T lymphocyte activation--an inside overview.

Activated T lymphocytes play an important role in autoimmune disease. The process of T-cell activation is therefore of significant importance in understanding the pathogenesis of many rheumatic diseases. This process can be observed from outside the lymphocyte, but we have also gained increased understanding of many of the intracellular events of T-cell activation. This review tries to draw out the most important receptors, pathways, and transcription factors involved in the process.