HLA-E/Mtb specific CD4+ and CD8+ T cells have a memory phenotype in individuals with TB infection

This is the authors' abstract. We don't add key points for this paper.

Introduction Tuberculosis (TB) is the deadliest infectious disease worldwide and novel vaccines are urgently needed. HLA-E is a virtually monomorphic antigen presentation molecule and is not downregulated upon HIV co-infection. HLA-E restricted Mtb specific CD8+ T cells are present in the circulation of individuals with active TB (aTB) and Mtb infection (TBI) with or without HIV co-infection, making HLA-E restricted T cells interesting vaccination targets for TB. Methods Here, we performed in-depth phenotyping of HLA-E/Mtb specific and total T cell populations in individuals with TBI and in individuals with aTB or TBI and HIV using HLA-E/Mtb tetramers. Results and Discussion We show that HIV co-infection is the main driver in changing the memory distribution of HLA-E/Mtb specific CD4+ and CD8+ T cell subsets. HLA-E/Mtb specific CD4+ and CD8+ T cells were found to circulate with comparable frequencies in all individuals and displayed expression of KLRG1, PD-1 and 2B4 similar to that of total T cells. The presence of HLA-E/Mtb specific T cells in individuals with aTB and TBI highlights the potential of HLA-E as a vaccine target for TB.