Monoclonal anti-IgM can separate T cell from B cell proliferative responses in the frog, Xenopus laevis.
The role of SIgM+ lymphocytes in frog mitogen responses and mixed lymphocyte reactions was examined. A murine monoclonal antibody with specificity for Xenopus laevis IgM was produced. The anti-IgM activity was not inhibited by glycoproteins other than Xenopus IgM, but could be inhibited with periodate-treated frog IgM. Fluorescent microsphere-coupled anti-IgM was used to show that adult and larval thymocytes had few sIgM+ lymphocytes, whereas spleens contained 19 to 34% sIgM+ lymphocytes. The spleens of larvally thymectomized adults were greatly enriched for sIgM+ cells. Lymphocyte suspensions were depleted of sIgM+ cells by incubation of spleen cells on plastic Petri dishes coated with anti-IgM monoclonal antibody. Compared with unseparated controls, the nonadherent cells cultured in serum-free medium were enriched for Con A and PHA mitogen responses and mixed lymphocyte culture (MLC) reactivity. Nonadherent cells were partially depleted of LPS mitogen responsiveness. Depletion or enrichment of the mitogen response was not a result of changes in kinetics or dose-response characteristics of the cells. In 1% FCS-supplemented cultures, the LPS response was not depleted, whereas the PHA response was still enriched. Thus, thymus-dependent and thymus-independent mitogen and MLC responses can be separated by the criterion of sIgM positivity in this anuran species.
D000818:Animals; D000888:Antibodies, Anti-Idiotypic; D000911:Antibodies, Monoclonal; D001202:Ascitic Fluid / Q000276:immunology; D001402:B-Lymphocytes / Q000166:cytology*; D004306:Dose-Response Relationship, Immunologic; D005260:Female; D005455:Fluorescent Antibody Technique; D007075:Immunoglobulin M; D007700:Kinetics; D008070:Lipopolysaccharides / Q000494:pharmacology; D007959:Lymphocyte Culture Test, Mixed; D008221:Lymphoid Tissue / Q000276:immunology; D008297:Male; D051379:Mice; D008805:Mice, Inbred A; D008807:Mice, Inbred BALB C; D008934:Mitogens / Q000494:pharmacology; D011817:Rabbits; D011947:Receptors, Antigen, B-Cell; D013601:T-Lymphocytes / Q000166:cytology*; D014982:Xenopus laevis
D000888:Antibodies, Anti-Idiotypic; D000911:Antibodies, Monoclonal; D007075:Immunoglobulin M; D008070:Lipopolysaccharides; D008934:Mitogens; D011947:Receptors, Antigen, B-Cell