Do T cells care about the mitogen-activated protein kinase signalling pathways?

Mitogen-activated protein (MAP) kinases, which include the extracellular re sponse kinases, p38 and c-Jun amino terminal kinases (JNK), play a signific ant role in mediating signals triggered by cytokines, growth factors and en vironmental stress. The JNK and p38 MAP kinases have been involved in growt h, differentiation and cell death in different cell types. In the present p aper, we describe how the JNK and p38 MAP kinase signalling pathways are re gulated and their role during thymocyte development and the activation and differentiation of T cells in the peripheral immune system. The results fro m these studies demonstrate that the JNK and p38 MAP kinase signalling path ways regulate different aspects of T-cell mediated immune responses.