Objective: To 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.
Methods: 8 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.
Results: Many 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.
Conclusion: Some 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.