Antigen-expanded CD8+ gd T cells with NK-like phenotype and function respond in persistent infection [Bulk RNA-seq]

Gamma Delta (gd) T cells play unique protective roles in different settings of acute and chronic infections. However, what they respond to and how they function in the acute versus chronic phases of the same infection remains unclear. It is well documented that cytolytic gd T cells that express Vg9Vd2 TCRs and respond to phosphoantigens (pAgs) expand in acute Mycobacterium tuberculosis (Mtb) infection in humans. However, most infections with Mtb manifest as a chronic, clinically asymptomatic state. While past work indicates that gd T cells contribute to Mtb infection control, their response during this phase of Mtb infection is not well understood. Here, we analyze peripheral blood gd T cells from a South African adolescent cohort and show that a unique CD8+ gd T cell subset with features of “memory inflation” expand in chronic Mtb infection. Overall design: We performed bulk RNA sequencing (bulk-RNA-seq) on FACS sorted CD8+ and CD8- gd T cells from peripheral blood samples of five donors with persistent Mtb infection.