iRGD in combination with IL-2 reprograms tumor immunosuppression.

2019 ◽  
Vol 37 (8_suppl) ◽  
pp. 55-55
Author(s):  
Gregory P. Botta ◽  
Tatiana Hurtado De Mendoza ◽  
Harri Jarvelainen ◽  
Erkki Ruoslahti
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Microenvironment ◽  
Mouse Models ◽  
Cd8 T Cells ◽  
Cytotoxic T Cells ◽  
Single Agent ◽  
Ductal Adenocarcinoma ◽  
Live Cells ◽  
Subsequent Increase

55 Background: Fibrotic solid tumors have lagged in immunotherapy efficacy. Although breast cancer (BC) shows modest single-agent activity, pancreatic ductal adenocarcinoma (PDAC) immunotherapy has repeatedly failed in clinical trials. A protective desmoplastic, inflammatory reaction encapsulates BC and PDAC where it can make up to 80% of the tumor microenvironment (TME). Reports in BC and PDAC patients and mouse models suggest that tumoricidal effector CD8+ T-cells are indeed present, yet suppressed by regulatory CD4+/CD25+/FoxP3+ T-cells (Tregs) and myeloid cells. Long-term PDAC and BC survivors harbor CD8+ T-cells by immunohistochemistry (IHC), and although inactivated (CD107a-), they are not terminally exhausted (PD-1low). Further, when CD8+ T-cells were found in large quantities within a treatment-naïve biopsy, that patient had an increased overall survival. We hypothesize that low doses of the T-cell proliferative cytokine IL-2 can class switch the TME T-cells if specifically concentrated within the tumor by the stroma-penetrating peptide iRGD. Methods: Subcutaneous BC tumors (4T1) and PDAC (KPC ) tumors were formed in immunocompetent mouse models. Mice were treated with either vehicle, iRGD, IL-2, or both in combination. Tumors were preserved for IHC or enzymatically digested for FACS. CD45+ live cells were fluorescently labeled for effector T-cells (CD4+/CD44+ or CD8+/CD44+), Tregs (CD4+/CD25+/FoxP3+), or cytotoxic T-cells (CD8+/CD44+/Granzyme B+/IL-2+). Results: Versus normal controls, tumors from BC and PDAC both showed a subsequent increase in bulk CD3+ T-cells within the tumor microenvironment (14.3% ± 5 vs. 27.6% ± 8). A significant increase in CD3+ T-cells within all tumors (10%) occured with iRGD only, IL-2 only, or iRGD + IL-2 treatment. Whereas sub-populations of T-cells in the iRGD only and IL-2 only treatment groups was overwhelming composed of Tregs (5%) at CD4/Treg and CD8/Treg ratios of 1.75 and 0.5 respectively, the combination of iRGD + IL-2 shifted the T-cell sub-populations away from Tregs (1.5%) and towards increased CD4/Treg and CD8/Treg ratios (4 and 12 respectively). Conclusions: The combination of iRGD + IL-2 is capable of reprogramming the immunosuppressive Treg tumor microenvironment, increasing effector CD4+ and CD8+ T-cells.

scholarly journals Alterations in regulatory T cells and immune checkpoint molecules in pancreatic cancer patients receiving FOLFIRINOX or gemcitabine plus nab-paclitaxel

2021 ◽  
Author(s):  
L. Sams ◽  
S. Kruger ◽  
V. Heinemann ◽  
D. Bararia ◽  
S. Haebe ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Regulatory T Cells ◽  
Cd8 T Cells ◽  
Mononuclear Cells ◽  
Progression Free Survival ◽  
Ductal Adenocarcinoma ◽  
Immune Checkpoints ◽  
Prognostic Information ◽  
Peripheral Blood Mononuclear

Abstract Purpose This pilot study aimed on generating insight on alterations in circulating immune cells during the use of FOLFIRINOX and gemcitabine/nab-paclitaxel in pancreatic ductal adenocarcinoma (PDAC). Patients and methods Peripheral blood mononuclear cells were isolated before and 30 days after initiation of chemotherapy from 20 patients with advanced PDAC. Regulatory T cells (FoxP3+) and immune checkpoints (PD-1 and TIM-3) were analyzed by flow cytometry and immunological changes were correlated with clinical outcome. Results Heterogeneous changes during chemotherapy were observed in circulating T-cell subpopulations with a pronounced effect on PD-1+ CD4+/CD8+ T cells. An increase in FoxP3+ or PD-1+ T cells had no significant effect on survival. An increase in TIM3+/CD8+ (but not TIM3+/CD4+) T cells was associated with a significant inferior outcome: median progression-free survival in the subgroup with an increase of TIM-3+/CD8+ T cells was 6.0 compared to 14.0 months in patients with a decrease/no change (p = 0.026); corresponding median overall survival was 13.0 and 20.0 months (p = 0.011), respectively. Conclusions Chemotherapy with FOLFIRNOX or gemcitabine/nab-paclitaxel induces variable changes in circulating T-cell populations that may provide prognostic information in PDAC.

scholarly journals Interactions between Cancer-Associated Fibroblasts and T Cells in the Pancreatic Tumor Microenvironment and the Role of Chemokines

Cancers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2995
Author(s):  
Laia Gorchs ◽  
Helen Kaipe
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Microenvironment ◽  
Current Knowledge ◽  
Ductal Adenocarcinoma ◽  
Pancreatic Tumors ◽  
Cell Trafficking ◽  
Cancer Associated Fibroblasts ◽  
Cell Axis ◽  
Combinational Treatment

Less than 10% of patients diagnosed with pancreatic ductal adenocarcinoma (PDAC) survive 5 years or more, making it one of the most fatal cancers. Accumulation of T cells in pancreatic tumors is associated with better prognosis, but immunotherapies to enhance the anti-tumor activity of infiltrating T cells are failing in this devastating disease. Pancreatic tumors are characterized by a desmoplastic stroma, which mainly consists of activated cancer-associated fibroblasts (CAFs). Pancreatic CAFs have emerged as important regulators of the tumor microenvironment by contributing to immune evasion through the release of chemokines, cytokines, and growth factors, which alters T-cell migration, differentiation and cytotoxic activity. However, recent discoveries have also revealed that subsets of CAFs with diverse functions can either restrain or promote tumor progression. Here, we discuss our current knowledge about the interactions between CAFs and T cells in PDAC and summarize different therapy strategies targeting the CAF–T cell axis with focus on CAF-derived soluble immunosuppressive factors and chemokines. Identifying the functions of different CAF subsets and understanding their roles in T-cell trafficking within the tumor may be fundamental for the development of an effective combinational treatment for PDAC.

549 Characterizing double positive T cells in the tumor microenvironment: a tale of promiscuous cell fates

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A586-A586
Author(s):  
Sara Schad ◽  
Andrew Chow ◽  
Heng Pan ◽  
Levi Mangarin ◽  
Roberta Zappasodi ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Microenvironment ◽  
Cd8 T Cells ◽  
Human Melanoma ◽  
B16 Melanoma ◽  
T Cell Subsets ◽  
Double Positive ◽  
Cell Fates ◽  
Single Positive

BackgroundCD4 and CD8 T cells are genetically and functionally distinct cell subsets of the adaptive immune system that play pivotal roles in immune surveillance and disease control. During development in the thymus, transcription factors ThPOK and Runx3 regulate the differentiation and maturation of these two lineages into single positive T cells that enter the periphery with mutually exclusive expression of either the CD4 or CD8 co-receptor.1–2 Despite our expectation that these two cell fates are fixed, mature CD4+CD8+ double positive (DP) T cells have been described in the context of numerous immunological responses, including cancer, but their molecular and functional properties and therapeutic relevance remain controversial and largely unknown.3–5MethodsOur lab has identified and characterized a heterogenous DP T cell population in murine and human melanoma tumors comprised of CD4 and CD8 T cells re-expressing the opposite co-receptor and a parallel uptake in the opposite cell type’s phenotype and function. Using CD4 (Trp1) and CD8 (Pmel) transgenic TCR T cells specific to B16 melanoma antigens gp75 and gp100 respectively, we demonstrate the re-expression of the opposite co-receptor following adoptive T cell transfer in B16 melanoma tumor bearing mice.ResultsSpecifically, up to 50% of transferred CD4 Trp1 T cells will re-express CD8 to become a DP T cell in the tumor microenvironment. Further, these CD4 derived DP T cells upregulate CD8 lineage regulator Runx3 and cytolytic genes Gzmb, Gzmk, and Prf1 to become potent cytotoxic T cells. Alternatively, a subset of CD8 Pmel T cells differentiate into DP T cells characterized by the increased expression of CD4, ThPOK, and regulatory marker FoxP3 (figure 1). In addition, we utilized 10x single cell and ATAC sequencing to further characterize these divergent DP T cell populations among open repertoire T cells isolated from murine and human melanoma tumors.ConclusionsOur findings highlight the capability of single positive T cells to differentiate in response to antigen and local stimuli into novel T cell subsets with polyfunctional characteristics. The resulting cell subsets will potentially affect the tumor microenvironment in distinct ways. Our studies may inform therapeutic approaches to identify antigen specific T cells as well as innovative signaling pathways to target when genetically engineering T cells to optimize cytotoxic function in the setting of adoptive cell therapy.Ethics ApprovalThe human biospecimen analyses were approved by Memorial Sloan Kettering Cancer Center IRB #06-107ReferencesEllmeier W, Haust L & Tschismarov R. Transcriptional control of CD4 and CD8 coreceptor expression during T cell development. Cell Mol Life Sci 2013;70:4537–4553.Luckey MA, et al. The transcription factor ThPOK suppresses Runx3 and imposes CD4+ lineage fate by inducing the SOCS suppressors of cytokine signaling. Nature Immunology 2014; 15, 638–645.Bohner P, et al. Double positive CD4(+)CD8(+) T Cells are enriched in urological cancers and favor T Helper-2 polarization. Front Immunol 2019; 10, 622.Nascimbeni M, Shin E-C, Chiriboga L, Kleiner DE & Rehermann B. Peripheral CD4(+)CD8(+) T cells are differentiated effector memory cells with antiviral functions. Blood 2004;104:478–486.Nishida K, et al. Clinical importance of the expression of CD4+CD8+ T cells in renal cell carcinoma. Int Immunol 2020;32:347–357.

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

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.

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.

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 Tumor antigen–specific CD8 T cells infiltrating the tumor express high levels of PD-1 and are functionally impaired

Blood ◽  
2009 ◽  
Vol 114 (8) ◽  
pp. 1537-1544 ◽  
Author(s):  
Mojgan Ahmadzadeh ◽  
Laura A. Johnson ◽  
Bianca Heemskerk ◽  
John R. Wunderlich ◽  
Mark E. Dudley ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Microenvironment ◽  
T Lymphocytes ◽  
Cd8 T Cells ◽  
Tumor Antigen ◽  
Ki 67 ◽  
Normal Tissues ◽  
Functionally Impaired ◽  
Underlying Mechanisms

Abstract Tumor antigen–specific T cells are found within melanomas, yet tumors continue to grow. Although the tumor microenvironment is thought to influence the suppression of tumor-reactive T cells, the underlying mechanisms for this T-cell dysfunction are not clear. Here, we report that the majority of tumor infiltrating T lymphocytes (TIL), including MART-1/Melan-A melanoma antigen–specific CD8 T cells, predominantly expressed PD-1, in contrast to T cells in normal tissues and peripheral blood T lymphocytes (PBL). PD-1+ TIL expressed CTLA-4 and Ki-67, markers that were not expressed by PD-1− TIL and T cells in the normal tissues and PBL. Moreover, PD-1+ TIL were primarily HLA-DR+ and CD127−, in contrast to PD-1− TIL. Effector cytokine production by PD-1+ TIL was impaired compared with PD-1− TIL and PBL. Collectively, the phenotypic and functional characterizations of TIL revealed a significantly higher frequency and level of PD-1 expression on TIL compared with normal tissue T-cell infiltrates and PBL, and PD-1 expression correlated with an exhausted phenotype and impaired effector function. These findings suggest that the tumor microenvironment can lead to up-regulation of PD-1 on tumor-reactive T cells and contribute to impaired antitumor immune responses.

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.

scholarly journals CD73 Ectonucleotidase Restrains CD8+ T Cell Metabolic Fitness and Anti-tumoral Activity

2021 ◽  
Vol 9 ◽  
Author(s):  
Pedro Briceño ◽  
Elizabeth Rivas-Yañez ◽  
Mariana V. Rosemblatt ◽  
Brian Parra-Tello ◽  
Paula Farías ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cytotoxic T Cells ◽  
Cd8 T Cell ◽  
Tumor Burden ◽  
Effector Cells ◽  
Cd73 Expression ◽  
Metabolic Fitness

CD39 and CD73 are ectoenzymes that dephosphorylate ATP into its metabolites; ADP, AMP, and adenosine, and thus are considered instrumental in the development of immunosuppressive microenvironments. We have previously shown that within the CD8+ T cell population, naïve and memory cells express the CD73 ectonucleotidase, while terminally differentiated effector cells are devoid of this enzyme. This evidence suggests that adenosine might exert an autocrine effect on CD8+ T cells during T cell differentiation. To study the possible role of CD73 and adenosine during this process, we compared the expression of the adenosinergic signaling components, the phenotype, and the functional properties between CD73-deficient and WT CD8+ T cells. Upon activation, we observed an upregulation of CD73 expression in CD8+ T cells along with an upregulation of the adenosine A2A receptor. Interestingly, when we differentiated CD8+ T cells to Tc1 cells in vitro, we observed that these cells produce adenosine and that CD73-deficient cells present a higher cytotoxic potential evidenced by an increase in IFN-γ, TNF-α, and granzyme B production. Moreover, CD73-deficient cells presented a increased glucose uptake and higher mitochondrial respiration, indicating that this ectonucleotidase restrict the mitochondrial capacity in CD8+ T cells. In agreement, when adoptively transferred, antigen-specific CD73-deficient CD8+ T cells were more effective in reducing the tumor burden in B16.OVA melanoma-bearing mice and presented lower levels of exhaustion markers than wild type cells. All these data suggest an autocrine effect of CD73-mediated adenosine production, limiting differentiation and cytotoxic T cells’ metabolic fitness.

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