OR.90. Hyperactivation of CD8 T Cells During the Early Stages of a Persistent Viral Infection Precedes T Cell Exhaustion

ABSTRACT The PD-1/PD-L pathway plays a major role in regulating T-cell exhaustion during chronic viral infections in animal models, as well as in humans, and blockade of this pathway can revive exhausted CD8+ T cells. We examined the expression of PD-1 and its ligands, PD-L1 and PD-L2, in multiple tissues during the course of chronic viral infection and determined how the amount of PD-1 expressed, as well as the anatomical location, influenced the function of exhausted CD8 T cells. The amount of PD-1 on exhausted CD8 T cells from different anatomical locations did not always correlate with infectious virus but did reflect viral antigen in some tissues. Moreover, lower expression of PD-L1 in some locations, such as the bone marrow, favored the survival of PD-1Hi exhausted CD8 T cells, suggesting that some anatomical sites might provide a survival niche for subpopulations of exhausted CD8 T cells. Tissue-specific differences in the function of exhausted CD8 T cells were also observed. However, while cytokine production did not strictly correlate with the amount of PD-1 expressed by exhausted CD8 T cells from different tissues, the ability to degranulate and kill were tightly linked to PD-1 expression regardless of the anatomical location. These observations have implications for human chronic infections and for therapeutic interventions based on blockade of the PD-1 pathway.

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Chromatin State and Immunotherapy

Blood ◽

10.1182/blood-2018-99-109432 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. SCI-16-SCI-16

Author(s):

W. Nicholas Haining

Keyword(s):

T Cells ◽

T Cell ◽

Tumor Microenvironment ◽

Viral Infection ◽

Cd8 T Cells ◽

Research Funding ◽

Checkpoint Blockade ◽

Chronic Viral Infection ◽

T Cell Exhaustion ◽

Cell Exhaustion

Abstract The functional impairment of T cell-mediated immunity within the tumor microenvironment (TME) is a defining feature of many cancers. Checkpoint blockade therapy seeks to reinvigorate T cell responses by targeting inhibitory receptors such as PD-1, which are upregulated by dysfunctional TILs. However, the fundamental mechanisms underlying T cell dysfunction in the TME remain poorly understood, as are the mechanisms by which checkpoint blockade overcomes this dysfunction. Initial studies of dysfunctional CD8+ T cells in both human and mouse tumors suggested that they share features of T cell exhaustion, including co-inhibitory receptor upregulation and defects in cytokine production. However, more recent studies have suggested that TIL dysfunction is a unique state that is distinct from T cell exhaustion. Here we show that anti-PD-1 therapy acts on a specific subpopulation of CD8+ tumor-infiltrating lymphocytes (TILs) in melanoma mouse models as well as patients with melanoma. We find that dysfunctional CD8+ TILs possess canonical epigenetic and transcriptional features of T cell exhaustion, mirroring those seen in chronic viral infection. Similar to chronic viral infection, exhausted CD8+ TILs contain a subpopulation of "stem-like exhausted" T cells that have a distinct regulatory state. Stem-like exhausted TILs also have critical functional attributes that are not shared by the majority "terminally exhausted" TILs: they retain more polyfunctionality, persist following transfer into tumor-bearing mice, and differentiate to repopulate terminally exhausted TILs in the TME. As a result, stem-like exhausted CD8+ TILs are better able to control tumor growth than terminally exhausted cells. Stem-like exhausted, but not terminally exhausted, CD8+ TILs can respond to anti-PD-1 therapy without reversion of their exhausted epigenetic state. CD8+ T cells with a stem-like exhausted phenotype can be found in human melanoma samples and patients with a higher fraction of this subpopulation in their tumors have a significantly longer duration of response to combination checkpoint blockade therapy. Responsiveness to checkpoint blockade is therefore restricted to a subpopulation of exhausted TILs that retain specific functional properties which enable them to control tumors. Approaches to expand stem-like exhausted CD8+ T cells in the tumor microenvironment may be an important component of improving checkpoint blockade response. Disclosures Haining: Rheos Medicines: Consultancy; Iomx Therapeutics: Consultancy; Third Rock Ventures: Consultancy; Roche: Research Funding; Calico: Research Funding; Novartis: Research Funding; Tango Therapeutics: Consultancy, Equity Ownership.

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Partial restoration of immune response in Hepatitis C patients after viral clearance by direct-acting antiviral therapy

PLoS ONE ◽

10.1371/journal.pone.0254243 ◽

2021 ◽

Vol 16 (7) ◽

pp. e0254243

Author(s):

Meritxell Llorens-Revull ◽

Maria Isabel Costafreda ◽

Angie Rico ◽

Mercedes Guerrero-Murillo ◽

Maria Eugenia Soria ◽

...

Keyword(s):

Immune Response ◽

T Cells ◽

Hepatitis C ◽

T Cell ◽

Cd8 T Cells ◽

Viral Clearance ◽

Cd4 T Cell ◽

Care Hospital ◽

T Cell Exhaustion ◽

Cell Exhaustion

Background & aims HCV CD4+ and CD8+ specific T cells responses are functionally impaired during chronic hepatitis C infection. DAAs therapies eradicate HCV infection in more than 95% of treated patients. However, the impact of HCV elimination on immune responses remain controversial. Here, we aimed to investigate whether HCV cure by DAAs could reverse the impaired immune response to HCV. Methods We analyzed 27 chronic HCV infected patients undergoing DAA treatment in tertiary care hospital, and we determined the phenotypical and functional changes in both HCV CD8+ and CD4+ specific T-cells before and after viral clearance. PD-1, TIM-3 and LAG-3 cell-surface expression was assessed by flow cytometry to determine CD4+ T cell exhaustion. Functional responses to HCV were analyzed by IFN-Ɣ ELISPOT, intracellular cytokine staining (IL-2 and IFN-Ɣ) and CFSE-based proliferation assays. Results We observed a significant decrease in the expression of PD-1 in CD4+ T-cells after 12 weeks of viral clearance in non-cirrhotic patients (p = 0.033) and in treatment-naive patients (p = 0.010), indicating a partial CD4 phenotype restoration. IFN-Ɣ and IL-2 cytokines production by HCV-specific CD4+ and CD8+ T cells remained impaired upon HCV eradication. Finally, a significant increase of the proliferation capacity of both HCV CD4+ and CD8+ specific T-cells was observed after HCV elimination by DAAs therapies. Conclusions Our results show that in chronically infected patients HCV elimination by DAA treatment lead to partial reversion of CD4+ T cell exhaustion. Moreover, proliferative capacity of HCV-specific CD4+ and CD8+ T cells is recovered after DAA’s therapies.

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644 Tumor-mediated suppressive signaling and hypoxia supports altered chromatin landscapes that limit the transcriptional and functional potential of terminal T cell exhaustion

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2021-sitc2021.644 ◽

2021 ◽

Vol 9 (Suppl 3) ◽

pp. A673-A673

Author(s):

Rhodes Ford ◽

Natalie Rittenhouse ◽

Nicole Scharping ◽

Paolo Vignali ◽

Greg Delgoffe ◽

...

Keyword(s):

Gene Expression ◽

T Cells ◽

T Cell ◽

Tumor Microenvironment ◽

Histone Modifications ◽

Cd8 T Cells ◽

Tumor Hypoxia ◽

T Cell Subsets ◽

T Cell Exhaustion ◽

Cell Exhaustion

BackgroundCD8+ T cells are a fundamental component of the anti-tumor response; however, tumor-infiltrating CD8+ T cells (TIL) are rendered dysfunctional by the tumor microenvironment. CD8+ TIL display an exhausted phenotype with decreased cytokine expression and increased expression of co-inhibitory receptors (IRs), such as PD-1 and Tim-3. The acquisition of IRs mark the progression of dysfunctional TIL from progenitors (PD-1Low) to terminally exhausted (PD-1+Tim-3+). How the chromatin landscape changes during this progression has not been described.MethodsUsing a low-input ChIP-based assay called Cleavage Under Targets and Release Using Nuclease (CUT&RUN), we have profiled the histone modifications at the chromatin of tumor-infiltrating CD8+ T cell subsets to better understand the relationship between the epigenome and the transcriptome as TIL progress towards terminal exhaustion.ResultsWe have identified two epigenetic characteristics unique to terminally exhausted cells. First, we have identified a unique set of genes, characterized by active histone modifications that do not have correlated gene expression. These regions are enriched for AP-1 transcription factor motifs, yet most AP-1 family factors are actively downregulated in terminally exhausted cells, suggesting signals that promote downregulation of AP-1 expression negatively impacts gene expression. We have shown that inducing expression of AP-1 factors with a 41BB agonist correlates with increased expression of these anticorrelated genes. We have also found a substantial increase in the number of genes that exhibit bivalent chromatin marks, defined by the presence of both active (H3K4me3) and repressive (H3K27me3) chromatin modifications that inhibit gene expression. These bivalent genes in terminally exhausted T cells are not associated with plasticity and represent aberrant hypermethylation in response to tumor hypoxia, which is necessary and sufficient to promote downregulation of bivalent genes.ConclusionsOur study defines for the first time the roles of costimulation and the tumor microenvironment in driving epigenetic features of terminally exhausted tumor-infiltrating T cells. These results suggest that terminally exhausted T cells have genes that are primed for expression, given the right signals and are the basis for future work that will elucidate that factors that drive progression towards terminal T cell exhaustion at the epigenetic level and identify novel therapeutic targets to restore effector function of tumor T cells and mediate tumor clearance.

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Single-Cell Transcriptome Analysis Reveals RGS1 as a New Marker and Promoting Factor for T-Cell Exhaustion in Multiple Cancers

Frontiers in Immunology ◽

10.3389/fimmu.2021.767070 ◽

2021 ◽

Vol 12 ◽

Author(s):

Yunmeng Bai ◽

Meiling Hu ◽

Zixi Chen ◽

Jinfen Wei ◽

Hongli Du

Keyword(s):

T Cells ◽

T Cell ◽

Cd8 T Cells ◽

Poor Prognosis ◽

Effector T Cells ◽

T Cell Exhaustion ◽

Cell Exhaustion ◽

Cell Transcriptome ◽

Cancer Tissues ◽

Single Cell Transcriptome

T-cell exhaustion is one of the main reasons of tumor immune escape. Using single-cell transcriptome data of CD8+ T cells in multiple cancers, we identified different cell types, in which Pre_exhaust and exhausted T cells participated in negative regulation of immune system process. By analyzing the coexpression network patterns and differentially expressed genes of Pre_exhaust, exhausted, and effector T cells, we identified 35 genes related to T-cell exhaustion, whose high GSVA scores were associated with significantly poor prognosis in various cancers. In the differentially expressed genes, RGS1 showed the greatest fold change in Pre_exhaust and exhausted cells of three cancers compared with effector T cells, and high expression of RGS1 was also associated with poor prognosis in various cancers. Additionally, RGS1 protein was upregulated significantly in tumor tissues in the immunohistochemistry verification. Furthermore, RGS1 displayed positive correlation with the 35 genes, especially highly correlated with PDCD1, CTLA4, HAVCR2, and TNFRSF9 in CD8+ T cells and cancer tissues, indicating the important roles of RGS1 in CD8+ T-cell exhaustion. Considering the GTP-hydrolysis activity of RGS1 and significantly high mRNA and protein expression in cancer tissues, we speculated that RGS1 potentially mediate the T-cell retention to lead to the persistent antigen stimulation, resulting in T-cell exhaustion. In conclusion, our findings suggest that RGS1 is a new marker and promoting factor for CD8+ T-cell exhaustion and provide theoretical basis for research and immunotherapy of exhausted cells.

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Unraveling the Multifaceted Nature of CD8 T Cell Exhaustion Provides the Molecular Basis for Therapeutic T Cell Reconstitution in Chronic Hepatitis B and C

Cells ◽

10.3390/cells10102563 ◽

2021 ◽

Vol 10 (10) ◽

pp. 2563

Author(s):

Valeria Barili ◽

Andrea Vecchi ◽

Marzia Rossi ◽

Ilaria Montali ◽

Camilla Tiezzi ◽

...

Keyword(s):

T Cells ◽

Chronic Hepatitis ◽

T Cell ◽

Hepatitis B ◽

Chronic Hepatitis B ◽

Cd8 T Cells ◽

Stress Responses ◽

T Cell Exhaustion ◽

Virus Infections ◽

Cell Exhaustion

In chronic hepatitis B and C virus infections persistently elevated antigen levels drive CD8+ T cells toward a peculiar differentiation state known as T cell exhaustion, which poses crucial constraints to antiviral immunity. Available evidence indicates that T cell exhaustion is associated with a series of metabolic and signaling deregulations and with a very peculiar epigenetic status which all together lead to reduced effector functions. A clear mechanistic network explaining how intracellular metabolic derangements, transcriptional and signaling alterations so far described are interconnected in a comprehensive and unified view of the T cell exhaustion differentiation profile is still lacking. Addressing this issue is of key importance for the development of innovative strategies to boost host immunity in order to achieve viral clearance. This review will discuss the current knowledge in HBV and HCV infections, addressing how innate immunity, metabolic derangements, extensive stress responses and altered epigenetic programs may be targeted to restore functionality and responsiveness of virus-specific CD8 T cells in the context of chronic virus infections.

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CD8+T Cell Exhaustion During Persistent Viral Infection is Regulated Independently of the Virus-Specific T Cell Receptor

Immunological Investigations ◽

10.3109/08820139.2012.751397 ◽

2013 ◽

Vol 42 (3) ◽

pp. 204-220 ◽

Cited By ~ 8

Author(s):

Stephanie R. Jackson ◽

Melissa M. Berrien-Elliott ◽

Jennifer M. Meyer ◽

E. John Wherry ◽

Ryan M. Teague

Keyword(s):

T Cell ◽

Viral Infection ◽

T Cell Receptor ◽

Cd8 T Cell ◽

Cell Receptor ◽

T Cell Exhaustion ◽

Cell Exhaustion ◽

Persistent Viral Infection

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IL-21 from high-affinity CD4 T cells drives differentiation of brain-resident CD8 T cells during persistent viral infection

Science Immunology ◽

10.1126/sciimmunol.abb5590 ◽

2020 ◽

Vol 5 (51) ◽

pp. eabb5590 ◽

Cited By ~ 3

Author(s):

Heather M. Ren ◽

Elizabeth M. Kolawole ◽

Mingqiang Ren ◽

Ge Jin ◽

Colleen S. Netherby-Winslow ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Viral Infection ◽

Cd8 T Cells ◽

Cd4 T Cells ◽

Central Nervous System Infection ◽

Cell Receptor ◽

Cd4 T Cell ◽

Persistent Viral Infection ◽

High Affinity

Development of tissue-resident memory (TRM) CD8 T cells depends on CD4 T cells. In polyomavirus central nervous system infection, brain CXCR5hi PD-1hi CD4 T cells produce interleukin-21 (IL-21), and CD8 T cells lacking IL-21 receptors (IL21R−/−) fail to become bTRM. IL-21+ CD4 T cells exhibit elevated T cell receptor (TCR) affinity and higher TCR density. IL21R−/− brain CD8 T cells do not express CD103, depend on vascular CD8 T cells for maintenance, are antigen recall defective, and lack TRM core signature genes. CD4 T cell–deficient and IL21R−/− brain CD8 T cells show similar deficiencies in expression of genes for oxidative metabolism, and intrathecal delivery of IL-21 to CD4 T cell–depleted mice restores expression of electron transport genes in CD8 T cells to wild-type levels. Thus, high-affinity CXCR5hi PD-1hi CD4 T cells in the brain produce IL-21, which drives CD8 bTRM differentiation in response to a persistent viral infection.

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PD-1 up-regulation is correlated with HIV-specific memory CD8+ T-cell exhaustion in typical progressors but not in long-term nonprogressors

Blood ◽

10.1182/blood-2006-09-044826 ◽

2007 ◽

Vol 109 (11) ◽

pp. 4671-4678 ◽

Cited By ~ 207

Author(s):

Ji-Yuan Zhang ◽

Zheng Zhang ◽

Xicheng Wang ◽

Jun-Liang Fu ◽

Jinxia Yao ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Cd8 T Cells ◽

Cd8 T Cell ◽

Effector Memory ◽

T Cell Exhaustion ◽

Cell Exhaustion ◽

Specific Memory ◽

Memory Cd8 T Cell

Abstract The immunoreceptor PD-1 is significantly up-regulated on exhausted CD8+ T cells during chronic viral infections such as HIV-1. However, it remains unknown whether PD-1 expression on CD8+ T cells differs between typical progressors (TPs) and long-term nonprogressors (LTNPs). In this report, we examined PD-1 expression on HIV-specific CD8+ T cells from 63 adults with chronic HIV infection. We found that LTNPs exhibited functional HIV-specific memory CD8+ T cells with markedly lower PD-1 expression. TPs, in contrast, showed significantly up-regulated PD-1 expression that was closely correlated with a reduction in CD4 T-cell number and an elevation in plasma viral load. Importantly, PD-1 up-regulation was also associated with reduced perforin and IFN-γ production, as well as decreased HIV-specific effector memory CD8+ T-cell proliferation in TPs but not LTNPs. Blocking PD-1/PD-L1 interactions efficiently restored HIV-specific CD8+ T-cell effector function and proliferation. Taken together, these findings confirm the hypothesis that high PD-1 up-regulation mediates HIV-specific CD8+ T-cell exhaustion. Blocking the PD-1/PD-L1 pathway may represent a new therapeutic option for this disease and provide more insight into immune pathogenesis in LTNPs.

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