scholarly journals Dynamics of SIV-specific CXCR5+ CD8 T cells during chronic SIV infection

2017 ◽  
Vol 114 (8) ◽  
pp. 1976-1981 ◽  
Author(s):  
Geetha H. Mylvaganam ◽  
Daniel Rios ◽  
Hadia M. Abdelaal ◽  
Smita Iyer ◽  
Gregory Tharp ◽  
...  

A significant challenge to HIV eradication is the elimination of viral reservoirs in germinal center (GC) T follicular helper (Tfh) cells. However, GCs are considered to be immune privileged for antiviral CD8 T cells. Here, we show a population of simian immunodeficiency virus (SIV)-specific CD8 T cells express CXCR5 (C-X-C chemokine receptor type 5, a chemokine receptor required for homing to GCs) and expand in lymph nodes (LNs) following pathogenic SIV infection in a cohort of vaccinated macaques. This expansion was greater in animals that exhibited superior control of SIV. The CXCR5+ SIV-specific CD8 T cells demonstrated enhanced polyfunctionality, restricted expansion of antigen-pulsed Tfh cells in vitro,and possessed a unique gene expression pattern related to Tfh and Th2 cells. The increase in CXCR5+ CD8 T cells was associated with the presence of higher frequencies of SIV-specific CD8 T cells in the GC. Following TCR-driven stimulation in vitro, CXCR5+ but not CXCR5– CD8 T cells generated both CXCR5+ as well as CXCR5– cells. However, the addition of TGF-β to CXCR5– CD8 T cells induced a population of CXCR5+ CD8 T cells, suggesting that this cytokine may be important in modulating these CXCR5+ CD8 T cells in vivo. Thus, CXCR5+ CD8 T cells represent a unique subset of antiviral CD8 T cells that expand in LNs during chronic SIV infection and may play a significant role in the control of pathogenic SIV infection.

2007 ◽  
Vol 81 (11) ◽  
pp. 5819-5828 ◽  
Author(s):  
Vijayakumar Velu ◽  
Sunil Kannanganat ◽  
Chris Ibegbu ◽  
Lakshmi Chennareddi ◽  
Francois Villinger ◽  
...  

ABSTRACT Here, we study the temporal expression of the inhibitory receptor programmed death 1 (PD-1) on simian immunodeficiency virus (SIV) Gag-specific T cells following pathogenic SIV infection or following vaccination with a DNA/modified vaccinia virus Ankara (DNA/MVA) vaccine and simian/human immunodeficiency virus (SHIV) challenge in macaques. Following infection, the majority (>95%) of Gag-specific CD8 T cells expressed PD-1, and the level of PD-1 expression per cell increased over time. The level of PD-1 expression in lymph nodes and rectal mucosal tissue, the major sites of virus replication, was higher compared to blood. In vitro blockade of PD-1 resulted in enhanced proliferation of SIV-specific CD8 as well as CD4 T cells. In contrast, following vaccination, the majority of peak effector Gag-specific CD8 T cells expressed low levels of PD-1, and these levels decreased further as the cells differentiated into memory cells. In addition, following SHIV challenge of these vaccinated macaques, the level of PD-1 expression on Gag-specific CD8 T cells correlated positively with plasma viremia. These results demonstrate that SIV-specific CD8 T cells express PD-1 after exposure to antigen but downregulate expression under conditions of antigen clearance and enhance expression under conditions of antigen persistence. They also demonstrate that the level of PD-1 expression per cell rather than the presence or absence of expression plays an important role in regulating CD8 T-cell dysfunction in pathogenic SIV infection. In addition, they demonstrate that similar to HIV infection, the PD-1:PD-1 ligand inhibitory pathway is operational in pathogenic SIV infection, and the macaque/SIV model would be ideal to test the safety and therapeutic benefit of blocking this pathway in vivo.


1994 ◽  
Vol 179 (4) ◽  
pp. 1273-1283 ◽  
Author(s):  
R Manetti ◽  
F Gerosa ◽  
M G Giudizi ◽  
R Biagiotti ◽  
P Parronchi ◽  
...  

Interleukin 12 (IL-12) facilitates the generation of a T helper type 1 (Th1) response, with high interferon gamma (IFN-gamma) production, while inhibiting the generation of IL-4-producing Th2 cells in polyclonal cultures of both human and murine T cells and in vivo in the mouse. In this study, we analyzed the effect of IL-12, present during cloning of human T cells, on the cytokine profile of the clones. The culture system used allows growth of clones from virtually every T cell, and thus excludes the possibility that selection of precommitted Th cell precursors plays a role in determining characteristics of the clones. IL-12 present during the cloning procedures endowed both CD4+ and CD8+ clones with the ability to produce IFN-gamma at levels severalfold higher than those observed in clones generated in the absence of IL-12. This priming was stable because the high levels of IFN-gamma production were maintained when the clones were cultured in the absence of IL-12 for 11 d. The CD4+ and some of the CD8+ clones produced variable amounts of IL-4. Unlike IFN-gamma, IL-4 production was not significantly different in clones generated in the presence or absence of IL-12. These data suggest that IL-12 primes the clone progenitors, inducing their differentiation to high IFN-gamma-producing clones. The suppression of IL-4-producing cells observed in polyclonally generated T cells in vivo and in vitro in the presence of IL-12 is not observed in this clonal model, suggesting that the suppression depends more on positive selection of non-IL-4-producing cells than on differentiation of individual clones. However, antigen-specific established Th2 clones that were unable to produce IFN-gamma with any other inducer did produce IFN-gamma at low but significant levels when stimulated with IL-12 in combination with specific antigen or insoluble anti-CD3 antibodies. This induction of IFN-gamma gene expression was transient, because culture of the established clones with IL-12 for up to 1 wk did not convert them into IFN-gamma producers when stimulated in the absence of IL-12. These results suggest that Th clones respond to IL-12 treatment either with a stable priming for IFN-gamma production or with only a transient low level expression of the IFN-gamma gene, depending on their stage of differentiation.


2002 ◽  
Vol 197 (1) ◽  
pp. 19-26 ◽  
Author(s):  
Melanie S. Vacchio ◽  
Richard J. Hodes

Whereas ligation of CD28 is known to provide a critical costimulatory signal for activation of CD4 T cells, the requirement for CD28 as a costimulatory signal during activation of CD8 cells is less well defined. Even less is known about the involvement of CD28 signals during peripheral tolerance induction in CD8 T cells. In this study, comparison of T cell responses from CD28-deficient and CD28 wild-type H-Y–specific T cell receptor transgenic mice reveals that CD8 cells can proliferate, secrete cytokines, and generate cytotoxic T lymphocytes efficiently in the absence of CD28 costimulation in vitro. Surprisingly, using pregnancy as a model to study the H-Y–specific response of maternal T cells in the presence or absence of CD28 costimulation in vivo, it was found that peripheral tolerance does not occur in CD28KO pregnants in contrast to the partial clonal deletion and hyporesponsiveness of remaining T cells observed in CD28WT pregnants. These data demonstrate for the first time that CD28 is critical for tolerance induction of CD8 T cells, contrasting markedly with CD28 independence of in vitro activation, and suggest that the role of CD28/B7 interactions in peripheral tolerance of CD8 T cells may differ significantly from that of CD4 T cells.


2008 ◽  
Vol 205 (13) ◽  
pp. 2965-2973 ◽  
Author(s):  
Susan Gilfillan ◽  
Christopher J. Chan ◽  
Marina Cella ◽  
Nicole M. Haynes ◽  
Aaron S. Rapaport ◽  
...  

Natural killer (NK) cells and CD8 T cells require adhesion molecules for migration, activation, expansion, differentiation, and effector functions. DNAX accessory molecule 1 (DNAM-1), an adhesion molecule belonging to the immunoglobulin superfamily, promotes many of these functions in vitro. However, because NK cells and CD8 T cells express multiple adhesion molecules, it is unclear whether DNAM-1 has a unique function or is effectively redundant in vivo. To address this question, we generated mice lacking DNAM-1 and evaluated DNAM-1–deficient CD8 T cell and NK cell function in vitro and in vivo. Our results demonstrate that CD8 T cells require DNAM-1 for co-stimulation when recognizing antigen presented by nonprofessional antigen-presenting cells; in contrast, DNAM-1 is dispensable when dendritic cells present the antigen. Similarly, NK cells require DNAM-1 for the elimination of tumor cells that are comparatively resistant to NK cell–mediated cytotoxicity caused by the paucity of other NK cell–activating ligands. We conclude that DNAM-1 serves to extend the range of target cells that can activate CD8 T cell and NK cells and, hence, may be essential for immunosurveillance against tumors and/or viruses that evade recognition by other activating or accessory molecules.


2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A737-A737
Author(s):  
Anna Cole ◽  
Guillermo Rangel RIvera ◽  
Aubrey Smith ◽  
Megan Wyatt ◽  
Brandon Ware ◽  
...  

BackgroundIL-21 enhances the anti-tumor capacity of adoptively transferred CD8+ T cells, while IL-2 and IL-15 impair T cell immunity by driving their expansion to a more differentiated status. Yet, these cytokines can act on many different immune cells. Given the potency of IL-21, we tested if this cytokine directly augments T cells or rather if it enhances other immune cells in the culture that indirectly improves T cell therapy.MethodsTo test this question, splenocytes from pmel-1 transgenic mice were used, as all CD8+ T cells express a transgenic TCR specific for tumor-antigen gp10025–33 overexpressed on melanoma. We then peptide activated naïve CD8+ T cells enriched or not from the spleen of pmel-1 mice and expanded them in the presence of IL-21 or IL-2 (10 ng/mL) for four days. Expanded pmel-1 from these various cultures were then restimulated with irradiated splenocytes pulsed with gp10025–33 and grown an additional seven days with IL-2 (10 ng/mL), irrespective of their initial cytokine condition. The in vitro memory phenotype, exhaustion profile, and cytokine secretion of these cultures were then assayed. Furthermore, mice bearing B16KVP melanoma tumors were infused with pmel-1 T cells expanded via these various approaches and compared for their relative capacity to engraft, persist, and regress tumor in vivo.ResultsInterestingly, we discovered that IL-21-treated T cells generated from bulk splenocytes are phenotypically and functionally distinct from IL-21-treated isolated T cells. Upon restimulation, IL-21-treated T cells from bulk splenocytes exhibited an exhausted phenotype that was like anergic IL-2-treated T cells. Moreover, few cells expressed CD62L but expressed heightened markers of suppression, including TIM3, PD-1, and EOMES. Moreover, they produced more effector molecules, including granzyme B and IFN-gamma. In vivo IL-21-treated T cells expanded from bulk splenocytes engrafted and persisted poorly, in turn mediating suboptimal regression of melanoma. Conversely, IL-21 dramatically bolstered the engraftment and antitumor activity of T cells only if they were first isolated from the spleen prior to their expansion and infusion into the animal.ConclusionsCollectively, our data shows that IL-21 may improve ACT therapy best when used directly on antitumor CD8+ T cells. Further studies will illuminate the mechanism behind this striking difference and determine whether other cell subsets reactive to IL-21 cause T cell dysfunction and/or reduced bioavailability. These findings are important for defining the best culture conditions in which to use IL-21 for ACT.AcknowledgementsWe would like to acknowledge Emory University, The Winship Cancer Institute, and the Pediatrics/Winship Flow Cytometry Core.Ethics ApprovalAll animal procedures were approved by the Institutional Animal Care and Use Committee of Emory University, protocol number 201900225.


Author(s):  
Mohammad H. Rashid ◽  
Thaiz F. Borin ◽  
Roxan Ara ◽  
Raziye Piranlioglu ◽  
Bhagelu R. Achyut ◽  
...  

AbstractMyeloid-derived suppressor cells (MDSCs) are an indispensable component of the tumor microenvironment (TME), and our perception regarding the role of MDSCs in tumor promotion is attaining extra layer of intricacy in every study. In conjunction with MDSC’s immunosuppressive and anti-tumor immunity, they candidly facilitate tumor growth, differentiation, and metastasis in several ways that yet to be explored. Alike any other cell types, MDSCs also release a tremendous amount of exosomes or nanovesicles of endosomal origin and partake in intercellular communications by dispatching biological macromolecules. There has not been any experimental study done to characterize the role of MDSCs derived exosomes (MDSC exo) in the modulation of TME. In this study, we isolated MDSC exo and demonstrated that they carry a significant amount of proteins that play an indispensable role in tumor growth, invasion, angiogenesis, and immunomodulation. We observed higher yield and more substantial immunosuppressive potential of exosomes isolated from MDSCs in the primary tumor area than those are in the spleen or bone marrow. Our in vitro data suggest that MDSC exo are capable of hyper activating or exhausting CD8 T-cells and induce reactive oxygen species production that elicits activation-induced cell death. We confirmed the depletion of CD8 T-cells in vivo by treating the mice with MDSC exo. We also observed a reduction in pro-inflammatory M1-macrophages in the spleen of those animals. Our results indicate that immunosuppressive and tumor-promoting functions of MDSC are also implemented by MDSC-derived exosomes which would open up a new avenue of MDSC research and MDSC-targeted therapy.


2018 ◽  
Vol 215 (9) ◽  
pp. 2265-2278 ◽  
Author(s):  
Colleen M. Lau ◽  
Ioanna Tiniakou ◽  
Oriana A. Perez ◽  
Margaret E. Kirkling ◽  
George S. Yap ◽  
...  

An IRF8-dependent subset of conventional dendritic cells (cDCs), termed cDC1, effectively cross-primes CD8+ T cells and facilitates tumor-specific T cell responses. Etv6 is an ETS family transcription factor that controls hematopoietic stem and progenitor cell (HSPC) function and thrombopoiesis. We report that like HSPCs, cDCs express Etv6, but not its antagonist, ETS1, whereas interferon-producing plasmacytoid dendritic cells (pDCs) express both factors. Deletion of Etv6 in the bone marrow impaired the generation of cDC1-like cells in vitro and abolished the expression of signature marker CD8α on cDC1 in vivo. Moreover, Etv6-deficient primary cDC1 showed a partial reduction of cDC-specific and cDC1-specific gene expression and chromatin signatures and an aberrant up-regulation of pDC-specific signatures. Accordingly, DC-specific Etv6 deletion impaired CD8+ T cell cross-priming and the generation of tumor antigen–specific CD8+ T cells. Thus, Etv6 optimizes the resolution of cDC1 and pDC expression programs and the functional fitness of cDC1, thereby facilitating T cell cross-priming and tumor-specific responses.


2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Xiangyu Wang ◽  
Fengmian Wang ◽  
Zhi-Gang Zhang ◽  
Xiao-Mei Yang ◽  
Rong Zhang ◽  
...  

Serine/threonine protein kinase-3 (STK3) is a critical molecule of the Hippo pathway but little is known about its biological functions in the ovarian cancer development. We demonstrated the roles of STK3 in ovarian cancer. Existing databases were used to study the expression profile of STK3. STK3 was significantly downregulated in OC patients, and the low STK3 expression was correlated with a poor prognosis. In vitro cell proliferation, apoptosis, and migration assays, and in vivo subcutaneous xenograft tumor models were used to determine the roles of STK3. The overexpression of STK3 significantly inhibited cell proliferation, apoptosis, and migration of ovarian cancer cells in vitro and tumor growth in vivo. Bisulfite sequencing PCR analysis was performed to validate the methylation of STK3 in ovarian cancer. RNA sequencing and gene set enrichment analysis (GSEA) were used to compare the transcriptome changes in the STK3 overexpression ovarian cancer and control cells. The signaling pathway was analyzed by western blotting. STK3 promoted the migration of CD8+ T-cells by activating nuclear transcription factor κB (NF-κB) signaling. STK3 is a potential predictor of OC. It plays an important role in suppressing tumor growth of ovarian cancer and in chemotaxis of CD8+ T-cells.


2016 ◽  
Vol 113 (5) ◽  
pp. E568-E576 ◽  
Author(s):  
Jimena Perez-Lloret ◽  
Isobel S. Okoye ◽  
Riccardo Guidi ◽  
Yashaswini Kannan ◽  
Stephanie M. Coomes ◽  
...  

There is a paucity of new therapeutic targets to control allergic reactions and forestall the rising trend of allergic diseases. Although a variety of immune cells contribute to allergy, cytokine-secreting αβ+CD4+ T-helper 2 (TH2) cells orchestrate the type-2–driven immune response in a large proportion of atopic asthmatics. To identify previously unidentified putative targets in pathogenic TH2 cells, we performed in silico analyses of recently published transcriptional data from a wide variety of pathogenic TH cells [Okoye IS, et al. (2014) Proc Natl Acad Sci USA 111(30):E3081–E3090] and identified that transcription intermediary factor 1 regulator-alpha (Tif1α)/tripartite motif-containing 24 (Trim24) was predicted to be active in house dust mite (HDM)- and helminth-elicited Il4gfp+αβ+CD4+ TH2 cells but not in TH1, TH17, or Treg cells. Testing this prediction, we restricted Trim24 deficiency to T cells by using a mixed bone marrow chimera system and found that T-cell–intrinsic Trim24 is essential for HDM-mediated airway allergy and antihelminth immunity. Mechanistically, HDM-elicited Trim24−/− T cells have reduced expression of many TH2 cytokines and chemokines and were predicted to have compromised IL-1–regulated signaling. Following this prediction, we found that Trim24−/− T cells have reduced IL-1 receptor (IL-1R) expression, are refractory to IL-1β–mediated activation in vitro and in vivo, and fail to respond to IL-1β–exacerbated airway allergy. Collectively, these data identify a previously unappreciated Trim24-dependent requirement for IL-1R expression on TH2 cells and an important nonredundant role for T-cell–intrinsic Trim24 in TH2-mediated allergy and antihelminth immunity.


2020 ◽  
Vol 79 (7) ◽  
pp. 951-959 ◽  
Author(s):  
Paul Régnier ◽  
Alexandre Le Joncour ◽  
Anna Maciejewski-Duval ◽  
Anne-Claire Desbois ◽  
Cloé Comarmond ◽  
...  

ObjectiveTakayasu’s arteritis (TAK) is a large vessel vasculitis with important infiltration of proinflammatory T cells in the aorta and its main branches, but its aetiology is still unknown. Our work aims to explore the involvement of Janus Kinase/Signal Transducers and Activators of Transcription (JAK/STAT) signalling pathway in proinflammatory T cells differentiation and disease activity of TAK.MethodsWe analysed transcriptome and interferons gene signatures of fluorescence-activated cell sorting (FACS-sorted) CD4+ and CD8+ T cells from healthy donors (HD) and in 25 TAK (median age of 37.6 years including 21 active TAK with National Institutes of Health (NIH) score >1). Then we tested, in vitro and in vivo, the effects of JAK inhibitors (JAKinibs) in TAK.ResultsTranscriptome analysis showed 248 and 432 significantly dysregulated genes for CD4+ and CD8+ samples between HD and TAK, respectively. Among dysregulated genes, we highlighted a great enrichment for pathways linked to type I and type II interferons, JAK/STAT and cytokines/chemokines-related signalling in TAK. We confirmed by Real Time Reverse Transcription Polymerase Chain Reaction (RT-qPCR) the upregulation of type I interferons gene signature in TAK as compared with HD. JAKinibs induced both in vitro and in vivo a significant reduction of CD25 expression by CD4+ and CD8+ T cells, a significant decrease of type 1 helper T cells (Th1) and Th17 cells and an increase of Tregs cells in TAK. JAKinibs also decreased C reactive protein level, NIH score and corticosteroid dose in TAK patients.ConclusionsJAK/STAT signalling pathway is critical in the pathogenesis of TAK and JAKinibs may be a promising therapy.


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