title: Antigen presentation by B lymphocytes: mechanisms and functional significance.
abstract: B lymphocytes are remarkably efficient at presenting protein antigens that bind to their immunoglobulin (Ig) receptors to class II MHC-restricted CD4+ helper T cells. Ig molecules function as high-affinity binding sites for capturing antigens at limiting concentrations. In addition, Ig receptor-mediated endocytosis leads to an intracellular pathway of protein traffic that favors recycling of antigens and optimizes the processing of these antigens. As a result, small amounts of endocytosed antigens are capable of associating with MHC molecules and being presented in a form that can be specifically recognized by T lymphocytes. The antigen presenting function of B cells is particularly important in secondary antibody responses, which require low concentrations of antigens and MHC-restricted T-B cell cooperation.
authors.affiliation: Department of Pathology, Harvard Medical School Boston, MA 02115, USA.
authors.forename: A K
authors.initials: AK
authors.lastname: Abbas
mesh_terms: D000818:Animals; D017951:Antigen Presentation / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology*; D006801:Humans; D011947:Receptors, Antigen, B-Cell / Q000276:immunology*; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D011947:Receptors, Antigen, B-Cell