Synthesis, intracellular distribution, and secretion of immunoglobulin and H-2 antigen in muring splenocytes.
A/J spleen cells were labeled with [(3)H]leucine and at intervals thereafter were homogenized and separated into microsomes and cell sap. Ig and H-2 antigens were assayed in the cell fractions and cell supernatants using immunoprecipitation. In addition, cells labeled by enzymatic radioiodination were incubated to determine the rates of release of Ig and H-2 antigens from the surface. The results indicate that the majority of Ig and H-2 antigens remain membrane bound throughout their intracellular life. In contrast to Ig, H-2 antigens are neither secreted nor shed from the cell surface. It is suggested that Ig is a peripheral protein of the cell membrane, whereas H-2 antigens are integral ones. The release of Ig on a fragment of plasma membrane could occur at fixed cell surface areas that contain no H-2 antigens or from which they have migrated before release.
D000818:Animals; D001666:Binding Sites, Antibody; D002458:Cell Fractionation; D002462:Cell Membrane / Q000276:immunology; D002478:Cells, Cultured; D005260:Female; D006649:Histocompatibility Antigens / Q000032:analysis; D005779:Immunodiffusion; D007122:Immunoelectrophoresis; D007136:Immunoglobulins / Q000032:analysis / Q000096:biosynthesis*; D007457:Iodine Radioisotopes; D007519:Isoantigens; D007700:Kinetics; D007930:Leucine / Q000378:metabolism; D051379:Mice; D008815:Mice, Inbred Strains; D013154:Spleen / Q000166:cytology* / Q000276:immunology; D014316:Tritium
D006649:Histocompatibility Antigens; D007136:Immunoglobulins; D007457:Iodine Radioisotopes; D007519:Isoantigens; D014316:Tritium; D007930:Leucine