Role of complement receptors CD21/CD35 in B lymphocyte activation and survival.
In summary, the complement system has evolved an important function in regulation of humoral immunity to T-dependent antigens. Covalent attachment of activated C3 to antigen alters its fate by enhancing uptake on the surface of FDC via CD21/CD35; and by enhancing signal transduction via the B cell coreceptor CD21/CD19/Tapa-1. In the absence of complement receptors CD21/CD35 or C3 ligand, naive B cells bearing low affinity BCR fail to effectively survive within the lymphoid follicle following contact with antigen and death is mediated by a Fas-dependent mechanism. Alternatively, B cells sufficiently activated to initiate a GC reaction fail to survive in the absence of CD21-CD21L interaction.
Carroll
M
M
Center for Blood Research, Harvard Medical School, Boston, MA 02115, USA.
D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology*; D002470:Cell Survival; D008213:Lymphocyte Activation; D051379:Mice; D018345:Mice, Knockout; D008822:Mice, Transgenic; D017463:Receptors, Complement 3b / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D017464:Receptors, Complement 3d / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*
D017463:Receptors, Complement 3b; D017464:Receptors, Complement 3d