title: Activation of lymphocytes alters Fc receptor-beta 2-microglobulin interrelationship on the lymphocyte surface.
abstract: The effect of anti-beta 2-microglobulin (anti-B2Mi) on the expression of Fc receptors (FcR) of human lymphocytes was compared on resting and activated cells. Previously we reported that anti-B2Mi induces a "co-shedding" of FcR with the beta 2-microglobulin (B2Mi)-anti-B2Mi complexes when used under the conditions where the redistribution of membrane molecules is allowed (Sármay et al., Cell. Immunol. 56, 452, 1980; Sármay et al. Immunology 36, 339, 1979). Furthermore our group also described two types of FcR-bearing cells, one which shed their FcR during a temperature shift from 4 to 37 degrees C (FcRI+ cells) and the other which has an immobile type FcR under the same circumstances (FcRI+ cells) (Sándor et al., Immunology 38, 553, 1979; Sármay et al., Immunology 34, 315, 1978). In this work we have characterized the FcR released from the membrane as a consequence of anti-B2Mi treatment. We have found that they are the mobile, FcRI type. It was proved that the shedding of this FcRI is a consequence of the anti-B2MI-induced transformation of FcRII into the FcRI form on the membrane of the antibody-treated lymphocytes. On the activated T cells, however, anti-B2Mi is incapable of inducing the same phenomenon in the early phase of activation. In contrast, FcR expression is blocked by anti-B2Mi treatment similarly to that on resting lymphocytes, on the surface of activated B cells, or on activated T cells in the later phases of activation.
mesh_terms: D000818:Animals; D001609:Beta-Globulins / Q000378:metabolism*; D001666:Binding Sites, Antibody; D003208:Concanavalin A / Q000494:pharmacology; D006801:Humans; D007106:Immune Sera / Q000494:pharmacology; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000276:immunology* / Q000378:metabolism; D011043:Pokeweed Mitogens / Q000494:pharmacology; D011817:Rabbits; D011961:Receptors, Fc / Q000032:analysis*; D017452:Receptors, IgG; D012397:Rosette Formation; D001613:beta 2-Microglobulin / Q000276:immunology / Q000378:metabolism*
chemical_list: D001609:Beta-Globulins; D007106:Immune Sera; D011043:Pokeweed Mitogens; D011961:Receptors, Fc; D017452:Receptors, IgG; D001613:beta 2-Microglobulin; D003208:Concanavalin A