Harnessing CD8(+)CD28(−) Regulatory T Cells as a Tool to Treat Autoimmune Disease

T regulatory cell therapy presents a novel therapeutic strategy for patients with autoimmune diseases or who are undergoing transplantation. At present, the CD4(+) Treg population has been extensively characterized, as a result of defined phenotypic and functional readouts. In this review article, we discuss the development and biology of CD8(+) Tregs and their role in murine and human disease indications. A subset of CD8(+) Tregs that lack the surface expression of CD28 (CD8(+)CD28(−) Treg) has proved efficacious in preclinical models. CD8(+)CD28(−) Tregs are present in healthy individuals, but their impaired functionality in disease renders them less effective in mediating immunosuppression. We primarily focus on harnessing CD8(+) Treg cell therapy in the clinic to support current treatment for patients with autoimmune or inflammatory conditions.