title: 5C6-F4, a novel 100,000-dalton rat lymphocyte activation antigen defined by monoclonal antibody.
abstract: Con A-activated rat thymocytes were used to immunize mice, and immune spleen cells were fused with NS/1 myeloma cells. One clone, designated 5C6-F4, reacted strongly with Con A-activated rat thymocytes and some LPS-activated rat spleen cells but not with normal thymocytes, spleen cells, or bone marrow cells of rat origin. The 5C6-F4 did not react with Con A-activated thymocytes of mouse origin. Immunoprecipitation of 5C6-F4 antigen from surface-iodinated Con A-activated rat thymocytes or LPS-activated rat spleen cells revealed its m.w. to be approximately 100,000. The kinetic studies of the expression of 5C6-F4 antigen revealed that 5C6-F4 antigen was detectable at 6 hr after Con A stimulation of rat spleen cells, whereas IL 2 receptor (IL 2R) was detectable at 12 hr. The appearance of 5C6-F4 antigen and IL 2R precede the onset of DNA synthesis of Con A-activated spleen cells. Thus, 5C6-F4 antigen is classified as early activation antigen. The 5C6-F4 inhibits the lymphocyte proliferation induced by mitogen and the IL 2-driven rat T cell proliferation. Sequential immunoprecipitation study as well as binding inhibition study indicated that the 5C6-F4 antigen is distinct from IL 2R molecule. The 5C6-F4 antigen appears to be a novel rat lymphocyte activation antigen that exhibits immunoregulatory function and also may serve as a useful marker of T cell activation.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D000937:Antigen-Antibody Reactions; D000954:Antigens, Surface / Q000032:analysis* / Q000096:biosynthesis / Q000276:immunology; D001667:Binding, Competitive; D002460:Cell Line; D003208:Concanavalin A / Q000494:pharmacology; D005260:Female; D007376:Interleukin-2 / Q000378:metabolism / Q000502:physiology; D007700:Kinetics; D008070:Lipopolysaccharides / Q000494:pharmacology; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D008970:Molecular Weight; D051381:Rats; D011916:Rats, Inbred F344; D011917:Rats, Inbred Lew; D011919:Rats, Inbred Strains; D011971:Receptors, Immunologic / Q000032:analysis; D015375:Receptors, Interleukin-2; D013154:Spleen; D013601:T-Lymphocytes / Q000276:immunology*; D014018:Tissue Distribution; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7
chemical_list: D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D007376:Interleukin-2; D008070:Lipopolysaccharides; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7; D003208:Concanavalin A