Characterization of conformation-dependent anti-gp120 murine monoclonal antibodies produced by immunization with monomeric and oligomeric human immunodeficiency virus type 1 envelope proteins

Twenty-five conformation-dependent monoclonal antibodies (MAbs) produced by immunization of mice with oligomeric forms of the human immunodeficiency v irus type 1 (HIV-1) envelope (env) glycoprotein were used to map exposed, i mmunogenic regions on oligomeric env. Based on MAb cross-competition, react ivity with diverse env proteins, and reactivity with a panel of gp120 mutan ts, seven distinct epitope clusters were identified. These include the clas sic CD4 binding site, V1/V2, and V3. in addition, several novel epitope clu sters, including one mapping to the N- and C-termini of gp120, were identif ied. The locations of the seven epitope clusters on the gp120 core structur e are proposed.