Project description:Tissue-resident memory T cells (TRM) provide frontline protection against pathogens and emerging malignancies. Tumor-infiltrating lymphocytes (TIL) with TRM features are associated with improved clinical outcomes. However, the cellular interactions that program TRM differentiation and function are not well understood. Using murine genetic models and targeted spatial transcriptomics, we found that the CD8+ T cell-derived chemokine XCL1 is critical for TRM formation and conventional DC1 (cDC1) support the positioning of intestinal CD8+ T cells during acute viral infection. In tumors, enforced Xcl1 expression by antigen-specific CD8+ T cells promoted intratumoral cDC1 accumulation and T cell persistence, leading to improved overall survival. Notably, analysis of human TIL and TRM revealed conserved expression of XCL1 and XCL2. Thus, we have shown that the XCL1-XCR1 axis plays a non-cell autonomous role in guiding intestinal CD8+ TRM spatial differentiation and tumor control.
Project description:Dendritic cells (DCs) are major regulators of innate and adaptive immune responses. DCs can be classified into plasmacytoid DCs and conventional DCs (cDCs) type 1 and 2. Murine and human cDC1 share the mRNA expression of XCR1. Murine studies indicated a specific role of the XCR1-XCL1 axis in the induction of immune responses. Here, we describe that human cDC1 can be distinguished into XCR1- and XCR1+ cDC1 in lymphoid as well as non-lymphoid tissues. Steady state XCR1+ cDC1 display a pre-activated phenotype compared to XCR1- cDC1. Upon stimulation, XCR1+ cDC1, but not XCR1- cDC1, secreted high levels of inflammatory cytokines as well as chemokines. This was associated with enhanced activation of NK cells mediated by XCR1+ cDC1. Moreover, XCR1+ cDC1 excelled in inhibiting replication of Influenza A virus. Further, under DC differentiation conditions, XCR1- cDC1 developed into XCR1+ cDC1. After acquisition of XCR1 expression, XCR1- cDC1 secreted comparable level of inflammatory cytokines. Thus, XCR1 is a marker of terminally differentiated cDC1 that licenses the antiviral effector functions of human cDC1, while XCR1- cDC1 seem to represent a late immediate precursor of cDC1.
Project description:Dendritic cells (DC) play critical roles in central and peripheral T cell tolerance. DC found in the steady-state periphery undergo an homeostatic, tolerogenic, maturation that promotes interaction with naive T cells and induction of abortive responses. In contrast, thymic DC are thought to exist solely in an immature state. In this study, we show that XCR1+ thymic DC constitutively mature into a stage characterized by high levels of molecules involved in T cell activation. This unanticipated mature stage corresponded to a third of the XCR1+ thymic DC and fully accounted for their ability to cross-present self-antigens to developing T cells. Transcriptomic analysis of the XCR1+ DC found in thymus and steady-state periphery revealed that their maturation involves profound and convergent changes. Unexpectedly, maturation resulted in down-regulation of genes conferring their specific function on XCR1+ DC. Paradoxically, upon maturation, central and peripheral tolerogenic XCR1+ DC up-regulated many genes thought to drive pro-inflammatory T-cell responses. Thus, our results reveal that thymic XCR1+ DC undergo constitutive maturation and emphasize the common mechanisms operating for both central and peripheral tolerance induction by XCR1+ DC. DC were isolated from lymphoid organs as previously described (Vremec et al., 2000). DC subsets were sorted by flow cytometry according to the marker combinations described in the âcharacteristics: phenotypeâ field for each sample.
Project description:Dendritic cells (DC) play critical roles in central and peripheral T cell tolerance. DC found in the steady-state periphery undergo an homeostatic, tolerogenic, maturation that promotes interaction with naive T cells and induction of abortive responses. In contrast, thymic DC are thought to exist solely in an immature state. In this study, we show that XCR1+ thymic DC constitutively mature into a stage characterized by high levels of molecules involved in T cell activation. This unanticipated mature stage corresponded to a third of the XCR1+ thymic DC and fully accounted for their ability to cross-present self-antigens to developing T cells. Transcriptomic analysis of the XCR1+ DC found in thymus and steady-state periphery revealed that their maturation involves profound and convergent changes. Unexpectedly, maturation resulted in down-regulation of genes conferring their specific function on XCR1+ DC. Paradoxically, upon maturation, central and peripheral tolerogenic XCR1+ DC up-regulated many genes thought to drive pro-inflammatory T-cell responses. Thus, our results reveal that thymic XCR1+ DC undergo constitutive maturation and emphasize the common mechanisms operating for both central and peripheral tolerance induction by XCR1+ DC.
Project description:Tissue-resident memory CD8 T cells (TRM) offer fast, robust, and long-term protection at sites of re-infection1. Tumor-infiltrating lymphocytes (TIL) with characteristics of TRM maintain enhanced effector functions, predict responses to immunotherapy, and accompany better prognoses2,3. Thus, an improved understanding of the metabolic strategies that enable tissue residency could inform new approaches to empower T cell responses in tissues and solid tumors. To systematically define the basis for the metabolic reprogramming supporting TRM differentiation, survival, and function, we leveraged in vivo functional genomics, untargeted metabolomics, and transcriptomics of virus-specific memory CD8 T cell populations. We found that memory CD8 T cells deployed a range of adaptations to tissue residency, including a marked reliance on non-steroidal products of the mevalonate/cholesterol pathway, such as Coenzyme Q (CoQ), driven by increased activity of the transcription factor Srebp2. This metabolic adaptation was most pronounced in the small intestine (SI), where TRM interface with dietary cholesterol and maintain a heightened state of activation4, and was shared by functional TIL in diverse tumor types in mice and humans. Enforcing CoQ synthesis through Fdft1 deletion or Pdss2 overexpression promoted mitochondrial respiration, memory formation upon viral infection, and enhanced antitumor immunity. In sum, through a systematic exploration of TRM metabolism, we reveal how these programs can be leveraged to empower CD8 T cell memory formation in the context of acute infections and enhance antitumor immunity.
Project description:Tissue-resident memory CD8 T cells (TRM) offer fast, robust, and long-term protection at sites of re-infection1. Tumor-infiltrating lymphocytes (TIL) with characteristics of TRM maintain enhanced effector functions, predict responses to immunotherapy, and accompany better prognoses2,3. Thus, an improved understanding of the metabolic strategies that enable tissue residency could inform new approaches to empower T cell responses in tissues and solid tumors. To systematically define the basis for the metabolic reprogramming supporting TRM differentiation, survival, and function, we leveraged in vivo functional genomics, untargeted metabolomics, and transcriptomics of virus-specific memory CD8 T cell populations. We found that memory CD8 T cells deployed a range of adaptations to tissue residency, including a marked reliance on non-steroidal products of the mevalonate/cholesterol pathway, such as Coenzyme Q (CoQ), driven by increased activity of the transcription factor Srebp2. This metabolic adaptation was most pronounced in the small intestine (SI), where TRM interface with dietary cholesterol and maintain a heightened state of activation4, and was shared by functional TIL in diverse tumor types in mice and humans. Enforcing CoQ synthesis through Fdft1 deletion or Pdss2 overexpression promoted mitochondrial respiration, memory formation upon viral infection, and enhanced antitumor immunity. In sum, through a systematic exploration of TRM metabolism, we reveal how these programs can be leveraged to empower CD8 T cell memory formation in the context of acute infections and enhance antitumor immunity.
Project description:Tissue-resident memory CD8 T cells (TRM) offer fast, robust, and long-term protection at sites of re-infection1. Tumor-infiltrating lymphocytes (TIL) with characteristics of TRM maintain enhanced effector functions, predict responses to immunotherapy, and accompany better prognoses2,3. Thus, an improved understanding of the metabolic strategies that enable tissue residency could inform new approaches to empower T cell responses in tissues and solid tumors. To systematically define the basis for the metabolic reprogramming supporting TRM differentiation, survival, and function, we leveraged in vivo functional genomics, untargeted metabolomics, and transcriptomics of virus-specific memory CD8 T cell populations. We found that memory CD8 T cells deployed a range of adaptations to tissue residency, including a marked reliance on non-steroidal products of the mevalonate/cholesterol pathway, such as Coenzyme Q (CoQ), driven by increased activity of the transcription factor Srebp2. This metabolic adaptation was most pronounced in the small intestine (SI), where TRM interface with dietary cholesterol and maintain a heightened state of activation4, and was shared by functional TIL in diverse tumor types in mice and humans. Enforcing CoQ synthesis through Fdft1 deletion or Pdss2 overexpression promoted mitochondrial respiration, memory formation upon viral infection, and enhanced antitumor immunity. In sum, through a systematic exploration of TRM metabolism, we reveal how these programs can be leveraged to empower CD8 T cell memory formation in the context of acute infections and enhance antitumor immunity.
Project description:Tissue-resident memory CD8 T cells (TRM) offer fast, robust, and long-term protection at sites of re-infection1. Tumor-infiltrating lymphocytes (TIL) with characteristics of TRM maintain enhanced effector functions, predict responses to immunotherapy, and accompany better prognoses2,3. Thus, an improved understanding of the metabolic strategies that enable tissue residency could inform new approaches to empower T cell responses in tissues and solid tumors. To systematically define the basis for the metabolic reprogramming supporting TRM differentiation, survival, and function, we leveraged in vivo functional genomics, untargeted metabolomics, and transcriptomics of virus-specific memory CD8 T cell populations. We found that memory CD8 T cells deployed a range of adaptations to tissue residency, including a marked reliance on non-steroidal products of the mevalonate/cholesterol pathway, such as Coenzyme Q (CoQ), driven by increased activity of the transcription factor Srebp2. This metabolic adaptation was most pronounced in the small intestine (SI), where TRM interface with dietary cholesterol and maintain a heightened state of activation4, and was shared by functional TIL in diverse tumor types in mice and humans. Enforcing CoQ synthesis through Fdft1 deletion or Pdss2 overexpression promoted mitochondrial respiration, memory formation upon viral infection, and enhanced antitumor immunity. In sum, through a systematic exploration of TRM metabolism, we reveal how these programs can be leveraged to empower CD8 T cell memory formation in the context of acute infections and enhance antitumor immunity.