The role of TCR specificity in naturally arising CD25⁺ CD4 ⁺ regulatory T cell biology

CD25⁺ CD4⁺ T cells (T_R) are a naturally arising subset of regulatory T cells important for the preservation of self-tolerance and the prevention of autoimmunity. Although there is substantial data that TCR specificity is important for T_R development and function, relatively little is known about the antigen specificity of naturally arising T_R. Here, we will review the available evidence regarding naturally arising T_R TCR specificity in the context of T_R development, function, and homeostasis.