Human monoclonal antibodies to HIV-1: cross-reactions with gag and env products.

Human monoclonal antibodies were raised by in vitro immunization of normal human spleen cells with denatured HIV-1 and subsequent fusion to an Epstein-Barr virus (EBV) transformed cell line. Three monoclonals reacted with both gag-encoded p24 core protein and env-encoded gp41 transmembrane glycoprotein. The cross-reaction was confirmed by reactivity with p24- and gp41-derived recombinant peptides. The peptides share two amino acid sequences which may be the basis for the cross-reaction. Attempted epitope mapping using synthetic peptides was unsuccessful due to non-specific reactivity with the short linear peptides.