title: Reactivity of an HIV gag gene polypeptide expressed in E. coli with sera from AIDS patients and monoclonal antibodies to gag.
abstract: A segment of the gag gene of the human immunodeficiency virus (HIV) (HTLV-IIIB strain), the virus which causes acquired immunodeficiency syndrome (AIDS), has been cloned into the bacterial expression vector, pCQV2, and mapped to the right-hand portion of the gag gene containing the carboxyl-terminal portion of p24 and the amino-terminal portion of p15. Nucleic-acid sequencing of the insert-vector junctions further defined the 5'-terminal nucleotide of HIV sequence as nucleotide 997 and the 3'-terminal nucleotide as 1696. When used in an enzyme-linked immunosorbent assay (ELISA) with sera from HIV-infected patients, the cloned antigen reacted with a subset of sera which were positive on a standard ELISA using whole virus as antigen. Western-blot screening of these sera with whole virus indicated that all p24-positive sera were positive with the clone, suggesting that the carboxyl-terminal portion of p24 contains a highly antigenic epitope(s). A serum which was p24-negative p15-positive by Western blot analysis was also highly reactive, indicating that a p15 epitope is present in the cloned antigen. Epitope mapping with a series of monoclonal antibodies to gag resulted in positive ELISA with 2 of 3 anti-p24, 0 of 1 anti-p15, and 0 of 1 anti-p17 Western-blot-positive monoclonal antibodies, suggesting that one of the anti-p24 monoclonal antibodies reacts with epitopes amino-terminal to those coded from nucleotide 997, two anti-p24 monoclonals react with epitopes carboxyl-terminal to those coded from nucleotide 997, and the anti-p15 monoclonal reacts with epitopes carboxyl-terminal to those coded from nucleotide 1696.
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000276:immunology* / Q000382:microbiology; D000911:Antibodies, Monoclonal / Q000276:immunology; D000914:Antibodies, Viral / Q000276:immunology*; D000956:Antigens, Viral / Q000235:genetics*; D003001:Cloning, Molecular; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes; D015683:Gene Products, gag; D006678:HIV / Q000235:genetics* / Q000276:immunology; D015483:HIV Antibodies; D006679:HIV Seropositivity / Q000276:immunology*; D006801:Humans; D007163:Immunosorbent Techniques; D012191:Retroviridae Proteins / Q000235:genetics / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D000956:Antigens, Viral; D000939:Epitopes; D015683:Gene Products, gag; D015483:HIV Antibodies; D012191:Retroviridae Proteins