Membrane-Associated Proteinase 3 On Granulocytes and Myeloid Leukemia Mediates Reversible Inhibition of T Cell Proliferation Associated with Altered ZAP70 and ERK Signaling

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1031-1031
Author(s):  
Tian-Hui Yang ◽  
Karen Clise-Dwyer ◽  
S Lisa ◽  
St. John ◽  
Gheath Alatrash ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
Cd4 T Cells ◽  
Myeloid Leukemia ◽  
Erk Signaling ◽  
T Cell Proliferation ◽  
Proteinase 3 ◽  
Healthy Donors ◽  
Dose Dependent

Abstract Abstract 1031 Proteinase 3 (P3), a serine protease constitutively expressed in primary granules and on the membrane of some resting granulocytes, is the target of T cell-mediated autoimmunity in Wegener's granulomatosis (WG) and of anti-leukemia immunity mediated by PR1 (VLQELNVTV)-specific cytotoxic T lymphocytes (PR1-CTL). We have previously shown anti-CD3/CD28 induced proliferation of healthy donor T-cells to be significantly inhibited by peripheral blood polymorphonuclear neutrophils (PMNs) expressing membrane P3 (mP3) at a ratio of 3 PMNs to 1 PBMC. Our results indicate that mP3+ PMNs begin to exert inhibitory effects on T cell proliferation at a ratio of 2.2 mP3+ PMNs to 1 PBMC, a ratio greater than that seen in normal homeostatic conditions in peripheral blood. The inhibition was predominantly enzyme-independent and dose-dependent. Notably soluble P3 exerted similar effects on T cells as was seen with mP3. Additionally soluble P3 induced a G0 cell cycle arrest. Of significance, soluble P3 in acute myeloid leukemia (AML) patient serum can be up to 5-fold higher than that seen in healthy control serum. To confirm mP3 specificity, we FAC-sorted PMNs based on the mP3 co-expressed CD177 molecule to obtain highly purified (>98%) mP3+ and mP3− PMNs. Compared to activated PBMC alone, activated PBMC co-cultured at a ratio of 1:3 with mP3+ PMNs showed 58% and 57% inhibition of CD8+ and CD4+ T cells, respectively (CD8+ and CD4+: p< 0.003). PBMC co-cultured at that same ratio with mP3− PMNs showed less inhibition - only 29% and 26% inhibition of CD8+ and CD4+ T cells, respectively (CD8+: p<0.05; CD4+: p=ns). Inhibition of T cell proliferation by both mP3+PMNs and soluble P3 was blocked by anti-P3 mAbs but not by isotype-matched mAb. Furthermore, P3-mediated inhibition of T-cell proliferation is reversible since removal of PMNs or soluble P3 restored the proliferative capacity of the T cells. Because P3 is over-expressed in AML and chronic myeloid leukemia (CML), we hypothesized that mP3+ leukemia may suppress T-cell proliferation. Healthy donor T cell proliferation was studied with CFSE after stimulation with anti-CD3/CD28 mAbs in the presence or absence of mP3+ AML for five days. AML mediated a dose-dependent inhibition of T-cell proliferation contingent upon the level of mP3 expression (p<0.0001). Co-incubation of PBMC with AML displaying 91% mP3 positivity, reduced proliferation of CD8+ T cells to 29.6%, compared to 94.7% in the PBMC culture alone. This inhibition could be completely abrogated by addition of anti-P3 mAb, restoring the proliferation of CD8+ T cells to a level comparable to that seen in control. In contrast, no inhibition of CD8+ T cell proliferation was observed in co-cultures of T cells with AML in which only 6% of the AML cells expressed mP3. Thus, there is an inverse correlation between percent proliferation of T cells and the amount of mP3 on AML (R=0.4539, p<0.0001). In addition, AML expressing 91% mP3+ induced apoptosis of > 70% of the T cells at a ratio of 10 AML: 1 PBMC as assessed by uptake of aqua dye. The association between the amount of mP3 on AML and percent of apoptosis was significant (R=0.7852, p<0.0001), and apoptosis induced by mP3+AML appeared to be specific since T cells did not undergo apoptosis when anti-P3 mAb was added. The same correlation was not seen after PMNs from healthy donors (% mP3+: 62%±21.7, n=14) were co-incubated with PBMC. The percentage of cells undergoing apoptosis was less than 10%, regardless of the extent of PMN mP3 positivity. Of note, mP3 expression is significantly higher in bone marrow myeloid derived suppressor cells (MDSC) from leukemia patients compared to MDSC from healthy donors (79.4±5.23% (n=7), 22.4±11.55% (n=3), respectively; p= 0.0007). Because mP3 inhibited proliferation of T cells stimulated via the T cell receptor (TCR), i.e. anti-CD3/CD28, we compared effects of mP3 on ZAP70 and ERK signaling by phosphoflow cytometry. ZAP70 phosphorylation in CD8+ and CD4+ T cells was reduced by 78% and 80%, respectively, within 5 minutes of co-incubation with mP3+ PMNs compared with T cells stimulated with anti-CD3/CD28 mAbs alone, while ERK1/2 phosphorylation was completely blocked within 10 minutes, suggesting that P3-mediated inhibition of T cell proliferation involves downstream TCR signaling pathways. Taken together, these data support an important new function of membrane-bound P3 on PMN and leukemia in controlling adaptive T cell immunity. Disclosures: No relevant conflicts of interest to declare.

Membrane-Associated Proteinase 3 on Granulocytes and Myeloid Leukemia Mediates Reversible Inhibition of T Cell Proliferation

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 1916-1916
Author(s):  
Tian-Hui Yang ◽  
Karen Clise-Dwyer ◽  
Gheath Alatrash ◽  
Kathryn Ruisaard ◽  
Shoudan Liang ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
Cd4 T Cells ◽  
Myeloid Leukemia ◽  
Inhibitory Effect ◽  
T Cell Proliferation ◽  
Proteinase 3 ◽  
Healthy Donors ◽  
Membrane Bound

Abstract Abstract 1916 Proteinase 3 (P3), a serine protease constitutively expressed in primary granules and on the membrane of some resting granulocytes, is the target of T cell-mediated autoimmunity in Wegener's granulomatosis (WG) and of anti-leukemia immunity mediated by PR1 (VLQELNVTV)-specific cytotoxic T lymphocytes (PR1-CTL). We have shown that soluble P3 is increased by 5-fold in sera from acute myeloid leukemia (AML) patients compared to healthy controls, and soluble P3 mediates enzyme-independent inhibition of T-cell proliferation. Moreover, tumor-associated neutrophils (TANs) are associated with a poor prognosis in a number of cancers including renal cell carcinoma and lung cancer, and P3 is also over-expressed in a variety of AML and chronic myeloid leukemia (CML). Therefore, we hypothesized that membrane-bound P3 (mP3) may similarly regulate adaptive immunity by suppressing T-cell proliferation. To study this, T cells from healthy donors were labeled with the membrane dye CFSE and stimulated with anti-CD3 and anti-CD28 in the presence or absence of mP3-expressing PMNs for five days. The percentage of proliferating cells was determined by flow cytometry. Proliferation of autologous CD8+ and CD4+ T cells was significantly inhibited by 75% and 72%, respectively, when PMNs were co-incubated with lymphocytes at a ratio of 3:1, and by > 90% at 5:1. This cell contact-dependent inhibitory effect was limited to PMN since PBMCs added to lymphocytes in place of PMNs at 5:1 had no effect on T cell proliferation. To determine whether the inhibitory effect was specifically mediated by mP3, we FAC-sorted CD177+PMNs and CD177−PMNs to obtain highly purified (>98%) mP3+ and mP3− PMNs, respectively, because CD177 and mP3 are co-expressed on same subset of resting PMNs. At a ratio of 3:1 (CD177+PMNs or CD177−PMNs to lymphocytes), mP3+PMNs mediated > 75% growth inhibition of both CD8+ and CD4+ T cells compared to < 55% inhibition by mP3−PMNs (p<0.05). Furthermore, the inhibitory effect of mP3+PMNs on T cell proliferation was blocked (< 10% inhibition of proliferation) by anti-P3 but not by isotype control mAb. The inhibitory effect of mP3 was enzyme-independent because Elafin or α1-anti-trypsin did not affect inhibition by mP3+PMNs. In addition, mP3-mediated inhibition was fully reversible as T cells proliferated normally with anti-CD3/anti-CD28 stimulation after PMNs were removed from co-culture. Similarly, mP3+AML blasts inhibited autologous CD8+ and CD4+ T cell proliferation by 50% and 30%, respectively, at a 2:1 ratio of AML blasts: lymphocytes. Interestingly, bone marrow myeloid derived suppressor cells (MDSC) from leukemia patients express significantly higher mP3 (79.4±5.23% (mean±SEM, n=7)), compared to 22.4±11.55% mP3 on MDSC from healthy donors (p= 0.0007, n=3). Taken together, these data support an important new function of membrane-bound P3 on innate immune cells and leukemia in controlling adaptive T cell immunity. These findings suggest a novel mechanism whereby neutrophils could promote tumor growth in vivo through contact-mediated suppression of tumor-infiltrating lymphocytes by mP3 or by soluble P3 secreted by activated TANs in cancer and myeloid leukemia. Thus, targeting P3 with anti-P3 antibodies may be explored as a novel therapeutic strategy for leukemia and other cancers. Disclosures: No relevant conflicts of interest to declare.

Myeloid Leukemias Directly Suppress T Cell Proliferation Through STAT3 and Arginase Pathways

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3885-3885 ◽  
Author(s):  
Samantha Miner ◽  
Sawa Ito ◽  
Kazushi Tanimoto ◽  
Nancy F. Hensel ◽  
Fariba Chinian ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
Cell Lines ◽  
Cd4 T Cells ◽  
Myeloid Leukemia ◽  
Leukemia Cell ◽  
Suppressor Cells ◽  
T Cell Proliferation ◽  
Immune Editing

Abstract The immune-editing effect of myeloid leukemia has recently been reported in several studies. We previously demonstrated that the K562 leukemia-derived cell line suppresses T cell proliferation, which suggests that myeloid leukemia may function in a similar way to myeloid derived suppressor cells (MDSC). While the mechanism of suppression in leukemia is not fully understood, recent murine and human studies suggest that the STAT3 and arginase pathways play a key role in the immunosuppressive function of MDSC. We hypothesized that myeloid leukemia utilizes the MDSC STAT3 and arginase pathway to evade immune control, and block anti-leukemic immune responses. To evaluate the suppressive capacity of myeloid leukemia on T cell proliferation, we isolated CD34+ blasts and myeloid derived suppressor cells (MDSC: CD11b+CD14+) from blood of primary leukemia samples by FACS sorting (n=5). These cells were co-cultured with CFSE-labeled CD4+ T cells (n=9), previously isolated from healthy donor PBMCs using an automated cell separator (RoboSep). After stimulating with CD3/CD28 Dynabeads (Invitrogen, New York, USA) for 72 hours, proliferation was measured by CFSE dilution of the viable cell population. In three myeloid leukemias studied, CD4+ T cell proliferation was significantly suppressed in the presence of primary CD34 blasts and MDSC cells (p<0.001). Interestingly, CD34 blasts demonstrated a greater suppressive effect on T cells compared to MDSC cells for these samples (not statistically significant p=0.61). Next we repeated the proliferation assay using five leukemia cell lines: THP-1 and AML1 (derived from AML), K562 and CML1 (derived from CML), and the Daudi lymphoid-derived leukemia cell line. After staining with cell tracer dye and irradiating 100Gy, the cells were co-incubated with CFSE-labeled CD4+ T cells from healthy volunteers (n=6). We found that CD4+ T cell proliferation in the presence of the myeloid leukemia cell lines was significantly suppressed (mean proliferation 5.7±0.9% to 26.1±10.7%: p<0.0001 to 0.05) compared to lymphoid cell lines (mean proliferation 76.3±8.2%: p>0.05), consistent with the results obtained with the primary leukemia samples. To evaluate the impact of STAT3 and arginase on the immunosuppressive function of myeloid leukemia, the five cell lines were primed overnight with either arginase inhibitor (N(ω)-Hydroxy-nor-L-arginine; EMD Biosciences, Inc., California, USA) or two STAT3 inhibitors (STAT3 Inhibitor VI or Cucurbitacin I; EMD Millipore, Massachusetts, USA). Then, CD4+ T cells from healthy donors (n=3) were cultured with either (1) leukemia without any inhibitor (2) leukemia in the presence of inhibitor (3) leukemia primed with inhibitor. Priming leukemia with arginase inhibitor and STAT3 inhibitors almost completely abrogated their suppressive effect of T cell proliferation (p<0.001). We conclude that myeloid leukemia, like MDSC, directly immunosuppresses T cells, through STAT-3 and arginase. This finding may underlie the immune-editing of T cells by myeloid leukemia. Our results suggest that STAT3 inhibitors could be used to augment leukemia-targeted immunotherapy. Further investigation of T cell biology within the leukemia microenvironment is needed to further define immune editing mechanisms in myeloid leukemia. Figure 1 Figure 1. Figure 2 Figure 2. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Mapping of the autophagosomal degradome identifies IL-7Rα as key cargo in proliferating CD4+ T-cells

2021 ◽  
Author(s):  
Dingxi Zhou ◽  
Mariana Borsa ◽  
Daniel J. Puleston ◽  
Susanne Zellner ◽  
Jesusa Capera ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
Cd4 T Cells ◽  
Surface Expression ◽  
T Cell Proliferation ◽  
Gamma Chain ◽  
Direct Identification ◽  
The Common ◽  
First Time

CD4+ T cells orchestrate both humoral and cytotoxic immune responses. While it is known that CD4+ T cell proliferation relies on autophagy, direct identification of the autophagosomal cargo involved is still missing. Here, we created a transgenic mouse model, which, for the first time, enables us to directly map the proteinaceous content of autophagosomes in any primary cell by LC3 proximity labelling. IL-7Rα, a cytokine receptor mostly found in naive and memory T cells, was reproducibly detected in autophagosomes of activated CD4+ T cells. Consistently, CD4+ T cells lacking autophagy showed increased IL-7Rα surface expression, while no defect in internalisation was observed. Mechanistically, excessive surface IL-7Rα sequestrates the common gamma chain, impairing the IL-2R assembly and downstream signalling crucial for T cell proliferation. This study provides proof-of-principle that key autophagy substrates can be reliably identified with this model to help mechanistically unravel autophagy's contribution to healthy physiology and disease.

scholarly journals TSLP and IL-7 use two different mechanisms to regulate human CD4+ T cell homeostasis

2009 ◽  
Vol 206 (10) ◽  
pp. 2111-2119 ◽  
Author(s):  
Ning Lu ◽  
Yi-Hong Wang ◽  
Yui-Hsi Wang ◽  
Kazuhiko Arima ◽  
Shino Hanabuchi ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
Cd4 T Cells ◽  
Cd4 T Cell ◽  
Th2 Cells ◽  
T Cell Proliferation ◽  
T Cell Homeostasis ◽  
Cell Homeostasis ◽  
Th2 Differentiation

Whether thymic stromal lymphopoietin (TSLP) directly induces potent human CD4+ T cell proliferation and Th2 differentiation is unknown. We report that resting and activated CD4+ T cells expressed high levels of IL-7 receptor a chain but very low levels of TSLP receptor (TSLPR) when compared with levels expressed in myeloid dendritic cells (mDCs). This was confirmed by immunohistology and flow cytometry analyses showing that only a subset of mDCs, with more activated phenotypes, expressed TSLPR in human tonsils in vivo. IL-7 induced strong STAT1, -3, and -5 activation and promoted the proliferation of naive CD4+ T cells in the presence of anti-CD3 and anti-CD28 monoclonal antibodies, whereas TSLP induced weak STAT5 activation, associated with marginally improved cell survival and proliferation, but failed to induce cell expansion and Th2 differentiation. The effect of TSLP on enhancing strong human T cell proliferation was observed only when sorted naive CD4+ T cells were cultured with mDCs at levels as low as 0.5%. TSLP could only induce naive CD4+ T cells to differentiate into Th2 cells in the presence of allogeneic mDCs. These results demonstrate that IL-7 and TSLP use different mechanisms to regulate human CD4+ T cell homeostasis.

scholarly journals Allergen-Induced C5a/C5aR1 Axis Activation in Pulmonary CD11b+ cDCs Promotes Pulmonary Tolerance through Downregulation of CD40

Cells ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 300 ◽  
Author(s):  
Konstantina Antoniou ◽  
Fanny Ender ◽  
Tillman Vollbrandt ◽  
Yves Laumonnier ◽  
Franziska Rathmann ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cd4 T Cells ◽  
Cell Activation ◽  
T Cell Proliferation ◽  
C5a Receptor ◽  
The Impact

Activation of the C5/C5a/C5a receptor 1 (C5aR1) axis during allergen sensitization protects from maladaptive T cell activation. To explore the underlying regulatory mechanisms, we analyzed the impact of C5aR1 activation on pulmonary CD11b+ conventional dendritic cells (cDCs) in the context of house-dust-mite (HDM) exposure. BALB/c mice were intratracheally immunized with an HDM/ovalbumin (OVA) mixture. After 24 h, we detected two CD11b+ cDC populations that could be distinguished on the basis of C5aR1 expression. C5aR1− but not C5aR1+ cDCs strongly induced T cell proliferation of OVA-reactive transgenic CD4+ T cells after re-exposure to antigen in vitro. C5aR1− cDCs expressed higher levels of MHC-II and CD40 than their C5aR1+ counterparts, which correlated directly with a higher frequency of interactions with cognate CD4+ T cells. Priming of OVA-specific T cells by C5aR1+ cDCs could be markedly increased by in vitro blockade of C5aR1 and this was associated with increased CD40 expression. Simultaneous blockade of C5aR1 and CD40L on C5aR1+ cDCs decreased T cell proliferation. Finally, pulsing with OVA-induced C5 production and its cleavage into C5a by both populations of CD11b+ cDCs. Thus, we propose a model in which allergen-induced autocrine C5a generation and subsequent C5aR1 activation in pulmonary CD11b+ cDCs promotes tolerance towards aeroallergens through downregulation of CD40.

scholarly journals Bystander memory CD8 T cell proliferation after anti-CD40/IL-2 treatment is independent of CD4 T cells

2013 ◽  
Vol 1 (S1) ◽  
Author(s):  
Steven K Grossenbacher ◽  
Arta M Monjazeb ◽  
Julia Tietze ◽  
Gail D Sckisel ◽  
Annie Mirsoian ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
Cd4 T Cells ◽  
Cd8 T Cell ◽  
T Cell Proliferation ◽  
Memory Cd8 T Cell

Regulatory T Cells Expanded by Autologous Mature Human Dendritic Cells Expressing Indoleamine 2,3-Dioxygenase Are Potent Suppressors of T Cell Proliferation.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1553-1553
Author(s):  
Davi d J. Chung ◽  
Marco Rossi ◽  
Emanuela Romano ◽  
Jennifer Pressley ◽  
Christophe Antczak ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Regulatory T Cells ◽  
De Novo ◽  
T Cell Proliferation ◽  
Indoleamine 2,3 Dioxygenase ◽  
Naturally Occurring ◽  
Dose Dependent

Abstract Best characterized as initiators of immunity, dendritic cells (DCs) also play an integral role in immune modulation. Immature DCs, for example, process self-antigens to induce and maintain tolerance. The immunoregulatory effects of DCs, however, are not limited to immature subtypes. Immunogenic mature DCs can also induce T regs to curb immune responses. We have found that human monocyte-derived DCs (moDCs) upregulate the immunomodulatory enzyme indoleamine 2,3-dioxygenase (IDO) with maturation and expand functionally active, naturally occurring as well as inducible regulatory T cells (T regs) in an IDO-dependent manner. Priming of resting bulk T cells with autologous, IDO-expressing, mature moDCs in the absence of exogenous cytokines results in up to 10-fold expansion of CD4+CD25hiFoxp3+CD127neg T cells that mediate significant dose-dependent suppression of both allogeneic and autologous T cells stimulated de novo by DCs. The expansion of T regs by IDO-expressing moDCs involves cell-to-cell contact, CD80/CD86 ligation, and IL-2. Autologous priming in the presence of a competitive inhibitor of IDO, 1-methyl-tryptophan, diminishes T reg expansion. Candidate T regs were further characterized after cytofluorographic sorting primed bulk T cells into CD4+CD25hi, CD4+CD25int, and CD4+CD25neg subpopulations. Post-sort analysis showed that &gt;60% of the CD4+CD25hi cells coexpressed Foxp3, which was not present in the CD4+CD25neg cells. CD4+CD25hi T regs exerted dose-dependent inhibition of DC-stimulated allogeneic T cell proliferation, with &gt;90% inhibition at a suppressor to responder T cell ratio of 1:1 and ~50% inhibition at a ratio of 1:25. CD4+CD25int cells produced intermediate suppression depending on dose, and CD4+CD25neg cells were not inhibitory. CD4+CD25hi T regs mediated similar suppression of autologous T cell responses to stimulation de novo by DCs. CD4+CD25hi T regs also inhibited the generation of cytotoxic T lymphocytes (CTLs) specific for the Wilms’ tumor gene product (WT-1). The addition of CD4+CD25hi T regs to CTL-priming cultures resulted in a &gt;80% decrease in specific target cell lysis of a WT-1-expressing cell line. Separate studies showed that T reg-mediated suppression is contact dependent and also requires TGF-beta, suggesting inhibition by naturally occurring and inducible T regs, respectively. Depletion of CD4+CD25hi T cells from bulk T cells by negative immunoselection with anti-CD25 magnetic beads at the outset of autologous priming significantly blunts T reg expansion, indicating a requirement for pre-existing T regs in the bulk T cell population. T reg expansion also occurs in priming cultures using cytofluorographically-sorted CD4+CD25neg T cells, indicating de novo generation of T regs from CD4+CD25neg precursors. In summary, our results demonstrate a mechanism by which mature, IDO-expressing, human moDCs expand autologous, naturally occurring as well as inducible T regs that functionally suppress the proliferation of both autologous and allogeneic T cells. Inhibition of this counter-regulatory pathway should result in more sustained benefit from active DC-based immunotherapy.

scholarly journals A novel model for antigen-dependent activation of normal human T cells. Transmembrane signaling by crosslinkage of the CD3/T cell receptor-alpha/beta complex with the cluster determinant 2 antigen.

1990 ◽  
Vol 171 (6) ◽  
pp. 1965-1979 ◽  
Author(s):  
M Suthanthiran
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
T Cell Proliferation ◽  
Transmembrane Signaling ◽  
Receptor Alpha ◽  
Human T Cells ◽  
Normal Human

Transmembrane signaling of normal human T cells was explored with mAbs directed at TCR, CD2, CD4, CD5, or CD8 antigens and highly purified CD4+ T cells and CD8+ T cells. Our experiments explicitly show that: (a) crosslinkage of TCR with the CD2 antigen, and not independent crosslinking of TCR and of CD2 antigen or crosslinking of either protein with the CD4 or CD8 antigen induces significant proliferation independent of co-stimulatory signals (e.g., accessory cells, recombinant lymphokines, or tumor promoter), (b) F(ab')2 fragments of mAb directed at the TCR and F(ab')2 anti-CD2, crosslinked with F(ab')2 fragments of rabbit anti-mouse IgG, promote the proliferation of highly purified T cells, (c) a prompt and sustained increase in intracellular free Ca2+ concentration results from crosslinkage of TCR with the CD2 antigen, (d) T cell proliferation induced by this novel approach is curtailed by EGTA and by direct or competitive inhibitors of PKC, (e) crosslinkage of TCR with the CD2 antigen results in the transcriptional activation and translation of the gene for IL-2 and in the expression of IL-2 receptor alpha (CD25), (f) anti-CD25 mAbs inhibit T cell proliferation initiated by crosslinkage of TCR with the CD2 antigen, and recombinant IL-2 restores the proliferative response. Our first demonstration that crosslinkage of TCR with the CD2 antigen induces proliferation of normal human CD4+ T cells and CD8+ T cells, in addition to revealing a novel activation mechanism utilizable by the two major subsets of T cells, suggest that the CD2 antigen might be targeted for the regulation of antigen-specific T cell immunity (e.g., organ transplantation).

scholarly journals NK Cell Induced T Cell Anergy Depends on GRAIL Expression

Cells ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 790
Author(s):  
Grazyna Galazka ◽  
Malgorzata Domowicz ◽  
Alicja Ewiak-Paszynska ◽  
Anna Jurewicz
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
Nk Cells ◽  
Cd4 T Cells ◽  
Nk Cell ◽  
Regulatory Function ◽  
T Cell Proliferation ◽  
Thymidine Uptake ◽  
Cell Expression

NK cells (natural killer cells) being a part of the innate immune system have been shown to be involved in immunoregulation of autoimmune diseases. Previously we have shown that HINT1/Hsp70 treatment induced regulatory NK cells ameliorating experimental autoimmune encephalomyelitis (EAE) course and CD4+ T cells proliferation. NK cells were isolated from mice treated with HINT1/Hsp70 and co-cultured with proteolipid protein (PLP)-stimulated CD4+ T cells isolated from EAE mice. Cell proliferation was assessed by thymidine uptake, cytotoxicity by lactate dehydrogenase (LDH) release assay and fluorescence activated cell sorting (FACS) analysis, protein expression by Western blot, mRNA by quantitative RT-PCR. Gene related to anergy in lymphocytes (GRAIL) expression was downregulated by specific siRNA and GRAIL overexpression was induced by pcDNA-GRAIL transfection. HINT1/Hsp70 pretreatment of EAE SJL/J mice ameliorated EAE course, suppressed PLP-induced T cell proliferation by enhancing T cell expression of GRAIL as GRAIL downregulation restored T cell proliferation. HINT1/Hsp70 treatment induced immunoregulatory NK cells which inhibited PLP-stimulated T cell proliferation not depending on T cell necrosis and apoptosis. This immunoregulatory NK cell function depended on NK cell expression of GRAIL as GRAIL downregulation diminished inhibition of NK cell suppression of T cell proliferation. Similarly GRAIL overexpression in NK cells induced their regulatory function. HINT1/Hsp70 treatment generated regulatory NK cells characterized by expression of GRAIL.

The Effects of Stimulation with PMA/Ionomycin on CD4+ T cell Proliferation and Surface CD4 Molecule Modulation of Patients with LRBA Deficiency and CVID with the Unsolved Genetic Defect

2021 ◽  
Vol 21 ◽  
Author(s):  
Fereshte Salami ◽  
Sahar Shariati ◽  
Seyed Erfan Rasouli ◽  
Samaneh Delavari ◽  
Marziyeh Tavakol ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
Cd4 T Cells ◽  
Cd4 T Cell ◽  
T Cell Proliferation ◽  
Healthy Individuals ◽  
Cell Frequency ◽  
Before And After ◽  
Lrba Deficiency

Background: Common variable immunodeficiency (CVID) is the most prevalent symptomatic primary immunodeficiencies. LPS-responsive beige-like anchor protein (LRBA) deficiency is a combined immunodeficiency characterized by a CVID-like phenotype. Affected patients by LRBA and CVID present a wide range of clinical manifestations, including hypogammaglobulinemia, recurrent infections, autoimmunity, as well as T cell abnormality. Methods: The study population comprised of patients with CVID (n=10), LRBA deficiency (n=11), and healthy controls (n=12). CD4+ T cell frequency and CD4 MFI (mean fluorescence intensity) were evaluated using flow cytometry before and after stimulation with PMA/ION. Results: The frequencies of CD4+ T cells were significantly lower in patients with LRBA deficiency than in HCs before and after treatment. In the unstimulated state, the CD4+ T cells frequency in CVID patients was significantly lower than in HCs. There were no statistically significant differences between patients and healthy individuals in CD4+ T cell proliferation. Compared to HCs, LRBA and CVID patients showed a lower CD4 MFI in unstimulated conditions. Furthermore, CD4 MFI decreased in both patients and the control group following activation. Conclusion : Despite the reported decrease in CD4+ T cell frequency in patients with CVID and LRBA deficiency, our findings demonstrated that their CD4+ T cells have a normal proliferative response to stimuli similar to healthy individuals.

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