A crucial role for the p110delta subunit of phosphatidylinositol 3-kinase in B cell development and activation.
Clayton E., Bardi G., Bell SE., Chantry D., Downes CP., Gray A., Humphries LA., Rawlings D., Reynolds H., Vigorito E., Turner M.
Mice lacking the p110delta catalytic subunit of phosphatidylinositol 3-kinase have reduced numbers of B1 and marginal zone B cells, reduced levels of serum immunoglobulins, respond poorly to immunization with type II thymus-independent antigen, and are defective in their primary and secondary responses to thymus-dependent antigen. p110delta(-/-) B cells proliferate poorly in response to B cell receptor (BCR) or CD40 signals in vitro, fail to activate protein kinase B, and are prone to apoptosis. p110delta function is required for BCR-mediated calcium flux, activation of phosphlipaseCgamma2, and Bruton's tyrosine kinase. Thus, p110delta plays a critical role in B cell homeostasis and function.