Characterization of the murine T cell surface molecule, designated L3T4, identified by monoclonal antibody GK1.5: similarity of L3T4 to the human Leu-3/T4 molecule.
Monoclonal antibody GK1.5 recognizes a previously undescribed murine T cell surface molecule, designated L3T4, which migrates on SDS-PAGE under reducing conditions as a single band with an apparent m.w. of 52,000. L3T4 is expressed by approximately 80% of thymocytes and by approximately 20% of spleen cells. There appears to be poor correlation between expression of L3T4 by functional T cell clones and expression of Lyt-2, expression of the cytolytic phenotype, and class I MHC antigen reactivity. On the other hand, both a class II MHC antigen-reactive HTL clone and an Lyt-1- Mls-reactive HTL clone express L3T4. Analysis of the effect of mAb GK1.5 on PFC responses in adoptive transfer suggests that L3T4 is expressed by the helper/inducer subset of murine T cells. Expression of L3T4 by murine T cells, however, may correlate primarily with class II MHC antigen reactivity rather than with functional phenotype; mAb GK1.5 profoundly blocks antigen-specific cytolysis by the cloned class II MHC antigen-reactive CTL line A15-1.17. Antigen-specific cytolysis by A15-1.17 is blocked by mAb GK1.5 at a step before the lethal hit. Collectively, the flow cytometric, functional, and biochemical data indicate that L3T4 is similar to the human Leu-3/T4 molecule.
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000945:Antigens, Differentiation, T-Lymphocyte; D000950:Antigens, Ly / Q000276:immunology; D000954:Antigens, Surface / Q000032:analysis* / Q000235:genetics / Q000276:immunology; D001667:Binding, Competitive; D003602:Cytotoxicity, Immunologic; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D005434:Flow Cytometry; D006183:H-2 Antigens / Q000032:analysis / Q000235:genetics / Q000276:immunology; D006462:Hemolytic Plaque Technique; D006801:Humans; D006825:Hybridomas / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D008811:Mice, Inbred DBA; D051381:Rats; D011917:Rats, Inbred Lew; D013601:T-Lymphocytes / Q000145:classification / Q000276:immunology*
D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D000950:Antigens, Ly; D000954:Antigens, Surface; D006183:H-2 Antigens