Antigen Presentation to B Cells.

Unlike T cells that recognize digested peptides, B cells recognize their cognate antigen in its native form. The B cell receptor used in recognition can also be secreted to bind to antigens and initiate multiple effector functions such as phagocytosis, complement activation, or neutralization of receptors. While B cells can interact with soluble antigens, it is now clear that the presentation of membrane-bound antigen plays a crucial role in B cell activation, and in particular during affinity-maturation, the process during which high-affinity B cells are selected. In this review we discuss how native antigen is presented to B cells and its impact at several stages of B cell responses.