INFLUENCE OF DELETIONS IN N-TERMINUS OR C-TERMINUS OF HIV-1 GLYCOPROTEIN-120 ON BINDING OF INFECTIVITY-ENHANCING ANTIBODY

Human monoclonal antibody 2.3a was previously shown to enhance human i mmunodeficiency virus type 1 (HIV-1) infection in vitro. This enhancin g antibody recognizes a conserved epitope of envelope glycoprotein gp1 20. We report here that binding of the 2.3a antibody to gp120 is signi ficantly affected by deletions of certain N- or C-terminal residues of gp120. However, not all such deletions affect the epitope recognized by a broadly neutralizing human monoclonal antibody, 1.5e. These findi ngs suggest the feasibility of designing a gp120 antigen that is free of 2.3a epitope while retaining the conformation of the 1.5e epitope.