The HIV-1 variant that contains the GWG amino acid sequence in the crown of the principal neutralizing determinant (PND) has been detected in a few patients in Japan, France, and Brazil by direct sequencing. We describe for the first time the use of restriction fragment length polymorphism (RFLP) and limited DNA sequencing of the C2-V3 region of the HIV-1 envelope (env) gene to determine the prevalence of the variant in 75 HIV-1-infected Brazilian patients. Overall prevalence of the GWG sequence as indicated by RFLP was 57% (43 of 75). The prevalence in females (72%) was higher than that in males (32%) and newborns (40%). Two GFG sequences and 1 GLG sequence were also detected. This finding is relevant for the planning of vaccines and for studies of the epidemiology of HIV-1 in Brazil.
PIP: Most current HIV vaccine development research is focused on the third variable domain (V3) of the HIV-1 envelope gene product that contains the GWG amino acid sequence in the crown of the principal neutralizing determinant. Direct sequencing has detected this variant in patients in Japan, France, and Brazil. The present study used restriction fragment length polymorphism (RFLP) and limited DNA sequencing of the C2-V3 region of the HIV-1 envelope gene to determine the prevalence of the variant in 75 HIV-infected patients from Ribeirao Preto, Brazil. According to RFLP, the overall prevalence of the GWG sequence was 57% (72% in females, 32% in males, and 40% in newborns). Two GFG sequences and one GLG sequence were also detected, suggesting that the GWG variant could be the founder sequence. The gene dendrogram indicated the samples clustered together within the subtype B of the main group.