Regulatory T cell defects in rheumatoid arthritis

Regulatory T (Treg) cells have emerged as a distinct subset of lymphocytes that are responsible for limiting immune responses and avoiding pathologic autoimmunity. Evidence is accumulating that defects in Treg function are important in immune-mediated diseases such as rheumatoid arthritis (RA). We discuss herein the biology of Treg cells and emphasize what is known about Treg dysfunction in RA.