DNA methylation profiling identifies TBKBP1 as potent amplifier of cytotoxic activity in CMV-specific human CD8+T cells

Abstract

ABSTRACTEpigenetic mechanisms stabilize gene expression patterns during CD8+T cell differentiation. However, although adoptive transfer of virus-specific T cells is clinically applied to reduce the risk of virus infection or reactivation in immunocompromised individuals, the DNA methylation pattern of virus-specific CD8+T cells is largely unknown. Hence, we here performed whole-genome bisulfite sequencing of cytomegalovirus-specific human CD8+T cells and found that they display a unique DNA methylation pattern consisting of 79 differentially methylated regions when compared to bulk memory CD8+T cells. Among them wasTBKBP1, coding for TBK-binding protein 1 that can interact with TANK-binding kinase 1 (TBK1) and mediate pro-inflammatory responses in innate immune cells downstream of intracellular virus sensing. Since TBKBP1 has not yet been reported in T cells, we aimed to unravel its role in virus-specific CD8+T cells.TBKBP1demethylation in terminal effector CD8+T cells correlated withTBKBP1expression and was stable upon long-termin vitroculture. TBKBP1 overexpression resulted in enhanced TBK1 phosphorylation upon stimulation of CD8+T cells and significantly improved their virus neutralization capacity. Collectively, our data demonstrate that TBKBP1 modulates virus-specific CD8+T cell responses and could be exploited as therapeutic target to improve adoptive T cell therapies.