scholarly journals Revisiting the Role of γδ T Cells in Anti-CMV Immune Response after Transplantation

Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1031
Author(s):  
Ahmed Gaballa ◽  
Faisal Alagrafi ◽  
Michael Uhlin ◽  
Arwen Stikvoort
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Cell ◽  
Γδ T Cells ◽  
Cell Receptor ◽  
Post Transplantation ◽  
Tcr Repertoire ◽  
Next Generation Sequencing Ngs

Gamma delta (γδ) T cells form an unconventional subset of T lymphocytes that express a T cell receptor (TCR) consisting of γ and δ chains. Unlike conventional αβ T cells, γδ T cells share the immune signature of both the innate and the adaptive immunity. These features allow γδ T cells to act in front-line defense against infections and tumors, rendering them an attractive target for immunotherapy. The role of γδ T cells in the immune response to cytomegalovirus (CMV) has been the focus of intense research for several years, particularly in the context of transplantation, as CMV reactivation remains a major cause of transplant-related morbidity and mortality. Therefore, a better understanding of the mechanisms that underlie CMV immune responses could enable the design of novel γδ T cell-based therapeutic approaches. In this regard, the advent of next-generation sequencing (NGS) and single-cell TCR sequencing have allowed in-depth characterization of CMV-induced TCR repertoire changes. In this review, we try to shed light on recent findings addressing the adaptive role of γδ T cells in CMV immunosurveillance and revisit CMV-induced TCR reshaping in the era of NGS. Finally, we will demonstrate the favorable and unfavorable effects of CMV reactive γδ T cells post-transplantation.

scholarly journals The role of unconventional T cells in COVID-19

2021 ◽  
Author(s):  
Kristen Orumaa ◽  
Margaret R. Dunne
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Cell ◽  
Treatment Strategies ◽  
Γδ T Cells ◽  
Protective Role ◽  
T Cell Subsets ◽  
Viral Immunity ◽  
Mait Cells

AbstractCOVID-19 is a respiratory disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It was first documented in late 2019, but within months, a worldwide pandemic was declared due to the easily transmissible nature of the virus. Research to date on the immune response to SARS-CoV-2 has focused largely on conventional B and T lymphocytes. This review examines the emerging role of unconventional T cell subsets, including γδ T cells, invariant natural killer T (iNKT) cells and mucosal associated invariant T (MAIT) cells in human SARS-CoV-2 infection.Some of these T cell subsets have been shown to play protective roles in anti-viral immunity by suppressing viral replication and opsonising virions of SARS-CoV. Here, we explore whether unconventional T cells play a protective role in SARS-CoV-2 infection as well. Unconventional T cells are already under investigation as cell-based immunotherapies for cancer. We discuss the potential use of these cells as therapeutic agents in the COVID-19 setting. Due to the rapidly evolving situation presented by COVID-19, there is an urgent need to understand the pathogenesis of this disease and the mechanisms underlying its immune response. Through this, we may be able to better help those with severe cases and lower the mortality rate by devising more effective vaccines and novel treatment strategies.

scholarly journals T Cell Receptor Specificity Is Critical for the Development of Epidermal γδ T Cells

2001 ◽  
Vol 194 (10) ◽  
pp. 1473-1483 ◽  
Author(s):  
Isabel Ferrero ◽  
Anne Wilson ◽  
Friedrich Beermann ◽  
Werner Held ◽  
H. Robson MacDonald
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Cell Biology ◽  
Γδ T Cells ◽  
Cell Receptor ◽  
Wild Type ◽  
Normal Numbers ◽  
T Cell Biology

A particular feature of γδ T cell biology is that cells expressing T cell receptor (TCR) using specific Vγ/Vδ segments are localized in distinct epithelial sites, e.g., in mouse epidermis nearly all γδ T cells express Vγ3/Vδ1. These cells, referred to as dendritic epidermal T cells (DETC) originate from fetal Vγ3+ thymocytes. The role of γδ TCR specificity in DETC's migration/localization to the skin has remained controversial. To address this issue we have generated transgenic (Tg) mice expressing a TCR δ chain (Vδ6.3-Dδ1-Dδ2-Jδ1-Cδ), which can pair with Vγ3 in fetal thymocytes but is not normally expressed by DETC. In wild-type (wt) Vδ6.3Tg mice DETC were present and virtually all of them express Vδ6.3. However, DETC were absent in TCR-δ−/− Vδ6.3Tg mice, despite the fact that Vδ6.3Tg γδ T cells were present in normal numbers in other lymphoid and nonlymphoid tissues. In wt Vδ6.3Tg mice, a high proportion of in-frame Vδ1 transcripts were found in DETC, suggesting that the expression of an endogenous TCR-δ (most probably Vδ1) was required for the development of Vδ6.3+ epidermal γδ T cells. Collectively our data demonstrate that TCR specificity is essential for the development of γδ T cells in the epidermis. Moreover, they show that the TCR-δ locus is not allelically excluded.

scholarly journals The T cell receptor repertoire reflects the dynamics of the immune response to vaccination

2021 ◽  
Author(s):  
Kevin Mohammed ◽  
Austin Meadows ◽  
Sandra Hatem ◽  
Viviana Simon ◽  
Anitha D Jayaprakash ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Cell ◽  
Influenza Vaccine ◽  
T Cell Receptor ◽  
Cell Response ◽  
Cell Receptor ◽  
Physical Symptoms ◽  
T Cell Response ◽  
Tcr Repertoire

Early, high-resolution metrics are needed to ascertain the immune response to vaccinations. The T cell receptor (TCR), a heterodimer of one α and one β chain, is a promising target, with the complete TCR repertoire reflecting the T cells present in an individual. To this end, we developed Tseek, an unbiased and accurate method for profiling the TCR repertoire by sequencing the TCR α and β chains and developing a suite of tools for repertoire analysis. An added advantage is the ability to non-invasively analyze T cells in peripheral blood mononuclear cells (PBMCs). Tseek and the analytical suite were used to explore the T cell response to both the COVID-19 mRNA vaccine (n=9) and the seasonal inactivated Influenza vaccine (n=5) at several time points. Neutralizing antibody titers were also measured in the covid vaccine samples. The COVID-19 vaccine elicited a broad T cell response involving multiple expanded clones, whereas the Influenza vaccine elicited a narrower response involving fewer clones. Many distinct T cell clones responded at each time point, over a month, providing temporal details lacking in the antibody measurements, especially before the antibodies are detectable. In individuals recovered from a SARS-CoV-2 infection, the first vaccine dose elicited a robust T cell response, while the second dose elicited a comparatively weaker response, indicating a saturation of the response. The physical symptoms experienced by the recipients immediately following the vaccinations were not indicative of the TCR/antibody responses, while a weak TCR response seemed to presage a weak antibody response. We also found that the TCR repertoire acts as an individual fingerprint: donors of blood samples taken years apart could be identified solely based upon their TCR repertoire, hinting at other surprising uses the TCR repertoire may have. These results demonstrate the promise of TCR repertoire sequencing as an early and sensitive measure of the adaptive immune response to vaccination, which can help improve immunogen selection and optimize vaccine dosage and spacing between doses.

scholarly journals Donor γδ T Lymphocytes Promote Allogeneic Engraftment Across the Major Histocompatibility Barrier in Mice

Blood ◽  
1997 ◽  
Vol 89 (3) ◽  
pp. 1100-1109 ◽  
Author(s):  
William R. Drobyski ◽  
David Majewski
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Γδ T Cells ◽  
Cell Receptor ◽  
Marrow Graft ◽  
Hematopoietic Reconstitution ◽  
Donor T Cells ◽  
Αβ T Cells

Abstract T cells that express the αβ T-cell receptor are thought to be the T-cell population primarily responsible for facilitating alloengraftment. The role of γδ+ T cells that comprise only a minority of mature T cells in promoting allogeneic engraftment, however, has not been extensively studied. The purpose of this study was to determine whether γδ T cells were capable of facilitating alloengraftment in murine recipients of major histocompatibility complex-mismatched marrow grafts. We developed a model where engraftment of C57BL/6 × 129/F2 (H-2b) marrow in sublethally irradiated (800 cGy) recipients (AKR/J, H-2k) is dependent on the presence of mature donor T cells in the marrow graft. In this model, donor T-cell engraftment was significantly augmented by as few as 1 × 105 αβ T cells. The role of γδ T cells was then investigated using transgenic donors (C57BL/6 × 129 background) in which a portion of the T-cell receptor–β chain gene was deleted by gene targeting so that these mice lack αβ T cells. Addition of 10 × 106 naive γδ T cells to T-cell depleted marrow grafts was required to significantly increase alloengraftment, although donor T cells averaged <50% of total splenic T cells. To determine whether higher doses of γδ T cells would improve donor engraftment and eradicate residual host T cells, γδ T cells were ex vivo expanded with a γδ T-cell–specific monoclonal antibody and interleukin-2 and then transplanted into irradiated recipients. Transplantation of ≥ 160 × 106 activated γδ T cells was necessary to consistently and significantly augment donor cell chimerism and enhance hematopoietic reconstitution when compared to control mice, but host T cells persisted in these chimeras. Addition of 2.5 × 104 mature αβ T cells, which alone were incapable of facilitating engraftment, to T-cell depleted marrow grafts containing 160 × 106 activated γδ T cells resulted in long-term (<100 day) complete donor engraftment, indicating that limiting numbers of αβ T cells were required in the marrow graft for the eradication of residual host T cells. Using serial weight curves and B-cell reconstitution as end points, clinically significant graft-versus-host disease was not observed in these chimeras under these experimental conditions. These data show that, whereas less potent than αβ T cells, γδ T cells are able to promote engraftment and enhance hematopoietic reconstitution in allogeneic marrow transplant recipients.

scholarly journals Role of αβ and γδ T Cells in the Host Response toSalmonella Infection as Demonstrated in T-Cell-Receptor-Deficient Mice of Defined Ity Genotypes

1998 ◽  
Vol 66 (2) ◽  
pp. 882-882
Author(s):  
Bennett C. Weintraub ◽  
Lars Eckmann ◽  
Sharon Okamoto ◽  
Marc Hense ◽  
Stephen M. Hedrick ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Host Response ◽  
Γδ T Cells ◽  
Cell Receptor ◽  
Deficient Mice

scholarly journals T cell receptor is required for differentiation but not maintenance of intestinal intraepithelial lymphocytes

2020 ◽  
Author(s):  
Angelina M. Bilate ◽  
Mariya London ◽  
Tiago B. R. Castro ◽  
Luka Mesin ◽  
Suppawat Kongthong ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Cell Receptor ◽  
Intraepithelial Lymphocytes ◽  
Intestinal Epithelial ◽  
Conditional Deletion ◽  
Tcr Repertoire ◽  
Regulatory Properties

SummaryThe gut epithelium is populated by intraepithelial lymphocytes (IELs), a heterogeneous T cell population with cytotoxic and regulatory properties. Migrating peripheral CD4+ T cells, including regulatory (Treg) and conventional T cells (Tconv), acquire an IEL (CD4-IEL) program upon arrival at the epithelium. However, the specific role of the T cell receptor (TCR) in this process remains unclear. Single-cell TCR repertoire and transcriptomic analysis of intraepithelial CD4+ T cells revealed different extents of clonal expansion and TCR overlap between cell states; fully differentiated CD4-IELs from Tregs or Tconvs were the least diverse. Conditional deletion of TCR on differentiating CD4+ T cells or of MHCII on intestinal epithelial cells prevented CD4-IEL differentiation. However, TCR ablation on developed CD4-IELs did not affect their accumulation. These results indicate that local recognition of a limited set of antigens is an essential signal for the differentiation and adaptation of T cells to the epithelium.

scholarly journals Immunosurveillance by human γδ T lymphocytes: the emerging role of butyrophilins

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 782 ◽  
Author(s):  
Dieter Kabelitz ◽  
Marcus Lettau ◽  
Ottmar Janssen
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Lymphocytes ◽  
T Cell Receptor ◽  
T Cell Activation ◽  
Γδ T Cells ◽  
Cellular Transformation ◽  
Cell Receptor ◽  
Γδ T Cell

In contrast to conventional T lymphocytes, which carry an αβ T-cell receptor and recognize antigens as peptides presented by major histocompatibility complex class I or class II molecules, human γδ T cells recognize different metabolites such as non-peptidic pyrophosphate molecules that are secreted by microbes or overproduced by tumor cells. Hence, γδ T cells play a role in immunosurveillance of infection and cellular transformation. Until recently, it has been unknown how the γδ T-cell receptor senses such pyrophosphates in the absence of known antigen-presenting molecules. Recent studies from several groups have identified a unique role of butyrophilin (BTN) protein family members in this process, notably of BTN3A1. BTNs are a large family of transmembrane proteins with diverse functions in lipid secretion and innate and adaptive immunity. Here we discuss current models of how BTN molecules regulate γδ T-cell activation. We also address the implications of these recent findings on the design of novel immunotherapeutic strategies based on the activation of γδ T cells.

scholarly journals Crucial role of the pre-T-cell receptor α gene in development of ap but not γδ T cells

Nature ◽  
1995 ◽  
Vol 375 (6534) ◽  
pp. 795-798 ◽  
Author(s):  
Hans Jörg Fehling ◽  
Anna Krotkova ◽  
Claude Saint-Ruf ◽  
Harald von Boehmer
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Crucial Role ◽  
Γδ T Cells ◽  
Cell Receptor

scholarly journals Essential and Partially Overlapping Role of CD3γ and CD3δ for Development of αβ and γδ T Lymphocytes

1998 ◽  
Vol 188 (7) ◽  
pp. 1375-1380 ◽  
Author(s):  
Baoping Wang ◽  
Ninghai Wang ◽  
Mariolina Salio ◽  
Arlene Sharpe ◽  
Deborah Allen ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Gene Knockout ◽  
Γδ T Cells ◽  
Cell Receptor ◽  
Γδ T Cell ◽  
Thymic Development ◽  
Gene Knockout Mice

CD3γ and CD3δ are two highly related components of the T cell receptor (TCR)–CD3 complex which is essential for the assembly and signal transduction of the T cell receptor on mature T cells. In gene knockout mice deficient in either CD3δ or CD3γ, early thymic development mediated by pre-TCR was either undisturbed or severely blocked, respectively, and small numbers of TCR-αβ+ T cells were detected in the periphery of both mice. γδ T cell development was either normal in CD3δ−/− mice or partially blocked in CD3γ−/− mice. To examine the collective role of CD3γ and CD3δ in the assembly and function of pre-TCR and in the development of γδ T cells, we generated a mouse strain with a disruption in both CD3γ and CD3δ genes (CD3γδ−/−). In contrast to mice deficient in either CD3γ or CD3δ chains, early thymic development mediated by pre-TCR is completely blocked, and TCR-αβ+ or TCR-γδ+ T cells were absent in the CD3γδ−/− mice. Taken together, these studies demonstrated that CD3γ and CD3δ play an essential, yet partially overlapping, role in the development of both αβ and γδ T cell lineages.

Exacerbating Role of γδ T Cells in Chronic Colitis of T-Cell Receptor α Mutant Mice

2008 ◽  
Vol 134 (2) ◽  
pp. 481-490 ◽  
Author(s):  
Masanobu Nanno ◽  
Yasuyoshi Kanari ◽  
Tomoaki Naito ◽  
Nagamu Inoue ◽  
Tadakazu Hisamatsu ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Γδ T Cells ◽  
Cell Receptor ◽  
Mutant Mice ◽  
Chronic Colitis
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