Biology subjects

McGavern, D. B.

Publications and source records attributed to McGavern, D. B..

2 recordsLinked to original sources

bioRxiv2025

Angiogenic CD8 T cells from PWH induce Granzymes-dependent PAR1 activation promoting endothelial inflammation

In people with HIV (PWH), T cell immune activation and endothelial inflammation are contributors of the increased cardiovascular risk, however the mechanisms remain poorly understood. PAR1 connects the coagulation cascade, endothelial cells and CD8 T cells at the site of endothelial inflammation and we hypothesized that HIV driven CD8 T cell immune activation alters endothelial repair mechanisms. Endothelial repair is partially mediated by angiogenic T (Tang) cells that facilitate proliferation of endothelial cells, and differentiation of endothelial progenitor cells at site of vascular injury. During LCMV infection, we identified a subset of CD31highCD8 T cells that exhibited a long-lived memory precursor phenotype (CD127+KLRG1-) and secreted the proangiogenic cytokine vascular endothelial growth factor (VEGF) after viral control. Furthermore, in PWH, the frequencies of CD8 Tang cells were reduced and showed an activated phenotype and expression of granzymes. GZMA+GZMB+CD8 Tang cells correlated with atherosclerotic cardiovascular disease (ASCVD) risk. In vitro, granzyme dependent PAR1 activation led to calcium mobilization and secretion of proinflammatory cytokines IL-6, IL-8 and angiopoietin-2 by primary human endothelial cells. Altogether, these findings suggest that CD8 T cells are involved in immunity against viruses and endothelial homeostasis and HIV driven immune activation alters these functions.

immunology↗

bioRxiv2019

Single-cell profiling of tumor-reactive CD4+ T-cells reveals unexpected transcriptomic diversity

Most current tumor immunotherapy strategies leverage cytotoxic CD8+ T cells. Despite evidence for clinical potential of CD4+ tumor-infiltrating lymphocytes (TILs), their functional diversity has limited our ability to harness their activity. To address this issue, we have used single-cell mRNA sequencing to analyze the response of CD4+ T cells specific for a defined recombinant tumor antigen, both in the tumor microenvironment and draining lymph nodes (dLN). Designing new computational approaches to characterize subpopulations, we identify TIL transcriptomic patterns strikingly distinct from those elicited by responses to infection, and dominated by diversity among T-bet-expressing T helper type 1 (Th1)-like cells. In contrast, the dLN response includes follicular helper (Tfh)-like cells but lacks Th1 cells. We identify a type I interferon-driven signature in Th1-like TILs, and show that it is found in human liver cancer and melanoma, in which it is negatively associated with response to checkpoint therapy. Our study unveils unsuspected differences between tumor and virus CD4+ T cell responses, and provides a proof-of-concept methodology to characterize tumor specific CD4+ T cell effector programs. Targeting these programs should help improve immunotherapy strategies. One Sentence SummarySingle-cell RNA sequencing reveals novel and highly diverse transcriptomic patterns characteristic of CD4+ T cell responses to tumors.

immunology↗