Alloreactivity Directed Against the Widely Distributed HY Antigen Impairs Antitumor Immunity and Results in T-Cell Dysfunction

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2964-2964
Author(s):  
Jessica C Shand ◽  
Christian M. Capitini ◽  
Haiying Qin ◽  
Nicole Nasholm ◽  
Brynn B Duncan ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
T Cell ◽  
Dendritic Cell Vaccine ◽  
Effector Memory ◽  
Cell Vaccine ◽  
Antitumor Response ◽  
Cell Dysfunction ◽  
Tumor Bearing ◽  
T Cell Dysfunction

Abstract Abstract 2964 INTRODUCTION: The curative potential of allogeneic transplant for high-risk malignancy is based on the observation that alloreactivity can result in a clinically significant graft-versus-tumor (GVT) effect. However, we have observed that alloreactivity directed against non-tumor restricted miHA's reduces quantitative responses to vaccines targeting tumor-specific antigens. The relative impact of the GVHD-mediating antigen on the potency of the GVT response when the antigen is shared has not been well studied. METHODS: A murine allotransplant system in which the clinically relevant GVHD antigen HY drives both graft-versus-host disease and the antitumor response was utilized. Following lethal irradiation, combinations of B6 male (HY-expressing) and female (HY-naïve) donors and recipients were used in T-cell depleted bone marrow transplants to control for HY expression in hematopoetic and non-hematopoetic compartments. Delayed donor lymphocyte infusion (DLI) with female HY-specific transgenic T-cells was then performed which allowed tracking of antigen-specific cells. Mice were subsequently challenged with an immunogenic HY-expressing tumor (MB49). In tumor protection studies, transplant recipients received a male dendritic cell vaccine at the time of DLI. Recipients were monitored for clinical GVHD scoring, weight loss, tumor-free and overall survival. Surface phenotyping of HY-specific CD8 T cells from recipient bone marrow, tumor-draining lymph node (LN) and spleen was performed serially by flow cytometry using congenic markers. Statistical analyses were performed using paired Student t-tests and Kaplan-Meier survival estimates. RESULTS: Transplantation of female marrow and HY-specific T cells into male recipients produces a mild HY-targeted GVHD, indicated by weight loss and skin GVHD scores. Female recipients of female marrow and HY-specific DLI had 100% survival following HY-expressing tumor challenge. In contrast, male recipients had only 20 +/− 4.7% tumor-free survival (p<0.0001), despite receiving HY-reactive female marrow and HY-specific DLI. Administration of an HY-expressing male dendritic cell vaccine did not improve either tumor growth velocity or tumor-free survival in male recipients. Despite a poor antitumor response in males, expression of HY on nonhematopoetic tissues produced a significant expansion of HY specific T-cells following DLI, regardless of tumor-bearing status (30.5 −77.4% total CD8 from spleen, draining LN and marrow, vs 0.01–1% from female recipient controls, p<0.0001). This suggested that impaired tumor control was due to dysfunction, rather than deletion, of HY-specific T cells. Indeed, nearly 100% of HY-specific CD8 isolated from the spleen, tumor-draining lymph node, and bone marrow of male recipients expressed high levels of PD-1, a phenomenon observed at all time points in tumor-bearing and non tumor-bearing male recipients with HY-directed GVHD. Non-HY specific CD8 cells did not express PD-1 (p<0.0001). Further, HY-specific CD8 from spleen and tumor-draining LN of male recipients display a significantly increased percentage of CD44+CD62L- effector memory (72.4 +/− 17.2%) vs. CD44+CD62L+ central memory (15.9 +/− 9.7%, p= 0.006) cells compared to non-HY specific CD8 cells (26.5% +/− 2.8 % vs. 28.2 +/− 12.7%, p= 0.52) from male and female recipient controls. CONCLUSIONS: In an experimental system where HY is expressed on both recipient nonhematopoetic tissue and tumor, HY-directed alloreactivity impairs the antitumor response despite antigen-specific DLI and effective vaccination. Characterization of alloreactive CD8 T cells in this setting reveals a persistence of effector memory and high levels of PD-1 expression, which suggest T-cell dysfunction as a possible mechanism. Further studies of T-cell dysfunction in this model may identify targets for therapeutic blockade following adoptive immunotherapy with particular relevance to those clinical situations where GVHD does not enhance GVT. Disclosures: No relevant conflicts of interest to declare.

Combination cancer immunotherapy targeting PD-1 and GITR can rescue CD8+T cell dysfunction and maintain memory phenotype

2018 ◽  
Vol 3 (29) ◽  
pp. eaat7061 ◽  
Author(s):  
Bei Wang ◽  
Wen Zhang ◽  
Vladimir Jankovic ◽  
Jacquelynn Golubov ◽  
Patrick Poon ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Death ◽  
T Cell ◽  
Programmed Cell Death ◽  
Cancer Immunotherapy ◽  
Effector Memory ◽  
Cell Phenotype ◽  
Checkpoint Inhibition ◽  
Cell Dysfunction ◽  
T Cell Dysfunction

Most patients with cancer do not develop durable antitumor responses after programmed cell death protein 1 (PD-1) or programmed cell death ligand 1(PD-L1) checkpoint inhibition monotherapy because of an ephemeral reversal of T cell dysfunction and failure to promote long-lasting immunological T cell memory. Activating costimulatory pathways to induce stronger T cell activation may improve the efficacy of checkpoint inhibition and lead to durable antitumor responses. We performed single-cell RNA sequencing of more than 2000 tumor-infiltrating CD8+T cells in mice receiving both PD-1 and GITR (glucocorticoid-induced tumor necrosis factor receptor–related protein) antibodies and found that this combination synergistically enhanced the effector function of expanded CD8+T cells by restoring the balance of key homeostatic regulators CD226 and T cell immunoreceptor with Ig and ITIM domains (TIGIT), leading to a robust survival benefit. Combination therapy decreased CD8+T cell dysfunction and induced a highly proliferative precursor effector memory T cell phenotype in a CD226-dependent manner. PD-1 inhibition rescued CD226 activity by preventing PD-1–Src homology region 2 (SHP2) dephosphophorylation of the CD226 intracellular domain, whereas GITR agonism decreased TIGIT expression. Unmasking the molecular pathways driving durable antitumor responses will be essential to the development of rational approaches to optimizing cancer immunotherapy.

Multiple Inhibitory Receptors Are Expressed on Central Memory and Memory Stem T Cells Infiltrating the Bone Marrow of AML Patients Relapsing after Allo-HSCT

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 4564-4564 ◽  
Author(s):  
Maddalena Noviello ◽  
Francesco Manfredi ◽  
Tommaso Perini ◽  
Giacomo Oliveira ◽  
Filippo Cortesi ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
T Cell ◽  
Research Funding ◽  
Central Memory ◽  
Cd8 Cells ◽  
Effector Functions ◽  
Cell Dysfunction ◽  
T Cell Dysfunction ◽  
Cell Effector

Abstract Background:Allogeneic Hematopoietic Stem Cell Transplantation (HSCT) is the only cure for high-risk acute myeloid leukemia (AML). Unfortunately, relapse still remains the major cause of death after HSCT. We investigated if T-cell dysfunction is associated to post-transplant relapse. Patients and Methods: To this,we longitudinally analyzed the T-cell dynamics in bone marrow (BM) and peripheral blood (PB) of 32 AML patients receiving HSCT from HLA identical (HLAid, 20 pts) or HLA haploidentical (haplo, 12 pts) donors. Samples were analysed by multi-parametric flow cytometry to investigate the expression of inhibitory receptors (IRs) on CD4 and CD8 T-cell subsets defined by CD45RA, CD62L and CD95 expression, and to assess the proportion of regulatory T cells (Tregs; CD4+CD25+FoxP3+). Results were also analyzed with the BH-SNE algorithm, an unbiased computational method for the analysis of FACS data. To evaluate T-cell effector functions, the CD107a degranulation assay was performed and the production of cytokines (IL-2, IFNg and TNFa) was measured by intracellular staining. BM and PB were collected 60 days after HSCT and at relapse (median 237 days; 16 pts) or, when complete remission was maintained (CR; 16 pts), at 1 year. Samples from 8 healthy donors (HD) were used as controls. Results:After transplant, BM and PB T cells showed a lower CD4/CD8 ratio (p<0.01) and a preferential late differentiation profile (p<0.05) when compared to HD. A higher proportion of BM Tregs was documented at relapse (p<0.01), independently from the donor source. We next investigated the expression of several IRs as T-cell exhaustion markers. After haplo-HSCT, PD-1, CTLA-4, 2B4 and Tim-3 were significantly upregulated in BM and PB T cells at all time-points, compared to HD and independently from the clinical outcome. Conversely, after HLAid-HSCT, at the late time-point, patients who relapsed, displayed a higher frequency of BM infiltrating T cells expressing PD-1, CTLA-4 and Tim-3 than CR pts (p<0.05) and HD (p<0.01). We then investigated the profile of each T-cell subset in our cohort. In the BM of HD the IR expression was confined to effector memory and effectors. While a similar IR distribution was observed in CR, at relapse, PD-1, 2B4 and Tim-3 were also upregulated in BM infiltrating central memory (p<0.01) and memory stem T cells (p<0.05). Interestingly, at relapse, leukemia expressed PD-L1 (9/9 cases) and Galectin-9 (6/9). The levels of Tim-3 on BM CD8 cells associates with that of Galectin-9 on autologous blasts (p<0.05), suggesting a preferential role for this immunomodulatory axis after HSCT. Based on phenotype similarities, the BH-SNE algorithm positioned HD samples separately from transplanted pts in bi-dimensional maps. 93 significant clusters were identified. Clusters associated with relapse after HLA-id (5) and after haplo (15) were composed of T cells expressing multiple IRs, while CR-specific clusters were diminished in IR fluorescence. To verify whether the T-cell exhaustion phenotypic profile at relapse associates with functional impairment, we evaluated T-cell effector functions upon polyclonal stimulation. Strikingly, we observed a lower degranulation ability of CD8 cells at relapse when compared to CR (p<0.05). In two patients, selected based on samples availability, we isolated and expanded by rapid expansion protocol (REP) T cells expressing one or more IRs (IR+) or no IR (IR-). Expansion rates were high and similar in IR+ and IR- T cells (mean fold increase 624 and 781, respectively at day 21). The degranulation ability measured ex-vivo in those patients (mean 4.4% on CD8 cells) was dramatically increased upon REP expansion (95% and 88.9% for IR+ and IR-, respectively). Similarly, the frequency of IFN-g producing CD8 cells increased in IR+ and IR- cells upon REP, indicating that the T-cell dysfunction observed at relapse can be efficiently reversed. We next challenged IR+ and IR- T cells against autologous blasts. Preliminary results suggest that IR+ T cells are enriched in leukemia specificity (elimination index of 66% and 44% in IR+ and IR- cells respectively at an E/T ratio of 100:1). Conclusions: After HSCT, the molecular signature of exhausted CD8 cells in relapsing pts includes PD-1, CTLA-4, 2B4 and Tim-3. The expression of IRs on early differentiated central memory and memory stem T cells at relapse suggests a wide, though reversible, immunological dysfunction mediated by AML relapsing blasts. Disclosures Bondanza: TxCell: Research Funding; MolMed SpA: Research Funding; Formula Pharmaceuticals: Honoraria. Ciceri:MolMed SpA: Consultancy. Bonini:TxCell: Membership on an entity's Board of Directors or advisory committees; Molmed SpA: Consultancy.

scholarly journals Mapping the Evolution of T Cell Transcriptional States during DLI Response and Resistance Using Single-Cell Data

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 821-821
Author(s):  
Pavan Bachireddy ◽  
Elham Azizi ◽  
Vinhkhang N Nguyen ◽  
Shuqiang Li ◽  
Donna S Neuberg ◽  
...  
Keyword(s):  
Gene Expression ◽  
Bone Marrow ◽  
T Cells ◽  
T Cell ◽  
Single Cell ◽  
Phenotypic Diversity ◽  
Fold Change ◽  
Cell Clusters ◽  
Cell Dysfunction ◽  
T Cell Dysfunction

Abstract Donor lymphocyte infusion (DLI) is a potentially curative immune therapy for leukemic relapse after allogeneic hematopoietic stem cell transplant (allo-SCT). We previously reported that durable response to DLI for chronic myelogenous leukemia (CML) was associated with reversal of exhaustion of bone marrow-infiltrating T cells. Critical questions remain, however, regarding the exact cellular identities and transcriptional states of those T cell subtypes mediating exhaustion, anti-leukemia responses, and resistance to DLI. To map evolving phenotypic T cell states in situ at single cell resolution, we profiled viable cells isolated from cryopreserved bone marrow mononuclear cells (BMMCs) from a median of 3 timepoints (range: 2-6) before and after DLI from 12 patients with relapsed CML after T-cell depleted allo-SCT, using single cell RNA sequencing (scRNAseq, via the 10x Genomics Chromium platform). For reference, we also characterized a healthy donor marrow sample. Six of 12 patients were long-term responders to CD8-depleted DLI ("R's") and the remaining 6 were nonresponders ("NR's,"). In total, 381,462 cells derived from 43 unique patient-timepoints met our quality metrics, with a median of 2548 mRNA molecules/cell and 8735 cells/sample. By merging data across the cohort and removing batch effects (using the tool Biscuit), we curated a set of 62 distinct cell states, including subtypes of T, B, NK, monocytes, progenitors and CD34+ stem cells, whose identities were determined by both cell type and time point. We evaluated if response to DLI was associated with distinct T cell transcriptional phenotypes ("states"). We observed a marked increase in the number of T cell clusters in post-DLI samples (mean 41, range: 35-46) compared to matched pre-DLI samples, (mean 38, range: 34-41) after controlling for cell number (p-value <0.001). To investigate how DLI might increase the phenotypic diversity of T cell states, we calculated the phenotypic volume, defined as the change in co-variance of gene expression. Both R and NR cases exhibited increases in phenotypic volume induced by DLI (log fold change=104.6, p<1x10-6), suggesting DLI induces multiple, independent gene expression modules differentially in each T cell state. At both pre- and post-DLI timepoints, phenotypic volumes in R cases were higher than that of NR cases, (mean R-pre vs mean NR-pre, log-fold change = 199.1, p<1x10-6; mean R-post vs mean NR-post, log-fold change = 49.3, p=1.5x10-6), but a far greater increase in phenotypic volume was observed within NRs than within R's (log-fold change [NR-post vs pre] = 203.8 vs log fold change [R-post vs pre) = 54.1; p<1 x10-6]. Thus, while DLI expands phenotypic diversity in all T cell states, it differentially affects R's and NR's. We next compared global T cell dysfunction between R vs NR cases by summarizing scores for various dysfunction signatures across all T cells. We again observed increased T cell exhaustion signatures in R-pre T cells but also detected increased tolerance and anergy in NR-post T cells, suggesting multiple forms of T cell dysfunction in DLI resistance. We found that the clusters dominated by post-DLI R T cells were characterized by greater diversity of T helper subsets (Th1, Tfh, Th2, Th9, and Th22) and enrichment for exhaustion, type I and II IFN pathways, proinflammatory gene sets and CD8 T cell activation. Clusters dominated by NR T cells displayed increases in Th17 and Treg signatures, anergy and tolerance. Anergic cells were enriched for Treg signatures and did not share cluster membership with tolerant cells, which did not enrich for a specific subtype. Both types expressed only CD3D without CD8A or CD4, suggesting decreased antigen responsiveness. Single cell analysis of TCR repertoires and co-evolving leukemia cells will be updated at the meeting. Altogether, these data suggest that (1) pretreatment T cell phenotypic diversity may be important for DLI response; (2) that DLI increases such diversity differentially in responders than in nonresponders; and (3) even in the absence of clinical response, nonresponders undergo significant T cell phenotypic remodeling. Further studies will involve functional validation of dysfunctional T cell clusters and identification of therapeutic targets for reversing DLI resistance. Disclosures Soiffer: Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees. Wu:Neon Therapeutics: Equity Ownership.

scholarly journals T cell dysfunction in the diabetes-prone BB rat. A role for thymic migrants that are not T cell precursors.

1988 ◽  
Vol 167 (1) ◽  
pp. 132-148 ◽  
Author(s):  
H M Georgiou ◽  
A C Lagarde ◽  
D Bellgrau
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
T Cell ◽  
Gamma Radiation ◽  
Bb Rat ◽  
Cell Dysfunction ◽  
Thymus Tissue ◽  
Radiation Resistant ◽  
T Cell Dysfunction ◽  
Bone Marrow Derived Cells

Diabetes-prone BB (BB-DP) rats express several T cell dysfunctions which include poor proliferative and cytotoxic responses to alloantigen. The goal of this study was to determine the origin of these T cell dysfunctions. When BB-DP rats were thymectomized, T cell depleted, and transplanted with neonatal thymus tissue from diabetes-resistant and otherwise normal DA/BB F1 rats, the early restoration of T cell function proceeded normally on a cell-for-cell basis; i.e., peripheral T cells functioned like those from the thymus donor. Because the thymus in these experiments was subjected to gamma irradiation before transplantation and there was no evidence of F1 chimerism in the transplanted BB-DP rats, it appeared that the BB-DP T cell precursors could mature into normally functioning T cells if the maturation process occurred in a normal thymus. If the F1 thymus tissue was treated with dGua before transplantation, the T cells of these animals functioned poorly like those from untreated BB-DP rats. dGua poisons bone marrow-derived cells, including gamma radiation-resistant cells of the macrophage/dendritic cell lineages, while sparing the thymic epithelium. Therefore, the reversal of the T cell dysfunction depends on the presence in the F1 thymus of gamma radiation-resistant, dGua-sensitive F1 cells. Conversely, thymectomized and T cell-depleted F1 rats expressed T cell dysfunction when transplanted with gamma-irradiated BB thymus grafts. T cell responses were normal in animals transplanted with dGua-treated BB thymus grafts. With increasing time after thymus transplantation, T cells from all animals gradually expressed the functional phenotype of the bone marrow donor. Taken together these results suggest that BB-DP bone marrow-derived cells that are not T cell precursors influence the maturation environment in the thymus of otherwise normal BB-DP T cell precursors.

scholarly journals The PD-1/PD-L1 Axis Contributes to T Cell Dysfunction in Chronic Lymphocytic Leukemia

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1778-1778
Author(s):  
Davide Brusa ◽  
Sara Serra ◽  
Marta Coscia ◽  
Davide Rossi ◽  
Gianluca Gaidano ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Lymphocytes ◽  
B Lymphocytes ◽  
Lymphocytic Leukemia ◽  
Effector Memory ◽  
Cell Dysfunction ◽  
Differentiated Cells ◽  
Cd8 T Lymphocytes ◽  
T Cell Dysfunction

Abstract Abstract 1778 Chronic lymphocytic leukemia (CLL) is characterized by a progressive accumulation of mature B lymphocytes and it is marked by profound defects in T cell function. The mechanisms responsible for T cell dysfunction remain unclear, even if several observations show that T cells from CLL patients express markers of chronic activation. One of this marker is Programmed death-1 (PD-1), a cell surface molecule that inhibits activation of immune cells and it is involved in tumor escape mechanisms through binding of the specific PD-L1 ligand. The aim of this work is to evaluate the expression and function of the PD-1/PD-L1 axis in the CLL context. Using multiparameter flow cytometry, we showed that CD4+ and CD8+ T lymphocytes from CLL patients (n=117) express significantly higher levels of the PD-1 receptor, as compared to the same cell subpopulations purified from age- and sex-matched normal donors (n=33; 52% vs 34%, p <0.001). In keeping with the notion that PD-1 is a marker of cell exhaustion, CD4+ and CD8+ T lymphocytes from CLL patients displayed increased numbers of effector memory and terminally differentiated cells, respectively, with a concomitant decrease in naïve and central memory cells, when compared to controls. The number of effector memory and terminally differentiated cells positively associated with a more advanced stage of disease, treatment requirements and unfavorable genomic aberrations. Moreover, leukemic lymphocytes expressed higher levels of PD-L1 than circulating B lymphocytes from normal donors. PD-1 and PD-L1 expression significantly increased when T or B lymphocytes were treated with mitogenic signals, suggesting that this interaction might work efficiently in an activated environment. This hypothesis was tested by immunohistochemical analyses determining PD-1 and PD-L1 expression in the proliferation centers of lymph nodes sections from CLL patients. The results obtained indicate that PD-L1+ proliferating CLL cells are in close contact with CD4+/PD-1+ T lymphocytes. Lastly, functional experiments performed using anti-PD-1 antibodies or recombinant soluble PD-L1 clearly indicate that the PD-1/PD-L1 axis contributes to driving IL-4 secretion and to the inhibition of IFN-g production by CD8+ T cells. In conclusion, these results show that CD4+ and CD8+ T lymphocytes from CLL patients express high levels of the surface marker PD-1 and exhibit an exhausted phenotype, while B leukemic cells express the PD-L1 ligand. Functional data suggest that PD-1/PD-L1 interactions are critical in skewing the T cell compartment towards a Th2 phenotype, by impairing IFN-g secretion by CD8+ cells. Taken together, these observations suggest that pharmacological manipulation of the PD-1/PD-L1 axis might be relevant in restoring T cell functions in the CLL microenvironment. Disclosures: Inghirami: OncoEthix SA: Research Funding.

scholarly journals S100A9 Contributes to T Cell Dysfunction through Its Interaction with RAGE in MDS

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 4228-4228
Author(s):  
Wendy Kandell ◽  
Thu Le Trinh ◽  
Xianghong Chen ◽  
Pingyan Cheng ◽  
Danielle Gilvary ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
T Cell ◽  
Cell Function ◽  
Surface Expression ◽  
Activated T Cells ◽  
Cell Dysfunction ◽  
T Cell Dysfunction ◽  
Rage Expression

We have previously reported that the overexpression of S100A9 drives the development of Myelodysplastic Syndrome (MDS) through expansion of Myeloid Derived Suppressor Cells (MDSC) and promotion of pyroptosis. Despite the identified role of S100A9's effects on MDSC, and hematopoietic stem and progenitor cells (HSPC), as well as their establishment of an immunosuppressive microenvironment, the effects of S100A9 on adaptive immunity in MDS progression are less clear. Here, we report for the first time the unidentified role of S100A9 on T cell function in MDS that may lead to impaired immunosurveillance in the disease. Danger Associated Molecular Pattern (DAMP) S100A9 is a known ligand for the Pattern Recognition Receptor (PRR) Receptor for Advanced Glycation Endproducts (RAGE). We investigated RAGE surface expression by flow cytometry on MDS bone marrow resident T cells vs those derived from healthy donor bone marrow. We found significantly (p=0.04) higher RAGE surface expression on T cells from MDS bone marrow, and this expression was restricted to the CD4 lineage. To ascertain the effects of S100A9 on RAGE+CD4+ T cell function, we performed flow cytometry in a time course experiment post-T cell activation. Without S100A9 treatment, cell surface RAGE expression was low in activated T cells from healthy donors, but extended treatment with recombinant human S100A9 resulted in increased RAGE expression, suggesting a positive feedback loop for this DAMP. Unlike activated T cells, T cells not exposed to activating conditions did not display upregulated RAGE expression after S100A9 treatment. This indicates that this may be a post-activation switch, acting as a checkpoint for the T cell in the context of excessive damage signaling by DAMP S100A9. In order to further characterize the functional consequences of RAGE engagement, we performed transcription factor staining paired with a cytometric bead array for secreted cytokines in activated T cells treated with S100A9. Tumor Necrosis Factor Alpha (TNFa), IL-10 and IL-6 were induced by S100A9, indicating perhaps some degree of polarization induced by this DAMP. Commercially available RAGE V-domain inhibitor FPS-ZM1 blunted this cytokine signaling, indicating a significant portion of this cytokine production is indeed mediated through RAGE. In addition, we performed lipophilic dye dilution assays to track the effects S100A9 has on T cell proliferation following activation. S100A9 significantly decreased proliferative response under normal stimulatory conditions. Similar inhibition was seen in T cells derived from PBMC, MDS, or healthy donor bone marrow resident T cells, suggesting that the consequences of RAGE engagement are not disease specific. To rule out apoptosis as a potential cause for this halt in proliferation, we stained the cells with Annexin V and Propidium Iodide. To further elucidate how S100A9 might be affecting T cell proliferation, we analyzed cell cycle profiles following activation and S100A9 treatment. T cells treated with S100A9 showed a repressed cell cycle prior to G2, compared to T cells activated without any S100A9 treatment, suggesting a possible G1/S arrest. The evidence obtained in our study suggests any role of T cell dysfunction mediated by RAGE in MDS may be directly linked to the increased levels of S100A9 in the bone marrow microenvironment. Our work represents a novel mechanism of T cell dysfunction that may lead to a lack of responsiveness in the context of a disease known to overexpress the RAGE ligand S100A9. Capitalizing on this novel checkpoint can potentially be used both as novel biomarker and as a therapeutic target in the future to restore T cell immunosurveillance to a functional state in MDS. Disclosures List: Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding.

scholarly journals IMMU-24. TEMOZOLOMIDE INDUCED IMMUNE DYSFUNCTION REQUIRES THE PRESENCE OF INTRACRANIAL TUMORS

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii109-ii110
Author(s):  
Aida Karachi ◽  
Farhad Dastmalchi ◽  
Ashley O’Malley ◽  
Changlin Yang ◽  
Duane Mitchell ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Standard Dose ◽  
Suppressor Cells ◽  
Immune Dysfunction ◽  
Ifn Gamma ◽  
Cell Dysfunction ◽  
Tumor Bearing ◽  
T Cell Dysfunction ◽  
Immune Changes

Abstract Temozolomide was recently shown to cause peripheral and intra-tumoral T cell dysfunction in a dosing schedule dependent fashion. Standard dose (SD) temozolomide (TMZ) resulted in T cell dysfunction precluding response to immune checkpoint inhibition that was avoided with a metronomic dosing (MD) schedule. Building on these studies, we investigated the TMZ-induced immune changes in tumor and non-tumor bearing models to understand the interaction of an intracranial tumor on host immunity. C57BL/6 mice underwent intracranial implantation of GL-261 tumor cells. Tumor bearing animals and naïve animals with no tumor were treated with standard dose (50 mg/kg x 5 days) or metronomic dose (25mg/kg x 10 days) of TMZ. Peripheral blood and spleens were collected for flow cytometry, ELISA and luciferase killing assay. Tumor bearing animals treated with SD TMZ demonstrated an increase in circulating myeloid derived suppressor cells (MDSCs), an upregulation of exhaustion markers on endogenous host CD8 T cells (TIM3, LAG3) and a decrease in IFN-gamma secretion from adoptively transferred T cells (tested via ELISA). The cell killing capability of adoptively transferred T cells was not reduced after exposure to a TMZ treated host. Non-tumor bearing animals treated with SD TMZ did not demonstrate an increase in circulating MDSCs or exhaustion markers on endogenous T cells. IFN-gamma secretion from adoptively transferred T cells was still reduced in these animals. The host immune dysfunction induced by TMZ is dependent on the presence of an intracranial malignancy. The mechanisms causing these changes are under active investigation.

scholarly journals Tim-3 adaptor protein Bat3 is a molecular checkpoint of T cell terminal differentiation and exhaustion

2021 ◽  
Vol 7 (18) ◽  
pp. eabd2710
Author(s):  
Chen Zhu ◽  
Karen O. Dixon ◽  
Kathleen Newcomer ◽  
Guangxiang Gu ◽  
Sheng Xiao ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Adaptor Protein ◽  
Transcriptional Analysis ◽  
T Cell Exhaustion ◽  
Cell Exhaustion ◽  
Cell Dysfunction ◽  
Autoreactive T Cell ◽  
Autoimmune Conditions ◽  
T Cell Dysfunction

T cell exhaustion has been associated with poor prognosis in persistent viral infection and cancer. Conversely, in the context of autoimmunity, T cell exhaustion has been favorably correlated with long-term clinical outcome. Understanding the development of exhaustion in autoimmune settings may provide underlying principles that can be exploited to quell autoreactive T cells. Here, we demonstrate that the adaptor molecule Bat3 acts as a molecular checkpoint of T cell exhaustion, with deficiency of Bat3 promoting a profound exhaustion phenotype, suppressing autoreactive T cell–mediated neuroinflammation. Mechanistically, Bat3 acts as a critical mTORC2 inhibitor to suppress Akt function. As a result, Bat3 deficiency leads to increased Akt activity and FoxO1 phosphorylation, indirectly promoting Prdm1 expression. Transcriptional analysis of Bat3−/− T cells revealed up-regulation of dysfunction-associated genes, concomitant with down-regulation of genes associated with T cell effector function, suggesting that absence of Bat3 can trigger T cell dysfunction even under highly proinflammatory autoimmune conditions.

scholarly journals Sympathetic Enhancement of Memory T-Cell Homing and Hypertension Sensitization

2020 ◽  
Vol 126 (6) ◽  
pp. 708-721 ◽  
Author(s):  
Liang Xiao ◽  
Luciana Simao do Carmo ◽  
Jason D. Foss ◽  
Wei Chen ◽  
David G. Harrison
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
T Cell ◽  
Sympathetic Nerves ◽  
Designer Drug ◽  
Effector Memory ◽  
Bone Marrow Niche ◽  
Sympathetic Outflow ◽  
Ang Ii ◽  
Cell Homing

Rationale: Effector memory T lymphocytes (T EM cells) exacerbate hypertension in response to repeated hypertensive stimuli. These cells reside in the bone marrow for prolonged periods and can be reactivated on reexposure to the hypertensive stimulus. Objective: Because hypertension is associated with increased sympathetic outflow to the bone marrow, we hypothesized that sympathetic nerves regulate accumulation and reactivation of bone marrow–residing hypertension-specific T EM cells. Methods and Results: Using unilateral superior cervical ganglionectomy in wild-type C57BL/6 mice, we showed that sympathetic nerves create a bone marrow environment that supports residence of hypertension-specific CD8 + T cells. These cells, defined by their proliferative response on coculture with dendritic cells from Ang (angiotensin) II–infused mice, were reduced in denervated compared with innervated bone of Ang II–infused mice. Adoptively transferred CD8 + T cells from Ang II–infused mice preferentially homed to innervated compared with denervated bone. In contrast, ovalbumin responsive T cells from OT-I mice did not exhibit this preferential homing. Increasing superior cervical ganglion activity by activating Gq-coupled designer receptor exclusively activated by designer drug augmented CD8 + T EM bone marrow accumulation. Adoptive transfer studies using mice lacking β2AR (β2 adrenergic receptors) indicate that β2AR in the bone marrow niche, rather than T-cell β2AR is critical for T EM cell homing. Inhibition of global sympathetic outflow using Gi-coupled DREADD (designer receptor exclusively activated by designer drug) injected into the rostral ventrolateral medulla or treatment with a β2AR antagonist reduced hypertension-specific CD8 + T EM cells in the bone marrow and reduced the hypertensive response to a subsequent response to low dose Ang II. Conclusions: Sympathetic nerves contribute to the homing and survival of hypertension-specific T EM cells in the bone marrow after they are formed in hypertension. Inhibition of sympathetic nerve activity and β2AR blockade reduces these cells and prevents the blood pressure elevation and renal inflammation on reexposure to hypertension stimuli.

TIGIT Induces (CD3+) T Cell Dysfunction by Inhibiting Glucose Metabolism and its Reversal by TIGIT and/or PD-1 Blockade in Colorectal Cancer

2021 ◽  
Author(s):  
qi shao ◽  
Lei Wang ◽  
maoling yuan ◽  
Xiaohong Jin ◽  
changping wu
Keyword(s):  
Colorectal Cancer ◽  
T Cells ◽  
T Cell ◽  
Glucose Metabolism ◽  
Tumor Growth ◽  
Tumor Cells ◽  
Peripheral Blood ◽  
Cancer Tissue ◽  
Cell Dysfunction ◽  
T Cell Dysfunction

Abstract Background: T-cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain (TIGIT) is an immunosuppressive receptor expressed on the surface of immune cells, suppressing immune responses by activating the intracellular negative regulatory signals. TIGIT plays an important role in the pathogenesis of various tumors, but its immune escape in colorectal cancer remains unclear.Methods: In this study, TIGIT expression in the peripheral blood and tissue microarrays was detected flow cytometry and immunofluorescence and its relationship with prognosis was evaluated. The proliferation and cytokines of TIGIT+ T cells were measured. Glucose metabolism and key enzymes were detected by qPCR or western blot. After establishing the co-cultured system and xenotransplant models, TIGIT antibody alone or combined with PD-1 antibody was blocked to observe the tumor growth.Results: We found that the proportion of CD3+TIGIT+ T cells was increased in peripheral blood and cancer tissue in colorectal cancer patients when compared with the healthy donors. These cells exhibited functional defects, low proliferative activity, impaired cytokine production and reduced glucose metabolism. A strong association was also observed between the elevated TIGIT expression and poor prognosis. In the in vitro co-culture assays of T cells and tumor cells, the suppressed glucose metabolic activity of T cells was reversed by TIGIT blockade. In addition, this blockade induced the apoptosis and reduced G2/M transit in tumor cells. The antitumor efficacy of TIGIT Ab therapy was further demonstrated in a human colorectal xenograft mice model while co-blockers of TIGIT and PD-1 exhibited synergistic suppressing effects on tumor growth.Conclusions: It is suggest that while TIGIT induces CD3+ T cell dysfunction in colorectal cancer, co-targeting TIGIT and PD-1 can lead to an effective antitumor response and may serve as a novel therapeutic strategy for colorectal patients.

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