title: Ia antigen: a murine B lymphocyte receptor for transformed cell induction of interferon-alpha/beta.
abstract: A receptor on the surface of nonsensitized mouse spleen cells that recognizes a glycoprotein from transformed mouse L-929 cells is described. The interaction of the receptor and glycoprotein inducer results in the production of MoIFN alpha/beta. An assay was developed to assess certain biologic and physicochemical characteristics of the receptor. The receptor and glycoprotein inducer bound in a concentration-dependent manner, which tends to indicate a direct interaction between the two. The receptor was not ubiquitous; spleen cells but not normal mouse embryo cells appeared to be the source. It was specific for MoIFN alpha/beta inducers from transformed cells, but not from other MoIFN alpha/beta or gamma inducers such as NDV, LPS, PWM, or SEA. The receptor appeared to be a cell surface protein in that its activity was abolished by trypsinization of whole spleen cells. Previous studies indicated that the receptor was probably located on B cells. Gel filtration indicated that the receptor had a m.w. of 30,000 to 60,000. Because the receptor appeared to be: 1) B lymphocyte associated, 2) a surface protein, and 3) 30,000 to 60,000 daltons, a similarity to Ia antigen was suggested. This possibility was confirmed by showing binding of the receptor to an anti-IaK antibody-Sepharose affinity column. PAGE analysis of the affinity-purified receptor revealed a single protein band with a m.w. of approximately 60,000. ELISA of the above gel slices with anti-Ia antibody further confirmed the specificity of the column. A physical association of the receptor and inducer was demonstrated by showing binding of the glycoprotein inducer to a receptor (Ia antigen)-Sepharose affinity column. Furthermore, the receptor (Ia antigen) was highly purified by a glycoprotein inducer-Sepharose affinity column.
mesh_terms: D000818:Animals; D001667:Binding, Competitive; D002846:Chromatography, Affinity; D003429:Cross Reactions; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000032:analysis; D005260:Female; D000949:Histocompatibility Antigens Class II / Q000032:analysis* / Q000276:immunology; D007369:Interferon Inducers / Q000032:analysis* / Q000502:physiology; D007370:Interferon Type I / Q000096:biosynthesis; D007739:L Cells / Q000276:immunology; D008213:Lymphocyte Activation; D051379:Mice; D008808:Mice, Inbred CBA; D008970:Molecular Weight; D011947:Receptors, Antigen, B-Cell / Q000032:analysis* / Q000276:immunology / Q000502:physiology; D013154:Spleen / Q000166:cytology
chemical_list: D000939:Epitopes; D000949:Histocompatibility Antigens Class II; D007369:Interferon Inducers; D007370:Interferon Type I; D011947:Receptors, Antigen, B-Cell