Construction, package and identification of replication-deficient recombinant adenovirus expression vector of HCV C

Cloning of HCV E2 gene and expression and purification of HCV envelope glycoprotein E2

AIM: To obtain large amount of HCV E2 protein, and to understand the function of the protein and to prepare the antibody against this protein.

METHODS: A 831bp of E2 gene fragment was amplified by PCR method from HCV genome and cloned into pET32a(+) vector, an E. coli expression vector, to construct a recombinant plasmid pET32a-HCVE2.The plasmid was transformed into E. coli BL-21 (DE3) to express E2 protein with IPTG induced. The protein E2 fused with HIS tag was purification by Ni-NTA resin column. The protein E2 fused with His tag was detected by SDS-PAGE electrophoresis and Western blot.

RESULTS: A novel protein with molecular weight of M_r 55 000 was expressed upon induction with IPTG in E. coli. The expressed product showed good reactivity to anti-His tag antibody and the HCV positive serum.

CONCLUSION: Cloning of HCV E2 gene and the expression and purification of envelope glycoprotein E2 lay a foundation of further study on HCV E2 protein and the receptors of hepatitis virus C.

RNA interference: Antiviral weapon and beyond

RNA interference (RNAi) is a remarkable type of gene regulation based on sequence-specific targeting and degradation of RNA. The term encompasses related pathways found in a broad range of eukaryotic organisms, including fungi, plants, and animals. RNA interference is part of a sophisticated network of interconnected pathways for cellular defense, RNA surveillance, and development and it may become a powerful tool to manipulate gene expression experimentally. RNAi technology is currently being evaluated not only as an extremely powerful instrument for functional genomic analyses, but also as a potentially useful method to develop specific dsRNA based gene-silencing therapeutics. Several laboratories have been interested in using RNAi to control viral infection and many reports in Nature and in Cell show that short interfering (si) RNAs can inhibit infection by HIV-1, polio and hepatitis C viruses in a sequence-specific manner. RNA-based strategies for gene inhibition in mammalian cells have recently been described, which offer the promise of antiviral therapy.