Construction of DNA vaccine expressing codon-modified HIV-1 consensus env gene derived from subtype CRF01_AE infected individuals in China

Abstract

Objective To construct a DNA vaccine containing codon-modified HIV-1 consensus env gene which will be a candidate vaccine in multiple vector-based therapeutic AIDS vaccine strategy.Methods HIV-1 CRF01_AE env genes were amplified using subtype-specific primmer sets and cloned to pcDNA 3.1.The consensus sequence was acquired by alignment of all the env sequences with software.Then codons of the consensus env sequence were modified according to mammalian codon usage.The modified env gene mod.AE env was cloned into pVR vector to get DNA vaccine pVR-mod.AE env.The expression level of wild type and codon-modified env gene was analyzed by Western Blot assay.Results Phylogenetic analysis of the full-length env nucleotide sequences confirmed that all 32 isolates were grouped within CRF01_AE.The DNA vaccine expressing the codon-modified consensus env gene derived from these 32 sequences was constructed successfully.The codon modification increased the expression level of Env protein significantly.Conclusion The codon modification of CRF01_AE env gene and construction of DNA vaccine expressing this gene was successful. Key words: AIDS vaccines; Genes, env; Plasmids; Codon