CLL Is Associated with Development of Subclinical Cytomegalovirus Viraemia and Accumulation of Large Populations of “exhausted” CMV-Specific CD4+ T Cells

Abstract Chronic Lymphocytic Leukaemia (CLL) is associated with T cell dysfunction and increased expression of markers of T cell exhaustion. Cytomegalovirus is a common herpesvirus infection and is associated with development of accelerated immune senescence in older adults. Within patients with CLL, CMV leads to marked expansion of virus-specific CD4 and CD8 T cells and development of oligoclonal T cell populations. However these features are not known to be associated with clinical symptoms and CMV viral load remains essentially undetectable by conventional qPCR. In this study we used digital PCR to determine CMV viral load in patients with CLL and correlated this with the magnitude and phenotype of the CMV-specific T cell immune response. In particular, we utilised HLA class II tetramers for the first time, in order to assess the contribution of CMV-specific T cell populations to the profile of T cell exhaustion seen in this disease. 68 CMV-seropositive CLL patients and 19 age-matched healthy donors (HD) were recruited for study. All patients were either untreated or had not received chemotherapy for at least 6 months. CMV viral load was determined within purified monocyte populations using a digital droplet PCR method. Viral load per monocyte was increased in CLL patients compared to HD (p=0.04), with the highest viral loads detected in stage C patients. In order to investigate the CMV-specific immune response, nine HLA class I tetramers were generated, containing viral epitopes from pp65, pp50 and IE-1, and two class II tetramers were also available, with epitopes from glycoprotein B and pp65. CMV-specific CD4 T cell responses were increased in CLL patients (n=14) compared to HD (n=11) (4.1 % vs. 0.9 %; p=0.049). Remarkably, in one patient more than half (50.9%) of all CD4 T cells were directed against a single CMV epitope. CD4 CMV-specific T cells were nearly always effector memory in phenotype (78%), somewhat in contrast to CD8 populations where the memory phenotype is split between effector memory (CCR7-, CD45RA-) and terminally differentiated memory cells (CCR7-, CD45RA+). PD1 is an important marker of T cell exhaustion and expression was increased on both CD8 T cells (16.9% Vs 9.6%; p=0.003); and CD4 T cells (16.2 % Vs 8.7 %; p=0.0007) in CLL patients compared to HD. Interestingly, PD1 expression was much higher on CMV-specific CD4 T cells compared to the total CD4 T cell repertoire (50.6% Vs 21%; p=0.01), whereas the opposite profile was observed in relation to CD8 populations. CMV-specific CD4 T cells demonstrated a Th1 cytotoxic phenotype with production of TNF-alpha, IFN-y and Granzyme B. Production of IFN-y and TNF-alpha was reduced in PD1+ populations, consistent with an exhausted phenotype. No CD25+FoxP3 + regulatory T cells were observed within the CMV-specific CD4 T cell population which is of interest given the well documented expansion of this population in patients with CLL. In order to investigate the replicative history of CMV-specific T cells we investigated the telomere length of antigen-specific cells using single cell telomere length analysis. CMV-specific cells had markedly shortened telomere lengths compared to background CD4 and CD8 T cells, with the mean difference of 0.911 kb (maximum 1.836 kb) indicating that they have undergone extensive proliferation in vivo. This work is the first to use digital PCR to measure the subclinical CMV load within peripheral blood and also to examine CMV-specific CD4 T cells using HLA class II tetramers. Our results indicate that immune control of CMV viral load is impaired during the clinical progression of CLL and that a proportion of virus-specific CD4 T cells show signs of exhaustion. These data may reflect ‘cross presentation’ of viral protein by B-CLL tumour cells, which are known to have poor capacity for antigen presentation. The potential clinical importance of these observations is now being addressed. Disclosures No relevant conflicts of interest to declare.

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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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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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PD-1+ T Cell Subsets in Follicular Lymphoma Tumor Microenvironment and Their Implications for Prognosis and Therapy

Blood ◽

10.1182/blood.v118.21.2648.2648 ◽

2011 ◽

Vol 118 (21) ◽

pp. 2648-2648

Author(s):

Fuliang Chu ◽

Wencai Ma ◽

Tomohide Yamazaki ◽

Myriam Foglietta ◽

Durga Nattama ◽

...

Keyword(s):

Flow Cytometry ◽

T Cells ◽

T Cell ◽

Follicular Lymphoma ◽

Cd8 T Cells ◽

Cd4 T Cells ◽

T Cell Subsets ◽

Prognostic Impact ◽

T Cell Exhaustion ◽

Cell Exhaustion

Abstract Abstract 2648 Background: Programmed death (PD)-1, a coinhibitory receptor expressed by effector T cells (Teffs) is highly expressed on intratumoral T cells (mean 61%, range 34–86% for CD4+ T cells and mean 44%, range 31–69% for CD8+ T cells) in follicular lymphoma (FL), a finding associated with impaired ability to recognize autologous tumor (Nattamai et al, ASH 2007). Hence, PD-1 expression would be expected to confer an unfavorable prognosis in FL. However, correlation of PD-1 with clinical outcome in FL has been inconsistent with two studies showing favorable (Carreras et al, J Clin Oncol 2009; Wahlin et al, Clin Cancer Res 2010) and one study showing unfavorable (Richendollar et al, Hum Pathol 2011) outcome. While differences in method of analysis and type of treatment may explain the disparate results, a more complex model may be necessary to understand the prognostic impact of PD-1 in FL as PD-1 is expressed not only on antitumor Teffs but also on protumor follicular helper T cells (Tfh) and regulatory T cells (Tregs). Methods: To determine the nature of PD-1+ T cells in FL we performed comprehensive genomic and immunologic studies. By flow cytometry, we observed that the intratumoral CD4+ T cells in FL may be categorized into 3 subsets based on PD-1 expression - PD-1 high (PD-1hi), intermediate (PD-1int), and low (PD-1lo). The intratumoral CD8+ T cells consisted of PD-1int and PD-1lo subsets. The 3 CD4+ T cell subsets were FACSorted from FL tumors (n=3) and whole genome gene expression profiling (GEP) was performed. T cell subsets sorted similarly from tonsils served as controls for reactive follicular hyperplasia (FH) (n=3). Differentially expressed genes in GEP studies were confirmed at the mRNA level by real-time PCR (n=5) and at the protein level by flow cytometry when antibodies were available (n=5–10). Results: Our results suggested that CD4+PD-1hi T cells are Tfh cells (CXCR5hiBcl6hi ICOShiCD40LhiSAPhiPRDM1loIL-4hiIL-21hi); the CD4+PD-1int T cells consisted of a mixture of activated Teffs (CD45RO+CD45RA−) including Th1 (Tbet+IFNg+), Th2 (IL-10+), and Th17 cells (RORc+IL-17+), and Tregs (Foxp3+CD25hiCD127lo); and the CD4+PD-1lo T cells consisted of a mixture of activated Teffs (CD45RO+CD45RA− but IFNg−IL-4−IL-10−IL-17−), Tregs, and naïve T cells (CD45RO−CD45RA+CCR7+). Although these subsets were present in both FL and FH, there were important differences. IL-4 expression was significantly higher in Tfh in FL vs. FH and may play a role in the pathogenesis of FL. IL-17 expression was low and expression of coinhibitory molecules BTLA and CD200 was high in CD4+PD-1int T cells in FL vs. FH. BTLA and CD200 were also increased in CD8+PD-1int T cells in FL vs. FH. However, other coinhibitory molecules (LAG-3, Tim-3, CD160, CTLA-4, CD244, KLRG1) were not significantly different between FL and FH. CD4+PD-1int T cells also had higher expression of BATF, a transcription factor associated with T cell exhaustion in FL vs. FH. Together, these results suggest that the CD4+PD-1int T cells in FL may be in a state of T cell exhaustion whereas the CD4+PD-1int T cells in FH may represent recently activated Teffs. Consistent with this, blocking PD-1 with anti-PD-1 blocking antibody significantly enhanced proliferation and the production of Th1 (IFNg, TNFa) but not Th2 (IL-4, IL-5, IL-10, IL-13) cytokines by intratumoral CD4+ and CD8+ T cells in response to stimulation with autologous FL tumor cells (n=3). As expected, Tregs were increased in number in FL vs. FH and were present in the PD-1int and PD-1lo T cell subsets. We found 74% (range 40–97%) of FL Tregs expressed PD-1. Among the CD4+PD-1lo and CD8+PD-1lo T cells, there were more activated Teffs and fewer naïve T cells in FL vs. FH. Conclusions: Our results suggest that the PD-1+ T cells in FL are comprised of a mixture of antitumor Teffs and protumor Tfh and Tregs. The prognostic impact of PD-1+ T cells in FL may dependent on the relative frequency of these subsets as ligation of PD-1 may produce favorable (inhibition of protumor Tfh and Tregs) or unfavorable (inhibition of antitumor Teffs) outcomes by inhibiting or promoting tumor growth, respectively. Conversely, our results imply that agents that block PD-1/PD-ligand pathway may have the opposite effect on these T cell subsets and enumeration of the intratumoral PD-1+ T cell subsets may serve as biomarker to predict response to these agents in FL and possibly other B-cell malignancies. Disclosures: Dong: GSK: Consultancy; Genentech: Honoraria; Tempero: Consultancy; Ono: Consultancy; AnaptysBio: Consultancy. Neelapu:Cure Tech Ltd: Research Funding.

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The expression of class II major histocompatibility molecules on breast tumors delays T cell exhaustion, expands the T cell repertoire and slows tumor growth

10.1101/294124 ◽

2018 ◽

Author(s):

Tyler R. McCaw ◽

Mei Li ◽

Dmytro Starenki ◽

Sara J. Cooper ◽

Selene Meza-Perez ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Tumor Growth ◽

Tumor Cells ◽

Cd8 T Cells ◽

Cd4 T Cells ◽

T Cell Exhaustion ◽

Major Histocompatibility ◽

Cell Exhaustion ◽

Mhcii Expression

AbstractThe expression of major histocompatibility complex II (MHCII) on tumor cells correlates with survival and responsiveness to immunotherapy. However, the mechanisms underlying these observations are poorly defined. Using a murine breast tumor line, we tested how MHCII expression affected anti-tumor immunity. We found that MHCII-expressing tumors grew more slowly than controls and recruited more functional CD4+ and CD8+ T cells. Additionally, MHCII-expressing tumors contained more TCR clonotypes expanded to a larger degree than control tumors. Functional CD8+ T cells in tumors depended on CD4+ T cells. However, both CD4+ and CD8+ T cells eventually became exhausted, even in MHCII-expressing tumors. PD1 blockade had no impact on tumor growth, potentially because tumor cells poorly expressed PD-L1. These results suggest tumor cell expression of MHCII facilitates the local activation of CD4+ T cells and indirectly helps the activation and expansion of CD8+ T cells, but by itself, cannot prevent T cell exhaustion.PrécisThe expression of MHCII on tumor cells augments CD4 and CD8 T cell responses, expands the TCR repertoire and delays exhaustion. Hence, strategies to induce MHCII expression may be a powerful adjuvant to immunotherapeutic regimens of solid tumors.

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The Exhausted Intratumoral T Cell Population in B-Cell Non-Hodgkin Lymphoma Is Defined By LAG-3, PD-1 andtim-3 Expression

Blood ◽

10.1182/blood.v126.23.2661.2661 ◽

2015 ◽

Vol 126 (23) ◽

pp. 2661-2661 ◽

Cited By ~ 2

Author(s):

Zhi-Zhang Yang ◽

Tammy Price-troska ◽

Anne J Novak ◽

Stephen M Ansell

Keyword(s):

T Cells ◽

T Cell ◽

B Cell ◽

Cd8 T Cells ◽

Conflicts Of Interest ◽

Early Time ◽

Effector Memory ◽

T Cell Exhaustion ◽

Cell Exhaustion ◽

Ifn Γ

Abstract T-cell exhaustion plays an important role in attenuating the function of immune cells in B-cell non-Hodgkin's lymphoma (NHL) and PD-1 expression is typically used to identify exhausted T-cells. We have however previously shown that not all PD-1+ cells are exhausted and that PD-1 is differentially expressed on two distinct T-cell subpopulations, with high expression on T follicular helper cells and dim expression on exhausted T cells. Other markers are therefore needed to more clearly identify exhausted intratumoral T cells. To further define exhaustion of intratumoral T cells, we determined the co-expression, regulation and function of PD-1, TIM-3 and LAG-3 on CD4+ or CD8+ T cells by flow cytometry. Using biopsy specimens from follicular B-cell NHL, we found that the percentages of PD-1+ and TIM-3+ T cells were 53.1% (range: 17.2-81.2%, n=32) and 34.5% (range: 14.9-62.6%, n=34) in CD4+ T cells and 46.8% (range: 12.8-81.7%, n=32) and 40.4% (range: 15.0-78.4%, n=34) in CD8+ T cells, respectively. We observed that TIM-3 was predominantly expressed on PD-1dim T cells and TIM-3+ cells accounted for 40% of CD4+ PD-1dim or 45% of CD8+ PD-1dim T cells. Similarly, LAG-3 was variably expressed on intratumoral T cells from B-cell NHL. A median of 9.54% (range: 3.01-15.46, n=6) of CD4+ or 20.48% (7.93-33.9, n=8) of CD8+ T cells express LAG-3. We found that LAG-3+ T cells almost exclusively came from PD-1+ TIM-3+ cells, forming a defined population of intratumoral PD-1+ TIM-3+ LAG-3+ CD4+ or CD8+ T cells. While the majority of LAG-3+ T cells were effector memory T cells (CD45RA- CCR7-), some LAG-3-expressing T cells displayed a phenotype of terminally-differentiated T cells (CD45RA+ CCR7-). Functionally, the intratumoral TIM-3+ LAG-3+ T cells exhibited reduced capacity to produce cytokines (IL-2, IFN-γ) and granules (perforin, granzyme B). Similar to TIM-3, LAG-3 expression was strongly up-regulated on CD4+ or CD8+ T cells by IL-12, a cytokine that has been shown to induce T-cell exhaustion. Interestingly, we observed that while expression of TIM-3 on CD8+ T cells was upregulated by IL-12 at an early time point (day 1), LAG-3 was only induced after TIM-3 up-regulation (day 3) and almost exclusively on TIM-3+ T cells. Furthermore, we found that blockade of both TIM-3 and LAG-3 signaling was able to reverse the exhausted phenotype of CD8+ T cells resulting in increased IFN-γ and IL-2 production. This effect was further enhanced when CD8+ T cells were treated with both anti-TIM-3 and anti-LAG-3 Abs. Taken together, these results suggest that PD-1, TIM-3 and LAG-3 were involved in the induction of exhaustion of T cells in B-cell NHL. We find that PD-1, TIM-3 and LAG-3 are expressed on the same T cells and that blocking TIM-3 and LAG-3 can reverse T-cell exhaustion signaling. These results suggest that PD-1, TIM-3 and LAG-3 play a synergistic role in the development of T cell exhaustion in NHL. Disclosures No relevant conflicts of interest to declare.

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T-Cells From Patients with CLL Exhibit Phenotypic and Transcription Factor Profiles of Exhaustion Independent of CMV Serostatus

Blood ◽

10.1182/blood.v118.21.1780.1780 ◽

2011 ◽

Vol 118 (21) ◽

pp. 1780-1780

Author(s):

John C. Riches ◽

Jeff Davies ◽

Sameena Iqbal ◽

Rewas Fatah ◽

Samir Agrawal ◽

...

Keyword(s):

T Cells ◽

Transcription Factor ◽

T Cell ◽

Cd8 T Cells ◽

Immune Dysfunction ◽

Effector Memory ◽

Chronic Viral Infection ◽

T Cell Exhaustion ◽

Cell Exhaustion ◽

Healthy Donors

Abstract Abstract 1780 Cancer is associated with immune dysfunction, contributing to the failure to mount an effective anti-tumor immune response. T-cell exhaustion, a state of acquired T-cell dysfunction initially described in the context of chronic viral infections, has recently been described in human solid tumors. We have previously demonstrated alterations in gene expression and defects in function in T-cells from patients with chronic lymphocytic leukemia (CLL) and noted similarities to those described in exhausted T-cells in murine models. Therefore, we used multiparameter flow cytometry to determine if T-cells from patients with untreated CLL (n=23) had surface phenotypic and transcription factor profiles of exhaustion. When compared with healthy controls (n=10), an increased proportion of circulating CD8+ T-cells showed an effector-memory phenotype (p=0.018), with a shift towards a greater proportion of CCR7-CD45RA+ terminally differentiated cells. We found increased expression of markers of exhaustion including CD279 (PD-1) (p=0.0057), CD160 (p=0.0006), CD244 (p=0.0057), and CD57 (p=0.011), and decreased expression of CD28 (p=0.0058) on CLL CD8+ T-cells compared with healthy CD8+ T-cells. Increased expression of PD-1 (p=0.0019), CD160 (p=0.0011), CD57 (p=0.007), and LAG-3 (p=0.038) was also noted on CLL CD4+ T-cells. We next determined the level of the transcription factors T-bet and eomesodermin and the transcriptional repressor Blimp-1, as these proteins have been implicated in CD8+ effector-memory differentiation and development of T-cell exhaustion. Importantly, CD8+ T-cells from CLL patients showed increased expression of T-bet (p=0.038), eomesodermin (p=0.0037), and Blimp-1 (p=0.0002), compared with CD8+ T-cells from healthy donors. Furthermore, PD-1 expression identified a subset of exhausted CD8+ T-cells with high intranuclear staining of Blimp-1 that was markedly expanded in patients with CLL (p=0.0002). Previous studies have identified expanded populations of CMV specific CD8+ T-cells in CMV seropositive CLL patients. As chronic viral infection is a known cause of T-cell exhaustion, we determined whether our findings were limited to CMV seropositive patients. We observed that increased expression of T-bet and decreased expression of CD28 was seen only in CD8+ T-cells from CMV seropositive patients. T-bet represses expression of PD-1 and sustains CD8+ T-cell responses during chronic viral infection, and we noted relatively lower expression of PD-1 on CD8+ T-cells in seropositive compared with seronegative patients (p=0.049), although PD-1 expression was still higher than in healthy controls. However, CD8+ T-cells from both CMV seronegative and seropositive patients had significantly higher expression of CD160, CD244, and CD57 compared to CD8+ T-cells from healthy donors (Table 1). Furthermore, CD8+ T-cells from both CMV seronegative and seropositive patients had increased expression of Blimp-1 and eomesodermin. Table 1. Surface phenotype/transcription factor profile of CLL according to CMV serostatus Healthy CLL: CMV IgG negative (n=8) CLL: CMV IgG positive (n=8) Phenotype PD-1 LOW INCREASED** INCREASED* CD160 LOW INCREASED** INCREASED** CD57 LOW INCREASED* INCREASED** CD244 LOW INCREASED* INCREASED*** CD28 HIGH NO CHANGE DECREASED** Transcription factor T-bet LOW NO CHANGE INCREASED** Eomes LOW INCREASED* INCREASED*** Blimp-1 LOW INCREASED*** INCREASED*** * p<0.05, ** p<0.01, *** p<0.001 In conclusion, T-cells from patients with CLL show phenotypic and transcription factor profiles of T-cell exhaustion that is not limited to the CMV-seropositive group. These findings may explain the acquired immune deficiency in patients with CLL, and provide potential therapeutic targets to reverse immune dysfunction in this disease. Disclosures: Gribben: Roche: Honoraria; Celgene: Honoraria; GSK: Honoraria; Mundipharma: Honoraria; Gilead: Honoraria; Pharmacyclics: Honoraria.

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Phenotypic and functional differences of HBV core-specific versus HBV polymerase-specific CD8+ T cells in chronically HBV-infected patients with low viral load

Gut ◽

10.1136/gutjnl-2018-316641 ◽

2019 ◽

Vol 68 (5) ◽

pp. 905-915 ◽

Cited By ~ 37

Author(s):

Anita Schuch ◽

Elahe Salimi Alizei ◽

Kathrin Heim ◽

Dominik Wieland ◽

Michael Muthamia Kiraithe ◽

...

Keyword(s):

T Cells ◽

Viral Load ◽

T Cell ◽

Cd8 T Cells ◽

Molecular Mechanisms ◽

T Cell Responses ◽

T Cell Exhaustion ◽

Detection Rates ◽

Cell Exhaustion ◽

Cell Responses

ObjectiveA hallmark of chronic HBV (cHBV) infection is the presence of impaired HBV-specific CD8+ T cell responses. Functional T cell exhaustion induced by persistent antigen stimulation is considered a major mechanism underlying this impairment. However, due to their low frequencies in chronic infection, it is currently unknown whether HBV-specific CD8+ T cells targeting different epitopes are similarly impaired and share molecular profiles indicative of T cell exhaustion.DesignBy applying peptide-loaded MHC I tetramer-based enrichment, we could detect HBV-specific CD8+ T cells targeting epitopes in the HBV core and the polymerase proteins in the majority of 85 tested cHBV patients with low viral loads. Lower detection rates were obtained for envelope-specific CD8+ T cells. Subsequently, we performed phenotypic and functional in-depth analyses.ResultsHBV-specific CD8+ T cells are not terminally exhausted but rather exhibit a memory-like phenotype in patients with low viral load possibly reflecting weak ongoing cognate antigen recognition. Moreover, HBV-specific CD8+ T cells targeting core versus polymerase epitopes significantly differed in frequency, phenotype and function. In particular, in comparison with core-specific CD8+ T cells, a higher frequency of polymerase-specific CD8+ T cells expressed CD38, KLRG1 and Eomes accompanied by low T-bet expression and downregulated CD127 indicative of a more severe T cell exhaustion. In addition, polymerase-specific CD8+ T cells exhibited a reduced expansion capacity that was linked to a dysbalanced TCF1/BCL2 expression.ConclusionsOverall, the molecular mechanisms underlying impaired T cell responses differ with respect to the targeted HBV antigens. These results have potential implications for immunotherapeutic approaches in HBV cure.

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Immunogenomic, single-cell and spatial dissection of CD8+T cell exhaustion reveals critical determinants of cancer immunotherapy

10.1101/2021.11.22.468617 ◽

2021 ◽

Author(s):

Stefan Naulaerts ◽

Daniel M Borras ◽

Asier Antoranz Martinez ◽

Julie Messiaen ◽

Yannick Van Herck ◽

...

Keyword(s):

Wound Healing ◽

T Cells ◽

T Cell ◽

Single Cell ◽

Cd8 T Cells ◽

Cd8 T Cell ◽

Immune Checkpoints ◽

Effector Memory ◽

T Cell Exhaustion ◽

Cell Exhaustion

Tumoural-CD8+T cells exhibit exhausted or dysfunctional states. Contrary to immunotherapy-responsive exhausted-CD8+T cells, the clinical features of dysfunctional-CD8+T cells are disputed. Hence, we conducted large-scale multi-omics and multi-dimensional mapping of CD8+T cell-states across multiple cancer patient-cohorts. This identified tumour-specific continuum of CD8+T cell-states across 6 human cancers, partly imprinted by organ-specific immuno-modulatory niches. Herein, melanoma and glioblastoma enriched prototypical exhausted (CD8+TEXT) and severely-dysfunctional (CD8+TSDF) states, respectively. Contrary to CD8+TEXT, CD8+TSDF displayed transcriptomic and epigenetic effector/cytolytic dysfunctions, and dysregulated effector/memory single-cell trajectories, culminating into maladaptive pro-death stress and cell-cycle defects. Suboptimal antigen-priming underscored CD8+TSDF, which was distinct from immune-checkpoints 'rich' CD8+TEXT, reflecting chronic antigen-stimulation. Continuum variation also existed on tumour spatial-level, with convergent (CD8+TEXT-supportive vascular regions) and divergent features (dysfunctional CD4+T::CD8+TSDF cell-to-cell interactions) between melanoma and glioblastoma. Globally, IFNG-IL2 disparities, paucity of intra-tumoural CD4+/CD8+T cells, and myeloid TGFB/wound healing responses, distinguished CD8+TSDF-landscape. Within immuno-oncology clinical-trials, anti-PD1 immunotherapy failed to 'reinvigorate' CD8+TSDF-landscape, and instead facilitated effector-dysfunction and TGFB/wound healing. However, cellular immunotherapies (dendritic cell-vaccines, adoptive T-cell therapy) ameliorated assorted CD8+TSDF-landscape disparities, highlighting a roadmap for anti-glioblastoma multimodal-immunotherapy. Collectively, our study comprehensively expands clinical-knowledge on CD8+T cell-exhaustion and suggests that tumour-specific, pre-existing CD8+TEXT/TSDF-states, determine immunotherapy-responses.

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Longitudinal Changes in Cd4+, Cd8+ T Cell Phenotype and Activation Marker Expression Following Antiretroviral Therapy Initiation among Patients with Cryptococcal Meningitis

Journal of Fungi ◽

10.3390/jof5030063 ◽

2019 ◽

Vol 5 (3) ◽

pp. 63

Author(s):

Alice Bayiyana ◽

Samuel Okurut ◽

Rose Nabatanzi ◽

Godfrey Zziwa ◽

David R. Boulware ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Antiretroviral Therapy ◽

Cell Surface ◽

Cd8 T Cells ◽

Cryptococcal Meningitis ◽

Cd8 T Cell ◽

Cd4 T Cell ◽

Effector Memory ◽

Memory Subset

Despite improvement in the prognosis of HIV/AIDS (human immunodeficiency virus/acquired immune deficiency syndrome) patients on antiretroviral therapy (ART), cryptococcal meningitis (CM) still causes 10–15% mortality among HIV-infected patients. The immunological impact of ART on the CD4+ and CD8+ T cell repertoire during cryptococcal co-infection is unclear. We determined longitudinal phenotypic changes in T cell subsets among patients with CM after they initiated ART. We hypothesized that ART alters the clonotypic phenotype and structural composition of CD4+ and CD8+ T cells during CM co-infection. For this substudy, peripheral blood mononuclear cells (PBMC) were isolated at four time points from CM patients following ART initiation during the parent study (ClinicalTrials.gov number, NCT01075152). Phenotypic characterization of CD4+ and CD8+ T cells was done using T cell surface marker monoclonal antibodies by flow cytometry. There was variation in the expression of immunophenotypic markers defining central memory (CD27+CD45R0+), effector memory (CD45R0+CD27–), immune activation (CD38+ and Human Leucocyte Antigen DR (HLA-DR+), and exhaustion (Programmed cell death protein one (PD-1) in the CD4+ T cell subset. In comparison to the CD4+ T cell population, the CD8+ central memory subset declined gradually with minimal increase in the effector memory subset. Both CD4+ and CD8+ T cell immune exhaustion and activation markers remained elevated over 12 weeks. The relative surge and decline in the expression of T cell surface markers outlines a variation in the differentiation of CD4+ T cells during ART treatment during CM co-infection.

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Reduced immune-regulatory molecule expression on human colonic memory CD4 T cells in older adults

Immunity & Ageing ◽

10.1186/s12979-021-00217-0 ◽

2021 ◽

Vol 18 (1) ◽

Author(s):

Stephanie M. Dillon ◽

Tezha A. Thompson ◽

Allison J. Christians ◽

Martin D. McCarter ◽

Cara C. Wilson

Keyword(s):

T Cells ◽

T Cell ◽

Cd8 T Cells ◽

Cd4 T Cells ◽

Older Persons ◽

Age Groups ◽

T Cell Immunity ◽

Cd4 T Cell ◽

Cell Immunity ◽

Memory Cd4 T Cells

Abstract Background The etiology of the low-level chronic inflammatory state associated with aging is likely multifactorial, but a number of animal and human studies have implicated a functional decline of the gastrointestinal immune system as a potential driver. Gut tissue-resident memory T cells play critical roles in mediating protective immunity and in maintaining gut homeostasis, yet few studies have investigated the effect of aging on human gut T cell immunity. To determine if aging impacted CD4 T cell immunity in the human large intestine, we utilized multi-color flow cytometry to measure colonic lamina propria (LP) CD4 T cell frequencies and immune-modulatory marker expression in younger (mean ± SEM: 38 ± 1.5 yrs) and older (77 ± 1.6 yrs) adults. To determine cellular specificity, we evaluated colon LP CD8 T cell frequency and phenotype in the same donors. To probe tissue specificity, we evaluated the same panel of markers in peripheral blood (PB) CD4 T cells in a separate cohort of similarly aged persons. Results Frequencies of colonic CD4 T cells as a fraction of total LP mononuclear cells were higher in older persons whereas absolute numbers of colonic LP CD4 T cells per gram of tissue were similar in both age groups. LP CD4 T cells from older versus younger persons exhibited reduced CTLA-4, PD-1 and Ki67 expression. Levels of Bcl-2, CD57, CD25 and percentages of activated CD38+HLA-DR+ CD4 T cells were similar in both age groups. In memory PB CD4 T cells, older age was only associated with increased CD57 expression. Significant age effects for LP CD8 T cells were only observed for CTLA-4 expression, with lower levels of expression observed on cells from older adults. Conclusions Greater age was associated with reduced expression of the co-inhibitory receptors CTLA-4 and PD-1 on LP CD4 T cells. Colonic LP CD8 T cells from older persons also displayed reduced CTLA-4 expression. These age-associated profiles were not observed in older PB memory CD4 T cells. The decline in co-inhibitory receptor expression on colonic LP T cells may contribute to local and systemic inflammation via a reduced ability to limit ongoing T cell responses to enteric microbial challenge.

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