Project description:T cells bearing gamma delta T cell antigen receptors (TCRs) function in lymphoid stress surveillance. However, the contribution of gamma delta TCRs to such responses is unclear. Here we found that the TCR of a human V gamma4Vdelta5 clone directly bound endothelial protein C receptor (EPCR), which allowed gamma delta T cells to recognize both endothelial cells targeted by cytomegalovirus and epithelial tumors. EPCR is a major histocompatibility complex–like molecule that binds lipids analogously to the antigen-presenting molecule CD1d. However, the V gamma4Vdelta5 TCR bound EPCR independently of lipids, in an antibody-like way. Moreover, the recognition of target cells by gamma delta T cells required a multimolecular stress signature composed of EPCR and costimulatory ligand(s). Our results demonstrate how a gamma delta TCR mediates recognition of broadly stressed human cells by engaging a stress-regulated self antigen. 2E9 is an antibody that blocks gd-TCR recognition of human cells that are the targets of the clone LES. 2E9 also stains cells that are targeted by LES. Therefore, to identify the TCR ligand expressed by 2E9-positive cells, Gene Expression was compared in two cell lines that stain with 2E9 (K562 and U937) versus two cell lines that do not (Hutu80 and Huh7).
Project description:T cells bearing gamma delta T cell antigen receptors (TCRs) function in lymphoid stress surveillance. However, the contribution of gamma delta TCRs to such responses is unclear. Here we found that the TCR of a human V gamma4Vdelta5 clone directly bound endothelial protein C receptor (EPCR), which allowed gamma delta T cells to recognize both endothelial cells targeted by cytomegalovirus and epithelial tumors. EPCR is a major histocompatibility complex–like molecule that binds lipids analogously to the antigen-presenting molecule CD1d. However, the V gamma4Vdelta5 TCR bound EPCR independently of lipids, in an antibody-like way. Moreover, the recognition of target cells by gamma delta T cells required a multimolecular stress signature composed of EPCR and costimulatory ligand(s). Our results demonstrate how a gamma delta TCR mediates recognition of broadly stressed human cells by engaging a stress-regulated self antigen.
Project description:The beta2 integrin subunit (CD18) is thought to regulate gamma delta T cells in vivo. The objective of this study was to determine the gene expression changes mediated by loss of CD18 in lung gamma delta T cells. Single cell RNA sequencing was performed on gamma delta T cells (CD3+ gamma delta TCR+) isolated from the lungs of wild type C57BL/6 mice (N=2) and CD18 knockout (Itgb2-/-) mice (N=1).
Project description:Background: Malignant clones of primary cutaneous T-cell lymphomas (CTCL) can show a CD4+, CD8+ or T-cell receptor γδ+ phenotype, but their individual impact on tumor biology and skin lesion formation remains ill-defined. We perform a comprehensive molecular characterization of CD4+ vs. CD8+ and TCR-γ/δ+ CTCL lesions. Methods: We performed scRNA-seq of 18 CTCL skin biopsies to compare classic CD4+ advanced-stage mycosis fungoides (MF) with TCR-γ/δ+ MF and primary cutaneous CD8+ aggressive epidermotropic cytotoxic T-cell lymphoma (Berti’s lymphoma). Results: Malignant clones of TCR-γ/δ+ MF and Berti’s lymphoma showed similar clustering patterns distinct from CD4+ MF, along with increased expression of cytotoxic markers such as NKG7, CTSW, GZMA, and GZMM. Only advanced-stage CD4+MF clones expressed central memory T-cell markers (SELL, CCR7, LEF1), alongside B1/B2 blood involvement, whereas TCR-γ/δ+ MF and Berti’s lymphoma harbored a more tissue-resident phenotype (CD69, CXCR4, NR4A1) without detectable cells in the blood. CD4+ MF and TCR-γ/δ+ MF skin lesions harbored strong type 2 immune activation across myeloid cells, while Berti’s lymphoma was more skewed towards type 1 immune responses. Both CD4+ MF and TCR-γ/δ+ MF lesions showed upregulation of keratinocyte hyperactivation markers such as S100As and KRT16 genes. This increase was entirely absent in Berti’s lymphoma, possibly reflecting an aberrant keratinocyte response to invading tumor cells, that could contribute to the formation of the typical ulcero-necrotic lesions within this entity. Conclusions: Our scRNAseq profiling study reveals specific molecular patterns associated with distinct CTCL subtypes.
Project description:The Ag receptors on alpha/beta and gamma/delta T cells differ not only in the nature of the ligands that they recognize but also in their signaling potential. We hypothesized that the differences in alpha/beta - and gamma/delta TCR signal transduction were due to differences in the intracellular signaling pathways coupled to these two TCRs. To investigate this, we employed transcriptional profiling to identify genes encoding signaling molecules that are differentially expressed in mature alpha/beta and gamma/delta T cell populations. Unexpectedly, we found that B lymphoid kinase (Blk), a Src family kinase expressed primarily in B cells, is expressed in gamma/delta T cells but not in alpha/beta T cells. Analysis of Blk-deficient mice revealed that Blk is required for the development of IL-17-producing gamma/delta T cells. Furthermore, Blk is expressed in lymphoid precursors and, in this capacity, plays a role in regulating thymus cellularity during ontogeny. Naive alpha/beta and gamma/delta T cells isolated from mouse lymph nodes and purified by negative selection were compared using MOE430 2.0 GeneChip.