Objective:To construct and test the immunogenicity of codon-optimized DNA vaccines expressing gp120 from key representative HIV-1 subtypes AE,BC and B′(ThB) in China. Methods:Based on HIV-1 epidemiological information and sequence analysis of HIV-1 envelope glycoprotein(Env) of subtypes AE,BC and ThB in China,we designed the consensus gp120 sequence for each subtype AE,BC or ThB. These consensus gp120 genes were codon-optimized using codons preferred for high level expression in mammalian systems and chemically synthesized. The codon optimized gp120 genes were subcloned into the DNA vaccine vector pSW3891. The expression of gp120 by the constructed DNA vaccine plasmids in 293T cells was confirmed by Western blot. New Zealand rabbits were immunized with gp120 DNA vaccines using electroporation method,and gp120-specific antibodies in rabbit sera were evaluated by ELISA. Results:In the codon optimized gp120 gene,the frequency of the mammalian cell preferred codons was higher than that of the wild type gp120 gene. Three codon optimized gp120 DNA vaccines of consensus subtypes AE,BC or ThB were constructed and the expression of gp120 antigens was confirmed in transiently transfected 293T cells. The rabbits immunized with these gp120 DNA vaccines elicited HIV-1 Env-specific antibody responses. Conclusion:Three codon optimized DNA vaccines expressing consensus gp120 of HIV-1 sybtypes AE,BC and ThB were successfully constructed with proven expression and immunogenicity in eliciting HIV-1 Env-specific humoral responses.