MONOCLONAL ANTIIDIOTYPIC ANTIBODIES THAT MIMIC THE EPITOPE ON GP120 DEFINED BY ANTI-HIV-1 MONOCLONAL-ANTIBODY 0.5-BETA

Objective: To develop effective, specific and safe anti-idiotypic anti body (Ab2) vaccines against HIV-1. Design: Murine monoclonal Ab2 were generated against anti-HIV-1 antibody 0.5beta (Abl), which binds to gp 120, neutralizes HIV-1 and inhibits virus-induced syncytia formation. Methods: Mice were immunized with Abl, and Ab2 were produced from immu nized mice by the hybridoma technique. The Ab2 were characterized in v itro, injected into rabbits, and the anti-anti-idiotypes (Ab3) induced in the rabbits were analyzed for binding and antiviral reactivities b y enzyme-linked immunosorbent assay, p24gag release and syncytia forma tion assays. Results: Seven Ab2 bound to the antigen-combining site of Abl, one of which (UD7) induced Ab3 in rabbits that were Ab1-like in their binding reactivities to PB1 (recombinant gp120 fragment) or pept ides of gp120, and shared idiotypes with the Abl. Crude Ab3-containing sera specifically and effectively neutralized the virus. Conclusion: Monoclonal Ab2 UD7 has potential as a vaccine against HIV-1.