Enhanced humoral immune responses against T-independent antigens in Fc alpha/muR-deficient mice.

ABSTRACT: IgM is an antibody class common to all vertebrates that plays a primary role in host defenses against infection. Binding of IgM with an antigen initiates the complement cascade, accelerating cellular and humoral immune responses. However, the functional role of the Fc receptor for IgM in such immune responses remains obscure. Here we show that mice deficient in Fc alpha/muR, an Fc receptor for IgM expressed on B cells and follicular dendritic cells (FDCs), have enhanced germinal center formation and affinity maturation and memory induction of IgG3(+) B cells after immunization with T-independent (TI) antigens. Moreover, Fc alpha/muR-deficient mice show prolonged antigen retention by marginal zone B (MZB) cells and FDCs. In vitro studies demonstrate that interaction of the IgM immune comple

SUBMITTER: Honda S 

PROVIDER: S-EPMC2699373 | biostudies-literature | 2009 Jul

REPOSITORIES: biostudies-literature