RESUMO
<p><b>OBJECTIVE</b>To characterize the variation in V3 loop of HIV-1 B'strains circulating in Chinese blood donors.</p><p><b>METHODS</b>The c2-c3 regions of the HIV envelop gene were amplified by nest-PCR from 32 HIV-1-infected blood donors in He Nan province in China. The BIOEDIT and MEGA software are used to analyze the sequences of V3 loop.</p><p><b>RESULTS</b>There are five types of central motifs of the 32 samples, in which GPGR and GPGQ are most common. More variations associated with T tropic/SI phenotype can be seen in AIDS group.</p><p><b>CONCLUSION</b>The V3 tip motifs of HIV-1B' strains circulating in Chinese blood donors are various, the different characterization of V3 loop between AIDS and asymptomatic patients indicates different biological phenotype and pathogenesis which warrant additional investigation.</p>