Impact of hypoxia on immune cells in human atherosclerotic plaques

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
D Vorobyeva ◽  
A Lebedeva ◽  
A Elizarova ◽  
E Maryukhnich ◽  
V Gontarenko ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell Activation ◽  
Cell Activation ◽  
Ex Vivo ◽  
Atherosclerotic Plaques ◽  
Funding Source ◽  
Ex Vivo Model ◽  
Activation Markers ◽  
Hypoxic Conditions ◽  
The Impact

Abstract Background Inflammation plays a major role in atherosclerotic plaques' progression and was shown to be associated with the formation of hypoxic areas within the plaques. However, the data about the impact of hypoxia on atherosclerosis are contradictory, in part due to inadequacy of in vitro and animal models to reproduce faithfully the complexity of human atherosclerotic plaques. Purpose The aim of this study was to investigate the effect of hypoxia on immune status in the ex vivo system of human atherosclerotic plaques. Methods We collected 25 atherosclerotic plaques from patients undergoing carotid endarterectomy, cut plaques into ring-shaped slices and cultured them for 24 hours at the liquid/air interface on collagen sponges under hypoxic (2% O2) and normoxic (12% O2) conditions. After 24 hours we evaluated T-cell activation status within plaques according to the presence of membrane activation markers by means of multiparametric flow cytometry and the activity of cytokine production using xMAP technology. Results We found that CD8 T cells from human atherosclerotic plaques cultured under hypoxic conditions compared to normoxic conditions have a decreased expression of CD69 activation marker (42.7 [34.3; 50.9]% vs 53.8 [33.3; 63.3]%, n=10, p=0.047) and lower level of CD69 and HLA-DR coexpression (16.0 [10.5; 22.3] vs 22.6 [11.3; 28.2], n=10, p=0.02). CD4 T cells did not show any significant changes in expression of activation markers under hypoxia. Hypoxic conditions also resulted in a reduced IL-10 production (104.2 [53.8; 170.9] vs 235.2 [158.5; 335.3] pg/100 mg of tissue, n=20, p=0.0001) and increased VEGF production (116.1 [79.8; 253.5] vs 89.9 [71.1; 148.8] pg/100 mg of tissue, n=20, p=0.033). Conclusions Our results indicate that hypoxia causes a decrease in the activity of cytotoxic T cells and increases stimuli for angiogenesis within the human atherosclerotic plaques. The established ex vivo model of human atherosclerotic plaques culture under hypoxia enables further studies of the hypoxia impact on atherosclerosis. Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): Russian Science Foundation grant

scholarly journals Blinatumomab-Induced T Cell Activation at Single Cell Transcriptome Resolution

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3886-3886
Author(s):  
Hong Yin ◽  
Yi Huo ◽  
Zhen Sheng ◽  
Chi-Ming Li ◽  
Daniel C Ellwanger ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Single Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Ex Vivo ◽  
Target Cells ◽  
Ex Vivo Model ◽  
Naive T Cells ◽  
Naïve T Cells

Introduction Blinatumomab, a bi-specific T cell engager (BiTE®) combining the VH and VL domains of two antibodies against human CD19 and CD3, has been approved by U.S. Food and Drug Administration (FDA) for the treatment of patients with relapsed or refractory B precursor ALL (r/r B-ALL) for its clinical benefit demonstrated in different clinical trials. Clinical trials have also shown that there are still patients refractory to blinatumomab. It is thus important to understand the resistance mechanisms. Blinatumomab connects patients' autologous T cells and target cells to form immunologic synapse which potently triggers the activation signaling cascades in T cells and guides T cells to recognize and induce perforin/granzyme-mediated lysis of CD19+ B-ALL cells. Previous studies showed blinatumomab-mediated cytotoxicity involves different T cell subpopulations. But response of each T cell subpopulation to blinatumomab treatment remained largely unknown. Methods and Results In this study, we used 10X Genomics based single cell RNA sequencing to analyze the transcriptome of single T cells before and after blinatumomab treatment. First, ex vivo blinatumomab cytotoxicity model was established, in which healthy PBMCs were used as effector cells and cocultured with target cells (RS4;11 cells or SUP-B15 cells) at an effector-to-target cell ratio of 10:1 with 0.1 ng/mL blinatumomab. Then, PBMCs and BMMCs from 2 B-ALL patients were cultured with 10 ng/mL blinatumomab. Cells from both ex vivo model and patient samples were sequenced using 10X Genomics platform. In total, transcriptome of 17920 single T cells from the ex vivo model and 2271 single T cells from patient sample were analyzed. Based on T cell trajectory analysis, we identified four distinct populations of blinatumomab-activated T cells, which were derived from CD8+ effector memory T (TEM) cells, CD4+ central memory (TCM) cells, naïve T cells and Tregs, respectively. The differentially expressed genes in activated clusters were analyzed to reflect T cell activation mechanisms. The result showed blinatumomab induced the upregulation of aerobic glycolysis pathway (PKM, PGAM1, ENO1, GAPDH and LDHA), cytoskeleton dynamics pathway (ACTD1, ACTB, NME1 and TUBA1B), IFN-responsive pathway (GBP1, PSME2, WARS, CXCL10 and STAT1), and the upregulation of well-known immune-related genes (TNFRSF4, TNFRSF18, LAG3, CD69, IL2RA, MIR155HG, BATF, SH2D2A, LTA, NFKBIA and NDFIP2). We found blinatumomab-activated CD8+ TEM cells showed stronger cytotoxic capability than other activated populations with specific production of cytotoxic factors (PRF1, IFNG and FASLG) and cytokines (CCL2, CCL3, CCL3L1, CCL4, CCL4L2, CCL8, XCL1, XCL2, TNFSF9 and TNFSF14). Last, differential gene expression analysis revealed that co-stimulatory (TNFRSF4,TNFRSF9 and TNFRSF18) and co-inhibitory receptors (LAG3 and TIGIT) were similarly up-regulated in clusters activated from memory and naïve T cells, indicating ligand dependent T cell functional outcomes induced by blinatumomab. Conclusion In summary, we used single cell sequencing to map the blinatumomab-mediated T cell activation state transition and reveal the molecular changes in different T cell subpopulations. Memory T cells, naïve T cells and Tregs were identified functional populations after blinatumomab treatment. CD8+ TEM accounted for the majority of blinatumomab-induced cytotoxicity. Furthermore, T cell co-regulatory receptors were identified as potential targets accountable for blinatumomab sensitivity or resistance mechanisms. The study demonstrated that the collected cellular transcriptional profiles can serve as resource to explore novel strategies to enhance the efficacy of blinatumomab. Disclosures Yin: Amgen: Employment. Huo:Amgen: Employment. Sheng:Amgen: Employment. Li:Amgen: Employment. Ellwanger:Amgen: Employment. Lu:Amgen: Employment. Homann:Amgen: Employment. Wang:Amgen: Employment. Ren:Ruijin hospital: Employment.

Abstract P167: Title: Prediction of Arterial Stiffness from Early T-cell Activation among HIV and HCV Co-infected Women in the Women's Interagency HIV Study (WIHS)

Circulation ◽  
2012 ◽  
Vol 125 (suppl_10) ◽  
Author(s):  
Roksana Karim ◽  
Naoko Kono ◽  
Robert Kaplan ◽  
Wendy J Mack ◽  
Howard N Hodis ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Arterial Stiffness ◽  
Hiv Infection ◽  
T Cell Activation ◽  
Cell Activation ◽  
Infection Status ◽  
Activation Markers ◽  
Color Flow ◽  
The Impact

Introduction: Activation of T-lymphocytes, a hallmark of HIV infection, reaches a set point early in HIV infection and persists even after viral suppression with highly active antiretroviral therapy (HAART). Early T-cell activation predicts subsequent CD4 depletion, progression to AIDS and survival. HIV-infected subjects are at high risk for premature atherosclerosis. Little is known regarding the impact of early T cell activation on arterial stiffness. While Kaplan et al. (2011) were the first and only group to show a cross-sectional association, we investigate here if early T cell activation can predict future arterial stiffness. Hypothesis: High early T cell activation will predict increased arterial stiffness, measured 5.5 (IQR=2.5-7.5) years later, in HIV and HCV co-infected women. Methods: A longitudinal study nested within the WIHS, an ongoing prospective cohort study. Percentages of CD4 and CD8 T cell activation, assessed by CD38 and HLA-DR co-expression using 3-color flow cytometry, were measured on average 5.5 years before arterial stiffness assessments (carotid artery distensibility, and Young’s elastic modulus for elasticity) using B-mode carotid ultrasound. Multiple linear regression models evaluated the association between log-transformed T cell activation markers (independent variables) and arterial stiffness (dependent variable). Analyses were stratified by HCV co-infection status and by pre- and post-HAART assessment of T cell activation. Results: A total of 376 HIV+ women (185 HCV+) were included in the analysis. Participants were on average 46(SD=9) years old, 59% Black, and 49% were current smokers. Activation of both CD4 and CD8 T cells significantly univariately predicted reduced distensibility and elasticity among HIV-infected women. CD4 activation continued to significantly predict distensibility (β(SEM)= −3.51(1.30) 10 −6* N −1* m 2 , p=0.01), and elasticity (0.11(0.04)10 5* N * m 2 , p=0.004) with adjustment for age, race, BMI, smoking, ART, CD4 count, and HIV RNA. CD8 activation was no longer associated after adjustment. When stratified by HCV co-infection status, the prediction of arterial stiffness parameters from early CD4 activation was somewhat stronger among the HIV+/HCV+ women compared to HIV+/HCV- women (β(SEM)= −4.44(1.93), p=0.02 vs. −3.04(1.84), p=0.10 for distensibility, and 0.17(0.06), p=0.003 vs. 0.09(0.05), p=0.09 for elasticity); however the test for interaction was not statistically significant. In a subset of 188 women, CD4 activation measured both pre- and post-HAART significantly predicted later arterial stiffness. Conclusions: CD4 activation level predicts future arterial stiffness in HIV-infected women, perhaps more markedly among HCV co-infected women. These data confirm the proinflammatory impact of activated T cells that can cause vascular dysfunction and shed light on the early onset of atherogenesis.

Preoperative checkpoint inhibition (CPI) and cryoablation (Cryo) in women with early-stage breast cancer (ESBC).

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. 592-592 ◽  
Author(s):  
Elizabeth Anne Comen ◽  
Yolanda Bryce ◽  
David B. Page ◽  
Stephen Barnett Solomon ◽  
Micaela Rodine ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell Activation ◽  
Cd8 T Cells ◽  
Cell Activation ◽  
Early Stage ◽  
Checkpoint Inhibition ◽  
Activation Markers ◽  
Immune Correlates ◽  
Immune Biomarkers ◽  
The Impact

592 Background: Checkpoint inhibition (CPI) combined with local strategies that cause local tumor destruction, such as cryo may augment tumor specific immunity and improve survival. We previously demonstrated in 18 ESBC patients (pts) that pre-operative (pre-op) cryo with ipilimumab (ipi) is not only safe but also generates robust local and systemic immune responses (NCT01502592). Given the added activity of dual CPI in other tumors, we undertook a second pilot study of pre-op ipi/nivolumab (nivo)/cryo to confirm the safety of this combination and the impact on immune biomarkers. Methods: In both pilot studies, eligible pts had operable ≥1.5cm invasive HER2 negative ESBC. CPI was administered 8-15d prior to, and cryo was performed 7-10d prior to, standard-of-care (SOC) surgery. Toxicity evaluation continued for 12wks after drug administration. Blood for immune correlates was obtained at baseline, cryo, surgery and 2-4 weeks thereafter. Tumor samples were obtained at cryo and surgery. Flow-cytometry of peripheral lymphocytes was compared to previously reported ipi/cryo responses. Results: After a median follow-up of 66 months all 18 ESBC ipi/cryo pts, including 3 TNBC pts, are recurrence free. In the ipi/nivo/cryo study, the safety primary endpoint was met when 5 pts underwent SOC surgery without delay. Ipi/nivo/cryo was well tolerated overall. One pt on an aromatase inhibitor had grade 4 liver toxicity 8 weeks after surgery. One pt, 3 weeks after her SOC surgery, developed grade 1 hyperthyroidism, preventing a secondary axillary dissection from proceeding as scheduled. Robust activation of peripheral CD4+ and CD8+ T cells peaked at week 2 post ipi/nivo with the majority of activated CD8+ T cells expressing PD1. Comparing the correlatives of the ipi/nivo/cryo study with the prior ipi/cryo study, we observed higher expression of activation markers (Ki-67, ICOS, CTLA-4, LAG-3) on peripheral T cells and downregulation of suppressor cells. Conclusions: Ipi/cryo-treated pts, including 3 TNBC pts, remain recurrence free after > 5y. Combining cryo with ipi/nivo preop is feasible, safe, and associated with greater T cell activation than ipi/cryo alone. These results informed an ongoing randomized phase 2 study of pre-op ipi/nivo/cryo versus SOC in women with residual TNBC after neoadjuvant chemotherapy (NCT03546686). Clinical trial information: NCT02833233.

scholarly journals Ex vivo modelling of PD-1/PD-L1 immune checkpoint blockade under acute, chronic, and exhaustion-like conditions of T-cell stimulation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alexander Roberts ◽  
Lindsay Bentley ◽  
Tina Tang ◽  
Fay Stewart ◽  
Chiara Pallini ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Immune Checkpoint ◽  
Inflammatory Cytokine ◽  
Cell Activation ◽  
Ex Vivo ◽  
In Vitro Assays ◽  
The Impact

AbstractBlockade of PD-1/PD-L1 interactions is proving an exciting, durable therapeutic modality in a range of cancers whereby T cells are released from checkpoint inhibition to revive their inherent anti-tumour activity. Here we have studied various ways to model ex vivo T cell function in order to compare the impact of the clinically utilised anti-PD-1 antibody, pembrolizumab (Keytruda) on the activation of human T cells: focussing on the release of pro-inflammatory IFNγ and anti-inflammatory IL-10 to assess functionality. Firstly, we investigated the actions of pembrolizumab in an acute model of T-cell activation with either immature or mature allogeneic dendritic cells (DCs); pembrolizumab enhanced IFNγ and IL-10 release from purified CD4+ T-cells in the majority of donors with a bias towards pro-inflammatory cytokine release. Next, we modelled the impact of pembrolizumab in settings of more chronic T-cell activation. In a 7-day antigen-specific response to EBV peptides, the presence of pembrolizumab resulted in a relatively modest increase in both IFNγ and IL-10 release. Where pembrolizumab was assessed against long-term stimulated CD4+ cells that had up-regulated the exhaustion markers TIM-3 and PD-1, there was a highly effective enhancement of the otherwise exhausted response to allogeneic DCs with respect to IFNγ production. By contrast, the restoration of IL-10 production was considerably more limited. Finally, to assess a direct clinical relevance we investigated the consequence of PD-1/PD-L1 blockade in the disease setting of dissociated cells from lung and colon carcinomas responding to allogeneic DCs: here, pembrolizumab once more enhanced IFNγ production from the majority of tumour preparations whereas, again, the increase in IL-10 release was modest at best. In conclusion, we have shown that the contribution of PD-1—revealed by using a canonical blocking antibody to interrupt its interaction with PD-L1—to the production of an exemplar pro- and anti-inflammatory cytokine, respectively, depends in magnitude and ratio on the particular stimulation setting and activation status of the target T cell. We have identified a number of in vitro assays with response profiles that mimic features of dissociated cell populations from primary tumours thereby indicating these represent disease-relevant functional assays for the screening of immune checkpoint inhibitors in current and future development. Such in vitro assays may also support patient stratification of those likely to respond to immuno-oncology therapies in the wider population.

scholarly journals Biomarkers for Comorbidities Modulate the Activity of T-Cells in COPD

2021 ◽  
Vol 22 (13) ◽  
pp. 7187
Author(s):  
Kaschin Jamal Jameel ◽  
Willem-Jakob Gallert ◽  
Sarah D. Yanik ◽  
Susanne Panek ◽  
Juliane Kronsbein ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Systemic Inflammation ◽  
T Cell Activation ◽  
Cell Activation ◽  
Ex Vivo ◽  
Enzyme Linked Immunosorbent Assay ◽  
Activation Markers ◽  
Gm Csf

In smoking-induced chronic obstructive pulmonary disease (COPD), various comorbidities are linked to systemic inflammation and infection-induced exacerbations. The underlying mechanisms are unclear but might provide therapeutic targets. T-cell activity is central in systemic inflammation and for infection-defense mechanisms and might be influenced by comorbidities. Hypothesis: Circulating biomarkers of comorbidities modulate the activity of T-cells of the T-helper type 1 (Th1) and/or T-cytotoxic type 1 (Tc1). T-cells in peripheral blood mononuclear cells (PBMCs) from non-smokers (NS), current smokers without COPD (S), and COPD subjects (total n = 34) were ex vivo activated towards Th1/Tc1 and were then stimulated with biomarkers for metabolic and/or cardiovascular comorbidities (Brain Natriuretic Peptide, BNP; chemokine (C-C motif) ligand 18, CCL18; C-X3-C motif chemokine ligand 1, CX3CL1; interleukin-18, IL-18) or for asthma- and/or cancer-related comorbidities (CCL22; epidermal growth factor, EGF; IL-17; periostin) each at 10 or 50 ng/mL. The Th1/Tc1 activation markers interferon-γ (IFNγ), tumor necrosis factor-α (TNFα), and granulocyte-macrophage colony-stimulating factor (GM-CSF) were analyzed in culture supernatants by Enzyme-Linked Immunosorbent Assay (ELISA). Ex-vivo activation induced IFNγ and TNFα without differences between the groups but GM-CSF more in S vs. NS. At 10 ng/mL, the different biomarkers increased or reduced the T-cell activation markers without a clear trend for one direction in the different categories of comorbidities or for the different T-cell activation markers. At 50 ng/mL, there was a clear shift towards suppressive effects, particularly for the asthma— and cancer-related biomarkers and in cells of S and COPD. Comorbidities might suppress T-cell immunity in COPD. This could explain the association of comorbidities with frequent exacerbations.

scholarly journals CCL21 mediates CD4+ T-cell costimulation via a DOCK2/Rac-dependent pathway

Blood ◽  
2009 ◽  
Vol 114 (3) ◽  
pp. 580-588 ◽  
Author(s):  
Kathrin Gollmer ◽  
François Asperti-Boursin ◽  
Yoshihiko Tanaka ◽  
Klaus Okkenhaug ◽  
Bart Vanhaesebroeck ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cd4 T Cells ◽  
Cell Activation ◽  
Early Time ◽  
Cell Receptor ◽  
Tcr Signaling ◽  
Activation Markers

Abstract CD4+ T cells use the chemokine receptor CCR7 to home to and migrate within lymphoid tissue, where T-cell activation takes place. Using primary T-cell receptor (TCR)–transgenic (tg) CD4+ T cells, we explored the effect of CCR7 ligands, in particular CCL21, on T-cell activation. We found that the presence of CCL21 during early time points strongly increased in vitro T-cell proliferation after TCR stimulation, correlating with increased expression of early activation markers. CCL21 costimulation resulted in increased Ras- and Rac-GTP formation and enhanced phosphorylation of Akt, MEK, and ERK but not p38 or JNK. Kinase-dead PI3KδD910A/D910A or PI3Kγ-deficient TCR-tg CD4+ T cells showed similar responsiveness to CCL21 costimulation as control CD4+ T cells. Conversely, deficiency in the Rac guanine exchange factor DOCK2 significantly impaired CCL21-mediated costimulation in TCR-tg CD4+ T cells, concomitant with impaired Rac- but not Ras-GTP formation. Using lymph node slices for live monitoring of T-cell behavior and activation, we found that G protein-coupled receptor signaling was required for early CD69 expression but not for Ca2+ signaling. Our data suggest that the presence of CCL21 during early TCR signaling lowers the activation threshold through Ras- and Rac-dependent pathways leading to increased ERK phosphorylation.

A Randomized Phase II Trial of Idiotype Vaccination and Adoptive Autologous T-Cell Transfer in Multiple Myeloma patients

Blood ◽  
2021 ◽  
Author(s):  
Muzaffar H Qazilbash ◽  
Neeraj Y Saini ◽  
Cha Soung-chul ◽  
Zhe Wang ◽  
Edward Stadtmauer ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Phase Ii ◽  
T Cell Activation ◽  
Cd8 T Cells ◽  
Cell Activation ◽  
Phase Ii Trial ◽  
Ex Vivo ◽  
Vaccine Strategy ◽  
Randomized Phase Ii

We hypothesized that combining adoptively transferred autologous T cells with a cancer vaccine strategy would enhance therapeutic efficacy by adding anti-myeloma idiotype-keyhole limpet hemocyanin (Id-KLH) vaccine to vaccine-specific co-stimulated T cells. In this randomized, phase II trial, eligible patients received either the control (KLH only) or Id-KLH vaccine, an auto-transplant, vaccine-specific co-stimulated T-cells expanded ex-vivo, and two booster doses of the assigned vaccine. In 36 patients (20 in KLH, 16 in Id-KLH) enrolled, no dose-limiting toxicity was seen in either arm. At last evaluation, 6 (30%) and 8 (50%) had achieved complete remission in KLH-only and Id-KLH, respectively (p=0.22) and no difference in 3-year progression-free survival was observed (59% and 56%, respectively; p=0.32). In a 594 Nanostring nCounter gene panel analyzed for immune reconstitution (IR), compared with KLH-only patients, there was a greater change in IR genes in T-cells in Id-KLH patients relative to baseline. Specifically, upregulation of genes associated with activation, induction of effector function, and generation of memory CD8+ T cells after Id-KLH, but not after KLH control vaccination, was observed. Similarly, responding patients across both arms were associated with upregulation of genes associated with T-cell activation. At baseline, all patients had greater expression of CD8+ T-cell exhaustion markers. These changes were associated with functional Id-specific immune responses in a subset of Id-KLH patients analyzed. In conclusion, in this combination immunotherapy approach, we observed a significantly more robust IR in CD4+ and CD8+ T cells in the Id-KLH arm, supporting further investigation of vaccine and adoptive immunotherapy strategies.

scholarly journals In Vivo Role of Dendritic Cells in a Murine Model of Pulmonary Cryptococcosis

2006 ◽  
Vol 74 (7) ◽  
pp. 3817-3824 ◽  
Author(s):  
Karen L. Wozniak ◽  
Jatin M. Vyas ◽  
Stuart M. Levitz
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell Activation ◽  
Cell Activation ◽  
Ex Vivo ◽  
Interleukin 2 ◽  
Mouse Lung

ABSTRACT Dendritic cells (DC) have been shown to phagocytose and kill Cryptococcus neoformans in vitro and are believed to be important for inducing protective immunity against this organism. Exposure to C. neoformans occurs mainly by inhalation, and in this study we examined the in vivo interactions of C. neoformans with DC in the lung. Fluorescently labeled live C. neoformans and heat-killed C. neoformans were administered intranasally to C57BL/6 mice. At specific times postinoculation, mice were sacrificed, and lungs were removed. Single-cell suspensions of lung cells were prepared, stained, and analyzed by microscopy and flow cytometry. Within 2 h postinoculation, fluorescently labeled C. neoformans had been internalized by DC, macrophages, and neutrophils in the mouse lung. Additionally, lung DC from mice infected for 7 days showed increased expression of the maturation markers CD80, CD86, and major histocompatibility complex class II. Finally, ex vivo incubation of lung DC from infected mice with Cryptococcus-specific T cells resulted in increased interleukin-2 production compared to the production by DC from naïve mice, suggesting that there was antigen-specific T-cell activation. This study demonstrated that DC in the lung are capable of phagocytosing Cryptococcus in vivo and presenting antigen to C. neoformans-specific T cells ex vivo, suggesting that these cells have roles in innate and adaptive pulmonary defenses against cryptococcosis.

scholarly journals TRPM2 Is Not Required for T-Cell Activation and Differentiation

2022 ◽  
Vol 12 ◽  
Author(s):  
Niels C. Lory ◽  
Mikolaj Nawrocki ◽  
Martina Corazza ◽  
Joanna Schmid ◽  
Valéa Schumacher ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Transient Receptor Potential ◽  
Cell Function ◽  
Intestinal Inflammation ◽  
Activation Markers

Antigen recognition by the T-cell receptor induces a cytosolic Ca2+ signal that is crucial for T-cell function. The Ca2+ channel TRPM2 (transient receptor potential cation channel subfamily M member 2) has been shown to facilitate influx of extracellular Ca2+ through the plasma membrane of T cells. Therefore, it was suggested that TRPM2 is involved in T-cell activation and differentiation. However, these results are largely derived from in vitro studies using T-cell lines and non-physiologic means of TRPM2 activation. Thus, the relevance of TRPM2-mediated Ca2+ signaling in T cells remains unclear. Here, we use TRPM2-deficient mice to investigate the function of TRPM2 in T-cell activation and differentiation. In response to TCR stimulation in vitro, Trpm2-/- and WT CD4+ and CD8+ T cells similarly upregulated the early activation markers NUR77, IRF4, and CD69. We also observed regular proliferation of Trpm2-/- CD8+ T cells and unimpaired differentiation of CD4+ T cells into Th1, Th17, and Treg cells under specific polarizing conditions. In vivo, Trpm2-/- and WT CD8+ T cells showed equal specific responses to Listeria monocytogenes after infection of WT and Trpm2-/- mice and after transfer of WT and Trpm2-/- CD8+ T cells into infected recipients. CD4+ T-cell responses were investigated in the model of anti-CD3 mAb-induced intestinal inflammation, which allows analysis of Th1, Th17, Treg, and Tr1-cell differentiation. Here again, we detected similar responses of WT and Trpm2-/- CD4+ T cells. In conclusion, our results argue against a major function of TRPM2 in T-cell activation and differentiation.

scholarly journals Inconsistent Reversal of HIV-1 Latency Ex Vivo by Antigens of HIV-1, CMV, and Other Infectious Agents

2020 ◽  
Author(s):  
Thomas Vollbrecht ◽  
Aaron O. Angerstein ◽  
Bryson Menke ◽  
Nikesh M. Kumar ◽  
Michelli Faria Oliveira ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cd4 T Cells ◽  
Cell Activation ◽  
Ex Vivo ◽  
Latent Reservoir ◽  
Antigen Specificity ◽  
Pcr Assay ◽  
Hiv 1

Abstract BackgroundA reservoir of replication-competent but latent virus is the main obstacle to a cure for HIV-infection. Much of this reservoir resides in memory CD4 T cells. We hypothesized that these cells can be reactivated with antigens from HIV and other common pathogens to reverse latency. ResultsWe obtained mononuclear cells from the peripheral blood of antiretroviral-treated patients with suppressed viremia. We tested pools of peptides and proteins derived from HIV and from other pathogens including CMV for their ability to reverse latency ex vivo by activation of memory responses. We assessed activation of the CD4 T cells by measuring the up-regulation of cell-surface CD69. We assessed HIV-expression using two assays: a real-time PCR assay for virion-associated viral RNA and a droplet digital PCR assay for cell-associated, multiply spliced viral mRNA. Reversal of latency occurred in a minority of cells from some participants, but no single antigen induced HIV-expression ex vivo consistently. When reversal of latency was induced by a specific peptide pool or protein, the extent was proportionally greater than that of T cell activation. ConclusionsIn this group of patients in whom antiretroviral therapy was started during chronic infection, the latent reservoir does not appear to consistently reside in CD4 T cells of a predominant antigen-specificity. Peptide-antigens reversed HIV-latency ex vivo with modest and variable activity. When latency was reversed by specific peptides or proteins, it was proportionally greater than the extent of T cell activation, suggesting partial enrichment of the latent reservoir in cells of specific antigen-reactivity.

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