| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
,
* Center for Pulmonary and Infectious Disease Control,
Department of Microbiology and Immunology, and
Department of Medicine, University of Texas Health Center, Tyler, TX 75708;
Department of Microbiology and Immunology, Faculty of Health Sciences, and Cancer Research Center, Ben Gurion University of the Negev, Beer Sheva, Israel;
¶ Amgen, Seattle, WA 98101; and
|| Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109
 |
Abstract |
|---|
 Top Abstract IntroductionMaterials and MethodsResultsDiscussionDisclosuresReferences |
|---|
|
Introduction |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionDisclosuresReferences |
|---|
T cells (12, 13, 14, 15), while DNAM-1 is expressed on NK and T cells (16).
NK cell-activating receptors have multiple ligands that trigger cytotoxicity. For example, NKG2D binds to the polymorphic MHC class I-related chain (MIC)A and MICB (12), which are expressed at low levels in gut epithelium and are up-regulated during heat shock or during infection with CMV (17, 18). NKG2D also binds to UL-16 binding proteins (ULBPs), which are MHC class I-like molecules that are expressed by tumor cell lines. ULBPs enhance the capacity of NK cells to lyse tumors and to produce cytokines such as IFN- and TNF-
(19, 20). For the natural cytotoxicity receptors, viral hemagglutinins were recently identified as ligands that bind NKp46 and NKp44 (21, 22), triggering lysis of infected cells. NKp30 and NKp46 also recognize membrane-associated heparan sulfate proteoglycans on tumor cells (23). The ligand for 2B4 (CD244) is CD48, and the ligands for DNAM-1 are poliovirus receptor (CD155) and Nectin-2 (CD112). These receptor-ligand interactions have been implicated in T cell and NK cell cytotoxicity (24, 25, 26).
Most studies of NK cell receptor-ligand interactions have evaluated lysis of tumor cells and virally infected cells, but little is known of the mechanisms that control lysis of mononuclear phagocytes that are infected with intracellular bacteria. We previously showed that NK cells used the NKp46 receptor to lyse Mycobacterium tuberculosis-infected monocytes (27). In the current study, we determined the relative contribution of five activating NK cell receptors to the lysis of infected monocytes and alveolar macrophages. In addition, we evaluated the ligands for NKG2D on M. tuberculosis-infected mononuclear phagocytes and studied the role of TLR2 in up-regulating expression of one of these ligands.
|
Materials and Methods |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionDisclosuresReferences |
|---|
Blood was obtained from 15 healthy donors. Bronchoalveolar lavage fluid was obtained from eight healthy donors. No donor had clinical or laboratory evidence of tuberculosis or HIV infection. In all donors for whom bronchoscopy was performed, the pathologic process was unilateral, and bronchoalveolar lavage was performed in the normal lung. Informed consent was obtained from all donors. All studies were approved by the Institutional Review Board of the University of Texas Health Center (Tyler, TX).
Cytofluorometric analysis and Abs
The following Abs were used for immunolabeling: FITC anti-CD14, FITC anti-CD3, PE-conjugated anti-CD56, FITC anti-2B4, and PE-conjugated anti-DNAM-1 (all from BD Pharmingen), and immunostaining was performed by standard techniques (28). In some cases, indirect immunolabeling was performed using mouse mAb to human NKG2D (M585), MICA/B (6D4, as ascites), ULBP1, ULBP2, and ULBP3 (M295, M312, and M551, respectively; Amgen), and mouse polyclonal antisera specific for NKp46 and NKp30 as primary Abs (21) and a FITC goat anti-mouse secondary Ab (Southern Biotechnology Associates).
Based on forward and side light scatter characteristics, we gated on lymphocytes or monocytes, and the percentage of cells labeled with specific surface markers was determined with a FACSCalibur (BD Biosciences).
The mAbs to NKG2D, MICA/B, ULBP1, ULBP2, and ULBP3, and antisera to NKp46 and NKp30 used for immunolabeling were also used for neutralization experiments. The DNAM-1 mAb DX11 and 2B4 mAb 2-69 (both from BD Pharmingen) were used for neutralization.
Reagents for studies of TLR2
We used an Ab against TLR2 (2392), which was a kind gift of Dr. P. Godowski (Genentech, San Francisco, CA) and a hexameric peptide Pam3-Cys-Ser-Ser-Asn-Lys-Ser-OH of the 19 kD M. tuberculosis lipoprotein (29), which was generously donated by Dr. R. Modlin, University of California (Los Angeles, CA).
Culture of alveolar macrophages
Bronchoalveolar lavage fluid was passed through sterile gauze and centrifuged at 834 x g for 5 min. The cell pellet was resuspended in RPMI 1640, and 1.2 x 106 cells were allowed to adhere to each well of flat-bottom 12-well plates. Approximately 90% of the bronchoalveolar lavage cells were macrophages, as judged by Giemsa staining. Nonadherent cells were removed, and adherent cells were >98% alveolar macrophages. Some of the adherent cells were uninfected and others were infected with single cell suspensions of M. tuberculosis strain H37Ra at a multiplicity of infection (MOI) of 20:1.
Preparation of target cells for cytotoxicity assays
PBMC were isolated by differential centrifugation over Ficoll-Paque (Amersham Pharmacia Biotech). Monocytes were isolated with magnetic beads conjugated to anti-CD14 (Miltenyi Biotec), and positively selected cells were >95% CD14+, as measured by flow cytometry. Monocytes (106/well) were plated in 12-well plates (BD Labware) in 1 ml of RPMI 1640 (Invitrogen Life Technologies) containing 10% heat-inactivated human serum (Pel-Freez Biologicals). Some monocytes were uninfected and others were infected with single cell suspensions of M. tuberculosis strain H37Ra at a MOI of 5:1, as previously described (30). Cells were incubated for 4 h at 37°C in a humidified 5% CO2 atmosphere, washed to remove extracellular bacilli, and cultured in RPMI 1640 containing 10% heat-inactivated human serum. Approximately 25–40% of the monocytes were infected. After 48 h, cells were collected using a cell scraper, and used as targets in cytotoxicity experiments. These cells were >90% monocytes, as assessed by staining with nonspecific esterase. Cell viability was >90%, as judged by trypan blue exclusion.
In some experiments immature dendritic cells, prepared by treating monocytes with 20 U/ml of GM-CSF and 10 U/ml of IL-4 for 4 days, were used as targets. In other experiments Chinese hamster ovary (CHO)-K cells were used as targets.
Isolation of NK cells
CD3+ cells were depleted from PBMC with magnetic beads conjugated to anti-CD3 (Miltenyi Biotec), and from the negative cell fraction, CD56+ cells were isolated by positive selection with magnetic beads conjugated to anti-CD56 (Miltenyi Biotec). The positive cells were 95–100% CD56+ and 95–97% CD3–, as measured by flow cytometry, and were used as effector cells.
Culture of monocytes and NK cells
Infected and uninfected monocytes or alveolar macrophages were plated in round-bottom 96-well plates (Costar) at 5 x 103/well in 200 µl of RPMI 1640 containing penicillin (Invitrogen Life Technologies) and 10% heat-inactivated human serum in the presence or absence of NK cells (2 x 105/well at a 40:1 E:T cell ratio).
Cytotoxicity assay
NK cell-mediated cytotoxicity against infected and uninfected monocytes and alveolar macrophages was assayed in a 51Cr release assay, using standard methods (31). Briefly, target cells were labeled overnight with 100 µCi of sodium chromate. Target cells were washed three times, and triplicate wells of 104 cells/well were mixed with effector cells at an E:T ratio of 40:1 in 200 µl of RPMI 1640 with 10% heat-inactivated human serum. Ten hours after incubation, 100 µl of supernatant was removed from each well, and radioactivity was measured in a gamma counter. The percentage of lysis was calculated using: 100 x [(experimental release – spontaneous release/maximum release – spontaneous release)].
Statistical analysis
Results are shown as the mean ± SE. For data that were normally distributed, comparisons between groups were performed by a paired or unpaired t test, as appropriate. For data that were not normally distributed, the Wilcoxon rank-sum test was used. Values of p < 0.05 were considered statistically significant.
|
Results |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionDisclosuresReferences |
|---|
To determine the surface distribution of NK cell activating receptors after exposure to M. tuberculosis-infected monocytes, we isolated NK cells and monocytes from PBMC of healthy donors. NK cells were cultured with uninfected or M. tuberculosis-infected monocytes, as outlined in Materials and Methods, and stained with Abs to the NK cell-activating receptors. Expression of NKp46 was markedly increased on NK cells upon exposure to M. tuberculosis-infected cells, and expression of NKp30 and NKG2D were also up-regulated (Fig. 1). In contrast, expression of DNAM-1 and 2B4 was not up-regulated on NK cells after coculture with infected monocytes (data not shown).
|
To determine the relative contribution of the different receptors to lysis of infected monocytes, we incubated freshly isolated NK cells from five healthy donors with mAb or antisera to the five NK cell receptors, before addition of M. tuberculosis-infected monocytes. Anti-NKp46 and anti-NKG2D reduced the net percentage of lysis of infected monocytes from 29 ± 8% to 10 ± 3% (p = 0.01) and to 7 ± 5% (p = 0.01), respectively (Fig. 2A). In contrast, neutralization of NKp30, DNAM-1, and 2B4 did not reduce lysis of infected monocytes (Fig. 2B). Anti-NKp30 inhibited NK cell lysis of autologous immature dendritic cells from five donors (6 ± 3% vs 17 ± 5%; p = 0.01) as previously described (32), indicating that this Ab neutralized NKp30. Similarly, anti DNAM-1 reduced NK cell lysis of CHO-K cells from 24 ± 2% to 14 ± 2% (p = 0.01) as previously described (24). Anti-NKG2D and anti-NKp46 both inhibited the capacity of NK cells from six donors to lyse M. tuberculosis-infected monocytes in a dose-dependent manner (data not shown). We also determined the synergic effect of anti-NKG2D and anti-NKp46 on the lysis of infected monocytes. At suboptimal concentration (5 µg/ml) anti-NKG2D and anti-NKp46 Abs totally inhibited the lysis (Fig. 2C).
|
The data above suggest that NKp46 and NKG2D are the dominant receptors that mediate lysis of M. tuberculosis-infected monocytes. NKG2D recognizes a variety of ligands, such as MICA, MICB, and the proteins ULBP1, ULBP2, and ULBP3, which are normally expressed at low levels but are up-regulated during stress (19). To identify the ligands for NKG2D on M. tuberculosis-infected monocytes, we measured cell surface ligand expression on infected and uninfected CD14+ monocytes from five healthy donors by flow cytometry. ULBP1 expression was significantly up-regulated on infected monocytes, compared with uninfected cells (12.5 ± 2.4% vs 5.2 ± 1.3%; p = 0.002) (Fig. 3). In contrast, there were no differences in expression of MICA/B, ULBP2, and ULBP3 on infected and uninfected monocytes (Fig. 3).
|
To confirm that ULBP1 was the major ligand responsible for NK cell-mediated lysis of infected monocytes, we cultured freshly isolated NK cells with M. tuberculosis-infected monocytes, in the presence of anti-ULBP1 or isotype control Abs (10 µg/ml). Anti-ULBP1 significantly inhibited NK cell-mediated lysis of infected monocytes (net specific lysis 0 vs 29 ± 8%, p < 0.001) (Fig. 4).
|
The most physiologically relevant mononuclear phagocytes involved in defense against M. tuberculosis are alveolar macrophages, which M. tuberculosis first encounters in the lungs. To determine whether these current findings with monocytes apply to alveolar macrophages, we tested the capacity of NK cells from four donors to lyse M. tuberculosis-infected allogeneic alveolar macrophages. We also performed similar experiments with NK cells and autologous alveolar macrophages from three additional donors. NK cells lysed M. tuberculosis-infected alveolar macrophages to a markedly greater extent than uninfected macrophages (mean net specific lysis of 38 ± 8% for allogeneic macrophages and 30 ± 2% for autologous macrophages) (Fig. 5).
|
|
To determine whether ULBP1 was the dominant receptor for NKG2D in infected alveolar macrophages, we incubated NK cells with infected autologous alveolar macrophages, in the presence of Abs to different NKG2D ligands. Anti-ULBP1 significantly inhibited lysis (14 ± 11% vs 46 ± 14%, p < 0.001), but anti-MICA/B did not (Fig. 7). The sum of these findings suggests that NKp46 and NKG2D are the major NK cell-activating receptors that control lysis of M. tuberculosis-infected alveolar macrophages, and that ULBP1 is the major NKG2D ligand used.
|
TLR signaling through the MyD88 adaptor up-regulates transcription of the retinoic acid inducible-1 family of NKG2D ligands in mice (33). Because the M. tuberculosis 19-kD lipoprotein binds to TLR2 and activates macrophages to produce monokines and Ag presentation (34), we investigated the possibility that TLR signaling in M. tuberculosis-infected mononuclear phagocytes induces expression of ULBP1. Monocytes from five healthy donors were cultured in medium alone, infected with H37Ra at an MOI of 5:1, or cultured with the hexameric peptide of the 19-kD M. tuberculosis lipoprotein. After 48 h, monocytes were stained with anti-ULBP1. The percentage of ULBP1-expressing cells increased from 2.0 ± 0.4% in uninfected cells to 7.4 ± 1.3% in M. tuberculosis-infected cells and to 7.7 ± 2.1% in monocytes stimulated with the lipopeptide (Fig. 8). When M. tuberculosis-infected cells were incubated with anti-TLR2, ULBP1 expression was inhibited (3.2 ± 1.1% vs 7.4 ± 1.3%, p < 0.001) (Fig. 8A). Anti-TLR2 inhibited NK cell lysis of monocytes stimulated with the hexameric peptide (1.4 ± 1% vs 15.8 ± 3.4%, p < 0.03) (Fig. 8B). This suggests that TLR2 mediates up-regulation of ULBP1 expression on infected monocytes.
|
|
Discussion |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionDisclosuresReferences |
|---|
NKp46, NKp30, and NKp44 are exclusively expressed on NK cells and play a major role in NK cell-mediated cytotoxicity. NKp46 and NKp30 are constitutively expressed, but NKp44 is present only on activated NK cells. Because NKp44 mRNA is not up-regulated in NK cells exposed to M. tuberculosis-infected monocytes (27), we focused our current study on NKp30 and NKp46. Infected monocytes expressed higher levels of NKp46 than NKp30, and only neutralization of NKp46 inhibited NK cell lysis of infected mononuclear phagocytes, indicating that NKp30 did not play a significant role in this process. Because TGF-
down-regulates surface expression of NKp30 but not NKp46 (35), and M. tuberculosis-infected monocytes produce a high concentration of TGF- (36), which may inhibit expression of NKp30, limiting its role in NK cell lysis of these cells.
Although mammalian ligands for NKp46 and NKp30 have not been identified, it is likely that such ligands are present on specific cell types. For example, dendritic cells are thought to express ligands for NKp30 but not NKp46 (32). In contrast, our results suggest that infected monocytes and alveolar macrophages express ligands for NKp46 but not NKp30. The NKp46 ligand on M. tuberculosis-infected macrophages may be structurally similar to viral hemagglutinin, which binds to NKp46 but not NKp30 (21, 22).
2B4 is an activating receptor on NK cells that binds to CD48 on target cells and triggers cytotoxicity by a subpopulation of NK cells (26). Although exposure of NK cells to M. tuberculosis-infected monocytes up-regulated expression of 2B4, this receptor did not play a primary role in lysis of infected cells, suggesting that abnormalities in 2B4 expression or signaling should not enhance susceptibility to tuberculosis. This finding is consistent with clinical evidence that patients with X-linked lymphoproliferative disorder, who have defective signaling through 2B4 but normal NKp46 function (37), are highly susceptible to EBV infection but not to infections with intracellular bacteria (10).
DNAM-1 is a transmembrane glycoprotein of the Ig superfamily that is constitutively expressed by NK cells, T cells, and monocytes (38, 39). When DNAM-1 on NK cells binds to the poliovirus receptor (CD155) or to Nectin-2 (CD112), this can result in lysis of certain tumor targets (24). These DNAM-1 ligands are highly expressed on endothelial cells, but not on monocytes (40). We found that DNAM-1 did not play a primary role in the capacity of NK cells to lyse M. tuberculosis-infected monocytes, suggesting that DNAM-1 ligands are not markedly up-regulated on infected mononuclear phagocytes. Alternatively, in polyclonal NK cell populations for which cytotoxicity is controlled by several NK receptors, the effects of NKp46 and NKG2D and their ligands may dominate over effects of DNAM-1 and its ligands, similar to findings reported for cytolytic activity of primary NK cells against tumor targets (24).
NKG2D interacts with six ligands: MICA and MICB, ULBP1, ULBP2, ULBP3, and ULBP4. MICA and MICB are not expressed by most cell types, but are induced in epithelial cells during heat shock (24) and in endothelial cells and fibroblasts that are infected with CMV (41). MICA was up-regulated in monocyte-derived dendritic cells after infection with extremely large numbers of M. tuberculosis (MOI of 2000:1) (42). In contrast, we found no increase in MICA/B expression during infection with smaller numbers of organisms (MOI of 5:1), which is likely to be more representative of conditions due to natural infection. The four ULBPs are differentially regulated by specific stimuli. For example, fibroblasts infected with CMV express ULBP1, ULBP2, and ULBP3 at different time points after infection (43). Our results indicate that infection of mononuclear phagocytes with M. tuberculosis up-regulates ULBP1, but not the other NKG2D ligands.
TLRs are central to innate immune responses by mononuclear phagocytes, and ligands for TLR2, TLR3, TLR5, and TLR9 directly stimulate human NK cells to produce IFN- and to lyse tumor cell targets (44, 45). In contrast, the TLR9 ligand, CpG oligodeoxynucleotide activates NK cells through soluble factors produced by plasmacytoid dendritic cells (46). We found that a hexameric peptide of the 19-kDa lipoprotein of M. tuberculosis, a ligand for TLR-2 (34), up-regulates expression of the NKG2D ligand ULBP1 on M. tuberculosis-infected monocytes, providing a third potential mechanism by which TLRs modulate the function of NK cells. Enhanced ULBP1 expression is likely to stimulate binding to NKG2D, facilitating NK cell lysis of infected cells. Our findings extend recent observations in a murine model, in which TLR2, TLR3, and TLR4 up-regulated expression of the NKG2D ligands, retinoic acid early inducible-1 proteins (33), which share 20% homology with ULBP1 (47).
In summary, we found that NKp46 and NKG2D are the dominant receptors that contribute to NK cell lysis of M. tuberculosis-infected mononuclear phagocytes, including alveolar macrophages. The major NKG2D ligand on infected mononuclear phagocytes is ULBP1, and its expression depends on TLR2. Our results indicate that interactions between the TLR2 pathway and NK cells can contribute to the local immune response to M. tuberculosis infection.
|
Acknowledgments |
|---|
|
Disclosures |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionDisclosuresReferences |
|---|
|
Footnotes |
|---|
1 This work was supported by the National Institutes of Health Grants AI44935 and AI054629, the American Lung Association Grant RG-1006-N, the Cain Foundation for Infectious Disease Research, and the Center for Pulmonary and Infectious Disease Control. P.F.B. holds the Margaret E. Byers Cain Chair for Tuberculosis Research. 
2 Address correspondence and reprint requests to Dr. Ramakrishna Vankayalapati, Center for Pulmonary and Infectious Disease Control, University of Texas Health Center, 11937 US Highway 271, Tyler, TX 75708-3154. E-mail address: Krishna.vankayalapati{at}uthct.edu
3 Abbreviations used in this paper: DNAM, DNAX accessory molecule; ULBP, UL-16 binding protein; MIC, MHC class I-related chain; MOI, multiplicity of infection.
Received for publication October 13, 2004. Accepted for publication June 9, 2005.
|
References |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionDisclosuresReferences |
|---|
in defense against murine cytomegalovirus infection and enhancement of this defense pathway by interleukin 12 administration. J. Exp. Med. 182:1045.-1056. . J. Infect. Dis. 174:1073.-1079. [Medline]
T cells of MICA and MICB. Proc. Natl. Acad. Sci. USA 96:6879.-6884. 1 inhibits expression of NKp30 and NKG2D receptors: consequences for the NK-mediated killing of dendritic cells. Proc. Natl. Acad. Sci. USA 100:4120.-4125. by blood monocytes from patients with active tuberculosis and presence of TGF- in tuberculous granulomatous lung lesions. J. Immunol. 154:465.-473. [Abstract]
T cells by NKG2D via engagement by MIC induced on virus-infected cells. Nat. Immunol. 2:255.-260. [Medline]
2V2 T cells enhances their antigen-dependent effector function. Immunity 15:83.-93. [Medline]
-defensin production. Blood 104:1778.-1783. This article has been cited by other articles:
|
|
 |
|
  R. Dhiman, M. Indramohan, P. F. Barnes, R. C. Nayak, P. Paidipally, L. V. M. Rao, and R. Vankayalapati IL-22 Produced by Human NK Cells Inhibits Growth of Mycobacterium tuberculosis by Enhancing Phagolysosomal Fusion J. Immunol., November 15, 2009; 183(10): 6639 - 6645. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. Paidipally, S. Periasamy, P. F. Barnes, R. Dhiman, M. Indramohan, D. E. Griffith, D. Cosman, and R. Vankayalapati NKG2D-Dependent IL-17 Production by Human T Cells in Response to an Intracellular Pathogen J. Immunol., August 1, 2009; 183(3): 1940 - 1945. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. E. Butler, M. B. Moore, S. R. Presnell, H.-W. Chan, N. J. Chalupny, and C. T. Lutz Proteasome Regulation of ULBP1 Transcription J. Immunol., May 15, 2009; 182(10): 6600 - 6609. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Lapaque, T. Walzer, S. Meresse, E. Vivier, and J. Trowsdale Interactions between Human NK Cells and Macrophages in Response to Salmonella Infection J. Immunol., April 1, 2009; 182(7): 4339 - 4348. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Kloss, P. Decker, K. M. Baltz, T. Baessler, G. Jung, H.-G. Rammensee, A. Steinle, M. Krusch, and H. R. Salih Interaction of Monocytes with NK Cells upon Toll-Like Receptor-Induced Expression of the NKG2D Ligand MICA J. Immunol., November 15, 2008; 181(10): 6711 - 6719. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. X. H. Sanabria, D. A. Vargas-Inchaustegui, L. Xin, and L. Soong Role of Natural Killer Cells in Modulating Dendritic Cell Responses to Leishmania amazonensis Infection Infect. Immun., November 1, 2008; 76(11): 5100 - 5109. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. C. Wesselkamper, B. L. Eppert, G. T. Motz, G. W. Lau, D. J. Hassett, and M. T. Borchers NKG2D Is Critical for NK Cell Activation in Host Defense against Pseudomonas aeruginosa Respiratory Infection J. Immunol., October 15, 2008; 181(8): 5481 - 5489. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. Marcenaro, B. Ferranti, M. Falco, L. Moretta, and A. Moretta Human NK cells directly recognize Mycobacterium bovis via TLR2 and acquire the ability to kill monocyte-derived DC Int. Immunol., September 1, 2008; 20(9): 1155 - 1167. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Esin, G. Batoni, C. Counoupas, A. Stringaro, F. L. Brancatisano, M. Colone, G. Maisetta, W. Florio, G. Arancia, and M. Campa Direct Binding of Human NK Cell Natural Cytotoxicity Receptor NKp44 to the Surfaces of Mycobacteria and Other Bacteria Infect. Immun., April 1, 2008; 76(4): 1719 - 1727. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C.-C. Lu, H.-C. Lai, S.-C. Hsieh, and J.-K. Chen Resveratrol ameliorates Serratia marcescens-induced acute pneumonia in rats J. Leukoc. Biol., April 1, 2008; 83(4): 1028 - 1037. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Vales-Gomez, S. E. Chisholm, R. L. Cassady-Cain, P. Roda-Navarro, and H. T. Reyburn Selective Induction of Expression of a Ligand for the NKG2D Receptor by Proteasome Inhibitors Cancer Res., March 1, 2008; 68(5): 1546 - 1554. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Roy, P. F. Barnes, A. Garg, S. Wu, D. Cosman, and R. Vankayalapati NK Cells Lyse T Regulatory Cells That Expand in Response to an Intracellular Pathogen J. Immunol., February 1, 2008; 180(3): 1729 - 1736. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Ebihara, H. Masuda, T. Akazawa, M. Shingai, H. Kikuta, T. Ariga, M. Matsumoto, and T. Seya Induction of NKG2D ligands on human dendritic cells by TLR ligand stimulation and RNA virus infection Int. Immunol., October 1, 2007; 19(10): 1145 - 1155. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Guan, M. Moretto, D. J. Bzik, J. Gigley, and I. A. Khan NK Cells Enhance Dendritic Cell Response against Parasite Antigens via NKG2D Pathway J. Immunol., July 1, 2007; 179(1): 590 - 596. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Nedvetzki, S. Sowinski, R. A. Eagle, J. Harris, F. Vely, D. Pende, J. Trowsdale, E. Vivier, S. Gordon, and D. M. Davis Reciprocal regulation of human natural killer cells and macrophages associated with distinct immune synapses Blood, May 1, 2007; 109(9): 3776 - 3785. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 U. Schleicher, J. Liese, I. Knippertz, C. Kurzmann, A. Hesse, A. Heit, J. A.A. Fischer, S. Weiss, U. Kalinke, S. Kunz, et al. NK cell activation in visceral leishmaniasis requires TLR9, myeloid DCs, and IL-12, but is independent of plasmacytoid DCs J. Exp. Med., April 16, 2007; 204(4): 893 - 906. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Draghi, A. Pashine, B. Sanjanwala, K. Gendzekhadze, C. Cantoni, D. Cosman, A. Moretta, N. M. Valiante, and P. Parham NKp46 and NKG2D Recognition of Infected Dendritic Cells Is Necessary for NK Cell Activation in the Human Response to Influenza Infection J. Immunol., March 1, 2007; 178(5): 2688 - 2698. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. Saikali, J. P. Antel, J. Newcombe, Z. Chen, M. Freedman, M. Blain, R. Cayrol, A. Prat, J. A. Hall, and N. Arbour NKG2D-Mediated Cytotoxicity toward Oligodendrocytes Suggests a Mechanism for Tissue Injury in Multiple Sclerosis J. Neurosci., January 31, 2007; 27(5): 1220 - 1228. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. G. Feng, M. Kaviratne, A. G. Rothfuchs, A. Cheever, S. Hieny, H. A. Young, T. A. Wynn, and A. Sher NK Cell-Derived IFN-{gamma} Differentially Regulates Innate Resistance and Neutrophil Response in T Cell-Deficient Hosts Infected with Mycobacterium tuberculosis J. Immunol., November 15, 2006; 177(10): 7086 - 7093. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Garg, P. F. Barnes, A. Porgador, S. Roy, S. Wu, J. S. Nanda, D. E. Griffith, W. M. Girard, N. Rawal, S. Shetty, et al. Vimentin Expressed on Mycobacterium tuberculosis-Infected Human Monocytes Is Involved in Binding to the NKp46 Receptor J. Immunol., November 1, 2006; 177(9): 6192 - 6198. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
). Monocytes from five healthy donors were infected with M. tuberculosis strain H37Ra. After 48 h, CD14+ cells were stained with Abs to different NKG2D ligands, and the percentage of positively stained cells was determined. Mean value with SE is shown.
) or with either a TLR2 stimulus (H37Ra or the hemaxeric peptide of the 19-kD M. tuberculosis lipoprotein (0.25 µg/ml)) and an isotype control Ab (10 µg/ml) (
) or a TLR2 stimulus and anti-TLR2 (10 µg/ml) (
). Monocytes were incubated with the Abs on ice for 1 h, before addition of H37Ra or the hexameric peptide. After 48 h, cells were stained with anti-ULBP1. Mean value with SE is shown. B, Neutralization of TLR2 on the capacity of NK cells to lyse M. tuberculosis–infected monocytes. Monocytes from five healthy persons were cultured with the hexameric peptide of the 19-kD M. tuberculosis lipoprotein, as described in A. After 48 h, cells were used as target cells for autologous NK cells. Net specific lysis was determined, and mean value with SE is shown.