Project description:In order to characterize pathogen specific T cell responses against Salmonella volunteers challenged with Salmonella enterica serovar Typhi (S. Typhi) or Salmonella Paratyphi A (S. Paratyphi). we used mass cytometry, to identify effector CD4+ T cells circulating during infection. We identified a population of CCR7-CD38+ cells accumulating during infection, and via unbiased single cell cloning and expansion we demonstrated that these CCR7-CD38+ cells are enriched in Salmonella specific T cells. In this experiment we performed TCR repertoire analysis of CCR7-CD38+ and CCR7-CD38- cells to determine the clonality of CCR7-CD38+ cells, the overlap between the repertoire of CCR7-CD38+ cells and of non-activated effector CCR7-CD38- cells, and to identify within CCR7-CD38+ and CCR7-CD38- cells the presence of the CDR3b TCR sequence of the pathogen specific T cell clones isolated from CCR7-CD38+ cells
Project description:Mucosal-associated invariant T (MAIT) cells are innate-like T cells that recognize microbial metabolites through a semi-invariant T cell receptor (TCR). Major questions remain regarding the extent of human MAIT cell functional and clonal diversity. To address these, we analyzed the single-cell transcriptome and TCR repertoire of blood and liver MAIT cells and developed functional RNA sequencing, a method to integrate function and TCR clonotype at single-cell resolution. MAIT cell clonal diversity was comparable to conventional memory T cells, with private TCR repertoires shared across matched tissues. Baseline functional diversity was low and largely related to tissue site. MAIT cells showed stimulus-specific transcriptional responses in vitro, with cells positioned along gradients of activation. Clonal identity influenced resting and activated transcriptional profiles but intriguingly was not associated with the capacity to produce IL- 17. Overall, MAIT cells show phenotypic and functional diversity according to tissue localization, stimulation environment and clonotype.
Project description:Mucosal-associated invariant T (MAIT) cells are innate-like T cells that recognize microbial metabolites through a semi-invariant T cell receptor (TCR). Major questions remain regarding the extent of human MAIT cell functional and clonal diversity. To address these, we analyzed the single-cell transcriptome and TCR repertoire of blood and liver MAIT cells and developed functional RNA sequencing, a method to integrate function and TCR clonotype at single-cell resolution. MAIT cell clonal diversity was comparable to conventional memory T cells, with private TCR repertoires shared across matched tissues. Baseline functional diversity was low and largely related to tissue site. MAIT cells showed stimulus-specific transcriptional responses in vitro, with cells positioned along gradients of activation. Clonal identity influenced resting and activated transcriptional profiles but intriguingly was not associated with the capacity to produce IL- 17. Overall, MAIT cells show phenotypic and functional diversity according to tissue localization, stimulation environment and clonotype.
Project description:Mucosal-associated invariant T (MAIT) cells are innate-like T cells that recognize microbial metabolites through a semi-invariant T cell receptor (TCR). Major questions remain regarding the extent of human MAIT cell functional and clonal diversity. To address these, we analyzed the single-cell transcriptome and TCR repertoire of blood and liver MAIT cells and developed functional RNA sequencing, a method to integrate function and TCR clonotype at single-cell resolution. MAIT cell clonal diversity was comparable to conventional memory T cells, with private TCR repertoires shared across matched tissues. Baseline functional diversity was low and largely related to tissue site. MAIT cells showed stimulus-specific transcriptional responses in vitro, with cells positioned along gradients of activation. Clonal identity influenced resting and activated transcriptional profiles but intriguingly was not associated with the capacity to produce IL- 17. Overall, MAIT cells show phenotypic and functional diversity according to tissue localization, stimulation environment and clonotype.
Project description:MAIT cells are innate-like T cells that recognize microbial metabolites through a semi-invariant T cell receptor (TCR). Major questions remain regarding the extent of human MAIT cell functional and clonal diversity. To address these, we analyzed the single-cell transcriptome and TCR repertoire of blood and liver MAIT cells and developed functional RNA-sequencing (fRNA-seq), a method to integrate function and TCR clonotype at single-cell resolution. MAIT cell clonal diversity was comparable to conventional memory T cells, with private TCR repertoires shared across matched tissues. Baseline functional diversity was low and largely related to tissue site. MAIT cells showed stimulus-specific transcriptional responses in vitro, with cells positioned along gradients of activation. Clonal identity influenced resting and activated transcriptional profiles, but intriguingly was not associated with the capacity to produce IL-17. Overall, MAIT cells show phenotypic and functional diversity according to tissue localization, stimulation environment, and clonotype.
Project description:MAIT cells are innate-like T cells that recognize microbial metabolites through a semi-invariant T cell receptor (TCR). Major questions remain regarding the extent of human MAIT cell functional and clonal diversity. To address these, we analyzed the single-cell transcriptome and TCR repertoire of blood and liver MAIT cells and developed functional RNA-sequencing (fRNA-seq), a method to integrate function and TCR clonotype at single-cell resolution. MAIT cell clonal diversity was comparable to conventional memory T cells, with private TCR repertoires shared across matched tissues. Baseline functional diversity was low and largely related to tissue site. MAIT cells showed stimulus-specific transcriptional responses in vitro, with cells positioned along gradients of activation. Clonal identity influenced resting and activated transcriptional profiles, but intriguingly was not associated with the capacity to produce IL-17. Overall, MAIT cells show phenotypic and functional diversity according to tissue localization, stimulation environment, and clonotype.
Project description:<p>Diversity and size of the antigen-specific T cell receptor (TCR) repertoire are two critical determinants for successful control of chronic infection. Varicella zoster virus (VZV) that establishes latency during childhood is able to escape control mechanisms, in particular with increasing age. We examined the TCR diversity of VZV-specific CD4 T cells in individuals older than 50 years by studying three identical twin pairs and three unrelated individuals before and after vaccination with live attenuated VZV. While all individuals had a small number of dominant T cell clones, the breadth of the VZV-specific repertoire differed markedly among different individuals. A genetic influence was seen for the sharing of individual TCR sequences from antigen-specific cells, but not for repertoire richness or the selection of clonal dominance. VZV vaccination favored the expansion of infrequent VZV-specific TCRs including those from naïve T cells while leaving dominant T cell clones mostly unaffected.</p>
Project description:Tissue repair processes maintain proper organ function following mechanical or infection related damage. In addition to anti-bacterial properties, MAIT cells express a tissue repair transcriptomic program and promote skin wound healing when expanded. Herein, we use a human‑like full‑thickness skin excision mouse model to assess the underlying mechanisms of MAIT cell tissue repair function. Single-cell RNAseq analysis suggests that skin MAIT cells already express a repair program at steady state. Following skin excision, MAIT cells promote keratinocyte proliferation thereby accelerating healing. Using skin grafts, parabiosis and adoptive transfer experiments, we show that MAIT cells migrate into the wound from other tissues in a TCR independent but CXCR6 dependent manner. Amphiregulin secreted by MAIT cells following excision promotes wound healing. The repair function is independent of sustained TCR stimulation. Overall, our study provides mechanistic insight into MAIT cell wound healing function in the skin.
Project description:Transcriptional profiling of human mesenchymal stem cells comparing normoxic MSCs cells with hypoxic MSCs cells. Hypoxia may inhibit senescence of MSCs during expansion. Goal was to determine the effects of hypoxia on global MSCs gene expression.