[Establishment of stable cell line and expression and purification of HIV gp120 in Drosophila S2 cells].
Constructing eukaryotic expressing vector of pMT/Bip/V5-His A-HIV gp120 and transfecting S2 cells to establish stable gp120-expressing S2 cell line. The gp120 gene of HIV CRF07-BC epidemic in China was amplified by polymerase chain reaction from the recombinant vector PRSV-gp120 and confirmed by DNA sequence analysis. The DNA fragment of HIV gp120 was digested with the restriction endonucleases NcoI and XhoI, then inserted into eukaryotic expressing vector pMT/BiP/V5-His A. A selection vector containing the streptomyces griseochromogenes bsd gene conferring blasticidin resistance was cotransfected into drosophila S2 cells by Cellfectin II reagent. The stable cell line was established following repeated screening by blasticidin. HIV gp120 was purified by a Ni-NTA affinity column followed by molecular sieve chromatography. Recombinant protein was characterized by SDS-PAGE, Western blot and ELISA. The eukaryotic expressing vector pMT/BiP/V5-His A-HIV gp120 was constructed, stable expressing cell line was established, and protein was expressed and purified successfully. This result will contribute to functional study of gp120 and vaccine design against AIDS.