Project description:Durability of an antitumor immune response is mediated in part by the persistence of progenitor exhausted CD8 T cells (Tpex). Tpex serve as a source for the pool of effector T cells, and in the absence of their cognate antigen, they are able to preserve their quantity through a process of self-renewal. However, it remains unknown how TCR engagement impacts the self-renewal capacity of Tpex in settings of continued antigen exposure. Here, we used a Lewis lung carcinoma model that elicits an optimal or attenuated TCR signal in CD8 T cells to investigate its effect on Tpex persistence during tumor development. Longitudinal phenotyping and single-cell transcriptomics of tumor-specific T cells revealed that formation of the Tpex reservoir in tumor-draining lymph nodes, and its subsequent replenishment of intratumoral Tpex, is dependent on optimal TCR engagement. Notably, adoptive transfer of optimally primed Tpex into a tumor setting with attenuated TCR stimulation significantly accelerates their terminal differentiation, contrasting to the sustained self-renewal occuring with optimal TCR stimulation. This TCR-reinforced Tpex development and self-renewal is coupled to proximal positioning to dendritic cell niches and epigenetic imprinting that involves increased chromatin accessibility at Egr2 and Tcf1 target loci. Collectively, our study highlights the critical role of TCR engagement in sustaining Tpex during tumor progression
Project description:Durability of an antitumor immune response is mediated in part by the persistence of progenitor exhausted CD8 T cells (Tpex). Tpex serve as a source for the pool of effector T cells, and in the absence of their cognate antigen, they are able to preserve their quantity through a process of self-renewal. However, it remains unknown how TCR engagement impacts the self-renewal capacity of Tpex in settings of continued antigen exposure. Here, we used a Lewis lung carcinoma model that elicits an optimal or attenuated TCR signal in CD8 T cells to investigate its effect on Tpex persistence during tumor development. Longitudinal phenotyping and single-cell transcriptomics of tumor-specific T cells revealed that formation of the Tpex reservoir in tumor-draining lymph nodes, and its subsequent replenishment of intratumoral Tpex, is dependent on optimal TCR engagement. Notably, adoptive transfer of optimally primed Tpex into a tumor setting with attenuated TCR stimulation significantly accelerates their terminal differentiation, contrasting to the sustained self-renewal occuring with optimal TCR stimulation. This TCR-reinforced Tpex development and self-renewal is coupled to proximal positioning to dendritic cell niches and epigenetic imprinting that involves increased chromatin accessibility at Egr2 and Tcf1 target loci. Collectively, our study highlights the critical role of TCR engagement in sustaining Tpex during tumor progression
Project description:Durability of an antitumor immune response is mediated in part by the persistence of progenitor exhausted CD8 T cells (Tpex). Tpex serve as a source for the pool of effector T cells, and in the absence of their cognate antigen, they are able to preserve their quantity through a process of self-renewal. However, it remains unknown how TCR engagement impacts the self-renewal capacity of Tpex in settings of continued antigen exposure. Here, we used a Lewis lung carcinoma model that elicits an optimal or attenuated TCR signal in CD8 T cells to investigate its effect on Tpex persistence during tumor development. Longitudinal phenotyping and single-cell transcriptomics of tumor-specific T cells revealed that formation of the Tpex reservoir in tumor-draining lymph nodes, and its subsequent replenishment of intratumoral Tpex, is dependent on optimal TCR engagement. Notably, adoptive transfer of optimally primed Tpex into a tumor setting with attenuated TCR stimulation significantly accelerates their terminal differentiation, contrasting to the sustained self-renewal occuring with optimal TCR stimulation. This TCR-reinforced Tpex development and self-renewal is coupled to proximal positioning to dendritic cell niches and epigenetic imprinting that involves increased chromatin accessibility at Egr2 and Tcf1 target loci. Collectively, our study highlights the critical role of TCR engagement in sustaining Tpex during tumor progression
Project description:Durability of an antitumor immune response is mediated in part by the persistence of progenitor exhausted CD8 T cells (Tpex). Tpex serve as a source for the pool of effector T cells, and in the absence of their cognate antigen, they are able to preserve their quantity through a process of self-renewal. However, it remains unknown how TCR engagement impacts the self-renewal capacity of Tpex in settings of continued antigen exposure. Here, we used a Lewis lung carcinoma model that elicits an optimal or attenuated TCR signal in CD8 T cells to investigate its effect on Tpex persistence during tumor development. Longitudinal phenotyping and single-cell transcriptomics of tumor-specific T cells revealed that formation of the Tpex reservoir in tumor-draining lymph nodes, and its subsequent replenishment of intratumoral Tpex, is dependent on optimal TCR engagement. Notably, adoptive transfer of optimally primed Tpex into a tumor setting with attenuated TCR stimulation significantly accelerates their terminal differentiation, contrasting to the sustained self-renewal occuring with optimal TCR stimulation. This TCR-reinforced Tpex development and self-renewal is coupled to proximal positioning to dendritic cell niches and epigenetic imprinting that involves increased chromatin accessibility at Egr2 and Tcf1 target loci. Collectively, our study highlights the critical role of TCR engagement in sustaining Tpex during tumor progression
Project description:<p>High-throughput linking of T cell receptor (TCR) sequences to their binding antigens is vital for immune profiling, yet challenging. We present Tetramer associated TCR Sequencing (TetTCR-Seq) to address this challenge. Binding is determined using a library of DNA-barcoded antigen tetramers that are rapidly and inexpensively generated using an in vitro transcription/translation platform. We included CMV+ donors (CMV seropositive donors who are infected with Cytomegalovirus) to screen for CMV specific TCRs.</p>
Project description:Affinity and dose of T cell receptor (TCR) interaction with antigens govern the magnitude of CD4+ T cell responses, but questions remain regarding the quantitative translation of TCR engagement into downstream signals. We find that while the response of CD4+ T cells to antigenic stimulation is bimodal, activated cells exhibit analog responses proportional to signal strength. Gene expression output reflects TCR signal strength, providing a signature of T cell activation. Expression changes rely on a pre-established enhancer landscape and quantitative acetylation at AP-1 binding sites. Finally, we show that graded expression of activation genes depends on ERK pathway activation, suggesting that an ERK-AP-1 axis translates TCR signal strength into proportional activation of enhancers and genes essential for T cell function. CD4+ T cells from transgenic AND mice were sequenced under the conditions indicated. Replicates are included for each type of data (RNA-Seq, ChIP-Seq), and are numbered accordingly. The No Peptide condition serves as the untreated control for the peptide-treated samples, and inputs are provided for ChIP-Sequencing samples.
Project description:We wished to examine early transcriptional changes that occur after TCR engagement in CD8+ cytotoxic T lymphocytes (CTLs). To this end, we differentiated effector CTLs from OTI TCR transgenic mice for 7 days in vitro and then stimulated them with anti-CD3 for various times before lysing for RNA-seq. Results demonstrated significant transcriptional changes starting from 20 minutes. After 60 minutes, upregulated genes were most enriched for cytokines and transcriptional machinery.
Project description:Initial TCR-dependent engagement of CD8+ T cells results in T cell expansion, and the early events involved in priming influence the generation of diverse effector and memory populations. During infection, some of these activated T cells re-encounter cognate antigen, but whether this influences phenotypic heterogeneity is unclear. To address this issue, OT-I T cells, which are specific for the SIINFEKL peptide from OVA and express the Nur77-GFP reporter of recent TCR activation, were paired with transgenic T. gondii that express OVA to assess the impact of TCR activation on parasite-specific CD8+ T cell responses.