Human monoclonal and polyclonal anti-human immunodeficiency virus-1 antibodies share a common clonotypic specificity

Human monoclonal and purified polyclonal anti-human immunodeficiency virus (HIV)-1 antibodies were tested for binding to a murine monoclonal anti-idiotypic antibody (1F7, IgM, kappa). Four human monoclonal anti-p24 and three human monoclonal anti-gp120 antibodies express the 1F7 clonotype, while one human monoclonal anti-gp41 antibody does not bind to 1F7. Affinity-purified anti-p24 and anti-gp120 antibodies from HIV-1-infected individuals also react with 1F7. Western blot analysis and enzyme-linked immunosorbent assay confirmed that 1F7 reacts with human antibodies of different HIV-1 antigen specificities. A survey of sera from 329 HIV-1-infected individuals showed binding to 1F7 in 239 sera (72.6%) while 1F7 was not reacting with 109 HIV-1-negative sera. These results show that 1F7 idiotype is an HIV-1 infection-associated clonotypic marker shared by anti-HIV-1 antibodies with different epitope specificites.