Linear differentiation model of B10 cell development in vivo in mice and humans. B10 cells originate from a progenitor population (B10PRO). In mice, B10PRO cells are found in the CD1d−CD5− adult blood and lymph node B cell subsets and within the CD1d−CD5+ neonatal spleen and adult peritoneal cavity B cell subsets. CD40 stimulation induces B10PRO cells to become competent for IL-10 expression, while lipopolysaccharide (LPS) induces B10PRO cells to become competent for IL-10 expression and induces B10 cells to produce and secrete IL-10. CD1dhiCD5+ IL-10-competent B10 cells in the adult spleen are induced to express IL-10 following stimulation with phorbol esters (phorbol-12-myristate-13-acetate (PMA)) and ionomycin or LPS plus PMA and ionomycin for 5 hours. Following a transient period of IL-10 expression, a small subset of B10 cells can differentiate into antibody-secreting plasma cells (PC). B10 cells also possibly differentiate into memory B10 cells (B10M). B10 cell development in humans appears to follow the differentiation scheme observed in mice. B10 cells and B10PRO cells have been identified in human newborn and adult blood. B10+B10PRO cells in adult human blood express CD27 and CD24. Whether human B10 cells further differentiate into PCs or B10M remains to be determined. Solid arrows, known associations; dashed arrows, speculated associations. MHC-II, major histocompatibility complex class II.
Kalampokis et al. Arthritis Research & Therapy 2013 15(Suppl 1):S1 doi:10.1186/ar3907