Fig. 1
From: Differentiation, functions, and roles of T follicular regulatory cells in autoimmune diseases
Model for T follicular regulatory (Tfr)-cell differentiation. Pre-Tfr cells are generated in the T cell zone where thymic natural Treg cells interact with dendritic cells. Pre-Tfr cells migrate into the B cell follicle, strengthening the Tfr cell transcriptional program. Alternatively, pre-Tfr cells can exit the secondary lymphoid tissues and enter the peripheral blood as circulating Tfr (cTfr) cells. In the germinal center (GC), Tfr cells terminally differentiate into mature Tfr cells, and this process fine-tunes Tfh and B cells. cTfr cells may migrate into follicles and the GC after reactivation. Furthermore, interleukin (IL)-2 might facilitate Tfh cell conversion into Tfr cells in the GC. Markers involved in Tfr cell differentiation are presented in black font