Role of immune-regulatory cells in skin pathology.

The skin harbors a complex and unique immune system that protects against various pathologies, such as infection and cancer. Although many of the mechanisms of immune activation in the skin have been investigated, it is likewise important to uncover the immune-regulatory components that limit effective immunity or prevent autoimmunity. Several cell populations are involved in this immune-regulatory function, including CD4+ T cells that coexpress the transcription factor Foxp3, known as Tregs, and cells with immune-regulatory function known as myeloid-derived suppressor cells (MDSCs). This review focuses on the role that immune-regulatory cells, such as MDSCs and Tregs, play in cutaneous pathology, such as malignancy, psoriasis, dermatitis, burn wounds, and transplantation. Although their depletion may serve to augment immunity, expansion of these cells may be used to suppress excessive immune reactions. These cells are attractive, therapeutic targets for various conditions and thus, deserve further exploration.