T-lymphocyte and B-lymphocyte dichotomy in anuran amphibians: II. Further investigations on the E-rosetting lymphocyte by using monoclonal antibody azathioprine inhibition and mitogen-induced polyclonal expansion.
We have continued to search for characteristics of T-lymphocytes in anuran amphibians. Inhibition assays using the monoclonal antibodies OKT-11 and T-11, the T-cell immunosuppressive drug azathioprine, and mitogens confirmed the nature of E-rosetting peripheral blood lymphocytes (PBL) in Rana pipiens. Both monoclonal antibodies specifically inhibited E-rosetting in a dose-dependent fashion; absorption of the monoclonals by frog PBL specifically removed inhibition on human E-rosetting T-cells. Lysostripping frog E-receptors with monoclonals and a second FITC antibody revealed a fluorescent lymphocyte population which capped off the receptor as shown by subsequent inhibition of E-rosetting. Significant resynthesis of E-receptors occurred 24 hours after lysostripping, especially in nylon wool effluent fractions. Azathioprine allowed us to define tentatively two subpopulations of E-rosetting lymphocytes: one nylon wool adherent and sensitive to inhibition at low concentrations and another resistant but sensitive to higher (cytotoxic) concentrations of azathioprine. In addition, T-cell but not B-cell mitogens induced expansion of E-rosetting cell populations. Our results support a thymic origin for Rana pipiens' E-rosetting cells. With respect to evolution, human and frog E-receptors are probably homologous, sharing at least one and probably two different antigenic determinants.
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D001379:Azathioprine / Q000494:pharmacology; D001402:B-Lymphocytes / Q000187:drug effects / Q000276:immunology*; D003208:Concanavalin A / Q000494:pharmacology; D006801:Humans; D008213:Lymphocyte Activation / Q000187:drug effects; D010835:Phytohemagglutinins / Q000494:pharmacology; D011894:Rana pipiens / Q000276:immunology*; D012397:Rosette Formation; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology*
D000911:Antibodies, Monoclonal; D010835:Phytohemagglutinins; D003208:Concanavalin A; D001379:Azathioprine