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, χ). 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.