Constant and variable antigenic regions of the HIV

Human immunodeficiency virus (HIV) is the etiological agent in acquired immunodeficiency syndrome (AIDS). The presence of antibodies against HIV is indicative of prior exposure to HIV. Currently available antibody screening tests use HIV-infected cells as a source of viral antigens. This approach has resulted in inherent flaws, including a high rate of false-positive results. In order to develop a highly specific and sensitive test, various proteins of HIV [envelope (env), gag, pol] were cloned and expressed. In addition, we synthesized peptides corresponding to various regions of envelope (gp120, gp41), tat, art, and the protease gene products were synthesized. Using these synthetic peptides and cloned proteins, several conserved and highly antigenic epitopes in viral envelope were identified. Fusion proteins were made from the highly conserved and antigenic epitopes of env and gag. One of these fusion proteins, env-gag, was used to develop an enzyme immunoassay that would detect the antibodies against both env and gag epitopes. A clinical study of 13,781 samples demonstrated the very high specificity (99.9%) and sensitivity (100%) of this assay.