Three Antigenic Regions in p17 of Human Immunodeficiency Virus Type 1 (HIV‐1) Revealed by Mouse Monoclonal Antibodies and Human Antibodies in HIV‐1 Carrier Sera

Open Access
Publisher Website
Google Scholar
Abstract
We investigated the murine antibody response to recombinant p17 (rp17) of human immunodeficiency virus type 1 (HIV‐1) and the human antibody response directed to p17 in HIV‐1 infection. Three large peptides covering residues 12‐29, 53‐87 and 87‐115 of p17 were synthesized. The cysteine residues 57 and 87 of peptide 53‐87 were reoxidized to form a disulfide bridge. Eighteen out of 19 murine monoclonal anti‐rp17 antibodies had relatively high affinities (KA = 1.9 × 105−1.4 × 108 M−1) with one of the 3 p17 peptides in the liquid phase. Each monoclonal antibody reacted only with one particular peptide and had no reactivity with the other 2 p17 peptides. All the monoclonal antibodies reacted with rp17 in the liquid phase with a reasonable degree of affinity (KA = 2.0 × 105−1.8 × 107 M−1). Four HIV‐1 carrier sera, which were positive in ELISA using rp17 as the antigen, reacted positively in an ELISA using 3 p17 peptides which were used to titrate murine monoclonal antibodies. Murine monoclonal antibodies having specificity for the 3 p17 peptides stained live HIV‐1‐infected cells by means of indirect membrane immunofluorescence, irrespective of their specificity. This suggests that the various portions of p17 (at least 3 regions of p17) were exposed on the surface of live infected cells, probably as short polypeptide chains.