Essential Transcription Factors and Functional Roles of Follicular Helper T Cells in Human Autoimmune Diseases

Follicular helper T (TFH) cells are a subset of effector CD4+ T cells that support the differentiation of antigen-specific B cells in the germinal center. TFH cells are distinct from other established CD4+ T cell subsets and possess a list of transcription factors, including BCL6, IRF4, c-Maf, Batf, NFAT1-2, and STAT3. The mentioned factors direct several activities such as cell differentiation, migration to the follicles, cell-to-cell interaction, as well as cell programming. Given that TFH cells are essential for the germinal center formation, affinity maturation and the development of most high-affinity antibodies. TFH cells may play crucial roles in different pathologic conditions, particularly autoimmune diseases. However, the mechanisms that cause functional differences of TFH cell responses are not exactly defined. In this review first the immunological profile of TFH cells will be discussed then attempts will be made to give a broad picture on the role of this key subset of T cells in autoimmune diseases.