD34+ hematopoietic progenitors from human cord blood differentiate along two independent dendritic cell pathways in response to GM-CSF + TNF {alpha}. J. Exp. Med. 184: 695-706.[Abstract/Free Full Text]
  22. Caux, C., C. Massacrier, B. Vanbervliet, B. Dubois, I. Durand, M. Cella, A. Lanzavecchia, J. Banchereau. 1997. CD34+ hematopoietic progenitors from human cord blood differentiate along two independent dendritic cell pathways in response to granulocyte-macrophage colony-stimulating factor plus tumor necrosis factor a: II. Functional analysis. Blood 90: 1458-1470.[Abstract/Free Full Text]
  23. Grouard, G., M.-C. Rissoan, L. Filgueira, I. Durand, J. Banchereau, Y.-J. Liu. 1997. The enigmatic plasmacytoid T cells develop into dendritic cells with IL-3 and CD40-ligand. J. Exp. Med. 185: 1101-1111.[Abstract/Free Full Text]
  24. Osugi, Y., S. Vuckovic, D. N. J. Hart. 2002. Myeloid blood CD11c+ dendritic cells and monocyte-derived dendritic cells differ in their ability to stimulate T lymphocytes. Blood 100: 2858-2866.[Abstract/Free Full Text]
  25. Lutz, M. B., G. Schuler. 2002. Immature, semi-mature and fully mature dendritic cells: which signals induce tolerance or immunity?. Trends Immunol. 23: 445-449.[Medline]
  26. Jansen, J. H., G.-J. H. M. Wientjens, W. E. Fibbe, R. Willemze, H. C. Kluin-Nelemans. 1989. Inhibition of human macrophage colony formation by interleukin 4. J. Exp. Med. 170: 577-582.[Abstract/Free Full Text]
  27. Banchereau, J., V. Pascual, A. K. Palucka. 2004. Autoimmunity through cytokine-induced dendritic cell activation. Immunity 20: 539-550.[Medline]
  28. Mohamadzadeh, M., F. Berard, G. Essert, C. Chalouni, B. Pulendran, J. Davoust, G. Bridges, A. K. Palucka, J. Banchereau. 2001. Interleukin 15 skews monocyte differentiation into dendritic cells with features of Langerhans cells. J. Exp. Med. 194: 1013-1020.[Abstract/Free Full Text]
  29. Geissmann, F., C. Prost, J.-P. Monnet, M. Dy, N. Brousse, O. Hermine. 1998. Transforming growth factor {beta}1, in the presence of granulocyte/macrophage colony-stimulating factor and interleukin 4, induces differentiation of human peripheral blood monocytes into dendritic Langerhans cells. J. Exp. Med. 187: 961-966.[Abstract/Free Full Text]
  30. Luft, T., K. C. Pang, E. Thomas, P. Hertzog, D. N. J. Hart, J. Trapani, J. Cebon. 1998. Type I IFNs enhance the terminal differentiation of dendritic cells. J. Immunol. 161: 1947-1953.[Abstract/Free Full Text]
  31. Chomarat, P., C. Dantin, L. Bennett, J. Banchereau, A. K. Palucka. 2003. TNF skews monocyte differentiation from macrophages to dendritic cells. J. Immunol. 171: 2262-2269.[Abstract/Free Full Text]
  32. Dzionek, A., A. Fuchs, P. Schmidt, S. Cremer, M. Zysk, S. Miltenyi, D. W. Buck, J. Schmitz. 2000. BDCA-2, BDCA-3, and BDCA-4: three markers for distinct subsets of dendritic cells in human peripheral blood. J. Immunol. 165: 6037-6046.[Abstract/Free Full Text]
  33. Asselin-Paturel, C., A. Boonstra, M. Dalod, I. Durand, N. Yessaad, C. Dezutter-Dambuyant, A. Vicari, A. O’Garra, C. Biron, F. Briere, G. Trinchieri. 2001. Mouse type I IFN-producing cells are immature APCs with plasmacytoid morphology. Nat. Immunol. 2: 1144-1150.[Medline]
  34. Bjorck, P.. 2001. Isolation and characterization of plasmacytoid dendritic cells from Flt3 ligand and granulocyte-macrophage colony-stimulating factor-treated mice. Blood 98: 3520-3526.[Abstract/Free Full Text]
  35. Nakano, H., M. Yanagita, M. D. Gunn. 2001. CD11c+B220+Gr-1+ cells in mouse lymph nodes and spleen display characteristics of plasmacytoid dendritic cells. J. Exp. Med. 194: 1171-1178.[Abstract/Free Full Text]
  36. Robinson, S. P., S. Patterson, N. English, D. Davies, S. C. Knight, C. D. Reid. 1999. Human peripheral blood contains two distinct lineages of dendritic cells. Eur. J. Immunol. 29: 2769-2778.[Medline]
  37. Caux, C., B. Vanbervliet, C. Massacrier, I. Durand, J. Banchereau. 1996. Interleukin-3 cooperates with tumor necrosis factor {alpha} for the development of human dendritic/Langerhans cells from cord blood CD34+ hematopoietic progenitor cells. Blood 87: 2376-2385.[Abstract/Free Full Text]
  38. Pulendran, B., J. Banchereau, S. Burkeholder, E. Kraus, E. Guinet, C. Chalouni, D. Caron, C. Maliszewski, J. Davoust, J. Fay, K. Palucka. 2000. Flt3-ligand and granulocyte colony-stimulating factor mobilize distinct human dendritic cell subsets in vivo. J. Immunol. 165: 566-572.[Abstract/Free Full Text]
  39. Arpinati, M., C. L. Green, S. Heimfeld, J. E. Heuser, C. Anasetti. 2000. Granulocyte-colony stimulating factor mobilizes T helper 2-inducing dendritic cells. Blood 95: 2484-2490.[Abstract/Free Full Text]
  40. Blom, B., S. Ho, S. Antonenko, Y. J. Liu. 2000. Generation of interferon {alpha}-producing predendritic cell (Pre-DC)2 from human CD34+ hematopoietic stem cells. J. Exp. Med. 192: 1785-1796.[Abstract/Free Full Text]
  41. Maraskovsky, E., E. Daro, E. Roux, M. Teepe, C. R. Maliszewski, J. Hoek, D. Caron, M. E. Lebsack, H. J. McKenna. 2000. In vivo generation of human dendritic cell subsets by Flt3 ligand. Blood 96: 878-884.[Abstract/Free Full Text]
  42. Chen, W., S. Antonenko, J. M. Sederstrom, X. Liang, A. S. H. Chan, H. Kanzler, B. Blom, B. R. Blazar, Y.-J. Liu. 2004. Thrombopoietin cooperates with FLT3-ligand in the generation of plasmacytoid dendritic cell precursors from human hematopoietic progenitors. Blood 103: 2547-2553.[Abstract/Free Full Text]
  43. O’Doherty, U., M. Peng, S. Gezelter, W. J. Swiggard, M. Betjes, N. Bhardwaj, R. M. Steinman. 1994. Human blood contains two subsets of dendritic cells, one immunologically mature, and the other immature. Immunology 82: 487-493.[Medline]
  44. Siegal, F. P., N. Kadowaki, M. Shodell, P. A. Fitzgerald-Bocarsly, K. Shah, S. Ho, S. Antonenko, Y. J. Liu. 1999. The nature of the principal type 1 interferon-producing cells in human blood. Science 284: 1835-1837.[Abstract/Free Full Text]
  45. Cella, M., D. Jarrossay, F. Facchetti, O. Alebardi, H. Nakajima, A. Lanzavecchia, M. Colonna. 1999. Plasmacytoid monocytes migrate to inflamed lymph nodes and produce large amounts of type I interferon. Nat. Med. 5: 919-923.[Medline]
  46. Rissoan, M. C., V. Soumelis, N. Kadowaki, G. Grouard, F. Briere, R. de Waal Malefyt, Y. J. Liu. 1999. Reciprocal control of T helper cell and dendritic cell differentiation. Science 283: 1183-1186.[Abstract/Free Full Text]
  47. Kadowaki, N., S. Ho, S. Antonenko, R. de Waal Malefyt, R. A. Kastelein, F. Bazan, Y.-J. Liu. 2001. Subsets of human dendritic cell precursors express different Toll-like receptors and respond to different microbial antigens. J. Exp. Med. 194: 863-869.[Abstract/Free Full Text]
  48. Jarrossay, D., G. Napolitani, M. Colonna, F. Sallusto, A. Lanzavecchia. 2001. Specialization and complementarity in microbial molecule recognition by human myeloid and plasmacytoid dendritic cells. Eur. J. Immunol. 31: 3388-3398.[Medline]
  49. Fonteneau, J.-F., M. Gilliet, M. Larsson, I. Dasilva, C. Munz, Y.-J. Liu, N. Bhardwaj. 2003. Activation of influenza virus-specific CD4+ and CD8+ T cells: a new role for plasmacytoid dendritic cells in adaptive immunity. Blood 101: 3520-3526.[Abstract/Free Full Text]
  50. Schuler, G., R. M. Steinman. 1985. Murine epidermal Langerhans cells mature into potent immunostimulatory dendritic cells in vitro. J. Exp. Med. 161: 526-546.[Abstract/Free Full Text]
  51. Borkowski, T. A., J. J. Letterio, A. G. Farr, M. C. Udey. 1996. A role for endogenous transforming growth factor {beta}1 in Langerhans cell biology: the skin of transforming growth factor {beta}1 null mice is devoid of epidermal Langerhans cells. J. Exp. Med. 184: 2417-2422.[Abstract/Free Full Text]
  52. Valladeau, J., V. Duvert-Frances, J. J. Pin, C. Dezutter-Dambuyant, C. Vincent, C. Massacrier, J. Vincent, K. Yoneda, J. Banchereau, C. Caux, et al 1999. The monoclonal antibody DCGM4 recognizes Langerin, a protein specific of Langerhans cells, and is rapidly internalized from the cell surface. Eur. J. Immunol. 29: 2695-26704.[Medline]
  53. Valladeau, J., O. Ravel, C. Dezutter-Dambuyant, K. Moore, M. Kleijmeer, Y. Liu, V. Duvert-Frances, C. Vincent, D. Schmitt, J. Davoust, et al 2000. Langerin, a novel C-type lectin specific to Langerhans cells, is an endocytic receptor that induces the formation of Birbeck granules. Immunity 12: 71-81.[Medline]
  54. Caux, C., C. Massacrier, B. Vanbervliet, B. Dubois, C. Van Kooten, I. Durand, J. Banchereau. 1994. Activation of human dendritic cells through CD40 cross-linking. J. Exp. Med. 180: 1263-1272.[Abstract/Free Full Text]
  55. Cella, M., D. Scheidegger, K. Palmer-Lehmann, P. Lane, A. Lanzavecchia, G. Alber. 1996. Ligation of CD40 on dendritic cells triggers production of high levels of interleukin-12 and enhances T cell stimulatory capacity: T-T help via APC activation. J. Exp. Med. 184: 747-752.[Abstract/Free Full Text]
  56. Luft, T., M. Jefford, P. Luetjens, T. Toy, H. Hochrein, K.-A. Masterman, C. Maliszewski, K. Shortman, J. Cebon, E. Maraskovsky. 2002. Functionally distinct dendritic cell (DC) populations induced by physiologic stimuli: prostaglandin E2 regulates the migratory capacity of specific DC subsets. Blood 100: 1362-1372.[Abstract/Free Full Text]
  57. Scandella, E., Y. Men, S. Gillessen, R. Forster, M. Groettrup. 2002. Prostaglandin E2 is a key factor for CCR7 surface expression and migration of monocyte-derived dendritic cells. Blood 100: 1354-1361.[Abstract/Free Full Text]
  58. Mailliard, R. B., A. Wankowicz-Kalinska, Q. Cai, A. Wesa, C. M. Hilkens, M. L. Kapsenberg, J. M. Kirkwood, W. J. Storkus, P. Kalinski. 2004. {alpha}-Type-1 polarized dendritic cells: a novel immunization tool with optimized CTL-inducing activity. Cancer Res. 64: 5934-5937.[Abstract/Free Full Text]
  59. Kalinski, P., H. Schuitemaker, C. M. U. Hilkens, M. L. Kapsenberg. 1998. Prostaglandin E2 induces the final maturation of IL-12-deficient CD1a+ CD83+ dendritic cells: the levels of IL-12 are determined during the final dendritic cell maturation and are resistant to further modulation. J. Immunol. 161: 2804-2809.[Abstract/Free Full Text]
  60. Schuler-Thurner, B., E. S. Schultz, T. G. Berger, G. Weinlich, S. Ebner, P. Woerl, A. Bender, B. Feuerstein, P. O. Fritsch, N. Romani, G. Schuler. 2002. Rapid induction of tumor-specific type 1 T helper cells in metastatic melanoma patients by vaccination with mature, cryopreserved, peptide-loaded monocyte-derived dendritic cells. J. Exp. Med. 195: 1279-1288.[Abstract/Free Full Text]
  61. Moseman, E. A., X. Liang, A. J. Dawson, A. Panoskaltsis-Mortari, A. M. Krieg, Y.-J. Liu, B. R. Blazar, W. Chen. 2004. Human plasmacytoid dendritic cells activated by CpG oligodeoxynucleotides induce the generation of CD4+CD25+ regulatory T cells. J. Immunol. 173: 4433-4442.[Abstract/Free Full Text]
  62. Gilliet, M., Y.-J. Liu. 2002. Generation of human CD8 T regulatory cells by CD40 ligand-activated plasmacytoid dendritic cells. J. Exp. Med. 195: 695-704.[Abstract/Free Full Text]
  63. Santini, S. M., C. Lapenta, M. Logozzi, S. Parlato, M. Spada, T. Di Pucchio, F. Belardelli. 2000. Type I interferon as a powerful adjuvant for monocyte-derived dendritic cell development and activity in vitro and in Hu-PBL-SCID mice. J. Exp. Med. 191: 1777-1788.[Abstract/Free Full Text]
  64. Ratzinger, G., J. L. Reagan, G. Heller, K. J. Busam, J. W. Young. 2003. Differential CD52 expression by distinct myeloid dendritic cell subsets: implications for alemtuzumab activity at the level of antigen presentation in allogeneic graft-host interactions in transplantation. Blood 101: 1422-1429.[Abstract/Free Full Text]
  65. Munz, C., T. Dao, G. Ferlazzo, M. A. de Cos, K. Goodman, J. W. Young. 2005. Mature myeloid dendritic cell subsets have distinct roles for activation and viability of circulating human natural killer cells. Blood 105: 266-273.[Abstract/Free Full Text]
  66. Albert, M. L., B. Sauter, N. Bhardwaj. 1998. Dendritic cells acquire antigen from apoptotic cells and induce class I-restricted CTLs. Nature 392: 86-89.[Medline]
  67. Albert, M. L., S. F. A. Pearce, L. M. Francisco, B. Sauter, P. Roy, R. L. Silverstein, N. Bhardwaj. 1998. Immature dendritic cells phagocytose apoptotic cells via avb5 and CD36, and cross-present antigens to cytotoxic T lymphocytes. J. Exp. Med. 188: 1359-1368.[Abstract/Free Full Text]
  68. Albert, M. L., J. C. Darnell, A. Bender, L. M. Francisco, N. Bhardwaj, R. B. Darnell. 1998. Tumor-specific and anti-neuronal killer cells in paraneoplastic cerebellar degeneration. Nat. Med. 4: 1321-1324.[Medline]
  69. Guermonprez, P., L. Saveanu, M. Kleijmeer, J. Davoust, P. Van Endert, S. Amigorena. 2003. ER-phagosome fusion defines an MHC class I cross-presentation compartment in dendritic cells. Nature 425: 397-402.[Medline]
  70. Houde, M., S. Bertholet, E. Gagnon, S. Brunet, G. Goyette, A. Laplante, M. F. Princiotta, P. Thibault, D. Sacks, M. Desjardins. 2003. Phagosomes are competent organelles for antigen cross-presentation. Nature 425: 402-406.[Medline]
  71. Ackerman, A. L., C. Kyritsis, R. Tampe, P. Cresswell. 2003. Early phagosomes in dendritic cells form a cellular compartment sufficient for cross presentation of exogenous antigens. Proc. Natl. Acad. Sci. USA 100: 12889-12894.[Abstract/Free Full Text]
  72. Ackerman, A. L., C. Kyritsis, R. Tampe, P. Cresswell. 2005. Access of soluble antigens to the endoplasmic reticulum can explain cross-presentation by dendritic cells. Nat. Immunol. 6: 107-113.[Medline]
  73. Ebner, S., Z. Ehammer, S. Holzmann, P. Schwingshackl, M. Forstner, P. Stoitzner, G. M. Huemer, P. Fritsch, N. Romani. 2004. Expression of C-type lectin receptors by subsets of dendritic cells in human skin. Int. Immunol. 16: 877-887.[Abstract/Free Full Text]
  74. Sauter, B., M. L. Albert, L. Francisco, M. Larsson, S. Somersan, N. Bhardwaj. 2000. Consequences of cell death: exposure to necrotic tumor cells, but not primary tissue cells or apoptotic cells, induces the maturation of immunostimulatory dendritic cells. J. Exp. Med. 191: 423-434.[Abstract/Free Full Text]
  75. Goldszmid, R. S., J. Idoyaga, A. I. Bravo, R. Steinman, J. Mordoh, R. Wainstok. 2003. Dendritic cells charged with apoptotic tumor cells induce long-lived protective CD4+ and CD8+ T cell immunity against B16 melanoma. J. Immunol. 171: 5940-5947.[Abstract/Free Full Text]
  76. Kadowaki, N., S. Antonenko, S. Ho, M.-C. Rissoan, V. Soumelis, S. A. Porcelli, L. L. Lanier, Y.-J. Liu. 2001. Distinct cytokine profiles of neonatal natural killer T cells after expansion with subsets of dendritic cells. J. Exp. Med. 193: 1221-1226.[Abstract/Free Full Text]
  77. Bonifaz, L. C., D. P. Bonnyay, A. Charalambous, D. I. Darguste, S.-I. Fujii, H. Soares, M. K. Brimnes, B. Moltedo, T. M. Moran, R. M. Steinman. 2004. In vivo targeting of antigens to maturing dendritic cells via the DEC-205 receptor improves T cell vaccination. J. Exp. Med. 199: 815-824.[Abstract/Free Full Text]
  78. Geijtenbeek, T. B. H., S. J. van Vliet, E. A. Koppel, M. Sanchez-Hernandez, C. M. J. E. Vandenbroucke-Grauls, B. Appelmelk, Y. van Kooyk. 2003. Mycobacteria target DC-SIGN to suppress dendritic cell function. J. Exp. Med. 197: 7-17.[Abstract/Free Full Text]
  79. Kaufmann, S. H., U. E. Schaible. 2003. A dangerous liaison between two major killers: Mycobacterium tuberculosis and HIV target dendritic cells through DC-SIGN. J. Exp. Med. 197: 1-5.[Free Full Text]
  80. Granelli-Piperno, A., A. Golebiowska, C. Trumpfheller, F. P. Siegal, R. M. Steinman. 2004. HIV-1-infected monocyte-derived dendritic cells do not undergo maturation but can elicit IL-10 production and T cell regulation. Proc. Natl. Acad. Sci. USA 101: 7669-7674.[Abstract/Free Full Text]
  81. Gantner, B. N., R. M. Simmons, S. J. Canavera, S. Akira, D. M. Underhill. 2003. Collaborative induction of inflammatory responses by dectin-1 and Toll-like receptor 2. J. Exp. Med. 197: 1107-1117.[Abstract/Free Full Text]
  82. Ravetch, J. V., S. Bolland. 2001. IgG Fc receptors. Annu. Rev. Immunol. 19: 275-290.[Medline]
  83. Schmitt, D. A., D. Hanau, T. Bieber, C. Dezutter-Dambuyant, D. Schmitt, M. Fabre, G. Pauly, J.-P. Cazenave. 1990. Human epidermal Langerhans cells express only the 40-kilodalton Fc{gamma} receptor (Fc{gamma}RII). J. Immunol. 144: 4284-4290.[Abstract]
  84. Teunissen, M. B. M., J. Wormmeester, S. R. Krieg, P. J. Peters, I. M. C. Vogels, M. L. Kapsenberg, J. D. Bos. 1990. Human epidermal Langerhans cells undergo profound morphologic and phenotypical changes during in vitro culture. J. Invest. Dermatol. 94: 166-173.[Medline]
  85. Astier, A., H. de la Salle, C. de la Salle, T. Bieber, M.-E. Esposito-Farese, M. Freund, J.-P. Cazenave, W.-H. Fridman, J.-L. Teillaud, D. Hanau. 1994. Human epidermal Langerhans cells secrete a soluble receptor for IgG (FctR11/CD32) that inhibits the binding of immune complexes to FctR+ cells. J. Immunol. 152: 201-212.[Abstract]
  86. Randolph, G. J., G. Sanchez-Schmitz, R. M. Liebman, K. Schakel. 2002. The CD16+ (Fc{gamma}RIII+) subset of human monocytes preferentially becomes migratory dendritic cells in a model tissue setting. J. Exp. Med. 196: 517-527.[Abstract/Free Full Text]
  87. Boruchov, A. M., G. Heller, M.-C. Veri, E. Bonvini, J. V. Ravetch, and J. W. Young. 2005. Activating and inhibitory IgG Fc receptors mediate opposing functions on human dendritic cells. J. Clin. Invest. In press..
  88. Clynes, R., J. S. Maizes, R. Guinamard, M. Ono, T. Takai, J. V. Ravetch. 1999. Modulation of immune complex-induced inflammation in vivo by the coordinate Expression of activation and inhibitory Fc receptors. J. Exp. Med. 189: 179-185.[Abstract/Free Full Text]
  89. Weng, W. K., R. Levy. 2003. Two immunoglobulin G fragment C receptor polymorphisms independently predict response to rituximab in patients with follicular lymphoma. J. Clin. Oncol. 21: 3940-3947.[Abstract/Free Full Text]
  90. Cartron, G., L. Dacheux, G. Salles, P. Solal-Celigny, P. Bardos, P. Colombat, H. Watier. 2002. Therapeutic activity of humanized anti-CD20 monoclonal antibody and polymorphism in IgG Fc receptor Fc{gamma}RIIIa gene. Blood 99: 754.[Abstract/Free Full Text]
  91. Dhodapkar, K. M., J. Krasovsky, B. Williamson, M. V. Dhodapkar. 2002. Antitumor monoclonal antibodies enhance cross-presentation of cellular antigens and the generation of myeloma-specific killer T cells by dendritic cells. J. Exp. Med. 195: 125-133.[Abstract/Free Full Text]
  92. Kalergis, A. M., J. V. Ravetch. 2002. Inducing tumor immunity through the selective engagement of activating Fc{gamma} receptors on dendritic cells. J. Exp. Med. 195: 1653-1659.[Abstract/Free Full Text]
  93. Regnault, A., D. Lankar, V. Lacabanne, A. Rodriguez, C. Thery, M. Rescigno, T. Saito, S. Verbeek, C. Bonnerot, P. Ricciardi-Castagnoli, S. Amigorena. 1999. Fc{gamma} receptor-mediated induction of dendritic cell maturation and major histocom patibility complex class I-restricted antigen presentation after immune complex in ternalization. J. Exp. Med. 189: 371-380.[Abstract/Free Full Text]
  94. Dieu, M.-C., B. Vanbervliet, A. Vicari, J.-M. Bridon, E. Oldham, S. Ait-Yahia, F. Briere, A. Zlotnik, S. Lebecque, C. Caux. 1998. Selective recruitment of immature and mature dendritic cells by distinct chemokines expressed in different anatomic sites. J. Exp. Med. 188: 373-386.[Abstract/Free Full Text]
  95. de Saint-Vis, B., I. Fugier-Vivier, C. Massacrier, B. Vanbervliet, S. Ait-Yahia, J. Banchereau, Y.-J. Liu, S. Lebecque, C. Caux. 1998. The cytokine profile expressed by human dendritic cells is dependent on cell subtype and mode of activation. J. Immunol. 160: 1666-1676.[Abstract/Free Full Text]
  96. Dubois, B., C. Barthelemy, I. Durand, Y. J. Liu, C. Caux, F. Briere. 1999. Toward a role of dendritic cells in the germinal center reaction: triggering of B cell proliferation and isotype switching. J. Immunol. 162: 3428-3436.[Abstract/Free Full Text]
  97. Randolph, G. J., K. Inaba, D. F. Robbiani, R. M. Steinman, W. A. Muller. 1999. Differentiation of phagocytic monocytes into lymph node dendritic cells in vivo. Immunity 11: 753-761.[Medline]
  98. Geissmann, F., S. Jung, D. R. Littman. 2003. Blood monocytes consist of two principal subsets with distinct migratory properties. Immunity 19: 71-82.[Medline]
  99. Ebner, S., G. Ratzinger, B. Krosbacher, M. Schmuth, A. Weiss, D. Reider, R. A. Kroczek, M. Herold, C. Heufler, P. Fritsch, N. Romani. 2001. Production of IL-12 by human monocyte-derived dendritic cells is optimal when the stimulus Is given at the onset of maturation, and is further enhanced by IL-4. J. Immunol. 166: 633-641.[Abstract/Free Full Text]
  100. Trinchieri, G., S. Pflanz, R. A. Kastelein. 2003. The IL-12 family of heterodimeric cytokines: new players in the regulation of T cell responses. Immunity 19: 641-644.[Medline]
  101. Mailliard, R. B., Y.-I. Son, R. Redlinger, P. T. Coates, A. Giermasz, P. A. Morel, W. J. Storkus, P. Kalinski. 2003. Dendritic cells mediate NK cell help for Th1 and CTL responses: two-signal requirement for the induction of NK cell helper function. J. Immunol. 171: 2366-2373.[Abstract/Free Full Text]
  102. Martin-Fontecha, A., L. L. Thomsen, S. Brett, C. Gerard, M. Lipp, A. Lanzavecchia, F. Sallusto. 2004. Induced recruitment of NK cells to lymph nodes provides IFN-{gamma} for TH1 priming. Nat. Immunol. 5: 1260-1265.[Medline]
  103. Oppmann, B., R. Lesley, B. Blom, J. C. Timans, Y. Xu, B. Hunte, F. Vega, N. Yu, J. Wang, K. Singh, et al 2000. Novel p19 protein engages IL-12p40 to form a cytokine, IL-23, with biological activities similar as well as distinct from IL-12. Immunity 13: 715-725.[Medline]
  104. Fernandez, N. C., A. Lozier, C. Flament, P. Ricciardi-Castagnoli, D. Bellet, M. Suter, M. Perricaudet, T. Tursz, E. Maraskovsky, L. Zitvogel. 1999. Dendritic cells directly trigger NK cell functions: cross-talk relevant in innate anti-tumor immune responses in vivo. Nat. Med. 5: 405-411.[Medline]
  105. Ferlazzo, G., M. L. Tsang, L. Moretta, G. Melioli, R. M. Steinman, C. Munz. 2002. Human dendritic cells activate resting natural killer (NK) cells and are recognized via the NKp30 receptor by activated NK cells. J. Exp. Med. 195: 343-351.[Abstract/Free Full Text]
  106. Gerosa, F., B. Baldani-Guerra, C. Nisii, V. Marchesini, G. Carra, G. Trinchieri. 2002. Reciprocal activating interaction between natural killer cells and dendritic cells. J. Exp. Med. 195: 327-333.[Abstract/Free Full Text]
  107. Fujii, S., K. Shimizu, M. Kronenberg, R. M. Steinman. 2002. Prolonged IFN-{gamma}-producing NKT response induced with {alpha}-galactosylceramide-loaded DCs. Nat. Immunol. 3: 867-874.[Medline]
  108. Fujii, S.-i., K. Shimizu, C. Smith, L. Bonifaz, R. M. Steinman. 2003. Activation of natural killer T cells by {alpha}-galactosylceramide rapidly induces the full maturation of dendritic cells in vivo and thereby Acts as an adjuvant for combined CD4 and CD8 T cell immunity to a coadministered protein. J. Exp. Med. 198: 267-279.[Abstract/Free Full Text]
  109. Fujii, S.-i., K. Liu, C. Smith, A. J. Bonito, R. M. Steinman. 2004. The linkage of innate to adaptive immunity via maturing dendritic cells in vivo requires CD40 ligation in addition to antigen presentation and CD80/86 costimulation. J. Exp. Med. 199: 1607-1618.[Abstract/Free Full Text]
  110. Dhodapkar, M. V., M. D. Geller, D. H. Chang, K. Shimizu, S.-I. Fujii, K. M. Dhodapkar, J. Krasovsky. 2003. A reversible defect in natural killer T cell function characterizes the progression of premalignant to malignant multiple myeloma. J. Exp. Med. 197: 1667-1676.[Abstract/Free Full Text]
  111. Taniguchi, M., M. Harada, S. Kojo, T. Nakayama, H. Wakao. 2003. The regulatory role of V{alpha}14 NKT cells in innate and acquired immune response. Annu. Rev. Immunol. 21: 483-513.[Medline]
  112. Taniguchi, M., K. Seino, T. Nakayama. 2003. The NKT cell system: bridging innate and acquired immunity. Nat. Immunol. 4: 1164-1165.[Medline]
  113. Wu, D. Y., N. H. Segal, S. Sidobre, M. Kronenberg, P. B. Chapman. 2003. Cross-presentation of disialoganglioside GD3 to natural killer T cells. J. Exp. Med. 198: 173-181.[Abstract/Free Full Text]
  114. Brigl, M., L. Bry, S. C. Kent, J. E. Gumperz, M. B. Brenner. 2003. Mechanism of CD1d-restricted natural killer T cell activation during microbial infection. Nat. Immunol. 4: 1230-1237.[Medline]
  115. Gerosa, F., A. Gobbi, P. Zorzi, S. Burg, F. Briere, G. Carra, G. Trinchieri. 2005. The reciprocal interaction of NK cells with plasmacytoid or myeloid dendritic cells profoundly affects innate resistance functions. J. Immunol. 174: 727-734.[Abstract/Free Full Text]
  116. Jonuleit, H., E. Schmitt, G. Schuler, J. Knop, A. H. Enk. 2000. Induction of human IL-10-producing, non-proliferating CD4+ T cells with regulatory properties by repetitive stimulation with allogeneic immature dendritic cells. J. Exp. Med. 192: 1213-1222.[Abstract/Free Full Text]
  117. Jonuleit, H., E. Schmitt, H. Kakirman, M. Stassen, J. Knop, A. H. Enk. 2002. Infectious tolerance: human CD25+ regulatory T cells convey suppressor activity to conventional CD4+ T helper cells. J. Exp. Med. 196: 255-260.[Abstract/Free Full Text]
  118. Dieckmann, D., C. H. Bruett, H. Ploettner, M. B. Lutz, G. Schuler. 2002. Human CD4+CD25+ regulatory, contact-dependent T cells induce interleukin 10-producing, contact-independent type 1-like regulatory T cells [corrected]. J. Exp. Med. 196: 247-253.[Abstract/Free Full Text]
  119. Munn, D. H., M. Zhou, J. T. Attwood, I. Bondarev, S. J. Conway, B. Marshall, C. Brown, A. L. Mellor. 1998. Prevention of allogeneic fetal rejection by tryptophan catabolism. Science 281: 1191-1193.[Abstract/Free Full Text]
  120. Munn, D. H., M. D. Sharma, J. R. Lee, K. G. Jhaver, T. S. Johnson, D. B. Keskin, B. Marshall, P. Chandler, S. J. Antonia, R. Burgess, et al 2002. Potential regulatory function of human dendritic cells expressing indoleamine 2,3-dioxygenase. Science 297: 1867-1870.[Abstract/Free Full Text]
  121. Grohmann, U., R. Bianchi, C. Orabona, F. Fallarino, C. Vacca, A. Micheletti, M. C. Fioretti, P. Puccetti. 2003. Functional plasticity of dendritic cell subsets as mediated by CD40 versus B7 activation. J. Immunol. 171: 2581-2587.[Abstract/Free Full Text]
  122. Grohmann, U., F. Fallarino, R. Bianchi, C. Orabona, C. Vacca, M. C. Fioretti, P. Puccetti. 2003. A defect in tryptophan catabolism impairs tolerance in nonobese diabetic mice. J. Exp. Med. 198: 153-160.[Abstract/Free Full Text]
  123. Grohmann, U., C. Orabona, F. Fallarino, C. Vacca, F. Calcinaro, A. Falorni, P. Candeloro, M. L. Belladonna, R. Bianchi, M. C. Fioretti, P. Puccetti. 2002. CTLA-4-Ig regulates tryptophan catabolism in vivo. Nat. Immunol. 3: 1097-1101.[Medline]
  124. Fallarino, F., U. Grohmann, K. W. Hwang, C. Orabona, C. Vacca, R. Bianchi, M. L. Belladonna, M. C. Fioretti, M. L. Alegre, P. Puccetti. 2003. Modulation of tryptophan catabolism by regulatory T cells. Nat. Immunol. 4: 1206-1212.[Medline]
  125. Munn, D. H., M. D. Sharma, D. Hou, B. Baban, J. R. Lee, S. J. Antonia, J. L. Messina, P. Chandler, P. A. Koni, A. L. Mellor. 2004. Expression of indoleamine 2,3-dioxygenase by plasmacytoid dendritic cells in tumor-draining lymph nodes. J. Clin. Invest. 114: 280-290.[Medline]
  126. Terness, P., T. M. Bauer, L. Rose, C. Dufter, A. Watzlik, H. Simon, G. Opelz. 2002. Inhibition of allogeneic T cell proliferation by indoleamine 2,3-dioxygenase-expressing dendritic cells: mediation of suppression by tryptophan metabolites. J. Exp. Med. 196: 447-457.[Abstract/Free Full Text]
  127. Blanco, P., A. K. Palucka, M. Gill, V. Pascual, J. Banchereau. 2001. Induction of dendritic cell differentiation by IFN-{alpha} in systemic lupus erythematosus. Science 294: 1540-1543.[Abstract/Free Full Text]
  128. Yamazaki, S., T. Iyoda, K. Tarbell, K. Olson, K. Velinzon, K. Inaba, R. M. Steinman. 2003. Direct expansion of functional CD25+CD4+ regulatory T cells by antigen-processing dendritic cells. J. Exp. Med. 198: 235-247.[Abstract/Free Full Text]
  129. Tarbell, K. V., S. Yamazaki, K. Olson, P. Toy, R. M. Steinman. 2004. CD25+CD4+ T cells, expanded with dendritic cells presenting a single autoantigenic peptide, suppress autoimmune diabetes. J. Exp. Med. 199: 1467-1477.[Abstract/Free Full Text]
  130. Banchereau, J., A. K. Palucka, M. Dhodapkar, S. Burkeholder, N. Taquet, A. Rolland, S. Taquet, S. Coquery, K. M. Wittkowski, N. Bhardwaj, et al 2001. Immune and clinical responses in patients with metastatic melanoma to CD34+ progenitor-derived dendritic cell vaccine. Cancer Res. 61: 6451-6458.[Abstract/Free Full Text]
  131. Jonuleit, H., A. Giesecke-Tuettenberg, T. Tuting, B. Thurner-Schuler, T. B. Stuge, L. Paragnik, A. Kandemir, P. P. Lee, G. Schuler, J. Knop, A. H. Enk. 2001. A comparison of two types of dendritic cell as adjuvants for the induction of melanoma-specific T-cell responses in humans following intranodal injection. Int. J. Cancer 93: 243-251.[Medline]
  132. Dhodapkar, M. V., R. M. Steinman, J. Krasovsky, C. Munz, N. Bhardwaj. 2001. Antigen-specific inhibition of effector T cell function in humans after injection of immature dendritic cells. J. Exp. Med. 193: 233-238.[Abstract/Free Full Text]
  133. Hsu, F. J., C. Benike, F. Fagnoni, T. M. Liles, D. Czerwinski, B. Taidi, E. G. Engleman, R. Levy. 1996. Vaccination of patients with B-cell lymphoma using autologous antigen-pulsed dendritic cells. Nat. Med. 2: 52-58.[Medline]
  134. Thurner, B., I. Haendle, C. Roder, D. Dieckmann, P. Keikavoussi, H. Jonuleit, A. Bender, C. Maczek, D. Schreiner, P. von Den Driesch, et al 1999. Vaccination with mage-3A1 peptide-pulsed mature, monocyte-derived dendritic cells expands specific cytotoxic T cells and induces regression of some metastases in advanced stage IV melanoma. J. Exp. Med. 190: 1669-1678.[Abstract/Free Full Text]
  135. Timmerman, J. M., D. K. Czerwinski, T. A. Davis, F. J. Hsu, C. Benike, Z. M. Hao, B. Taidi, R. Rajapaksa, C. B. Caspar, C. Y. Okada, et al 2002. Idiotype-pulsed dendritic cell vaccination for B-cell lymphoma: clinical and immune responses in 35 patients. Blood 99: 1517-1526.[Abstract/Free Full Text]



This article has been cited by other articles:


Home page
CVIHome page
T. L. Whiteside, P. Piazza, A. Reiter, J. Stanson, N. C. Connolly, C. R. Rinaldo Jr., and S. A. Riddler
Production of a Dendritic Cell-Based Vaccine Containing Inactivated Autologous Virus for Therapy of Patients with Chronic Human Immunodeficiency Virus Type 1 Infection
Clin. Vaccine Immunol., February 1, 2009; 16(2): 233 - 240.
[Abstract] [Full Text] [PDF]


Home page
Exp. Biol. Med.Home page
K.-I. Inoue, E. Koike, H. Takano, R. Yanagisawa, T. Ichinose, and T. Yoshikawa
Effects of Diesel Exhaust Particles on Antigen-Presenting Cells and Antigen-Specific Th Immunity in Mice
Experimental Biology and Medicine, February 1, 2009; 234(2): 200 - 209.
[Abstract] [Full Text] [PDF]


Home page
JEMHome page
C. Schuster, C. Vaculik, C. Fiala, S. Meindl, O. Brandt, M. Imhof, G. Stingl, W. Eppel, and A. Elbe-Burger
HLA-DR+ leukocytes acquire CD1 antigens in embryonic and fetal human skin and contain functional antigen-presenting cells
J. Exp. Med., January 16, 2009; 206(1): 169 - 181.
[Abstract] [Full Text] [PDF]


Home page
J. Immunol.Home page
R. Mittal and N. V. Prasadarao
Outer Membrane Protein A Expression in Escherichia coli K1 Is Required to Prevent the Maturation of Myeloid Dendritic Cells and the Induction of IL-10 and TGF-{beta}
J. Immunol., August 15, 2008; 181(4): 2672 - 2682.
[Abstract] [Full Text] [PDF]


Home page
J. Leukoc. Biol.Home page
K. Mnasria, C. Lagaraine, F. Velge-Roussel, R. Oueslati, Y. Lebranchu, and C. Baron
Anti-CD25 antibodies affect cytokine synthesis pattern of human dendritic cells and decrease their ability to prime allogeneic CD4+ T cells
J. Leukoc. Biol., August 1, 2008; 84(2): 460 - 467.
[Abstract] [Full Text] [PDF]


Home page
J. Virol.Home page
N. Thones, A. Herreiner, L. Schadlich, K. Piuko, and M. Muller
A Direct Comparison of Human Papillomavirus Type 16 L1 Particles Reveals a Lower Immunogenicity of Capsomeres than Viruslike Particles with Respect to the Induced Antibody Response
J. Virol., June 1, 2008; 82(11): 5472 - 5485.
[Abstract] [Full Text] [PDF]


Home page
J. Virol.Home page
H. Barth, E. K. Schnober, C. Neumann-Haefelin, C. Thumann, M. B. Zeisel, H. M. Diepolder, Z. Hu, T. J. Liang, H. E. Blum, R. Thimme, et al.
Scavenger Receptor Class B Is Required for Hepatitis C Virus Uptake and Cross-Presentation by Human Dendritic Cells
J. Virol., April 1, 2008; 82(7): 3466 - 3479.
[Abstract] [Full Text] [PDF]


Home page
Mol Cancer ResHome page
A. Ricciardi, A. R. Elia, P. Cappello, M. Puppo, C. Vanni, P. Fardin, A. Eva, D. Munroe, X. Wu, M. Giovarelli, et al.
Transcriptome of Hypoxic Immature Dendritic Cells: Modulation of Chemokine/Receptor Expression
Mol. Cancer Res., February 1, 2008; 6(2): 175 - 185.
[Abstract] [Full Text] [PDF]


Home page
J. Immunol.Home page
M. A. Arias, G. Jaramillo, Y. P. Lopez, N. Mejia, C. Mejia, A. E. Pantoja, R. J. Shattock, L. F. Garcia, and G. E. Griffin
Mycobacterium tuberculosis Antigens Specifically Modulate CCR2 and MCP-1/CCL2 on Lymphoid Cells from Human Pulmonary Hilar Lymph Nodes
J. Immunol., December 15, 2007; 179(12): 8381 - 8391.
[Abstract] [Full Text] [PDF]


Home page
NeurologyHome page
S. A. Greenberg
Proposed immunologic models of the inflammatory myopathies and potential therapeutic implications
Neurology, November 20, 2007; 69(21): 2008 - 2019.
[Abstract] [Full Text] [PDF]


Home page
Am. J. Pathol.Home page
P. C. Maffia, S. E. Zittermann, M. L. Scimone, N. Tateosian, N. Amiano, D. Guerrieri, V. Lutzky, D. Rosso, H. E. Romeo, V. E. Garcia, et al.
Neutrophil Elastase Converts Human Immature Dendritic Cells into Transforming Growth Factor-{beta}1-Secreting Cells and Reduces Allostimulatory Ability
Am. J. Pathol., September 1, 2007; 171(3): 928 - 937.
[Abstract] [Full Text] [PDF]


Home page
Proc. Natl. Acad. Sci. USAHome page
A. A. Herrada, F. J. Contreras, J. A. Tobar, R. Pacheco, and A. M. Kalergis
Immune complex-induced enhancement of bacterial antigen presentation requires Fc{gamma} Receptor III expression on dendritic cells
PNAS, August 14, 2007; 104(33): 13402 - 13407.
[Abstract] [Full Text] [PDF]


Home page
Ann Rheum DisHome page
J G Walker, M J Ahern, M Coleman, H Weedon, V Papangelis, D Beroukas, P J Roberts-Thomson, and M D Smith
Characterisation of a dendritic cell subset in synovial tissue which strongly expresses Jak/STAT transcription factors from patients with rheumatoid arthritis
Ann Rheum Dis, August 1, 2007; 66(8): 992 - 999.
[Abstract] [Full Text] [PDF]


Home page
J. Immunol.Home page
A. Aldinucci, G. Gerlini, S. Fossati, G. Cipriani, C. Ballerini, T. Biagioli, N. Pimpinelli, L. Borgognoni, L. Massacesi, F. Moroni, et al.
A Key Role for Poly(ADP-Ribose) Polymerase-1 Activity during Human Dendritic Cell Maturation
J. Immunol., July 1, 2007; 179(1): 305 - 312.
[Abstract] [Full Text] [PDF]


Home page
J. Leukoc. Biol.Home page
M. Reich, P. F. van Swieten, V. Sommandas, M. Kraus, R. Fischer, E. Weber, H. Kalbacher, H. S. Overkleeft, and C. Driessen
Endocytosis targets exogenous material selectively to cathepsin S in live human dendritic cells, while cell-penetrating peptides mediate nonselective transport to cysteine cathepsins
J. Leukoc. Biol., April 1, 2007; 81(4): 990 - 1001.
[Abstract] [Full Text] [PDF]


Home page
J. Leukoc. Biol.Home page
R. S. Kornbluth and G. W. Stone
Immunostimulatory combinations: designing the next generation of vaccine adjuvants
J. Leukoc. Biol., November 1, 2006; 80(5): 1084 - 1102.
[Abstract] [Full Text] [PDF]


Home page
ThoraxHome page
T Tschernig, V C de Vries, A S Debertin, A Braun, T Walles, F Traub, and R Pabst
Density of dendritic cells in the human tracheal mucosa is age dependent and site specific
Thorax, November 1, 2006; 61(11): 986 - 991.
[Abstract] [Full Text] [PDF]


Home page
J. Immunol.Home page
J. R. Sheng, L. Li, B. B. Ganesh, C. Vasu, B. S. Prabhakar, and M. N. Meriggioli
Suppression of Experimental Autoimmune Myasthenia Gravis by Granulocyte-Macrophage Colony-Stimulating Factor Is Associated with an Expansion of FoxP3+ Regulatory T Cells
J. Immunol., October 15, 2006; 177(8): 5296 - 5306.
[Abstract] [Full Text] [PDF]


Home page
J. Immunol.Home page
A. Karni, M. Abraham, A. Monsonego, G. Cai, G. J. Freeman, D. Hafler, S. J. Khoury, and H. L. Weiner
Innate Immunity in Multiple Sclerosis: Myeloid Dendritic Cells in Secondary Progressive Multiple Sclerosis Are Activated and Drive a Proinflammatory Immune Response
J. Immunol., September 15, 2006; 177(6): 4196 - 4202.
[Abstract] [Full Text] [PDF]


Home page
JCOHome page
N.-K. V. Cheung, R. Sowers, A. J. Vickers, I. Y. Cheung, B. H. Kushner, and R. Gorlick
FCGR2A Polymorphism Is Correlated With Clinical Outcome After Immunotherapy of Neuroblastoma With Anti-GD2 Antibody and Granulocyte Macrophage Colony-Stimulating Factor
J. Clin. Oncol., June 20, 2006; 24(18): 2885 - 2890.
[Abstract] [Full Text] [PDF]


Home page
J. Immunol.Home page
Y. Campos-Martin, M. Colmenares, B. Gozalbo-Lopez, M. Lopez-Nunez, P. B. Savage, and E. Martinez-Naves
Immature Human Dendritic Cells Infected with Leishmania infantum Are Resistant to NK-Mediated Cytolysis but Are Efficiently Recognized by NKT Cells
J. Immunol., May 15, 2006; 176(10): 6172 - 6179.
[Abstract] [Full Text] [PDF]


Home page
J. Immunol.Home page
N. Sanchez-Sanchez, L. Riol-Blanco, and J. L. Rodriguez-Fernandez
The Multiple Personalities of the Chemokine Receptor CCR7 in Dendritic Cells
J. Immunol., May 1, 2006; 176(9): 5153 - 5159.
[Abstract] [Full Text] [PDF]


This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Request Permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Rossi, M.
Right arrow Articles by Young, J. W.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Rossi, M.
Right arrow Articles by Young, J. W.


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS