Project description:Tissue-resident memory CD8 T cells (TRM) provide protection from infection at barrier sites. In the small intestine, TRM cells are found in at least two distinct subpopulations: one with higher expression of effector molecules and another with greater memory potential. However, the origins of this diversity remain unknown. We proposed that distinct tissue niches drive TRM phenotypic heterogeneity. To test this, we leveraged spatial transcriptomics of human samples, a murine model of acute systemic viral infection, and a newly established strategy for pooled optically-encoded gene perturbations to profile the location, interaction, and transcriptome of pathogen-specific TRM differentiation at single-transcript resolution. We developed computational approaches to capture cellular locations along three anatomical axes of the small intestine and to visualize the spatiotemporal distribution of cell types and gene expression. Our study reveals that the intestinal architecture’s regionalized signaling supports two distinct TRM cell states: differentiated TRM and progenitor-like TRM cells, located in the upper versus lower villus, respectively. This diversity is mediated by distinct ligand-receptor activities, cytokine gradients, and specialized cellular contacts. Blocking TGFb or Cxcl9/10-sensing by antigen-specific CD8 T cells revealed a model consistent with anatomically delineated early fate specification. Ultimately, our framework for the study of tissue immune networks has revealed that T cell location and functional state are fundamentally intertwined.
Project description:Tissue-resident memory CD8 T cells (TRM) provide protection from infection at barrier sites. In the small intestine, TRM cells are found in at least two distinct subpopulations: one with higher expression of effector molecules and another with greater memory potential. However, the origins of this diversity remain unknown. We proposed that distinct tissue niches drive TRM phenotypic heterogeneity. To test this, we leveraged spatial transcriptomics of human samples, a murine model of acute systemic viral infection, and a newly established strategy for pooled optically-encoded gene perturbations to profile the location, interaction, and transcriptome of pathogen-specific TRM differentiation at single-transcript resolution. We developed computational approaches to capture cellular locations along three anatomical axes of the small intestine and to visualize the spatiotemporal distribution of cell types and gene expression. Our study reveals that the intestinal architecture’s regionalized signaling supports two distinct TRM cell states: differentiated TRM and progenitor-like TRM cells, located in the upper versus lower villus, respectively. This diversity is mediated by distinct ligand-receptor activities, cytokine gradients, and specialized cellular contacts. Blocking TGF or Cxcl9/10-sensing by antigen-specific CD8 T cells revealed a model consistent with anatomically delineated early fate specification. Ultimately, our framework for the study of tissue immune networks has revealed that T cell location and functional state are fundamentally intertwined.
Project description:Tissue-resident memory CD8 T (TRM) cells provide protection from infection at barrier sites. In the small intestine, TRM cells are found in at least two distinct subpopulations: one with higher expression of effector molecules and another with greater memory potential1. However, the origins of this diversity remain unknown. Here we proposed that distinct tissue niches drive the phenotypic heterogeneity of TRM cells. To test this, we leveraged spatial transcriptomics of human samples, a mouse model of acute systemic viral infection and a newly established strategy for pooled optically encoded gene perturbations to profile the locations, interactions and transcriptomes of pathogen-specific TRM cell differentiation at single-transcript resolution. We developed computational approaches to capture cellular locations along three anatomical axes of the small intestine and to visualize the spatiotemporal distribution of cell types and gene expression. Our study reveals that the regionalized signalling of the intestinal architecture supports two distinct TRM cell states: differentiated TRM cells and progenitor-like TRM cells, located in the upper villus and lower villus, respectively. This diversity is mediated by distinct ligand-receptor activities, cytokine gradients and specialized cellular contacts. Blocking TGFβ or CXCL9 and CXCL10 sensing by antigen-specific CD8 T cells revealed a model consistent with anatomically delineated, early fate specification. Ultimately, our framework for the study of tissue immune networks reveals that T cell location and functional state are fundamentally intertwined.
Project description:Tissue-resident memory CD8 T cells (TRM) provide protection from infection at barrier sites. In the small intestine, TRM cells are found in at least two distinct subpopulations: one with higher expression of effector molecules and another with greater memory potential. However, the origins of this diversity remain unknown. We proposed that distinct tissue niches drive TRM phenotypic heterogeneity. To test this, we leveraged spatial transcriptomics of human samples, a murine model of acute systemic viral infection, and a newly established strategy for pooled optically-encoded gene perturbations to profile the location, interaction, and transcriptome of pathogen-specific TRM differentiation at single-transcript resolution. We developed computational approaches to capture cellular locations along three anatomical axes of the small intestine and to visualize the spatiotemporal distribution of cell types and gene expression. Our study reveals that the intestinal architecture’s regionalized signaling supports two distinct TRM cell states: differentiated TRM and progenitor-like TRM cells, located in the upper versus lower villus, respectively. This diversity is mediated by distinct ligand-receptor activities, cytokine gradients, and specialized cellular contacts. Blocking TGF or Cxcl9/10-sensing by antigen-specific CD8 T cells revealed a model consistent with anatomically delineated early fate specification. Ultimately, our framework for the study of tissue immune networks has revealed that T cell location and functional state are fundamentally intertwined.
Project description:Tissue-resident memory CD8 T cells (TRM) kill infected cells and recruit additional immune cells to limit pathogen invasion at barrier sites. Small intestinal (SI) TRM cells consist of distinct subpopulations with higher expression of effector molecules or greater memory potential. We hypothesized that occupancy of diverse anatomical niches imprints these distinct TRM transcriptional programs. We leveraged human samples and a murine model of acute systemic viral infection to profile the location and transcriptome of pathogen-specific TRM cell differentiation at single-transcript resolution. We developed computational approaches to capture cellular locations along three anatomical axes of the small intestine and to visualize the spatiotemporal distribution of cell types and gene expression. TRM populations were spatially segregated: with more effector- and memory-like TRM preferentially localized at the villus tip or crypt, respectively. Modeling ligand-receptor activity revealed patterns of key cellular interactions and cytokine signaling pathways that initiate and maintain TRM differentiation and functional diversity, including different TGFβ sources. Alterations in the cellular networks induced by loss of TGFβRII expression revealed a model consistent with TGFβ promoting progressive TRM maturation towards the villus tip. Ultimately, we have developed a framework for the study of immune cell interactions with the spectrum of tissue cell types, revealing that T cell location and functional state are fundamentally intertwined.
Project description:Tissue resident memory T cells (TRM) provide superior protection against infection localised to extra-lymphoid compartments in the body. Here we show that CD103+CD8+ TRM cells develop in skin from killer cell lectin-like receptor (KLR)G1-negative precursors that selectively infiltrate the epithelial layer. In the skin, a combination of chemokine-guided epithelial entry, local interleukin (IL)-15 and transforming growth factor (TGF)-β signalling is required for formation and survival of these long-lived memory cells. Importantly, TRM differentiation results in the gradual acquisition of a unique transcriptional profile that differs from that expressed by memory cells in the circulation and other types of skin-resident intra-epithelial T cells, such as the dendritic epidermal T cells (DETC). We provide a comprehensive molecular and developmental framework for the local differentiation of a distinct type of peripheral memory T cell that contributes to an important first-line of immune defence in barrier tissues such as skin and mucosa. 24 samples were analyzed: 3 replicates of memory gB-T CD8+. CD103+ T cells isolated from the skin of C57/BL6 mice on day 30 p.i. with HSV KOS. 3 replicates of memory P14 CD8+ T cells isolated from gut of mice on day 60 p.i. with LCMV Armstrong. 3 replicates of memory gB-T CD8+ T cells from the lung of mice on day 30 p.i. with influenza WSN. 3 replicates of memory CD62L high CD8+ T cells from the spleen of mice on day 30 p.i. with HSV KOS. 3 replicates of memory CD62L low CD8+ T cells from the spleen of mice of day 30 p.i. with HSV KOS. 3 replicates of γδ-DETC isolated from the skin of C57/BL6 mice on day 30 p.i. with HSV KOS. 3 replicates of αβ-DETC from naive TCRδ-/- mice; and 3 replicates of naive gB-T CD8+ T cells from the spleen of naive gB-T transgenic mice.
Project description:Tissue resident memory (Trm) represent a newly described memory T cell population. We have previously characterized a population of Trm that persists within the brain following acute virus infection. Although capable of providing marked protection against a subsequent local challenge, brain Trm do not undergo recall expansion following dissociation from the tissue. Furthermore, these Trm do not depend on the same survival factors as the circulating memory T cell pool as assessed either in vivo or in vitro. To gain greater insight into this population of cells we compared the gene-expression profiles of Trm isolated from the brain to circulating memory T cells isolated from the spleen following an acute virus infection. Trm displayed altered expression of genes involved in chemotaxis, expressed a distinct set of transcription factors and overexpressed several inhibitory receptors. Cumulatively, these data indicates that Trm are a distinct memory T cell population disconnected from the circulating memory T cell pool and displaying a unique molecular signature which likely results in optimal survival and function within their local environment. 13 samples were analyzed: 5 replicates of memory OT-I CD8+.CD103- T cells isolated from the spleen of mice on day 20 p.i. with VSV-OVA. 5 replicates of memory OT-I CD8+CD103+ T cells isolated from the brain of mice on day 20 p.i. with VSV-OVA; and 3 replicates of memory OT-I.CD8+ CD103- T cells isolated from the brain of mice on day 20 p.i. with VSV-OVA