Epigenetically Controlled ZEB2 Expression Promotes the Cytotoxic Potential of CMV-Specific CD8⁺ T Cells

Zinc finger E-box binding protein 2 (ZEB2) is a key factor in the differentiation of naïve CD8⁺ T cells into effector and memory T cells. However, the precise regulatory role of ZEB2 in cytotoxic CD8⁺ T cells remains unknown. Our recent DNA methylation analysis of cytomegalovirus (CMV)-specific human CD8⁺ T cells revealed two differentially methylated regions (DMRs) within the ZEB2 locus. In the present study, we show that these ZEB2 DMRs undergo pronounced demethylation during T cell differentiation. In particular, terminally differentiated CD8⁺ T cells and cytotoxic CD4⁺ T cells show an almost complete demethylation. Demethylation of the ZEB2 DMRs correlates strongly with ZEB2 expression in all T cell subsets. Furthermore, DNA methylation patterns remain stable during long-term in vitro culture. ZEB2 knockout in CD8⁺ effector T cells results in altered gene expression profiles, affecting genes related to cell-cell adhesion and impairing the cytotoxic capacity in CMV-specific killing assays. Our data show that ZEB2 expression contributes to the differentiation of naïve CD8⁺ T cells into effector and memory T cells and regulates the functional properties of virus-specific cytotoxic CD8⁺ T cells.