title: The lymphocyte plasma membrane: locus of control in the immune response.
abstract: The lymphocyte plasma membrane is the locus of events which control the immune response. T and B lymphocytes, which mediate cellular and humoral immunity respectively, show distinctive plasma membrane morphologies and cell surface receptors. The dynamic state of these plasma components is emphasized by their lateral mobility in the fluid plane of the membrane, as well as variation in their structure or expression as the lymphocyte proliferates and differentiates in response to stimulation by antigen or mitogens. The best understood membrane glycoproteins are surface membrane immunoglobulins that serve as antigen receptors on B cells, and the histocompatability-beta2 microglobulin complex that has an immunoglobulin-like structure. Other less well defined surface structures showing modulation during the cell cycle may affect growth regulation of proliferating lymphocytes. Some of these are shared by fetal and neoplastic cells. Major theories of lymphocyte signaling are discussed, and the early events in lymphocyte activation are reviewed. While a complete model encompassing all these early events is not yet possible, the central issues can be usefully discussed in term of receptor-transducer-effector concepts derived by strong parallels from a knowledge of hormone-membrane interactions.
mesh_terms: D000818:Animals; D000936:Antigen-Antibody Complex; D000961:Antilymphocyte Serum; D001402:B-Lymphocytes / Q000276:immunology* / Q000648:ultrastructure; D001665:Binding Sites; D001666:Binding Sites, Antibody; D002462:Cell Membrane / Q000276:immunology*; D003176:Complement C3; D000242:Cyclic AMP / Q000494:pharmacology; D006152:Cyclic GMP / Q000494:pharmacology; D003601:Cytotoxicity Tests, Immunologic; D005455:Fluorescent Antibody Technique; D006023:Glycoproteins / Q000032:analysis; D006649:Histocompatibility Antigens; D006801:Humans; D007104:Immune Adherence Reaction; D007109:Immunity; D007111:Immunity, Cellular; D007141:Immunoglobulin Fc Fragments; D008213:Lymphocyte Activation; D008934:Mitogens / Q000494:pharmacology; D008954:Models, Biological; D011947:Receptors, Antigen, B-Cell; D013601:T-Lymphocytes / Q000276:immunology* / Q000648:ultrastructure
chemical_list: D000936:Antigen-Antibody Complex; D000961:Antilymphocyte Serum; D003176:Complement C3; D006023:Glycoproteins; D006649:Histocompatibility Antigens; D007141:Immunoglobulin Fc Fragments; D008934:Mitogens; D011947:Receptors, Antigen, B-Cell; D000242:Cyclic AMP; D006152:Cyclic GMP