Bulk RNA-sequencing of CD7+ and CD7- CD8 T cells from chronic LCMV infection
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ABSTRACT: The goal of this study is to determine transcriptional differences between PD-1+ CD7 hi and PD-1+ CD7 low CD8 T cells during chronic viral infection.
Project description:We have employed use of scRNA-seq (10X Genomics) to assess the transcriptional landscape of control and CD7-deleted TCR transgenic P14 cells during chronic LCMV Cl13 infection.
Project description:This study examines the origin and differentiation of stem-like CD8+ T cells that are essential for sustained T cell immunity in chronic viral infections and cancer and also play a key role in PD-1 directed immunotherapy. These PD-1+ TCF-1+ TOX+ stem-like CD8+ T cells, also referred to as precursors of exhausted T cells, have a distinct program that allows them to adapt to chronic antigen stimulation. Using the mouse model of chronic LCMV infection we found that virus specific stem-like CD8+ T cells are generated early (day 5) during chronic infection suggesting that this crucial fate commitment occurs irrespective of infection outcome. Indeed, we found that nearly identical populations of stem-like CD8+ T cells were generated early after acute or chronic LCMV infection and that antigen was essential for maintaining the stem-like phenotype. We next performed reciprocal adoptive transfer experiments to determine the fate of these early stem-like CD8+ T cells after viral clearance versus persistence. Following transfer of day 5 stem-like CD8+ T cells from chronically infected into acutely infected mice, these cells downregulated canonical markers of the chronic stem-like CD8+ T cells and expressed markers (CD127 and CD62L) associated with central memory CD8+ T cells. Reciprocally, when day 5 stem-like cells from acutely infected mice were transferred into chronically infected mice these CD8+ T cells functioned like chronic resource cells and responded effectively to PD-1 therapy. These findings highlight the ability of these early PD-1+ TCF-1+ TOX+ stem-like CD8+ T cells to adapt their differentiation trajectory to either an acute or chronic viral infection. Most importantly, our study shows that the host is prepared a priori to deal with a potential chronic infection.
Project description:Chimeric antigen receptor-T cell (CAR-T) therapy in T cell malignancies faces fratricide, T cell aplasia, and product contamination. We developed an universal anti-CD7 CAR-T cells in which TRAC, CD7 and HLA-II were disrupted, while E-cadherin (a NK cell inhibitory molecule) was introduced, to mitigate graft versus host disease (GvHD), fratricide and rejection. Furthermore, we designed a subtle receptor, bbzg-CAR, comprising not only conventional domains (anti-CD7 scFv, 4-1BB co-stimulatory domain, and CD3ζ signaling domain), but also the intracellular domain of common γ chain. Bbzg-CAR-T exerted anti-tumor effects superior to those of conventional universal CAR-T cells. In adoptive therapy for relapsed/refractory (r/r) patients, no dose-limiting toxicity, GvHD, immune effector cell-associated neurotoxicity or severe cytokine release syndrome (grade≥3) was observed. Nine patients (82%) showed objective response with, complete response rates of 75% and 33.3% in r/r leukemia and lymphoma respectively. Preliminary safety and efficacy of this universal CAR-T product was achieved in CD7+ malignancies.
Project description:Chronic viral infections are characterized by a state of CD8 T cell dysfunction termed exhaustion. A better understanding of the mechanisms that regulate CD8 T cell responses during chronic infection is required to improve immunotherapies that restore function in exhausted CD8 T cells. Here we identify a novel population of virus-specific CD8 T cells with a T follicular helper (Tfh)-like signature in mice chronically infected with lymphocytic choriomeningitis virus (LCMV). These Tfh-like CD8 T cells expressed the programmed cell death-1 (PD-1) inhibitory receptor but at the same time also expressed co-stimulatory molecules and had a gene signature that was related to CD8 T cell memory precursor cells and hematopoietic stem cells (HSC). These Tfh-like CD8 T cells acted as stem cells during chronic infection undergoing self-renewal and also differentiating into the terminally exhausted CD8 T cells that were present in both lymphoid and non-lymphoid tissues. The Tfh-like CD8 T cells were found only in lymphoid tissues and resided predominantly in the T cell zones along with naïve CD8 T cells. Interestingly, the proliferative burst after PD-1 blockade came almost exclusively from this Tfh-like CD8 T cell subset. Importantly, the transcription factor TCF1 played a cell intrinsic and essential role in the generation of Tfh-like CD8 T cells. Taken together, our study identifies Tfh-like CD8 T cells as the critical subset for maintaining the pool of virus-specific CD8 T cells during chronic infection and as the cells that proliferate after PD-1 blockade. These findings provide a better understanding of T cell exhaustion and have implications towards optimizing PD-1 directed immunotherapy. 8 samples isolated from CD8 T-cells in LCMV clone 13 GK1.5 infected mice (2 naïve, 3 CXCR5+Tim3-, 3 CXCR5-Tim3+) cells were analyzed