Antigen-specific B-lymphocyte activation.

B lymphocytes comprise a major component of the adaptive mammalian immune system, having the exclusive ability to produce and secrete immunoglobulins (Ig) of various forms (isotypes). This property alone renders B-cell activation critical to immunity, but the fully activated B cell also functions in antigen presentation and the production of a variety of cytokines and chemokines. There are many signals that must be coordinated to achieve and properly regulate antigen-specific B-lymphocyte activation and the development of humoral memory. This review seeks to summarize these components, and to highlight recent advances in each area that contribute to a greater understanding of the complex processes involved in B-cell activation.