The production and characterization of murine monoclonal antibodies to a DNA receptor on human leukocytes.
Two murine mAb have been generated with a reactivity toward a 30,000 m.w. DNA binding protein found on the cell surface of human leukocytes; mAb 12A has an IgG1/k isotype, and mAb 24T has an IgG2b/k isotype. Both react with the DNA binding domain or adjacent region of the putative DNA receptor and inhibit the binding of [3H]DNA to PBMC at concentrations as low as 100 ng/ml. Stoichiometric studies indicate that both mAb react with monocytes and T cells with a kDa of 10(-7) M; about 0.5 x 10(6) molecules bind per cell at saturation. Flow cytometry indicated that 67% of lymphocytes and 98% of monocytes bore the DNA receptor. Dual labeling studies showed that 90% of B cells and 50% of T cells express the receptor; 50% of CD4+ T cells are receptor positive. Immunomatrices constructed with both mAb 12A and 24T allowed the receptor to be purified to a high degree of purity. A single protein of Mr 30,000 was readily observed after SDS-PAGE and silver staining of the gel; after electropheretic transfer of nitrocellulose this protein was shown to be a DNA binding molecule by use of a probe of biotin labeled DNA. These experiments provide further evidence to support the existence of a specific DNA receptor on human leukocytes; the availability of mAb to the receptor should be useful in its further characterization.
D000911:Antibodies, Monoclonal / Q000276:immunology*; D000954:Antigens, Surface / Q000276:immunology*; D001665:Binding Sites; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000276:immunology*; D000939:Epitopes; D005434:Flow Cytometry; D006657:Histones / Q000276:immunology; D008970:Molecular Weight; D009000:Monocytes / Q000276:immunology; D011956:Receptors, Cell Surface / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology
D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; C033365:DNA receptor; D004268:DNA-Binding Proteins; D000939:Epitopes; D006657:Histones; D011956:Receptors, Cell Surface; D004247:DNA