Regulatory T cells induced by B cells: A novel subpopulation of regulatory T cells

Regulatory t cells play a crucial role in the homeostasis of the immune response. in addition to cd4+foxp3+ regulatory t cells,several subsets of foxp3- regulatory t cells,such as t helper 3 (th3) cells and type 1 regulatory t (tr1) cells,have been described in mice and human. accumulating evidence shows that naïve b cells contribute to tolerance and are able to promote regulatory t cell differentiation. naïve b cells can convert cd4+cd25- t cells into cd25+foxp3- regulatory t cells,named treg-of-b cells by our group. treg-of-b cells express lag3,icos,gitr,ox40,pd1,and ctla4 and secrete il-10. intriguingly,b-t cell-cell contact but not il-10 is essential for treg-of-b cells induction. moreover,treg-of-b cells possess both il-10-dependent and il-10-independent inhibitory functions. treg-of-b cells exert suppressive activities in antigen-specific and non-antigen-specific manners in vitro and in vivo. here,we review the phenotype and function of foxp3+ regulatory t cells,th3 cells,tr1 cells,and treg-of-b cells. © 2017 the author(s).