Monoclonal anti-idiotypic 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 antibody (Ab2) vaccines against HIV-1.

DESIGN

Murine monoclonal Ab2 were generated against anti-HIV-1 antibody 0.5 beta (Ab1), which binds to gp120, neutralizes HIV-1 and inhibits virus-induced syncytia formation.

METHODS

Mice were immunized with Ab1, and Ab2 were produced from immunized mice by the hybridoma technique. The Ab2 were characterized in vitro, injected into rabbits, and the anti-anti-idiotypes (Ab3) induced in the rabbits were analyzed for binding and antiviral reactivities by enzyme-linked immunosorbent assay, p24gag release and syncytia formation assays.

RESULTS

Seven Ab2 bound to the antigen-combining site of Ab1, one of which (UD7) induced Ab3 in rabbits that were Ab1-like in their binding reactivities to PB1 (recombinant gp120 fragment) or peptides of gp120, and shared idiotypes with the Ab1. Crude Ab3-containing sera specifically and effectively neutralized the virus.

CONCLUSION

Monoclonal Ab2 UD7 has potential as a vaccine against HIV-1.