A novel, sensitive radioimmunoprecipitation assay for the detection of antibodies to human immunodeficiency virus-type 2

A radioimmunoprecipitation assay that provides an alternative to the Western blot assay was developed for characterizing antibodies against human immunodeficiency virus type-2 (HIV-2). The assay is based on radioiodination of antigen using Bolton-Hunter reagent. The antigen consists of a soluble preparation of the NIH-Z (HIV-2) strain of 1000X purified virus spiked with purified recombinant HIV-2 gp105. Radiolabeled proteins were immunoprecipitated by immune human sera, even at the early stages of seroconversion. This new assay provides a simple method for characterizing and titrating antibodies against HIV-2. The method is more sensitive, and is more efficient than Western blotting. The labeled viral proteins are well suited for biochemical studies.