Recent advances in CD8+ regulatory T cell research (Review)

Various subgroups of CD8(+) T lymphocytes do not only demonstrate cytotoxic effects, but also serve important regulatory roles in the body's immune response. In particular, CD8(+) regulatory T cells (CD8(+) Tregs), which possess important immunosuppressive functions, are able to effectively block the overreacting immune response and maintain the body's immune homeostasis. In recent years, studies have identified a small set of special CD8(+) Tregs that can recognize major histocompatibility complex class Ib molecules, more specifically Qa-1 in mice and HLA-E in humans, and target the self-reactive CD4(+)T ce lls. These findings have generated broad implications in the scientific community and attracted general interest to CD8(+) Tregs. The present study reviews the recent research progress on CD8(+) Tregs, including their origin, functional classification, molecular markers and underlying mechanisms of action.