title: Surface proteins of thymus-derived lymphocytes and bone-marrow-derived lymphocytes. Selective isolation of immunoglobulin and the theta-antigen by non-ionic detergents.
abstract: Accessible surface proteins of thymus-derived lymphocytes (T-cells) of normal CBA mice and bone-marrow-derived lymphocytes (B-cells) of congenitally athymic nu/nu mice were analysed. The surfaces of lymphocytes were radioiodinated by using the enzyme lactoperoxidase (EC 1.11.1.7), then solubilized either in acid-urea or in the non-ionic detergent Nonidet P-40. These lysates were then precipitated with antisera specific to either immunoglobulin or the theta-alloantigen in order to assess the presence of these surface markers. Comparable amounts of radioactivity in proteins specifically precipitable as immunoglobulin were obtained from T-lymphocytes and B-lymphocytes when the cells were disrupted by acid-urea. This immunoglobulin had mol. wt. approx. 180000 and was composed of light chains and mu-type heavy chains. When radioiodinated lymphocytes were solubilized with Nonidet P-40, 3-4% of radioiodinated high-molecular-weight protein of B-cells consisted of immunoglobulin, a result similar to that found with acid-urea extraction. However, with the detergent extraction, only 0.1% of T-cell surface protein was precipitable by anti-globulin reagents. The theta-alloantigen was isolated from CBA T-cells both by acid-urea and by detergent lysis. This protein possessed a mobility on polyacrylamide-gel electrophoresis in sodium dodecyl sulphate which was consistent with a mol. wt. of 60000. An identical component was isolated from the theta-positive thymoma WEHI 105. The theta-antigen was not isolated from B-cells by either of the extraction procedures used. These results provide further evidence that the surface membranes of normal T-cells and B-cells differ in physicochemical properties. In particular, various surface components possess differential solubilities in non-ionic or organic solvents. This observation provides an explanation for discrepant results that have appeared in the literature concerning the isolation of immunoglobulin from T-lymphocytes.
mesh_terms: D000818:Animals; D000906:Antibodies; D000888:Antibodies, Anti-Idiotypic; D000941:Antigens / Q000302:isolation & purification; D001402:B-Lymphocytes / Q000032:analysis*; D001853:Bone Marrow / Q000032:analysis; D001854:Bone Marrow Cells; D002462:Cell Membrane / Q000032:analysis*; D002498:Centrifugation; D003902:Detergents; D004591:Electrophoresis, Polyacrylamide Gel; D006041:Goats / Q000276:immunology; D007074:Immunoglobulin G; D007136:Immunoglobulins / Q000302:isolation & purification*; D007457:Iodine Radioisotopes; D007519:Isoantigens; D008214:Lymphocytes / Q000276:immunology; D051379:Mice; D008970:Molecular Weight; D010544:Peroxidases / Q000378:metabolism; D011506:Proteins / Q000032:analysis*; D011817:Rabbits / Q000276:immunology; D012967:Sodium Dodecyl Sulfate; D013499:Surface Properties; D013601:T-Lymphocytes / Q000032:analysis*
chemical_list: D000906:Antibodies; D000888:Antibodies, Anti-Idiotypic; D000941:Antigens; D003902:Detergents; D007074:Immunoglobulin G; D007136:Immunoglobulins; D007457:Iodine Radioisotopes; D007519:Isoantigens; D011506:Proteins; D012967:Sodium Dodecyl Sulfate; D010544:Peroxidases