scholarly journals Lactate regulation of activation in CD8+ T cells

2021 ◽  
Author(s):  
Laura Barbieri ◽  
Pedro Veliça ◽  
Paulo A Gameiro ◽  
Pedro P Cunha ◽  
Iosifina P Foskolou ◽  
...  
Keyword(s):  
T Cells ◽  
Cd8 T Cells ◽  
Cytotoxic T Cells ◽  
The Novel ◽  
Differentiation Markers ◽  
Glycolytic Activity ◽  
Lactate Utilization ◽  
Cell Transcriptome ◽  
Neutral Conditions ◽  
Extended Exposure

CD8+ T cells infiltrate virtually every tissue to find and destroy infected or mutated cells. They often traverse varying oxygen levels and nutrient-deprived microenvironments. High glycolytic activity in tissues can result in extended exposure of cytotoxic T cells to the metabolite lactate. Lactate can be immunosuppressive, at least in part due to its association with tissue acidosis. We show here that the lactate anion is well tolerated by CD8+ T cells in pH neutral conditions. We describe how lactate is taken up by activated CD8+ T cells and is capable of displacing glucose as a carbon source. Activation in the presence of a pH neutral form of lactate significantly alters the CD8+ T cell transcriptome, including the expression of key effector differentiation markers such as granzyme B and interferon-gamma. Our studies reveal the novel metabolic features of lactate utilization by activated CD8+ T cells, and highlight the importance of lactate in shaping the differentiation and activity of cytotoxic T cells.

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

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.

Regulation of Tim-3 function by binding to phosphatidylserine

2021 ◽  
Vol 478 (22) ◽  
pp. 3999-4004
Author(s):  
Lawrence P. Kane
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cd8 T Cells ◽  
Cell Activation ◽  
Transmembrane Protein ◽  
Cytotoxic T Cells ◽  
Cross Presentation ◽  
First Time

Tim-3 is a transmembrane protein that is highly expressed on subsets of chronically stimulated CD4+ helper and CD8+ cytotoxic T cells, with more transient expression during acute activation and infection. Tim-3 is also constitutively expressed by multiple types of myeloid cells. Like other TIM family members, Tim-3 can bind to phosphatidylserine displayed by apoptotic cells, and this interaction has been shown to mediate uptake of such cells by dendritic cells and cross-presentation of antigens to CD8+ T cells. In contrast, how the recognition of PS by Tim-3 might regulate the function of Tim-3+ T cells is not known. In their recent paper, Lemmon and colleagues demonstrate for the first time that recognition of PS by Tim-3 leads to enhanced T cell activation.

scholarly journals Whole blood immunophenotyping uncovers immature neutrophil-to-VD2 T-cell ratio as an early marker for severe COVID-19

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Guillaume Carissimo ◽  
Weili Xu ◽  
Immanuel Kwok ◽  
Mohammad Yazid Abdad ◽  
Yi-Hao Chan ◽  
...  
Keyword(s):  
T Cells ◽  
Cd8 T Cells ◽  
Whole Blood ◽  
Roc Analysis ◽  
Γδ T Cells ◽  
High Sensitivity ◽  
The Novel ◽  
Cellular Mechanisms ◽  
Cell Counts ◽  
Novel Coronavirus

Abstract SARS-CoV-2 is the novel coronavirus responsible for the current COVID-19 pandemic. Severe complications are observed only in a small proportion of infected patients but the cellular mechanisms underlying this progression are still unknown. Comprehensive flow cytometry of whole blood samples from 54 COVID-19 patients reveals a dramatic increase in the number of immature neutrophils. This increase strongly correlates with disease severity and is associated with elevated IL-6 and IP-10 levels, two key players in the cytokine storm. The most pronounced decrease in cell counts is observed for CD8 T-cells and VD2 γδ T-cells, which both exhibit increased differentiation and activation. ROC analysis reveals that the count ratio of immature neutrophils to VD2 (or CD8) T-cells predicts pneumonia onset (0.9071) as well as hypoxia onset (0.8908) with high sensitivity and specificity. It would thus be a useful prognostic marker for preventive patient management and improved healthcare resource management.

scholarly journals Impaired enolase 1 glycolytic activity restrains effector functions of tumor-infiltrating CD8+T cells

2019 ◽  
Vol 4 (31) ◽  
pp. eaap9520 ◽  
Author(s):  
Lelisa F. Gemta ◽  
Peter J. Siska ◽  
Marin E. Nelson ◽  
Xia Gao ◽  
Xiaojing Liu ◽  
...  
Keyword(s):  
T Cells ◽  
Cd8 T Cells ◽  
Tumor Infiltrating Lymphocytes ◽  
Biochemical Basis ◽  
Effector Functions ◽  
Glycolytic Activity ◽  
Functional Exhaustion ◽  
Critical Insight ◽  
Infiltrating Lymphocytes ◽  
Insight Into

In the context of solid tumors, there is a positive correlation between the accumulation of cytotoxic CD8+tumor-infiltrating lymphocytes (TILs) and favorable clinical outcomes. However, CD8+TILs often exhibit a state of functional exhaustion, limiting their activity, and the underlying molecular basis of this dysfunction is not fully understood. Here, we show that TILs found in human and murine CD8+melanomas are metabolically compromised with deficits in both glycolytic and oxidative metabolism. Although several studies have shown that tumors can outcompete T cells for glucose, thus limiting T cell metabolic activity, we report that a down-regulation in the activity of ENOLASE 1, a critical enzyme in the glycolytic pathway, represses glycolytic activity in CD8+TILs. Provision of pyruvate, a downstream product of ENOLASE 1, bypasses this inactivity and promotes both glycolysis and oxidative phosphorylation, resulting in improved effector function of CD8+TILs. We found high expression of both enolase 1 mRNA and protein in CD8+TILs, indicating that the enzymatic activity of ENOLASE 1 is regulated posttranslationally. These studies provide a critical insight into the biochemical basis of CD8+TIL dysfunction.

Stromal Cells Protect B-CLL Cells from Killing by Antigen-Specific Cytotoxic T Cells.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2814-2814
Author(s):  
Katja Zirlik ◽  
Meike Burger ◽  
Philipp Brantner ◽  
Gabriele Prinz ◽  
Maike Buchner ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Line ◽  
Cd8 T Cells ◽  
Stromal Cells ◽  
Stromal Cell ◽  
Cytotoxic T Cells ◽  
Protective Effects ◽  
Stromal Cell Line

Abstract B-cell malignancy-derived immunoglobulin (idiotype) and survivin, a member of the inhibitor of apoptosis gene family and a shared tumor-associated antigen, are expressed by B-CLL cells. Idiotype- and survivin-specific cytotoxic T cells (CTLs), capable of lysing primary autologous B-CLL cells, can be induced in patients with B-CLL. However, the leukemia cell microenvironment was shown to protect B-CLL cells from apoptosis. The protective effects of stromal cells can be reversed by CXCR4 antagonists in vitro and resensitize CLL cells to spontaneous and chemotherapy-induced apoptosis. The aim of the present study is to investigate whether stromal cell contact impairs CLL killing by CTLs raised against immunoglobulin- or survivin-derived peptides and whether the addition of CXCR4 inhibitors enhances T cell mediated cytotoxicity. To analyze the T cell response, we isolated CD8+ T cells and PBMCs from HLA-A2+ healthy donors. PBMCs were differentiated into dendritic cells (DCs) and CD40-activated B cells. CD8+ T cells were primarily stimulated with peptide-pulsed DCs and then restimulated weekly with peptide-pulsed CD40-activated B cells. Heteroclitic framework region (FR−), heteroclitic complementarity-determining region (CD−) derived peptides, and native and heteroclitic survivin-derived peptides were used for CTL induction. As expected, heteroclitic peptide modifications increased the binding affinity to HLA-A*0201 compared to the native peptide as predicted by the Parker Score (Median change of predicted half-time of dissociation to HLA class I molecules 1429 minutes) and measured by the T2 binding assay (Fluorescence Index (FI) native 0.2; FI heteroclitic 0.9). Cytotoxicity of T cells was assessed by chromium release assay and by flow cytometry against CFSE-labelled CLL cells alone and in co-culture with unlabelled stromal cells in the absence or presence of CXCR4 blocking agents. The induced CTLs efficiently lysed allogenic HLA-A2+ CLL cells (mean cytotoxicity at 30:1, 10:1, 3:1 effector-to-target (E:T) ratio: 15,5%+/−2,8; 7,5%+/−2,8; and 1,9%+/− 0,6), but not HLA-A2 negative CLL cells. Co-culture of CLL cells with the murine stromal cell line M2-10B4 resulted in protection of CLL cells from lysis by antigen-specific cytotoxic T cells in vitro, indeed suggesting a protective role of the microenvironment (mean cytotoxicity at 30:1, 10:1, 3:1 E:T ratio: 5,2%+/−4,1; 0,4%+/−1,6; 1,2%+/−2,0). In contrast to apoptosis induced by fludarabine, CXCR4 blocking agents did not reverse the protective effects of the stromal cell line on T cell mediated cytotoxicity (mean cytotoxicity 30:1, 10:1, 3:1 E:T ratio: 3,1%+/−2,4; 0,8%+/−2,5; 2,3%+/−1,6). These data indicate that the microenvironment may exert protective effects against immunotherapeutic strategies in CLL. However, the protective interaction is not entirely mediated by the CXCR4 - CXCL12 axis. Additional cell-cell interactions appear to play a role and need to be identified as therapeutic targets in order to effectively interrupt the protective effect of the microenvironment on T cell mediated cytotoxicity of B-CLL cells.

scholarly journals Expansion of HIV-specific CD4+ and CD8+ T cells by dendritic cells transfected with mRNA encoding cytoplasm- or lysosome-targeted Nef

Blood ◽  
2006 ◽  
Vol 107 (5) ◽  
pp. 1963-1969 ◽  
Author(s):  
Daniel G. Kavanagh ◽  
Daniel E. Kaufmann ◽  
Sherzana Sunderji ◽  
Nicole Frahm ◽  
Sylvie Le Gall ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Mononuclear Cells ◽  
Ex Vivo ◽  
Cytotoxic T Cells ◽  
T Cell Response ◽  
Peripheral Blood Mononuclear ◽  
T Cell Lines

Transfection with synthetic mRNA is a safe and efficient method of delivering antigens to dendritic cells for immunotherapy. Targeting antigens to the lysosome can sometimes enhance the CD4+ T-cell response. We transfected antigen-presenting cells (APCs) with mRNA encoding Gag-p24 and cytoplasmic, lysosomal, and secreted forms of Nef. Antigen-specific cytotoxic T cells were able to lyse the majority of transfected targets, indicating that transfection was efficient. Transfection of APCs with a Nef construct bearing lysosomal targeting signals produced rapid and prolonged antigen presentation to CD4+ and CD8+ T cells. Polyclonal CD4+ and CD8+ T-cell lines recognizing multiple distinct epitopes were expanded by coculture of transfected dendritic cells with peripheral blood mononuclear cells from viremic and aviremic HIV-infected subjects. Importantly, lysosome-targeted antigen drove a significantly greater expansion of Nef-specific CD4+ T cells than cytoplasmic antigen. The frequency of recognition of CD8 but not CD4 epitopes by mRNA-expanded T cells was inversely proportional to sequence entropy and was similar to ex vivo responses from a large chronic cohort. Thus human dendritic cells transfected with mRNA encoding lysosome-targeted HIV antigen can expand a broad, polyclonal repertoire of antiviral T cells, offering a promising approach to HIV immunotherapy.

scholarly journals The Novel Murine CD4+CD8+ Thymocyte Cell Line Exhibits Lineage Commitment into Both CD4+ and CD8+ T Cells by Altering the Intensity and the Duration of Anti-CD3 Stimulation In Vitro

2004 ◽  
Vol 172 (11) ◽  
pp. 6634-6641 ◽  
Author(s):  
Takashi Nishida ◽  
Yasunori Matsuki ◽  
Takeshi Ono ◽  
Takemi Oguma ◽  
Kyoko Tsujimoto ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Line ◽  
Cd8 T Cells ◽  
Lineage Commitment ◽  
The Novel

Expansion of CMV-specific CD8+CD45RA+CD27- T cells in B-cell chronic lymphocytic leukemia

Blood ◽  
2003 ◽  
Vol 102 (3) ◽  
pp. 1057-1063 ◽  
Author(s):  
Wendelina J. M. Mackus ◽  
Florine N. J. Frakking ◽  
Annette Grummels ◽  
Laila E. Gamadia ◽  
Godelieve J. de Bree ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Chronic Lymphocytic Leukemia ◽  
Immune Responses ◽  
B Cell ◽  
Cd8 T Cells ◽  
Cytotoxic T Cells ◽  
Lymphocytic Leukemia ◽  
The Absolute ◽  
Cell Chronic Lymphocytic Leukemia

Abstract In patients with B-cell chronic lymphocytic leukemia (B-CLL), the absolute number of T cells is increased. Although it has been suggested that these T cells might be tumor specific, concrete evidence for this hypothesis is lacking. We performed a detailed immunophenotypic analysis of the T-cell compartment in the peripheral blood of 28 patients with B-CLL (Rai 0, n = 12; Rai I-II, n = 10; Rai III-IV, n = 6) and 12 healthy age-matched controls and measured the ability of these patients to mount specific immune responses. In all Rai stages a significant increase in the absolute numbers of CD3+ cells was observed. Whereas the number of CD4+ cells was not different from controls, patients with B-CLL showed significantly increased relative and absolute numbers of CD8+ cells, which exhibited a CD45RA+CD27- cytotoxic phenotype. Analysis of specific immune responses with tetrameric cytomegalovirus (CMV)–peptide complexes showed that patients with B-CLL had significantly increased numbers of tetramer-binding CMV-specific CD8+ T cells. The rise in the total number of CD8+ cytotoxic T cells was evident only in CMV-seropositive B-CLL patients. Thus, our data suggest that in patients with B-CLL the composition of T cells is shifted toward a CD8+ cytotoxic cell type in an effort to control infections with persistent viruses such as CMV. Moreover, they offer an explanation for the high incidence of CMV reactivation in CLL patients treated with T cell–depleting agents, such as the monoclonal antibody (mAb) alemtuzumab (Campath; α-CD52 mAb). Furthermore, because in CMV-seronegative patients no increase in cytotoxic CD8+ T cells is found, our studies do not support the hypothesis that tumor-specific T cells account for T-cell expansion in B-CLL.

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