Understanding the GATA3-TBX21 axis in granzyme-based differentiation profiles of human CD8 T cells 4016

Abstract Description CD8 T cells, crucial components of adaptive immunity, are known to be susceptible to age-related molecular reprogramming that can lead to diminished immune responses in older adults. However, previous studies often confound age with chronic viral infection, limiting our understanding about the distinct effects of both in the context of CD8 T cell reprogramming. To explore this, our group performed immune profiling to characterize CD8 T cell subsets in healthy young and older adults with and without cytomegalovirus (CMV) infection. Our scRNAseq results demonstrated a clear distinction between Granzyme (GZM) B+ and GZMK+ cells in the CD8 memory compartment. While CMV infection resulted in an elevation of GZMB+ memory CD8 T cells, increased age resulted in elevated GZMK expression within multiple memory subsets. Further TEA-seq analysis showed an expected association between TBX21 activity and GZMB expression, while a novel association between GATA3 activity and GZMK expression was additionally uncovered, distinct from TBX21-GZMB. To directly link transcription factor activity and GZM expression, we developed a transfection protocol to perform CRISPR knockouts of GATA3 and TBX21 in resting, naive primary human CD8 T cells. We find that knockout of TBX21 resulted in a decrease of GZMB+ effector cells post-activation, with minimal GZMK expression observed. Thus, our results show a direct relationship between TBX21 in naive CD8 T cells and differentiation into GZMB+ effector cells. Topic Categories Immune Response Regulation: Molecular Mechanisms (IRM)