OBJECTIVETo study the polymorphisms and secondary structure of human immunodeficiency virus (HIV-1) tat exon 1 among subtype B' and B'/C HIV-1 infected people in China and to explore the relationship between the polymorphism of tat exon 1 and the disease progression.

METHODS8 subtype B' and 5 B'/C HIV-1 infected patients with slow disease progression were selected from Liaoning, Jilin and Yunnan province. 26 subtype B' and 9 B'/C HIV-1 infected patients with similar sex, age but with typical disease progression were selected. Provirus was extracted from the whole blood. The gene sequences of the Tat exon 1 were amplified by nest-polymerase chain reaction (nest-PCR). Products were purified and sequenced directly. The sequences were aligned, translated, amino acid substitution were analyzed and secondary structures were predicted.

RESULTSMany amino acid substitution could be found in the exon 1 of Tat in HIV-1 subtype B' and B'/C recombinant strain infected persons with different disease progression except A58T,none of them showed definitely relationship with HIV viral load and disease progression. 23N, 31S, 32Y and 46F were subtype-specific substitutions. No characteristic secondary structure of exon 1 of Tat was found.

CONCLUSIONSome of the mutations of tat exon 1 might be related to HIV viral load and disease progression. However, there was no relationship found between the secondary structure of Tat protein and the disease progression.