HLA-DRA and Sepsis: The mechanisms of sepsis-induced immunosuppression include the apoptosis of adaptive immune cells including the T-cell, NK cells, and B-cell, the decreased production of IFNγ and HLA-DRA, and the increased production of neutrophil immunosuppressive cytokines IL-10 and IL-6, and increased percentage of Treg cells[8,36,39,47,48] (Fig. 7).