Monoclonal antibody identifies a highly conserved and immunodominant epitope of the human immunodeficiency virus transmembrane protein

A murine monoclonal antibody (MAb), 10E9, has been generated which identifies a conserved and immunodominant epitope of the human immunodeficiency virus (HIV) transmembrane protein, gp41. The MAb reacts with the protein backbone of the mature env gene product and also with polyprotein precursor, gp160. Human sera were tested for their ability to competitively inhibit the immunoreactivity of MAb 10E9. Of 100 serum samples obtained from patients with acquired immune deficiency syndrome (AIDS) or AIDS-related complex (ARC), all showed strong inhibition to the reaction. In contrast, sera obtained from normal donors or those with other viral infections failed to perturb the binding activity of MAb 10E9. The geographic diversity of the AIDS/ARC patients studied provides evidence that the 10E9 epitope of gp41 is highly conserved.