Regulating Suppression

摘要

The vertebrate immune system has important self-check mechanisms that prevent it from destroying the host's own tissues. Regulatory T cells are part of this suppressive control, and on page 271 in this issue, Wing et al. (1) define the role of cyto-toxic T lymphocyte antigen 4 (CTLA-4)-a protein that is preferentially expressed by regulatory T cells-in restraining the immune response when needed and in maintaining self tolerance. Therapies based on CTLA-4 are currently used, or in clinical trials, for treating autoimmune conditions such as rheumatoid arthritis or to augment immune responses directed at tumors, respectively, so understanding the specific role of CTLA-4 in regulatory T cell function may further improve and expand such clinical approaches.