Regulatory T Cells

This chapter describes a number of regulatory T cell types-namely, CD4+CD25+, Tr1, Th3, NKT, and CD8+ with particular emphasis on CD4+CD25+ Treg cells. It is noted that with the identification of the Foxp3 transcription factor that cements the link between Treg function and self-tolerance, interest in Tregs has reached tremendously. Furthermore, there is a growing realization of the crucial physiologic role that Tregs play in maintaining the delicate equilibrium between immune responsiveness and immune pathology. Their precise mechanisms of action, their peptide specificities, and the interrelationships between the various subsets of Tregs are not known. However, the complexities and disparities encountered in the various systems utilized to analyze Treg function are outweighed by the considerable therapeutic potential of these cells. With respect to autoimmune disease, key recent advances in mice at least include the characterization of Treg function in health and disease, the identification of more precise protocols for the generation and identification of Tregs, and the demonstration that Treg therapy can ameliorate established disease. © 2006 Elsevier Inc. All rights reserved