Construction and in vitro expression of a codon optimized env gene of Chinese attenuated EIAV vaccine strain

Codon optimization of the immunogenic genes is an effective strategy for improving the protection efficacy of DNA vaccine.It is well known that different species have different bias in using the codons for protein expression.Equine infectious anemia virus(EIAV)differs greatly from mammalian in utilizing codons bias.Using over-lapping extension PCR techniques and restriction enzyme digestion,we constructed membrane-bound and secreted EIAV env gene with mammalian codons.The genes were inserted into pCAGGS and transfected into the monolayer 293T cells.The expression of env protein was detected by indirect immunofluorescence assay 48 h after transfection,and confirmed by Western blot analysis.The results indicated the optimized env genes had a prominent increase expression than the wild type genes,and the expression location were as predicted.This study provided a foundation for further research on the EIAV env gene and development of immunity assay and novel vaccines.