The antigen/antibody specificity exchanger: a new peptide based tool for re-directing antibodies of other specificities to recognize the V3 domain of HIV-1 gp120.

We recently showed that a synthetic peptide corresponding to the third complementary determining region of the heavy chain (CDRH3) of a monoclonal antibody (mAb) directed to the V3 domain of HIV-1 gp120 neutralizes HIV-1 in vitro. From the CDRH3 sequence we have now produced bifunctional antigen/antibody specificity exchanger (A/ASE) peptides containing both the HIV-1 mAb derived CDRH3 sequence and antigenic region sequences from the hepatitis B virus core/e antigen (HBc/eAg) and the poliovirus VP1. These A/ASE peptides were able to re-direct HBc/eAg and enteroviral VP1 specific mAbs, as well as polyclonal human HIV-1 negative sera to recognize the V3 domain of HIV-1. Furthermore, two out of three A/ASE peptides were able to neutralize HIV-1 in vitro. These bifunctional A/ASE peptides have a potential to be used as tools in research, diagnostics and maybe even therapeutics.