Platelets from Patients with Myocardial Infarction Can Activate T Cells in Vitro

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 3448-3448 ◽  
Author(s):  
Elena E. Solomou ◽  
Vasilios Gizas ◽  
Theodora Babali ◽  
Angelos Perperis ◽  
Evgenia Verigou ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
T Cells ◽  
T Cell ◽  
Unstable Angina ◽  
T Cell Activation ◽  
Healthy Subjects ◽  
Cell Activation ◽  
Control Group ◽  
Healthy Controls

Abstract Specific aim: Our aim was to examine whether T cells can be activated by the circulating activated platelets from patients with myocardial infarction (with ST elevation-STEMI) Methods: After written informed consent was obtained, peripheral blood mononuclear cells (PBMCs) were isolated from heparinized venous blood obtained from 20 patients with STEMI (18 men and 2 women) at the time of hospital admission at diagnosis, before receiving any treatment, as well as 5 days and 30 days later. We also analyzed 10 healthy subjects (8 men and 2 women), and 5 patients with unstable angina who served as the disease control group. PBMCs were analyzed by flow cytometry with the following markers and their isotypic controls: CD4, CD25, CD69, and FOXP3. We also isolated platelet rich plasma or plasma alone from the patients and the healthy subjects, and used in mixed cultures with PBMCs. Results: We first examined T cell activation by measuring CD69 expression on CD4 T cells following incubation with platelets obtained from patients with STEMI. T cells treated with platelets from patients with STEMI showed increased expression of CD69 (as an activation marker) compared with T cells treated with platelets from healthy subjects (p<0.05, Figure 1). There was no T cell activation following incubation with plasma alone from patients or healthy controls. We then examined the percentages of CD4+CD25+hi (regulatory T cells). There was no statistical difference in Tregs between patients at presentation and controls (healthy subjects and disease control group). Five days later, patients with STEMI displayed increased levels of Tregs compared with the 2 control groups; one month later, Treg numbers returned to the initial presentation levels (p<0.05, Figure 2) Conclusion: To our knowledge we describe for the first time that platelets from patients with STEMI can activate T cells in vitro. In patients with STEMI, an increase in Tregs possibly in an effort to suppress immune system activation secondary to platelet activation, appears shortly after the infarct and normalizes a month later. Figure 1. T cell activation after treatment with platelets from patients with STEMI compared with the platelets from healthy controls or plasma alone Figure 1. T cell activation after treatment with platelets from patients with STEMI compared with the platelets from healthy controls or plasma alone Figure 2. Increased T regs in patients with STEMI , 5 days after admission (STEMI EXIT) ( UA;unstable angina, STEMI 1mfup; STEMI after one month) Figure 2. Increased T regs in patients with STEMI , 5 days after admission (STEMI EXIT) ( UA;unstable angina, STEMI 1mfup; STEMI after one month) Disclosures No relevant conflicts of interest to declare.

scholarly journals Platelet-Induced T Cell Activation in Patients with Myocardial Infarction; The Role of miR155

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 4913-4913 ◽  
Author(s):  
Elena E. Solomou ◽  
Elena Kalyvioti ◽  
Evgenia Verigou ◽  
Katerina Katsanaki ◽  
Charalambos Gogos ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
T Cells ◽  
T Cell ◽  
Platelet Activation ◽  
T Cell Activation ◽  
Real Time Pcr ◽  
Healthy Subjects ◽  
Cell Activation ◽  
Control Group

Abstract Specific aim: We have previously shown that platelets from patients with myocardial infarction (with ST elevation-STEMI) can activate T cells in vitro. In this study we wanted to expand our initial observation and explore the mechanism of this T cell activation. Methods: After written informed consent was obtained, peripheral blood mononuclear cells (PBMCs) were isolated from heparinized venous blood obtained from 30 patients with STEMI (28 men and 2 women) at the time of hospital admission at diagnosis, before receiving any treatment, as well as 5 days and 30 days later. We also analyzed 15 healthy subjects (12 men and 3 women), and 7 patients with unstable angina who served as the disease control group. PBMCs were analyzed by flow cytometry with the following markers and their isotypic controls: CD4, CD25, CD127, FOXP3, and CD69. We also isolated platelet rich plasma or plasma alone from the patients and the healthy subjects, and used in mixed cultures with PBMCs. miR 155 levels were examined with real-time PCR. Results: Initially, we incubated T cells with platelets from patients with STEMI and examined T cell activation by CD69 expression. These T cells showed increased expression of CD69 compared to T cells treated with platelets from healthy subjects (p<0.05). No T cell activation was observed following incubation with plasma alone from patients or healthy controls. Next, the percentages of CD4+CD25+hi CD127low FOXP3+ (regulatory T cells, Tregs) were examined in all study subjects. Patients at presentation showed comparable Treg levels with the controls (healthy subjects and disease control group). Five days later, patients with STEMI displayed increased levels of Tregs compared with the controls (p<0.05) (Fig.2). To explore the mechanism of Treg up-regulation the miR155 levels through real time PCR were evaluated. Patients with STEMI showed comparable levels of miR155 at presentation, but five days later showed decreased miR155 levels compared to controls (p<0.001) (Fig. 1); we observed an inverse correlation between miR155 levels and Treg numbers in patients with STEMI. At re-evaluation, one month later, patients with STEMI displayed Treg numbers comparable to the initial presentation levels Conclusion: Herein, we show that platelets from patients with STEMI can activate T cells in vitro. This platelet activation in patients with STEMI, results in an increase in Tregs through down-regulation of miR155, that return to normal levels a month later. This Treg increase reflects possibly an effort to suppress immune system activation secondary to platelet activation, shortly after the infarct. Figure 1 Figure 1. Figure 2 Figure 2. Disclosures No relevant conflicts of interest to declare.

Immunomodulatory Influence by Interferon alpha and Imatinib Mesylate in Chronic Myeloid Leukemia.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 4534-4534
Author(s):  
Kazuaki Yokoyama ◽  
Tokiko Nagamura-Inoue ◽  
Shin Nakayama ◽  
Ikuo Ishige ◽  
Nobuhiro Ohno ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Chronic Myeloid Leukemia ◽  
T Cell Activation ◽  
Myeloid Leukemia ◽  
Cell Activation ◽  
Cell Function ◽  
Control Group ◽  
Immunological Parameters

Abstract Objectives: Imatinib mesylate (STI) is the first-line therapy for chronic myeloid leukemia in the chronic phase (CML-CP). However, STI as well as interferonα (IFN) has been reported to inhibit both T-cell activation and B cell function. To clarify the immunological differences by the type of therapy, we compared immunological parameters between CML patients in very good CyR to either STI or IFN as well as normal volunteers. We also studied the in vitro effects of STI on immune cell function. Patients and Methods: Each group comprised 14 subjects. The median treatment dose and duration were 6 MIU/week and 174 months for IFN, and 400 mg/day and 54 months for STI, respectively. Peripheral blood sample was used and subjected to multi-color flow cytometry (FCM) acquisition and analysis. For analysing TCR-mediated activation of T cells, we stained MNC with CFSE and stimulated those with anti-CD3/CD28 antibodies in the presence of STI at various concentrations for 4 days, followed by FCM. Results: The summary is shown in Table. WBC counts were well controlled at moderately lower levels than in the control group of normal volunteers: Hb levels were significantly reduced in the STI-group compared to the other two groups (P<0.0001), while platelet counts were lower in the IFN-group than in the control group (P<0.01). The number of T cells was significantly lower in both patient groups (P=0.0006), while the NK cell number was comparable among the three groups. Not only the absolute numbers of monocytes and B cells but also serum IgG and IgA titers were significantly lower in the STI- than IFN-group (P<0.0001). For T-cell subsets, the ratio of CD4/8 T cells was significantly lower, but that of CD26highCD4+ T cells was significantly higher in the IFN- than STI-group. TCR-triggered T cell proliferation was suppressed by STI in a dose dependent manner. Intriguingly, we also found that STI treatment resulted in significant down-regulation of CD4+CD26high T cell population which is considered as a subset of effector T cells. Collectively, our data imply that the two therapeutic agents induce a distinct immunological status in CML patients, and also raise the possibility that immunological surveillance of residual Ph clone may be somewhat defective in patients receiving STI for prolonged periods. In addition, STI revealed the inhibitory effect on TCR-mediated T cell activation in vitro. Finally, the periodic monitoring of immunological parameters is recommended for these patients. Control IFN STI No.of Subjects 14 14 14 Median age (range) 41 (30–63) 50 (39–73) 54 (29–65) Immune parameters Mean (SD) p value WBC (10^9/L) 5.50 (1.21) 4.81 (1.36) 3.95 (0.89) .0056 T cells (10^9/L) 1.02 (0.22) 0.63 (0.28) 0.59 (0.28) .0006 CD26high/CD4+T cells (%) 9.12 (5.19) 12.08 (5.01) 7.92 (3.65) .0407 Monocytes (10^8/L) 2.81 (0.53) 3.56 (1.52) 1.87 (1.10) .0003 B cells (10^8/L) 2.67 (1.34) 2.61 (1.67) 1.38 (0.94) .0201 Serum IgG (g/L) 15.63 (3.95) 10.32 (2.10) <.0001 Serum IgA (g/L) 3.70 (0.24) 2.32 (0.24) .0013

scholarly journals Immunomodulatory effects of different intravenous immunoglobulin preparations in chronic lymphocytic leukemia

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ana Colado ◽  
Esteban Enrique Elías ◽  
Valeria Judith Sarapura Martínez ◽  
Gregorio Cordini ◽  
Pablo Morande ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
Chronic Lymphocytic Leukemia ◽  
T Cell Activation ◽  
Cell Activation ◽  
Lymphocytic Leukemia ◽  
Immunomodulatory Effects ◽  
Immunoglobulin Preparations

AbstractHypogammaglobulinemia is the most frequently observed immune defect in chronic lymphocytic leukemia (CLL). Although CLL patients usually have low serum levels of all isotypes (IgG, IgM and IgA), standard immunoglobulin (Ig) preparations for replacement therapy administrated to these patients contain more than 95% of IgG. Pentaglobin is an Ig preparation of intravenous application (IVIg) enriched with IgM and IgA (IVIgGMA), with the potential benefit to restore the Ig levels of all isotypes. Because IVIg preparations at high doses have well-documented anti-inflammatory and immunomodulatory effects, we aimed to evaluate the capacity of Pentaglobin and a standard IVIg preparation to affect leukemic and T cells from CLL patients. In contrast to standard IVIg, we found that IVIgGMA did not modify T cell activation and had a lower inhibitory effect on T cell proliferation. Regarding the activation of leukemic B cells through BCR, it was similarly reduced by both IVIgGMA and IVIgG. None of these IVIg preparations modified spontaneous apoptosis of T or leukemic B cells. However, the addition of IVIgGMA on in vitro cultures decreased the apoptosis of T cells induced by the BCL-2 inhibitor, venetoclax. Importantly, IVIgGMA did not impair venetoclax-induced apoptosis of leukemic B cells. Overall, our results add new data on the effects of different preparations of IVIg in CLL, and show that the IgM/IgA enriched preparation not only affects relevant mechanisms involved in CLL pathogenesis but also has a particular profile of immunomodulatory effects on T cells that deserves further investigation.

Modulation of T-Cell Functions in KIR2DL3 (CD158b) Transgenic Mice

Blood ◽  
1999 ◽  
Vol 94 (7) ◽  
pp. 2396-2402 ◽  
Author(s):  
Anna Cambiaggi ◽  
Sylvie Darche ◽  
Sophie Guia ◽  
Philippe Kourilsky ◽  
Jean-Pierre Abastado ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Transgenic Mice ◽  
T Cell Activation ◽  
Cell Activation ◽  
Killer Cell ◽  
In Vitro Proliferation ◽  
Cell Functions ◽  
Double Transgenic Mice

In humans, a minor subset of T cells express killer cell Ig-like receptors (KIRs) at their surface. In vitro data obtained with KIR+ β and γδ T-cell clones showed that engagement of KIR molecules can extinguish T-cell activation signals induced via the CD3/T-cell receptor (TCR) complex. We analyzed the T-cell compartment in mice transgenic for KIR2DL3 (Tg-KIR2DL3), an inhibitory receptor for HLA-Cw3. As expected, mixed lymphocyte reaction and anti-CD3 monoclonal antibody (MoAb)-redirected cytotoxicity exerted by freshly isolated splenocytes can be inhibited by engagement of transgenic KIR2DL3 molecules. In contrast, antigen and anti-CD3 MoAb-induced cytotoxicity exerted by alloreactive cytotoxic T lymphocytes cannot be inhibited by KIR2DL3 engagement. In double transgenic mice, Tg-KIR2DL3 × Tg-HLA-Cw3, no alteration of thymic differentiation could be documented. Immunization of double transgenic mice with Hen egg white lysozime (HEL) or Pigeon Cytochrome-C (PCC) was indistinguishable from immunization of control mice, as judged by recall antigen-induced in vitro proliferation and TCR repertoire analysis. These results indicate that KIR effect on T cells varies upon cell activation stage and show unexpected complexity in the biological function of KIRs in vivo.

scholarly journals T cell receptor zeta/CD3-p59fyn(T)-associated p120/130 binds to the SH2 domain of p59fyn(T).

1993 ◽  
Vol 178 (6) ◽  
pp. 2107-2113 ◽  
Author(s):  
A J da Silva ◽  
O Janssen ◽  
C E Rudd
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
T Cell Activation ◽  
Intracellular Signaling ◽  
Cell Activation ◽  
Cell Receptor ◽  
Sh2 Domain ◽  
T Complex

Intracellular signaling from the T cell receptor (TCR)zeta/CD3 complex is likely to be mediated by associated protein tyrosine kinases such as p59fyn(T), ZAP-70, and the CD4:p56lck and CD8:p56lck coreceptors. The nature of the signaling cascade initiated by these kinases, their specificities, and downstream targets remain to be elucidated. The TCR-zeta/CD3:p59fyn(T) complex has previously been noted to coprecipitate a 120/130-kD doublet (p120/130). This intracellular protein of unknown identity associates directly with p59fyn(T) within the receptor complex. In this study, we have shown that this interaction with p120/130 is specifically mediated by the SH2 domain (not the fyn-SH3 domain) of p59fyn(T). Further, based on the results of in vitro kinase assays, p120/130 appears to be preferentially associated with p59fyn(T) in T cells, and not with p56lck. Antibody reprecipitation studies identified p120/130 as a previously described 130-kD substrate of pp60v-src whose function and structure is unknown. TCR-zeta/CD3 induced activation of T cells augmented the tyrosine phosphorylation of p120/130 in vivo as detected by antibody and GST:fyn-SH2 fusion proteins. p120/130 represents the first identified p59fyn(T):SH2 binding substrate in T cells, and as such is likely to play a key role in the early events of T cell activation.

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.

107 Effects of IL-2 and IL-15 on the proliferative and antitumor capacities of allogeneic CD20 CAR-engineered γδ T cells in a 3D B cell lymphoma spheroid assay

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A119-A119
Author(s):  
Lu Bai ◽  
Kevin Nishimoto ◽  
Mustafa Turkoz ◽  
Marissa Herrman ◽  
Jason Romero ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cytokine Production ◽  
Γδ T Cells ◽  
Γδ T Cell ◽  
Car T

BackgroundAutologous chimeric antigen receptor (CAR) T cells have been shown to be efficacious for the treatment of B cell malignancies; however, widespread adoption and application of CAR T cell products still face a number of challenges. To overcome these challenges, Adicet Bio is developing an allogeneic γδ T cell-based CAR T cell platform, which capitalizes on the intrinsic abilities of Vδ1 γδ T cells to recognize and kill transformed cells in an MHC-unrestricted manner, to migrate to epithelial tissues, and to function in hypoxic conditions. To gain a better understanding of the requirements for optimal intratumoral CAR Vδ1 γδ T cell activation, proliferation, and differentiation, we developed a three-dimensional (3D) tumor spheroid assay, in which tumor cells acquire the structural organization of a solid tumor and establish a microenvironment that has oxygen and nutrient gradients. Moreover, through the addition of cytokines and/or tumor stromal cell types, the spheroid microenvironment can be modified to reflect hot or cold tumors. Here, we report on the use of a 3D CD20+ Raji lymphoma spheroid assay to evaluate the effects of IL-2 and IL-15, positive regulators of T cell homeostasis and differentiation, on the proliferative and antitumor capacities of CD20 CAR Vδ1 γδ T cells.MethodsMolecular, phenotypic, and functional profiling were performed to characterize the in vitro dynamics of the intraspheroid CD20 CAR Vδ1 γδ T cell response to target antigen in the presence of IL-2, IL-15, or no added cytokine.ResultsWhen compared to no added cytokine, the addition of IL-2 or IL-15 enhanced CD20 CAR Vδ1 γδ T cell activation, proliferation, survival, and cytokine production in a dose-dependent manner but were only able to alter the kinetics of Raji cell killing at low effector to target ratios. Notably, differential gene expression analysis using NanoString nCounter® Technology confirmed the positive effects of IL-2 or IL-15 on CAR-activated Vδ1 γδ T cells as evidenced by the upregulation of genes involved in activation, cell cycle, mitochondrial biogenesis, cytotoxicity, and cytokine production.ConclusionsTogether, these results not only show that the addition of IL-2 or IL-15 can potentiate CD20 CAR Vδ1 γδ T cell activation, proliferation, survival, and differentiation into antitumor effectors but also highlight the utility of the 3D spheroid assay as a high throughput in vitro method for assessing and predicting CAR Vδ1 γδ T cell activation, proliferation, survival, and differentiation in hot and cold tumors.

scholarly journals Immune function of the blood-brain barrier: incomplete presentation of protein (auto-)antigens by rat brain microvascular endothelium in vitro.

1990 ◽  
Vol 110 (5) ◽  
pp. 1757-1766 ◽  
Author(s):  
W Risau ◽  
B Engelhardt ◽  
H Wekerle
Keyword(s):  
T Cells ◽  
Endothelial Cells ◽  
T Cell ◽  
T Lymphocytes ◽  
Rat Brain ◽  
Blood Brain Barrier ◽  
T Cell Activation ◽  
Cell Activation ◽  
Ifn Gamma

The endothelial blood-brain barrier (BBB) has a critical role in controlling lymphocyte traffic into the central nervous system (CNS), both in physiological immunosurveillance, and in its pathological aberrations. The intercellular signals that possibly could induce lymphocytes to cross the BBB include immunogenic presentation of protein (auto-)antigens by BBB endothelia to circulating T lymphocytes. This concept has raised much, though controversial, attention. We approached this problem by analyzing in vitro immunospecific interactions between clonal rat T lymphocyte lines with syngeneic, stringently purified endothelial monolayer cultures from adult brain micro-vessels. The rat brain endothelia (RBE) were established from rat brain capillaries using double collagenase digestion, density gradient fractionation and selective cytolysis of contaminating pericytes by anti-Thy 1.1 antibodies and complement. Incubation with interferon-gamma in most of the brain-derived endothelial cells induced Ia-antigens in the cytoplasm and on the cell surface in some of the cells. Before the treatment, the cells were completely Ia-negative. Pericytes were unresponsive to IFN-gamma treatment. When confronted with syngeneic T cell lines specific for protein (auto-)antigens (e.g., ovalbumin and myelin basic protein, MBP), RBE were completely unable to induce antigen-specific proliferation of syngeneic T lymphocytes irrespective of pretreatment with IFN-gamma and of cell density. RBE were inert towards the T cells, and did not suppress T cell activation induced by other "professional" antigen presenting cells (APC) such as thymus-derived dendritic cells or macrophages. IFN-gamma-treated RBE were, however, susceptible to immunospecific T cell killing. They were lysed by MBP-specific T cells in the presence of the specific antigen or Con A. Antigen dependent lysis was restricted by the appropriate (MHC) class II product. We conclude that the interaction of brain endothelial cells with encephalitogenic T lymphocytes may involve recognition of antigen in the molecular context of relevant MHC products, but that this interaction per se is insufficient to initiate the full T cell activation program.

scholarly journals Siplizumab, an Anti-CD2 Monoclonal Antibody, Induces a Unique Set of Immune Modulatory Effects Compared to Alemtuzumab and Rabbit Anti-Thymocyte Globulin In Vitro

2020 ◽  
Vol 11 ◽  
Author(s):  
Christian Binder ◽  
Felix Sellberg ◽  
Filip Cvetkovski ◽  
Erik Berglund ◽  
David Berglund
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Mixed Lymphocyte Reaction ◽  
T Cell Proliferation ◽  
Allogeneic Mixed Lymphocyte Reaction ◽  
Dependent Cell

Antibodies are commonly used in organ transplant induction therapy and to treat autoimmune disorders. The effects of some biologics on the human immune system remain incompletely characterized and a deeper understanding of their mechanisms of action may provide useful insights for their clinical application. The goal of this study was to contrast the mechanistic properties of siplizumab with Alemtuzumab and rabbit Anti-Thymocyte Globulin (rATG). Mechanistic assay systems investigating antibody-dependent cell-mediated cytotoxicity, antibody-dependent cell phagocytosis and complement-dependent cytotoxicity were used to characterize siplizumab. Further, functional effects of siplizumab, Alemtuzumab, and rATG were investigated in allogeneic mixed lymphocyte reaction. Changes in T cell activation, T cell proliferation and frequency of naïve T cells, memory T cells and regulatory T cells induced by siplizumab, Alemtuzumab and rATG in allogeneic mixed lymphocyte reaction were assessed via flow cytometry. Siplizumab depleted T cells, decreased T cell activation, inhibited T cell proliferation and enriched naïve and bona fide regulatory T cells. Neither Alemtuzumab nor rATG induced the same combination of functional effects. The results presented in this study should be used for further in vitro and in vivo investigations that guide the clinical use of immune modulatory biologics.

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.

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