Monoclonal antibodies and enzyme immunoassays specific for human interferon (IFN) omega 1: evidence that IFN-omega 1 is a component of human leukocyte IFN.
Four hybridoma cell lines secreting monoclonal IgG antibodies to human interferon (IFN) omega 1 (= IFN-alpha II 1) were developed, using spleen cells of mice immunized with IFN-omega 1 and/or a novel hybrid interferon, IFN-omega 1/alpha 2. All antibodies (OMG-2, -4, -5, and -7) neutralize the antiviral activity of IFN-omega 1 and show distinct patterns of reactivity with the hybrid proteins, IFN-omega 1/alpha 2 and IFN-alpha 2c/omega 1. However, none of the antibodies is able to neutralize human IFN-alpha, confirming earlier observations that IFN-omega 1 and IFN-alpha are antigenically unrelated. The epitope specificities of the antibodies were further characterized in direct and competitive enzyme immunoassays (ELISAs). All binary antibody combinations were tested for their suitability for a two-site ("sandwich") ELISA for IFN-omega 1, using horse radish peroxidase as the marker enzyme. A configuration employing OMG-2 for antigen capture and OMG-7 as the detector antibody resulted in the highest assay sensitivity (approximately 10 pg IFN-omega 1/ml) and was studied further. This one-step assay is highly specific for IFN-omega 1 and does not recognize human IFN-alpha, -beta, and -gamma, thus allowing for determination of IFN-omega 1 levels in natural mixtures of human IFNs. Using this ELISA, it was found that IFN-omega 1 is present in IFN preparations derived from virus-induced human peripheral blood leukocytes and may constitute as much as 15% of the total leukocyte IFN activity. IFN-omega 1 was also detected at somewhat lower levels in preparations of human "lymphoblastoid" IFN.
Ernst Boehringer-Institut für Arzneimittelforschung, Department of Cell Biology, Vienna, Austria.
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GR
Adolf
D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis / Q000276:immunology*; D001667:Binding, Competitive; D001681:Biological Assay; D003588:Cytopathogenic Effect, Viral; D004686:Encephalomyocarditis virus / Q000502:physiology; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000032:analysis; D005260:Female; D006801:Humans; D006825:Hybridomas; D007074:Immunoglobulin G / Q000096:biosynthesis / Q000276:immunology*; D007370:Interferon Type I / Q000032:analysis* / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D009500:Neutralization Tests; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D000939:Epitopes; D007074:Immunoglobulin G; D007370:Interferon Type I; C063743:interferon omega 1