The role of T cells in systemic lupus erythematosus: an update.

PURPOSE OF REVIEW: To describe our current understanding of the role of T cells in the pathophysiology of systemic lupus erythematosus (SLE).

RECENT FINDINGS: Over the last few years, the dominant role of T cells in autoimmunity and SLE was established. Genome-wide-association studies led to the discovery of multiple single-nucleotide polymorphisms associated with SLE. Most of these single-nucleotide polymorphisms fall within the noncoding DNA regions of immune response-related genes and few seem to contribute to the observed abnormal T cell function. The field of epigenetics research developed rapidly and provided us with new insights into the observed generalized hypomethylation in SLE T cells, the abnormal histone modifications and the role of RNA interference. Old observations, such as the decreased interleukin-2 production, are better understood with our evolved knowledge of many signal transduction pathways and the way they converge and regulate the transcription of different genes in T cells. Finally, we are now able to identify subpopulations of T cells, such as Th17 and T regulatory cells, and to define their role in SLE.

SUMMARY: T cells are key players in SLE, and over the last few years our understanding of their activation, signal transduction and gene regulation has evolved significantly.