Regulation of T cell function in mucosal tolerance.

Administering antigens through mucosal surfaces leads to the induction of antigen-specific T cell unresponsiveness. This property of the mucosal immune system is now beginning to be exploited in the design of immunotherapeutic strategies aimed at targeting disease-inducing T cell populations. The induction of high dose mucosal tolerance leads to the induction of T cell anergy. Recent studies have suggested that the induction of anergy in vivo may not necessarily be due to a lack of costimulation by APC. Instead, recognition of mucosal antigen leads to transient T cell activation which eventually gives rise to a population of regulatory T cells whose function is to modulate, rather than promote antigen-specific immune responses. These regulatory T cells mediate linked suppression in vivo thus enabling T cell responses directed to a multideterminant protein to be effectively controlled. The manner in which T cell responses to mucosally delivered antigens are regulated are examined herein.