Role of regulatory T cells in allergy and asthma.

Th2 cells play a critical role in the pathogenesis of allergy and asthma. However, the immunological mechanisms that downmodulate and protect against the development of these disorders are poorly understood. A spectrum of CD4(+) T cells, including Th3 cells, T(R) cells, CD4(+)CD25(+) cells and NKT cells play a critical role in regulating these diseases. A better understanding of the role of regulatory cells in allergic diseases may lead to the identification of novel therapeutic targets.