scholarly journals Human Glomerular Endothelial Cells Treated With Shiga Toxin Type 2 Activate γδ T Lymphocytes

Author(s):  
David Antonio Rosso ◽  
Micaela Rosato ◽  
Fernando Daniel Gómez ◽  
Romina Soledad Álvarez ◽  
Carolina Maiumi Shiromizu ◽  
...  

The hemolytic uremic syndrome associated with diarrhea, a consequence of Shiga toxin (Stx)-producing Escherichia coli infection, is a common cause of pediatric acute renal failure in Argentina. Stx type 2a (Stx2a) causes direct damage to renal cells and induces local inflammatory responses that involve secretion of inflammatory mediators and the recruitment of innate immune cells. γδ T cells constitute a subset of T lymphocytes, which act as early sensors of cellular stress and infection. They can exert cytotoxicity against infected and transformed cells, and produce cytokines and chemokines. In this study, we investigated the activation of human peripheral γδ T cells in response to the incubation with Stx2a-stimulated human glomerular endothelial cells (HGEC) or their conditioned medium, by analyzing in γδ T lymphocytes, the expression of CD69, CD107a, and perforin, and the production of TNF-α and IFN-γ. In addition, we evaluated by confocal microscopy the contact between γδ T cells and HGEC. This analysis showed an augmentation in cellular interactions in the presence of Stx2a-stimulated HGEC compared to untreated HGEC. Furthermore, we observed an increase in cytokine production and CD107a expression, together with a decrease in intracellular perforin when γδ T cells were incubated with Stx2a-treated HGEC or their conditioned medium. Interestingly, the blocking of TNF-α by Etanercept reversed the changes in the parameters measured in γδ T cells incubated with Stx2a-treated HGEC supernatants. Altogether, our results suggest that soluble factors released by Stx2a-stimulated HGEC modulate the activation of γδ T cells, being TNF-α a key player during this process.

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Filip Rolski ◽  
Marcin Czepiel ◽  
Kazimierz Weglarczyk ◽  
Maciej Siedlar ◽  
Gabriela Kania ◽  
...  

Background: Inflammatory heart diseases represent an important clinical problem, nonetheless data regarding activation of cardiac microvascular endothelial cells (MVECs) are limited. Aim: To examine influence of TNF-α and exosomes produced by heart-reactive CD4+ T lymphocytes on activation of cardiac MVECs. Methods: Experimental autoimmune myocarditis (EAM) was induced in wild-type (WT) and TNF-α-deficient (TNF-KO) mice. CD4+ T lymphocytes were isolated from EAM mice at day 21 and activated in vitro to produce conditioned medium and exosomes. Activation of MVECs was assessed by specific assays and leukocyte-to-endothelial adhesion was analysed under shear flow condition using the BioFlux microfluidic system. Results: TNF-KO mice showed lower prevalence of myocarditis when compared to WT mice (50% vs. 90%). Stimulation of MVECs with secretome of antigen-activated autoreactive T cells resulted in upregulation of adhesion molecules (ICAM-1, VCAM-1 and P-selectin), increased ROS and decreased NO production. Addition of anti-TNF-α neutralizing antibodies effectively blocked adhesion of leukocytes to MVECs activated with the conditioned medium. Endothelial activation and dysfunction induced by the conditioned medium were independent of TNF-α produced by T cells. Stimulation of MVECs with T cell-derived exosomes increased ROS and decreased levels of NO and eNOS activation, but exosomes neither increased expression of adhesion molecules in MVECs nor induced their ability to bind leukocytes. Conclusions: TNF-α promotes MVEC activation and EAM development. In this model, autoreactive T cells activate MVECs, and TNF-a produced by MVECs rather than T cells is essential in this process. On the other hand, endothelial dysfunction caused by T cells seems to be mediated mainly by exosomes.


2018 ◽  
Vol 314 (3) ◽  
pp. R427-R432 ◽  
Author(s):  
Bhavisha A. Bakrania ◽  
Frank T. Spradley ◽  
Simon C. Satchell ◽  
David E. Stec ◽  
John M. Rimoldi ◽  
...  

Preeclampsia is a pregnancy-specific disorder of maternal hypertension and reduced renal hemodynamics linked to reduced endothelial function. Placental ischemia is thought to be the culprit of this disease, as it causes the release of factors like tumor necrosis factor (TNF)-α that induce vascular endothelin-1 (ET-1) production. Interestingly, placental ischemia-induced hypertension in rats [reduced uterine perfusion pressure (RUPP) model] is abolished by ETA receptor blockade, suggesting a critical role for ET-1. Although it has been found that systemic induction of heme oxygenase (HO)-1 is associated with reduced ET-1 production and attenuated hypertension, it is unclear whether HO-1 directly modulates the increased ET-1 response to placental factors. We tested the hypothesis that HO-1 or its metabolites inhibit ET-1 production in human glomerular endothelial cells induced by serum of RUPP rats or TNF-α. Serum (5%) from RUPP hypertensive (mean arterial blood pressure 119 ± 9 mmHg) vs. normotensive pregnant (NP, 101 ± 6 mmHg, P < 0.001) rats increased ET-1 production (RUPP 168.8 ± 18.1 pg/ml, NP 80.3 ± 22.7 pg/ml, P < 0.001, n = 12/group). HO-1 induction [25 µM cobalt photoporphyrin (CoPP)] abolished RUPP serum-induced ET-1 production (1.6 ± 0.8 pg/ml, P < 0.001), whereas bilirubin (10 µM) significantly attenuated ET-1 release (125.3 ± 5.2 pg/ml, P = 0.005). Furthermore, TNF-α-induced ET-1 production (TNF-α 31.0 ± 8.4 vs. untreated 7.5 ± 0.4 pg/ml, P < 0.001) was reduced by CoPP (1.5 ± 0.8 pg/ml, P < 0.001) and bilirubin (10.5 ± 4.3 pg/ml, P < 0.001). These results suggest that circulating factors released during placental ischemia target the maternal glomerular endothelium to increase ET-1, and that pharmacological induction of HO-1 or bilirubin could be a treatment strategy to block this prohypertensive pathway in preeclampsia.


1998 ◽  
Vol 66 (5) ◽  
pp. 1855-1860 ◽  
Author(s):  
Duncan M. Mwangi ◽  
Suman M. Mahan ◽  
John K. Nyanjui ◽  
Evans L. N. Taracha ◽  
Declan J. McKeever

ABSTRACT Peripheral blood mononuclear cells (PBMC) from immune cattle proliferate in the presence of autologous Cowdria ruminantium-infected endothelial cells and monocytes. Endothelial cells required treatment with T-cell growth factors to induce class II major histocompatibility complex expression prior to infection and use as stimulators. Proliferative responses to both infected autologous endothelial cells and monocytes were characterized by expansion of a mixture of CD4+, CD8+, and γδ T cells. However, γδ T cells dominated following several restimulations. Reverse transcription-PCR analysis of cytokine expression by C. ruminantium-specific T-cell lines and immune PBMC revealed weak interleukin-2 (IL-2), IL-4, and gamma interferon (IFN-γ) transcripts at 3 to 24 h after stimulation. Strong expression of IFN-γ, tumor necrosis factor alpha (TNF-α), TNF-β, and IL-2 receptor α-chain mRNA was detected in T-cell lines 48 h after antigen stimulation. Supernatants from these T-cell cultures contained IFN-γ protein. Our findings suggest that in immune cattle a C. ruminantium-specific T-cell response is induced and that infected endothelial cells and monocytes may present C. ruminantiumantigens to specific T lymphocytes in vivo during infection and thereby play a role in induction of protective immune responses to the pathogen.


Blood ◽  
2009 ◽  
Vol 114 (20) ◽  
pp. 4422-4431 ◽  
Author(s):  
Georg Gruenbacher ◽  
Hubert Gander ◽  
Andrea Rahm ◽  
Walter Nussbaumer ◽  
Nikolaus Romani ◽  
...  

Abstract CD56+ human dendritic cells (DCs) have recently been shown to differentiate from monocytes in response to GM-CSF and type 1 interferon in vitro. We show here that CD56+ cells freshly isolated from human peripheral blood contain a substantial subset of CD14+CD86+HLA-DR+ cells, which have the appearance of intermediate-sized lymphocytes but spontaneously differentiate into enlarged DC-like cells with substantially increased HLA-DR and CD86 expression or into fully mature CD83+ DCs in response to appropriate cytokines. Stimulation of CD56+ cells containing both DCs and abundant γδ T cells with zoledronate and interleukin-2 (IL-2) resulted in the rapid expansion of γδ T cells as well as in IFN-γ, TNF-α, and IL-1β but not in IL-4, IL-10, or IL-17 production. IFN-γ, TNF-α, and IL-1β production were almost completely abolished by depleting CD14+ cells from the CD56+ subset before stimulation. Likewise, depletion of CD14+ cells dramatically impaired γδ T-cell expansion. IFN-γ production could also be blocked by neutralizing the effects of endogenous IL-1β and TNF-α. Conversely, addition of recombinant IL-1β, TNF-α, or both further enhanced IFN-γ production and strongly up-regulated IL-6 production. Our data indicate that CD56+ DCs from human blood are capable of stimulating CD56+ γδ T cells, which may be harnessed for immunotherapy.


1990 ◽  
Vol 110 (5) ◽  
pp. 1757-1766 ◽  
Author(s):  
W Risau ◽  
B Engelhardt ◽  
H Wekerle

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.


2016 ◽  
Vol 48 (10) ◽  
pp. 1731-1739 ◽  
Author(s):  
Theodoros Eleftheriadis ◽  
Konstantina Tsogka ◽  
Georgios Pissas ◽  
Georgia Antoniadi ◽  
Vassilios Liakopoulos ◽  
...  

2021 ◽  
Author(s):  
Sha Chen ◽  
Tingting Lv ◽  
Guangyong Sun ◽  
Shuxiang Li ◽  
Weijia Duan ◽  
...  

Abstract Background & Aims Gamma-delta (γδ) T cells are involved in the development of diverse liver and autoimmune diseases, whereas the role of γδ T cells in primary biliary cholangitis (PBC) remains unclear. Methods We analyzed the number, phenotypes, and functional molecules of γδ T cells in PBC patients (n = 74) and sex- and age-matched healthy controls (HCs) (n = 74) by flow cytometric analysis. Results We identified two distinct functional subsets of circulating γδ T cells according to the CD3/TCRγδ complex: the TCRγδhigh and TCRγδlow subsets. Approximately three-quarters of cells in the TCRγδhigh subset were Vδ1 T cells, while Vδ2 T cells were enriched in the TCRγδlow subset in HCs. The frequency and absolute number of circulating TCRγδlow cells was significantly decreased in PBC patients compared with HCs (p < 0.001). Furthermore, the frequency of TCRγδlow cells was negatively correlated with disease severity and positively correlated with the ursodeoxycholic acid response. TCRγδlow cells exhibited a similar apoptotic and proliferative phenotype but enhanced liver-homing chemokine receptor (CXCR6) expression in PBC patients compared with HCs. In addition, both TCRγδhigh and TCRγδlow subsets were more activated in PBC compared with HCs, characterized by elevated expression levels of CD69 and HLA-DR. Finally, we found an increased granzyme B (GZMB) production and similar IFN-γ and TNF-α production of TCRγδlow cells in PBC patients compared with HCs. Conclusion The TCRγδlow subset might be a potential marker for disease progression and treatment response in PBC, which may play a crucial role in liver injury through increased CXCR6 expression and GZMB production.


2011 ◽  
Vol 4 (4) ◽  
pp. 211
Author(s):  
Serena Meraviglia ◽  
Carmela La Mendola ◽  
Valentina Orlando ◽  
Francesco Scarpa ◽  
Giuseppe Cicero ◽  
...  

The potent anti-tumor activities of γδ T cells, their ability to produce pro-inflammatory cytokines, and their strong cytolytic activity have prompted the development of protocols in which γδ agonists or ex vivo-expanded γδ cells are administered to tumor patients. γδ T cells can be selectively activated by either synthetic phosphoantigens or by drugs that enhance their accumulation into stressed cells as aminobisphosphonates, thus offering new avenues for the development of γδ T cell-based immunotherapies. The recent development of small drugs selectively activating Vγ9Vδ2 T lymphocytes, which upregulate the endogenous phosphoantigens, has enabled the investigators to design the experimental approaches of cancer immunotherapies; several ongoing phase I and II clinical trials are focused on the role of the direct bioactivity of drugs and of adoptive cell therapies involving phosphoantigen- or aminobisphosphonate-activated Vγ9Vδ2 T lymphocytes in humans. In this review, we focus on the recent advances in the activation/expansion of γδ T cells in vitro and in vivo that may represent a promising target for the design of novel and highly innovative immunotherapy in patients with hematologic malignancies.<br />


Sign in / Sign up

Export Citation Format

Share Document