Fig. 1: Bregs are induced through both “adaptive” and “innate” signals
From: Regulatory B cells: the cutting edge of immune tolerance in kidney transplantation
a B cells bind antigens through BCR, present them to cognate CD4+ T cells, become stimulated with CD40-CD40L, CD80/86-CD28, and IL-21, and then develop into Bregs. b LPS on TLR-2/4 and the DNA complex on TLR-9 can induce Bregs through the Myd88 pathway. Pro-inflammatory cytokines, including IL-1β, IL-2, IL-6, and IFN-α, help to induce Bregs. In addition, anti-inflammatory cytokine IL-35 also plays a role in Bregs induction through IL-12Rβ2 and IL-27Rα
