The analysis of 5 HIV-1 gpl20 sequences from different clades and expression of their corresponding proteins in vitro / 中华微生物学和免疫学杂志

ABSTRACT

Objective To characterize 5 gpl20 sequences from mainly circulating clades in China and expression of their gp120 glycoproteins. Methods gp120 genes were amplified from the PBMCs of 5 HIV-1 infected individuals in different provinces using nest PCR and their DNA sequences were determined. Sequence characteristics were analyzed and gp120 genes were sub-cloned into the mammalian expression vec-tor to produce gp120 glycoproteins. Results Sequence characteristics indicated these sequences belong to the clade Thai-B, CRF_BC and CRF_AE, respectively. There were some conservative N-linked glycosyla-tion sites and primary Furin protease cleavage motifs in the same positions within gp120 amino acid se-quences although these gp120 sequences were categorized into different clades. In comparison with referen-tial strains, amino acids deletions were found in the V1, V2, V4, V5 regions except for the V3 loop; above all, V3 tip motifs of Thai-B exhibited the more polymorphic forms than those of CRF_BC and CRF_AE. These 5 gp120 sequences were cloned into the eukaryotic expression vector and gpl20 glycoproteins were produced successfully. Conclusion Hyper-variable nature of Env should be considered while designing HIV-1 vaccine or test reagent, and gpl20 expression in vitro is helpful to further research on the Env patho-genesis and vaccine development against the mainly circulating HIV-1 isolates in China.