CHARACTERISTICS OF THE PRINCIPAL NEUTRALIZING DETERMINANT OF HIV-1 PREVALENT IN JAPAN

The principal neutralizing determinants (PNDs) of 29 human immunodeficiency virus type 1 (HIV-1) isolates in Japan were analyzed using polymerase chain reactions. The viruses were isolated from 16 hemophiliacs, 11 individuals infected by their sexual transmission and 1 patient infected by blood transfusion (total 28 patients). Two virus isolates which were obtained from the same individual at different periods were also analyzed. All individuals were Japanese except one. The results produced 32 different PND sequences. A highly conserved central core sequence (GPG) was present in 27 of 32 patients, similar to the number reported in the United States, despite the marked heterogeneity in flanking regions of PNDs. The PNDs of all the 16 HIV-1 isolates obtained from patients with coagulation disorders had GPG sequences. Secondary structure prediction of PNDs by a joint method suggested that they were composed of coil-beta-strand-coil-beta-strand-alpha-helix. It is suggested that the conserved core sequence has a type I turn. These findings may be useful in planning further clinical trials for passive vaccination.