title: Cell-surface immunoglobulin and insulin receptor expression in an EBV-negative lymphoma cell line and its EBV-converted sublines.
abstract: Membrane Ig and insulin receptors were assayed in the EBV-negative Ramos lymphoma line and its EBV-converted sublines by surface fluorescence. 125I-protein A-binding assay, immunoprecipitation, and insulin receptor assay. The original Ramos line expressed surface IgM but not IgD and had a low concentration of insulin receptors. Ten of 10 converted lines expressed IgD and a variable but usually high insulin-binding capacity. Molecular weight analysis of immunoprecipitated Ig showed the presence of 2 mu-chains and 2 delta-chains. One of each heavy chain type could be characterized as membrane Ig, whereas the other was cytoplasmic. Antisera against the lambda-chain precipitated mu and delta heavy chains as well, indicating that the delta-chain expressed on the membrane of the EBV-converted Ramos lines is bound to the lambda light chain. The results show that the differentiation of a Burkitt lymphoma line is not completely "frozen" and can be induced to change in a more "activated" direction by EBV conversion.
mesh_terms: D001665:Binding Sites; D002460:Cell Line; D011232:Chemical Precipitation; D004854:Herpesvirus 4, Human / Q000276:immunology*; D006801:Humans; D007143:Immunoglobulin Heavy Chains / Q000096:biosynthesis; D007147:Immunoglobulin Light Chains / Q000096:biosynthesis; D008223:Lymphoma / Q000276:immunology*; D008970:Molecular Weight; D011972:Receptor, Insulin; D011947:Receptors, Antigen, B-Cell
chemical_list: D007143:Immunoglobulin Heavy Chains; D007147:Immunoglobulin Light Chains; D011947:Receptors, Antigen, B-Cell; D011972:Receptor, Insulin