IL-10-producing regulatory B cells have been undoubtedly identified in mice and shown to downregulate
inflammation, making them potentially important for maintenance of tolerance. Several recent works
have also identified IL-10 producing regulatory B cells in humans and have begun to unravel their phenotype
and mode of suppression. Cell surface phenotype of human Bregs includes CD38, CD27, CD24 and CD5.
Mechanisms of suppression may imply inhibition of CD4+ T proliferation, inhibition of Th1 differentiation,
induction of regulatory T cells and suppression of monocytes activation. These recent findings imply that
manipulating IL-10 production by human B cells could be a useful therapeutic strategy for modulating immune
responses in humans.