3 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

We investigated the murine antibody response to recombinant p17 (rp17) of human immuno-deficiency virus type 1 (HIV-1) and the human antibod y response directed to p17 in HIV-1 infection. Three large peptides co vering residues 12-29, 53-87 and 87-115 of p17 were synthesized. The c ysteine residues 57 and 87 of peptide 53-87 were reoxidized to form a disulfide bridge. Eighteen out of 19 murine monoclonal anti-rp17 antib odies had relatively high affinities (K-A=1.9 X 10(5)-1.4 X 10(8) 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 reactivi ty with the other 2 p17 peptides. All the monoclonal antibodies reacte d with rp17 in the liquid phase with a reasonable degree of affinity ( K-A=2.0 X 10(5)-1.8 X 10(7) M(-1)). Four HIV-1 carrier sera, which wer e positive in ELISA using rp17 as the antigen, reacted positively in a n ELISA using 3 p17 peptides which were used to titrate murine monoclo nal antibodies. Murine monoclonal antibodies having specificity for th e 3 p17 peptides stained live HIV-1-infected cells by means of indirec t 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.