| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
* Departments of Medicine and Microbiology and Immunology,
Howard Hughes Medical Institute, University of California, San Francisco, CA 94143
 |
Abstract |
|---|
 Top Abstract IntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
|
Introduction |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
In an effort to create a model for chronic allergen exposure at the respiratory mucosa, we generated transgenic mice that expressed OVA under control of the surfactant protein C (SPC)3 promoter (13, 14). Despite expression in a number of tissues among numerous founders, the tissue consequences in these transgenic animals were essentially restricted to the lung. Although intrinsically tolerant to OVA, mice crossed to OVA-specific TCR-transgenic animals allowed us to examine the consequences of chronic Ag exposure at the mucosa in the setting of a reactive T cell repertoire. Although CD4 T cells that infiltrated the lungs of these double-transgenic mice were primed to produce IL-4 in vitro, they were held in check in vivo by the accumulation of CD25 CD4 regulatory T cells that inhibited immune effector function. When challenged with exogenous Ags, the regulatory T cells remained highly efficient in blocking type 2 effector function by CD4 T cells, but were unable to curtail the induction of airway hyperreactivity. The regulatory capacity of CD25 T cells may be limited in chronic complex diseases with substantial contributions by non-T cells.
|
Materials and Methods |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
Mice expressing OVA under control of the SPC promoter were produced to target Ag expression to lung type II pneumocytes in the alveoli (13, 14). A chicken egg OVA cDNA derived from pETOV (kindly provided by C. Turnnir, Stressgen Biotechnologies, Victoria, Canada) was inserted into the SPC.TRK plasmid (15). After confirmation by sequencing, the construct was linearized and injected into (C57BL.6 x 129)F1 oocytes to create transgenic founders. One line, SPC.OVA, was selected for further study after confirming OVA mRNA and protein in lung along with low serum OVA levels. SPC.OVA was backcrossed 10 generations onto BALB/c. Transgenic integration was confirmed from tail DNA using OVA-specific primers: 5'-GCGCAGCAAGCATGGAAT-3' and 5'-GGAAACACATCTGCCAAA-3'.
Mice
BALB/c and BALB/c DO11.10 OVA-specific TCR-transgenic mice were purchased from The Jackson Laboratory (Bar Harbor, ME). BALB/c TCR-C
-deficient (16), Rag-1-deficient (17), Stat6-deficient (18), and 4get mice containing a bicistronic knockin enhanced green fluorescent protein (eGFP) linked via an internal ribosome entry site with the IL-4 gene (19) were each backcrossed at least 10 generations onto BALB/c and maintained in the University of California, San Francisco specific pathogen-free animal care facility. SPC.OVA and DO11.10 mice were bred onto the Rag-1-deficient, Stat6-deficient, and 4get backgrounds. Intercrossing was used to generate SPC.OVA x DO11.10, SPC.OVA x DO11.10 x Rag-1-deficient, SPC.OVA x DO11.10 x Stat6-deficient, and SPC.OVA x DO11.10 x 4get mice. Crosses were confirmed using flow cytometry with mAb KJ1-26 specific for the DO11.10 TCR (20) and DNA typing.
OVA quantitation
Designated organs were frozen in liquid nitrogen, pulverized, and lysed in RNAzol B (Biotecx Laboratories, Houston, TX) for preparation of RNA. After reverse transcription (murine Moloney leukemia virus reverse transcriptase; Life Technologies, Gaithersburg, MD) with random hexamer primers (Promega, Madison, WI), PCR was used to amplify OVA cDNA using the above primers. Expression of OVA message was compared with the constitutively expressed hypoxanthine phosphoribosyltransferase using primers as described elsewhere (8).
OVA protein in serum and bronchoalveolar lavage was determined using ELISA. Briefly, rabbit anti-chicken OVA (Sigma-Aldrich, St. Louis, MO) was purified by ammonium sulfate precipitation and used at 5 µg/ml to coat flat-bottom microtiter wells (Immulon 4HBX; Dynex Technologies, Chantilly, VA). After blocking with 3% BSA in PBS and extensive washing, samples were titrated and incubated for 2 h at room temperature. After washing, purified biotinylated rabbit anti-chicken OVA was added at 1 µg/ml for 1 h. Wells were developed using streptavidin-conjugated alkaline phosphatase (Jackson ImmunoResearch Laboratories, West Grove, PA). Chicken OVA (Sigma-Aldrich) was used as a standard.
Cell preparation and analysis
Where designated, CD4 T cells from indicated mice were enriched from either dispersed lung or spleen cell preparations by Ab- and complement-mediated lysis of CD8, MHC class II, and heat-stable Ag-bearing cells as described previously (21). Otherwise, populations of CD4 T cells were fractionated based on CD25 cell surface expression using flow cytometry. Lungs were minced and dispersed into single-cell suspensions. RBCs were lysed in hypotonic buffer and the remaining cells were washed and maintained in tissue culture medium (RPMI 1640 with 10% heat-inactivated FCS, 50 µM 2-ME, 2 mM L-glutamine, and 100 U/ml penicillin and streptomycin). Dispersed spleen cells were purified over Ficoll before suspension in tissue culture medium. Cells were purified (>98%) by flow cytometry (Mo-Flo MultiLaser Flow Cytometer; Cytomation, Ft. Collins, CO) after staining with FITC-anti-CD4 (Caltag Laboratories, South San Francisco, CA), PE-anti-CD25 (BD PharMingen, San Diego, CA), TriColor-anti-B220 (Caltag Laboratories), and TriColor-anti-CD8 (Caltag Laboratories).
Proliferation assays were performed after distribution of indicated numbers of CD4 T cells with 106 irradiated APC prepared from TCR-C-deficient spleen cells and titrated concentrations of OVA peptide. After incubation for 48 h, 1 µCi of [3H]thymidine was added for 18 h and cultures were harvested for determination of radioactive uptake.
Polarization assays were performed by incubating indicated numbers of CD4 T cells with 107 irradiated APC and 1 µM OVA peptide under neutral (100 U/ml recombinant human IL-2) or Th2 conditions (100 U/ml recombinant human IL-2, 50 ng/ml recombinant murine IL-4, 50 µg/ml neutralizing anti-IFN-
mAb (XMG1.2), as described elsewhere (22).
Intracellular cytokines were assessed after stimulation of CD4 T cells with PMA (100 ng/ml) and ionomycin (2 µg/ml; Sigma-Aldrich). After 2 h, brefeldin A (Sigma-Aldrich) was added to a final concentration of 10 µg/ml for an additional 2 h to promote intracellular cytokine accumulation. Cells were fixed in 4% formaldehyde in PBS, permeabilized in 0.5% saponin in 1% FBS/PBS, and analyzed using TriColor-anti-CD4 (Caltag Laboratories), FITC-anti-IFN- (BD PharMingen), and PE-anti-IL-4 (BD PharMingen) or isotype control as described previously (23).
Adoptive transfers
Rag-1-deficient mice were reconstituted with CD4 T cell populations, purified by flow cytometry, at the indicated numbers in 0.3 ml of PBS. Cells were transferred by i.v. injection into the tail vein 24 h before Ag sensitization.
Immunizations and airway sensitization
Mice were immunized at the base of the tail with 25 µg of OVA in alum. After 1 wk, mice were reimmunized i.p. with 25 µg of OVA in alum. After 5 days, CD4 T cells were enriched from the draining lymph nodes and used in proliferation and cytokine assays as described above. For airway sensitization, mice were treated five times intranasally at 2-day intervals with 2.5 mg of OVA in 50 µl of PBS or with PBS alone.
Airway reactivity
Anesthetized mice were analyzed 2 days after the final OVA sensitization. The trachea was cannulated and mice were ventilated with 100% oxygen at physiologic rate and tidal volume using a rodent ventilator (Harvard Apparatus, South Natick, MA). After paralysis to eliminate spontaneous respirations, mice were maintained inside a whole-body plethysmograph for measurements of air flow, transthoracic pressure, and resistance. After establishing a stable baseline, acetylcholine (ACh) was injected i.v. over 1 s in escalating doses via the tail vein. Airway reactivity was expressed as the provocative concentration of ACh in micrograms per grams of body weight required to double the baseline transthoracic resistance, designated PC200, as calculated by linear interpolation of appropriate dose-response curves. Significant differences were calculated using the logarithm of PC200 by analysis of variance using reference to the specified control groups. Baseline pulmonary resistance in the absence of ACh did not differ among the various groups of mice studied.
Histopathology
Lungs were infused in situ with 1 ml of 3.7% formaldehyde in PBS through the tracheal cannula. The lungs were removed and immersed in the same fixative with the trachea tied closed for 24 h. The tissues were embedded in paraffin and 2- to 3-µm sections were cut and stained with H&E or periodic acid-Schiff (PAS) for light microscopy.
Serum IgE
Serum IgE was determined by a double mAb-based sandwich ELISA as described previously (8).
|
Results |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
To target high levels of Ag expression to the airway alveoli, OVA was expressed as a transgene under the control of the human SPC promoter (Fig. 1A). The construct was linearized and injected into (C57BL/6 x 129)F1 oocytes to create transgenic founder lines. After screening six founder lines, we selected for further study one line, designated SPC.OVA, based on robust lung tissue mRNA expression (data not shown) and high levels of OVA protein in bronchial lavage fluid (Fig. 1B). Functionally significant OVA protein expression was confined to the lung, as assessed by histologic examination of multiple tissues. SPC.OVA was backcrossed 10 generations to BALB/c without change in the distribution of OVA mRNA or protein expression (data not shown).
|
After immunization with OVA, spleen T cells from SPC.OVA mice failed to proliferate to a broad range of OVA peptide that induced strong proliferative responses in similarly immunized control BALB/c mice (Fig. 2A, left panel). The response to OVA by SPC.OVA T cells did not differ from the response by cells from unimmunized mice, confirming the deletion and/or tolerance of OVA-specific T cells, as expected by the presence of OVA protein in serum (Fig. 1B). In other transgenic Ag models, coexpression of an Ag-specific transgenic TCR has promoted escape from negative selection, presumably driven by the high thymic precursor frequency established by the TCR transgene (24, 25, 26). To assess whether similar outcomes might occur in the lung, we crossed the SPC.OVA mice to OVA-specific DO11.10 TCR-transgenic mice which contain CD4 T cells that recognize OVA peptide in the context of I-Ad MHC class II molecules (27). The clonotypic OVA-specific CD4 T cells from the spleen of double-transgenic mice, designated SPC.OVA x DO11.10, proliferated in a dose-dependent response that was comparable to clonotypic cells from DO11.10 TCR-transgenic mice (Fig. 2A, right panel). Thus, despite high-level Ag expression, clonotypic T cells from the double-transgenic mice maintained function. Analysis of numbers of clonotypic cells in thymus and spleen, however, revealed comparable numbers and percentages in the thymus but a 6-fold reduction in numbers of cells in the spleen as compared with control DO11.10 mice (Fig. 2B and data not shown).
|
The reduction in numbers of clonotypic DO11.10 T cells in the spleen of the double-transgenic mice raised the possibility of either activation-induced cell death (28) or recruitment into tissues where OVA was expressed at high levels. Although lungs of DO11.10 TCR-transgenic mice did not differ from normal tissues (Fig. 3A and data not shown), the lungs of SPC.OVA x DO11.10 mice contained peribronchiolar and perivascular lymphocytic infiltrates (Fig. 3B). Organized bronchus-associated lymphoid tissue structures, or BALT, were scattered throughout the lungs (Fig. 3C). Examination of the larger airways using PAS stains revealed areas of mucin-containing goblet cells adjacent to the infiltrates that were not apparent in control DO11.10 mice (Fig. 3D and data not shown).
|
genes. To restrict the T cell specificity to the single clonotype, transgenic DO11.10 TCR and SPC.OVA x DO11.10 mice were further crossed to create SPC.OVA x DO11.10 x Rag-1-deficient mice. Despite this reduction in TCR specificity, the accumulation of pulmonary infiltrates into organized BALT-like structures, as well as the presence of scattered regions of mucin-producing goblet cells, were unchanged (Fig. 3, E and F).
In various models of airway hyperreactivity, mucin production by airway epithelial cells is largely dependent on IL-4R-mediated signaling via Stat6 (29, 30). To assess whether the modest amounts of goblet cell hyperplasia that occurred in SPC.OVA x DO11.10 mice was similarly Stat6 dependent, we additionally intercrossed mice to generate SPC.OVA x DO11.10 x Stat6-deficient mice. Although the accumulation of spontaneous lung infiltrates remained unchanged, mucin production was entirely ablated on the Stat6-deficient background (Fig. 3, G and H).
Accumulation of CD25+ clonotypic T cells in lungs of SPC.OVA x DO11.10 mice
Dispersal of lung cells and analysis using surface markers revealed increased percentages of CD4 T cells and B cells in the SPC.OVA x DO11.10 mice compared with DO11.10 controls (Fig. 4A). Despite the presence of some mucin-containing goblet cell hyperplasia consistent with aspects of type 2 immunity, no eosinophils were detected. As compared with cells from control DO11.10 animals, substantial numbers of clonotypic CD4 T cells from the double-transgenic mice displayed an activated phenotype consisting of marked up-regulation of CD25 and CD69 and down-regulation of CD62 ligand (Fig. 4B). The appearance of CD25+ CD4 T cells did not require the expression of endogenous TCRs, since SPC.OVA x DO11.10 x Rag-1-deficient mice also accumulated activated OVA-specific T cells in lung and spleen (Fig. 4C). However transgenic Ag expression was a prerequisite on the Rag-1-deficient background for the generation of these cells because they were not present in single-transgenic DO11.10 x Rag-1-deficient mice (Fig. 4C). Crossing the double-transgenic mice onto the Stat6-deficient background also did not affect the accumulation of CD25+ clonotypic T cells relative to the wild-type background (Fig. 4C and data not shown). Thus, introduction of the TCR transgene into mice concomitant with Ag expression in the airway mucosa resulted in the appearance of Ag-specific, CD25+ CD4 T cells in spleen and their accumulation in pulmonary tissue.
|
The presence of infiltrating CD25+ CD4 T cells raised the possibility that these cells were effector cells activated by exposure to cognate Ag expressed in large amounts in lung tissues. Analysis of intracellular cytokine production of IL-4 and IFN- after PMA/ionomycin stimulation, however, revealed no difference in cells collected from SPC.OVA x DO11.10 and DO11.10 mice (see below). Pulmonary infiltrates consisting of Th2 or Th1 effector cells have been associated with increases in airway hyperreactivity to bronchoconstricting agents (31, 32, 33). Analysis of airway resistance to increasing doses of ACh, however, revealed no differences in basal airway hyperreactivity between SPC.OVA x DO11.10 and control DO11.10 mice (see below).
Regulatory T cells are a specialized population of CD4 T cells that express the IL-2R -chain (CD25) and suppress Ag-induced activation of T cells in vitro and in vivo (34). They have been invoked in a variety of autoimmune, infectious, and inflammatory diseases (35). To assess whether the CD25+ CD4 T cells in SPC.OVA x DO11.10 mice functionally resembled regulatory T cells, we separated CD4 T cells into CD25+ and CD25- subsets and examined their capacity to proliferate either alone or together in response to escalating doses of the cognate OVA peptide. Since SPC.OVA x DO11.10 x Rag-1-deficient mice accumulated comparable CD25+ clonotypic T cells (Fig. 4C), we performed similar experiments using fractionated cells from these animals. The CD25- CD4 T cells from both double-transgenic and double-transgenic/Rag-1-deficient mice proliferated to OVA in a dose-dependent fashion, in contrast to the CD25+ CD4 T cells from both groups of mice that remained unresponsive (Fig. 5A). When cultured with the CD25- T cells at the 1:4 ratio of CD25+:CD25- T cells that was present in the lungs of the mice, the CD25+ CD4 T cells suppressed proliferation to OVA peptide. Thus, whether on the wild-type or Rag-1-deficient background, the lung CD25+ CD4 T cells had the phenotype of regulatory T cells.
|
, suggested that T cells in the lung, in contrast to the spleen, were poised to express IL-4 more readily. Indeed, IL-4 expression, as quantitated using eGFP fluorescence, was comparable under neutral or polarizing Th2 conditions in lung T cells (Fig. 5B). To assess the individual contributions of the CD25+ and CD25- CD4 T cell subsets, we isolated the respective cell populations from the lung and spleen and examined their capacity to express eGFP after priming in the presence of IL-2 alone or in Th2-polarizing conditions (Fig. 5C). Under both conditions, the CD25- CD4 T cells expressed a more robust IL-4 response, and this was particularly evident using lung T cells. The CD25+ CD4 T cells were consistently more refractory to the induction of IL-4.
Taken together, the CD25+ CD4 T cells that accumulate in the lungs of double-transgenic mice do not proliferate in response to their cognate Ag, suppress the proliferation of CD25- CD4 T cells, and maintain resistance to IL-4 induction even under Th2 conditions in vitro.
CD25+ CD4 regulatory T cells from lung suppress Th2 effector function in vivo but do not inhibit Ag-induced airway hyperreactivity
Despite the accumulation of pulmonary infiltrates, saline-treated SPC.OVA x DO11.10 mice have basal airway reactivity to ACh that is not different from similarly treated single-transgenic DO11.10 mice (Fig. 6A). Repeated intranasal administration of OVA induces airway hyperreactivity and activated T cell responses in DO11.10 mice (38). Despite the expression of OVA in the lungs of the SPC.OVA x DO11.10 mice, we tested the capacity of exogenous OVA to induce airway hyperreactivity, perhaps due to activation of innate inflammatory systems. Indeed, after sensitization five times with OVA, airway hyperreactivity was induced to a comparable degree in both DO11.10 and in SPC.OVA x DO11.10 mice (Fig. 6A). Since the CD25+ CD4 regulatory T cells were not ablated by OVA sensitization (data not shown), we assessed whether Ag sensitization had completely overcome their regulatory function in vivo. Whether assayed using serum IgE or intracellular IL-4 production, the SPC.OVA x DO11.10 mice, however, revealed a marked suppression of type 2 effector function (Fig. 6, B and C). Histologic study revealed diminished numbers of both lymphocytes and eosinophils in the remaining peribronchial infiltrates and lung parenchyma (data not shown). These data indicated that Ag-induced airway hyperreactivity continued to be manifest even in the presence of Ag-specific regulatory T cells that functionally suppressed type 2 immunity in vivo.
|
|
|
Discussion |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
It is intriguing to compare the outcome of forced expression of self-Ag at the mucosa, as done here, with forced expression at systemic nonmucosal tissue sites, such as the liver or pancreas. In most systemic models, various checkpoints appear to interrupt a default type 1 immune differentiation pathway that, if unchecked, leads to tissue injury (24, 25, 40, 41). Indeed, suppression of type 1 immune responses to Bordetella infection of the respiratory tract by regulatory T cells has been reported (42). In contrast, our forced expression of self-Ag at the mucosa suggested the presence of a similar checkpoint appearing to interrupt default type 2 allergic tissue injury. Deposition of exogenous Ag on respiratory epithelia typically engenders type 2 immunity (43), perhaps reflecting release of specific epithelial chemokines and cytokines involved in allergic responses, such as eotaxin (44, 45). Alternatively, respiratory tract dendritic cells may intrinsically activate a type 2 differentiation pathway after migration and maturation to mediastinal lymph nodes (46). Although no IL-4 was produced in these double-transgenic mice as assessed directly ex vivo or by inference with respect to normal IgE levels, IL-4 was readily revealed when T cells were activated in the presence of IL-2. Activation with IL-2 overcomes inhibition by regulatory T cells (36, 37), leaving the effector T cells to reveal evidence for priming as Th2 cells by their high levels of IL-4 gene expression. Indeed, IL-4 expression was comparable to that achieved by Th2-polarized cells from control TCR-transgenic mice. Furthermore, the capacity of these effector T cells to express a type 2 cytokine program was blocked by cotransfer of regulatory T cells, demonstrating directly the capacity of these cells to inhibit type 2 immunity in vivo. Together, these data provide evidence for an endogenous type 2 bias in response to high Ag load at the respiratory mucosa that is kept in check through recruitment of regulatory T cells.
Additional evidence supporting a poised type 2 immune state in the double-transgenic mice was the consistent appearance of mucus production at levels above those seen in wild-type or single-transgenic mice. Although not as widespread as the goblet cell hyperplasia that occurs in Ag-sensitized mice (9), mucus production remained Stat6 dependent, suggesting an underlying IL-13-mediated activation pathway (47, 48). We were unable to demonstrate IL-13 protein levels above background using a sensitive ELISA assay from lung T cell supernatants from double-transgenic mice (data not shown), although this does not exclude a role for IL-13 produced by non-T cells. If so, the capacity of regulatory T cells to suppress cytokine effector function may be incomplete with respect to non-T cells.
The lung CD25+ CD4 regulatory T cells we describe have the phenotype of regulatory T cells generated in numerous autoimmune and inflammatory models (49). Their capacity to suppress type 2 immune responses has been infrequently examined, however. As we demonstrated, lung regulatory T cells suppressed type 2 immunity in vivo and in vitro. The mechanisms by which these cells inhibit effector function remain inconclusive. Most previous in vitro experimental systems have suggested a contact-mediated T cell-T cell mechanism as opposed to cytokines such as TGF
or IL-10 (36, 37). Although regulatory T cells express high levels of CTLA-4 (50, 51), we were unable to relieve suppression by treating mice with either CTLA-4/Ig fusion protein or with anti-CTLA-4 Fab (data not shown).
Despite the capacity to inhibit type 2 immunity in the presence of large amounts of Ag and effector T cells, the Ag-specific regulatory T cells did not affect acute airway hyperreactivity after Ag challenge. Even in the presence of endogenous Ag, exogenous administration of OVA was required to induce airway hyperreactivity. We hypothesize that chronic Ag expression at high levels in the airways induces strong immunosuppressive pathways in alveolar macrophages (for example, see Ref. 52), which have been shown to interrupt the Ag-presenting capacity of resident dendritic cells (53). Exogenous OVA may overcome the inherent macrophage homeostatic function and achieve Ag delivery by pulmonary dendritic cells which subsequently favors type 2 immunity (46). Indeed, endotoxin contamination in OVA, or direct aspiration of endotoxin during administration of Ag, may enhance dendritic cell maturation and transit (54). In the presence of CD25 regulatory T cells, Th2 effector function was markedly attenuated, but expression of type 2 immunity by non-T cells may be unaffected. These latter pathways may underlie the development of mucus cell hyperplasia and airway hyperreactivity that escapes the regulatory capacity of the CD25 CD4 T cells. As such, the mechanisms that drive innate type 2 immune responses to mucosal Ag challenge in the airway remain an important focus for further study.
|
Acknowledgments |
|---|
|
Footnotes |
|---|
2 Address correspondence and reprint requests to Dr. Richard M. Locksley, University of California, Box 0654, C-443, 521 Parnassus Avenue, San Francisco, CA 94143-0654. E-mail address: locksley{at}medicine.ucsf.edu
3 Abbreviations used in this paper: SPC, surfactant protein C; ACh, acetylcholine; BALT, bronchus-associated lymphoid tissue; eGFP, enhanced green fluorescent protein; PC200, provocative concentration of acetylcholine required to raise baseline airway resistance 200%; PAS, periodic acid-Schiff.
Received for publication November 22, 2002. Accepted for publication March 24, 2003.
|
References |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
-expressing cells. Science 256:1448. and interferon- by bronchoalveolar leukocytes from patients with bronchial asthma. Am. Rev. Respir. Dis. 147:291.[Medline]
-chains (CD25): breakdown of a single mechanism of self-tolerance causes various autoimmune diseases. J. Immunol. 155:1151.[Abstract]
Related articles in The JI:
This article has been cited by other articles:
|
|
 |
|
  H. S. McGee and D. K. Agrawal Naturally Occurring and Inducible T-Regulatory Cells Modulating Immune Response in Allergic Asthma Am. J. Respir. Crit. Care Med., August 1, 2009; 180(3): 211 - 225. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. Bopp, N. Dehzad, S. Reuter, M. Klein, N. Ullrich, M. Stassen, H. Schild, R. Buhl, E. Schmitt, and C. Taube Inhibition of cAMP Degradation Improves Regulatory T Cell-Mediated Suppression J. Immunol., April 1, 2009; 182(7): 4017 - 4024. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. T. Burchell, M. E. Wikstrom, P. A. Stumbles, P. D. Sly, and D. J. Turner Attenuation of allergen-induced airway hyperresponsiveness is mediated by airway regulatory T cells Am J Physiol Lung Cell Mol Physiol, March 1, 2009; 296(3): L307 - L319. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Presser, D. Schwinge, M. Wegmann, S. Huber, S. Schmitt, A. Quaas, J. H. Maxeiner, S. Finotto, A. W. Lohse, M. Blessing, et al. Coexpression of TGF-{beta}1 and IL-10 Enables Regulatory T Cells to Completely Suppress Airway Hyperreactivity J. Immunol., December 1, 2008; 181(11): 7751 - 7758. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. S. Wilson, J. T. Pesce, T. R. Ramalingam, R. W. Thompson, A. Cheever, and T. A. Wynn Suppression of Murine Allergic Airway Disease by IL-2:Anti-IL-2 Monoclonal Antibody-Induced Regulatory T Cells J. Immunol., November 15, 2008; 181(10): 6942 - 6954. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. Cook, N. Miyahara, N. Jin, J. M. Wands, C. Taube, C. L. Roark, T. A. Potter, E. W. Gelfand, R. L. O'Brien, and W. K. Born Evidence That CD8+ Dendritic Cells Enable the Development of {gamma}{delta} T Cells That Modulate Airway Hyperresponsiveness J. Immunol., July 1, 2008; 181(1): 309 - 319. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Suzuki, X. Zheng, X. Zhang, M. Li, C. Vladau, T. E. Ichim, H. Sun, L. R. Min, B. Garcia, and W.-P. Min Novel Vaccination for Allergy through Gene Silencing of CD40 Using Small Interfering RNA J. Immunol., June 15, 2008; 180(12): 8461 - 8469. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Z.-W. Xia, L.-Q. Xu, W.-W. Zhong, J.-J. Wei, N.-L. Li, J. Shao, Y.-Z. Li, S.-C. Yu, and Z.-L. Zhang Heme Oxygenase-1 Attenuates Ovalbumin-Induced Airway Inflammation by Up-Regulation of Foxp3 T-Regulatory Cells, Interleukin-10, and Membrane-Bound Transforming Growth Factor- 1 Am. J. Pathol., December 1, 2007; 171(6): 1904 - 1914. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. D. Leech, R. A. Benson, A. deVries, P. M. Fitch, and S. E. M. Howie Resolution of Der p1-Induced Allergic Airway Inflammation Is Dependent on CD4+CD25+Foxp3+ Regulatory Cells J. Immunol., November 15, 2007; 179(10): 7050 - 7058. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Joetham, K. Takeda, N. Miyahara, S. Matsubara, H. Ohnishi, T. Koya, A. Dakhama, and E. W. Gelfand Activation of naturally occurring lung CD4+CD25+ regulatory T cells requires CD8 and MHC I interaction PNAS, September 18, 2007; 104(38): 15057 - 15062. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. Kallinich, K. C. Beier, U. Wahn, P. Stock, and E. Hamelmann T-cell co-stimulatory molecules: their role in allergic immune reactions Eur. Respir. J., June 1, 2007; 29(6): 1246 - 1255. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Hubeau, I. Apostolou, and L. Kobzik Targeting of CD25 and Glucocorticoid-Induced TNF Receptor Family-Related Gene-Expressing T Cells Differentially Modulates Asthma Risk in Offspring of Asthmatic and Normal Mother Mice J. Immunol., February 1, 2007; 178(3): 1477 - 1487. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Z.-W. Xia, W.-W. Zhong, L.-Q. Xu, J.-L. Sun, Q.-X. Shen, J.-G. Wang, J. Shao, Y.-Z. Li, and S.-C. Yu Heme Oxygenase-1-Mediated CD4+CD25high Regulatory T Cells Suppress Allergic Airway Inflammation J. Immunol., November 1, 2006; 177(9): 5936 - 5945. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Kearley, J. E. Barker, D. S. Robinson, and C. M. Lloyd Resolution of airway inflammation and hyperreactivity after in vivo transfer of CD4+CD25+ regulatory T cells is interleukin 10 dependent J. Exp. Med., December 5, 2005; 202(11): 1539 - 1547. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
I. P. Lewkowich, N. S. Herman, K. W. Schleifer, M. P. Dance, B. L. Chen, K. M. Dienger, A. A. Sproles, J. S. Shah, J. Kohl, Y. Belkaid, et al. CD4+CD25+ T cells protect against experimentally induced asthma and alter pulmonary dendritic cell phenotype and function J. Exp. Med., December 5, 2005; 202(11): 1549 - 1561. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. M. Hawrylowicz Regulatory T cells and IL-10 in allergic inflammation J. Exp. Med., December 5, 2005; 202(11): 1459 - 1463. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. S. Wilson, M. D. Taylor, A. Balic, C. A.M. Finney, J. R. Lamb, and R. M. Maizels Suppression of allergic airway inflammation by helminth-induced regulatory T cells J. Exp. Med., November 7, 2005; 202(9): 1199 - 1212. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. J. M. van Oosterhout and N. Bloksma Regulatory T-lymphocytes in asthma Eur. Respir. J., November 1, 2005; 26(5): 918 - 932. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. D. Medoff, E. Seung, J. C. Wain, T. K. Means, G. S.V. Campanella, S. A. Islam, S. Y. Thomas, L. C. Ginns, N. Grabie, A. H. Lichtman, et al. BLT1-mediated T cell trafficking is critical for rejection and obliterative bronchiolitis after lung transplantation J. Exp. Med., July 5, 2005; 202(1): 97 - 110. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Jin, C. Taube, L. Sharp, Y.-S. Hahn, X. Yin, J. M. Wands, C. L. Roark, R. L. O'Brien, E. W. Gelfand, and W. K. Born Mismatched Antigen Prepares {gamma}{delta} T Cells for Suppression of Airway Hyperresponsiveness J. Immunol., March 1, 2005; 174(5): 2671 - 2679. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D S Robinson Regulation: the art of control? Regulatory T cells and asthma and allergy Thorax, August 1, 2004; 59(8): 640 - 643. [Full Text] [PDF]
|
|
|
|
|
|
Z. Jaffar, T. Sivakuru, and K. Roberts CD4+CD25+ T Cells Regulate Airway Eosinophilic Inflammation by Modulating the Th2 Cell Phenotype J. Immunol., March 15, 2004; 172(6): 3842 - 3849. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. A. Aronica, S. McCarthy, S. Swaidani, D. Mitchell, M. Goral, J. R. Sheller, and M. Boothby Recall Helper T Cell Response: T Helper 1 Cell-resistant Allergic Susceptibility without Biasing Uncommitted CD4 T Cells Am. J. Respir. Crit. Care Med., March 1, 2004; 169(5): 587 - 595. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
) or control BALB/c mice immunized with OVA (
) or saline control (
) and incubated at 105 cells/well with irradiated APC and the designated concentrations of OVA peptide for 48 h. Proliferation was analyzed by [3H]thymidine incorporation over the final 18 h. Data represent results from one of three comparable experiments. Right panel, Spleen CD4 T cells were purified from nonimmunized SPC.OVA x DO11.10 (
) mice were analyzed for percentages of CD4 and CD8 T cells and B220+ B cells using flow cytometry after staining with appropriate mAb. Macrophages and eosinophil percentages were evaluated after staining cytospin preparations. Bars represent means and SEM. B, Dispersed lung cells from DO11.10 and SPC.OVA x DO11.10 mice were analyzed after gating on CD4 cells for surface expression of the clonotypic TCR using mAb KJ1-26, and CD25, CD62 ligand, and CD69 using appropriate mAb. Depicted percentages represent boxed gates as a proportion of total CD4 lymphocytes. C, CD4 gated cells from spleen and lung cells of DO11.10 or SPC.OVA x DO11.10 mice that were crossed onto Rag-1-deficient (Rag-1-/-) or Stat6-deficient (Stat6-/-) backgrounds were analyzed for surface expression of the clonotypic TCR (KJ1-26) and CD25. Depicted percentages represent boxed gates as a proportion of total CD4 lymphocytes.
