scholarly journals IL-21 inhibits IL-17A-producing γδ T-cell response after infection with Bacillus Calmette-Guérin via induction of apoptosis

2016 ◽  
Vol 22 (8) ◽  
pp. 588-597 ◽  
Author(s):  
Yinxia Huang ◽  
Yumiko Matsumura ◽  
Shinya Hatano ◽  
Naoto Noguchi ◽  
Tesshin Murakami ◽  
...  

Innate γδ T cells expressing Vγ6 produce IL-17A at an early stage following infection with Mycobacterium bovis Bacillus Calmette-Guérin (BCG). In this study, we used IL-21 receptor knockout (IL-21R KO) mice and IL-21-producing recombinant BCG mice (rBCG-Ag85B-IL-21) to examine the role of IL-21 in the regulation of IL-17A-producing innate γδ T-cell response following BCG infection. IL-17A-producing Vγ6+ γδ T cells increased in the peritoneal cavity of IL-21R KO mice more than in wild type mice after BCG infection. In contrast, the number of IL-17A-producing Vγ6+ γδ T cells was significantly lower after inoculation with rBCG-Ag85B-IL-21 compared with control rBCG-Ag85B. Notably, exogenous IL-21 selectively induced apoptosis of IL-17A-producing Vγ6+ γδ T cells via Bim. Thus, these results suggest that IL-21 acts as a potent inhibitor of a IL-17A-producing γδ T-cell subset during BCG infection.

2021 ◽  
Author(s):  
Roshni Roy Chowdhury ◽  
John R Valainis ◽  
Oliver Kask ◽  
Mane Ohanyan ◽  
Meng Sun ◽  
...  

γδ T cells contribute to host immune defense uniquely; but how they function in different stages (e.g., acute versus chronic) of a specific infection remains unclear. As the role of γδ T cells in early, active Mycobacterium tuberculosis (Mtb) infection is well documented, we focused on elucidating the γδ T cell response in persistent or controlled Mtb infection. Systems analysis of circulating gd T cells from a South African adolescent cohort identified a distinct population of CD8+ γδ T cells that expanded in this state. These cells had features indicative of persistent antigenic exposure but were robust cytolytic effectors and cytokine/chemokine producers. While these γδ T cells displayed an attenuated response to TCR-mediated stimulation, they expressed Natural Killer (NK) cell receptors and had robust CD16 (FcgRIIIA)-mediated cytotoxic response, suggesting alternative ways for gd T cells to control this stage of the infection. Despite this NK-like functionality, the CD8+ γδ T cells consisted of highly expanded clones, which utilized TCRs with different Vg/d pairs. Theses TCRs could respond to an Mtb-lysate, but not to phosphoantigens, which are components of Mtb-lysate that activate gd T cells in acute Mtb infection, indicating that the CD8+ γδ T cells were induced in a stage-specific, antigen-driven manner. Indeed, trajectory analysis showed that these γδ T cells arose from naive cells that had traversed distinct differentiation paths in this infection stage. Importantly, increased levels of CD8+ γδ T cells were also found in other chronic inflammatory conditions, including cardiovascular disease and cancer, suggesting that persistent antigenic exposure may lead to similar γδ T cell responses.


2020 ◽  
Vol 298 (1) ◽  
pp. 153-164
Author(s):  
Elena Lo Presti ◽  
Francesco Dieli ◽  
Jean Jacques Fourniè ◽  
Serena Meraviglia

2020 ◽  
Vol 4 (7) ◽  
pp. 1198-1205 ◽  
Author(s):  
Zakia Djaoud ◽  
Peter Parham

Abstract Humans form 2 groups based on their innate immunity to Epstein-Barr virus (EBV). Group 1 makes a strong natural killer (NK)–cell and γδ T-cell response, whereas group 2 makes a strong NK-cell response, but a weak γδ T-cell response. To investigate the underlying basis for this difference in γδ T-cell immunity to EBV, we used next-generation sequencing to compare the γδ T-cell receptor (TCR) repertoires of groups 1 and 2. In the absence of EBV, group 1 TCRγ chains are enriched for complementarity determining region 3 (CDR3s) containing JγP, whereas group 2 TCRγ chains are enriched for CDR3s containing Jγ2. In group 1 donors, EBV activates many γδ T cells expressing Vγ9JγP, inducing proliferation that produces a large population of activated effector cells. The TCRs using Vγ9JγP are closely related to the TCRs of γδ T cells that respond to phosphoantigens. In group 2 donors, EBV activates a small subpopulation of γδ T cells, most expressing Vγ9JγP. In conclusion, we find that differences in the TCRγ-chain repertoire underlie the differential response of group 1 and group 2 to EBV.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xiaohui Wang ◽  
Xiang Lin ◽  
Zihan Zheng ◽  
Bingtai Lu ◽  
Jun Wang ◽  
...  

AbstractInnate immunity is important for host defense by eliciting rapid anti-viral responses and bridging adaptive immunity. Here, we show that endogenous lipids released from virus-infected host cells activate lung γδ T cells to produce interleukin 17 A (IL-17A) for early protection against H1N1 influenza infection. During infection, the lung γδ T cell pool is constantly supplemented by thymic output, with recent emigrants infiltrating into the lung parenchyma and airway to acquire tissue-resident feature. Single-cell studies identify IL-17A-producing γδ T (Tγδ17) cells with a phenotype of TCRγδhiCD3hiAQP3hiCXCR6hi in both infected mice and patients with pneumonia. Mechanistically, host cell-released lipids during viral infection are presented by lung infiltrating CD1d+ B-1a cells to activate IL-17A production in γδ T cells via γδTCR-mediated IRF4-dependent transcription. Reduced IL-17A production in γδ T cells is detected in mice either lacking B-1a cells or with ablated CD1d in B cells. Our findings identify a local host-immune crosstalk and define important cellular and molecular mediators for early innate defense against lung viral infection.


2021 ◽  
Author(s):  
Aline Teixeira ◽  
Alexandria Gillespie ◽  
Alehegne Yirsaw ◽  
Emily Britton ◽  
Janice Telfer ◽  
...  

Pathogenic Leptospira species cause leptospirosis, a neglected zoonotic disease recognized as a global public health problem. It is also the cause of the most common cattle infection that results in major economic losses due to reproductive problems. γδ T cells play a role in the protective immune response in livestock species against Leptospira while human γδ T cells also respond to Leptospira. Thus, activation of γδ T cells has emerged as a potential component for optimization of vaccine strategies. Bovine γδ T cells proliferate and produce IFN-γ in response to vaccination with inactivated leptospires and this response is mediated by a specific subpopulation of the WC1-bearing γδ T cells. WC1 molecules are members of the group B scavenger receptor cysteine rich (SRCR) superfamily and are composed of multiple SRCR domains, of which particular extracellular domains act as ligands for Leptospira. Since WC1 molecules function as both pattern recognition receptors and γδ TCR coreceptors, the WC1 system has been proposed as a novel target to engage γδ T cells. Here, we demonstrate the involvement of leptospiral protein antigens in the activation of WC1+ γδ T cells and identified two leptospiral outer membrane proteins able to interact directly with them. Interestingly, we show that the protein-specific γδ T cell response is composed of WC1.1+ and WC1.2+ subsets, although a greater number of WC1.1+ γδ T cells respond. Identification of protein antigens will enhance our understanding of the role γδ T cells play in the leptospiral immune response and in recombinant vaccine development.


Author(s):  
Hannah Kaminski ◽  
Coline Ménard ◽  
Bouchra El Hayani ◽  
And-Nan Adjibabi ◽  
Gabriel Marsères ◽  
...  

Abstract Cytomegalovirus (CMV) is a major infectious cause of death and disease after transplantation. We have previously demonstrated that the tissue-associated adaptive Vδ2neg γδ T cells are key effectors responding to CMV and associated with recovery, contrasting with their innatelike circulating counterparts, the Vγ9posVδ2pos T cells that respond to phosphoantigens but not to CMV. A third Vγ9negVδ2pos subgroup with adaptive functions has been described in adults. In the current study, we demonstrate that these Vγ9negVδ2pos T cells are also components of the CMV immune response while presenting with distinct characteristics from Vδ2neg γδ T cells. In a cohort of kidney transplant recipients, CMV seropositivity was the unique clinical parameter associated with Vγ9negVδ2pos T-cell expansion and differentiation. Extensive phenotyping demonstrated their substantial cytotoxic potential and activation during acute CMV primary infection or reinfection. In vitro, Vγ9negVδ2pos T cells responded specifically to CMV-infected cells in a T-cell receptor–dependent manner and through strong interferon γ production. Finally, Vγ9negVδ2pos T cells were the only γδ T-cell subset in which expansion was tightly correlated with the severity of CMV disease. To conclude, our results identify a new player in the immune response against CMV and open interesting clinical perspectives for using Vγ9negVδ2pos T cells as an immune marker for CMV disease severity in immunocompromised patients.


1993 ◽  
Vol 23 (8) ◽  
pp. 2034-2037 ◽  
Author(s):  
T. Petteri Arstila ◽  
Paavo Toivanen ◽  
Olli Lassila

2015 ◽  
Vol 22 (7) ◽  
pp. 742-753 ◽  
Author(s):  
Wendy C. Brown ◽  
Joshua E. Turse ◽  
Paulraj K. Lawrence ◽  
Wendell C. Johnson ◽  
Glen A. Scoles ◽  
...  

ABSTRACTWe have shown that in cattle previously immunized with outer membrane proteins, infection withAnaplasma marginaleinduces a functionally exhausted CD4 T-cell response to theA. marginaleimmunogen. Furthermore, T-cell responses following infection in nonimmunized cattle had a delayed onset and were sporadic and transient during persistent infection. The induction of an exhausted T-cell response following infection presumably facilitates pathogen persistence. In the current study, we hypothesized that the loss of epitope-specific T-cell responses requires the presence of the immunizing epitope on the pathogen, and T-cell dysfunction correlates with the appearance of regulatory T cells. In limited studies in cattle, regulatory T cells have been shown to belong to γδ T-cell subsets rather than be CD4 T cells expressing forkhead box protein P3 (FoxP3). Cattle expressing the DRB3*1101 haplotype were immunized with a truncatedA. marginalemajor surface protein (MSP) 1a that contains a DRB3*1101-restricted CD4 T-cell epitope, F2-5B. Cattle either remained unchallenged or were challenged withA. marginalebacteria that express the epitope or withA. marginalesubsp.centralethat do not. Peripheral blood and spleen mononuclear cells were monitored for MSP1a epitope F2-5B-specfic T-cell proliferative responses and were stained for γδ T-cell subsets or CD4+CD25+FoxP3+T cells before and during infection. As hypothesized, the induction of T-cell exhaustion occurred only following infection withA. marginale, which did not correlate with an increase in either CD4+CD25+FoxP3+T cells or any γδ T-cell subset examined.


2015 ◽  
Vol 112 (6) ◽  
pp. E556-E565 ◽  
Author(s):  
Tanya Dimova ◽  
Margreet Brouwer ◽  
Françoise Gosselin ◽  
Joël Tassignon ◽  
Oberdan Leo ◽  
...  

γδ T cells are unconventional T cells recognizing antigens via their γδ T-cell receptor (TCR) in a way that is fundamentally different from conventional αβ T cells. γδ T cells usually are divided into subsets according the type of Vγ and/or Vδ chain they express in their TCR. T cells expressing the TCR containing the γ-chain variable region 9 and the δ-chain variable region 2 (Vγ9Vδ2 T cells) are the predominant γδ T-cell subset in human adult peripheral blood. The current thought is that this predominance is the result of the postnatal expansion of cells expressing particular complementary-determining region 3 (CDR3) in response to encounters with microbes, especially those generating phosphoantigens derived from the 2-C-methyl-d-erythritol 4-phosphate pathway of isoprenoid synthesis. However, here we show that, rather than requiring postnatal microbial exposure, Vγ9Vδ2 T cells are the predominant blood subset in the second-trimester fetus, whereas Vδ1+ and Vδ3+ γδ T cells are present only at low frequencies at this gestational time. Fetal blood Vγ9Vδ2 T cells are phosphoantigen responsive and display very limited diversity in the CDR3 of the Vγ9 chain gene, where a germline-encoded sequence accounts for >50% of all sequences, in association with a prototypic CDR3δ2. Furthermore, these fetal blood Vγ9Vδ2 T cells are functionally preprogrammed (e.g., IFN-γ and granzymes-A/K), with properties of rapidly activatable innatelike T cells. Thus, enrichment for phosphoantigen-responsive effector T cells has occurred within the fetus before postnatal microbial exposure. These various characteristics have been linked in the mouse to the action of selecting elements and would establish a much stronger parallel between human and murine γδ T cells than is usually articulated.


2006 ◽  
Vol 7 (1-2) ◽  
pp. 81-96 ◽  
Author(s):  
Wasin Charerntantanakul ◽  
James A. Roth

The present review concentrates on the biological aspects of porcine T lymphocytes. Their ontogeny, subpopulations, localization and trafficking, and responses to pathogens are reviewed. The development of porcine T cells begins in the liver during the first trimester of fetal life and continues in the thymus from the second trimester until after birth. Porcine T cells are divided into two lineages, based on their possession of the [@@@]\rmalpha [@@@]β or γδ T-cell receptor. Porcine [@@@]\rmalpha [@@@]β T cells recognize antigens in a major histocompatibility complex (MHC)-restricted manner, whereas the γδ T cells recognize antigens in a MHC non-restricted fashion. The CD4+CD8−and CD4+CD8loT cell subsets of [@@@]\rmalpha [@@@]β T cells recognize antigens presented in MHC class II molecules, while the CD4−CD8+T cell subset recognizes antigens presented in MHC class I molecules. Porcine [@@@]\rmalpha [@@@]β T cells localize mainly in lymphoid tissues, whereas γδ T cells predominate in the blood and intestinal epithelium of pigs. Porcine CD8+[@@@]\rmalpha [@@@]β T cells are a prominent T-cell subset during antiviral responses, while porcine CD4+[@@@]\rmalpha [@@@]β T cell responses predominantly occur in bacterial and parasitic infections. Porcine γδ T cell responses have been reported in only a few infections. Porcine T cell responses are suppressed by some viruses and bacteria. The mechanisms of T cell suppression are not entirely known but reportedly include the killing of T cells, the inhibition of T cell activation and proliferation, the inhibition of antiviral cytokine production, and the induction of immunosuppressive cytokines.


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