RESUMO
Based on the NSP4 sequence of bovine rotavirus (BRV), the shRNA was designed and synthesized, and a shRNA recombinant lenti-virus vector RNAi-H1-89 was constructed. The recombinant RNAi-H1-89 Lenti-virus was packaged by transfecting the 293T cell with the recombinant vector RNAi-H1-89 and two helper plasmids using lipofectamine, and then used to infect MA104 cells. The MA104 cells were further infected with BRV strain G6 24h post-infection, with the LacZ shRNA recombinant lenti-virus as control. Thirty-six hours later, the CPE of the infected cells was observed under microscope, shRNA of NSP4 gene inhibited CPE in MA104 cell; the shRNA against NSP4 gene also inhibited NSP4 gene expression by RT-PCR, The virus titer in the cell culture supernatant was significant lower compared with the control group. The above results showed that RNAi-H1-89 against NSP4 gene could specifically silence NSP4 gene expression, and inhibit the proliferation of BRV.
Assuntos
Animais , Bovinos , Sequência de Bases , Linhagem Celular , DNA Recombinante , Genética , Glicoproteínas , Genética , Dados de Sequência Molecular , Plasmídeos , Genética , RNA Interferente Pequeno , Genética , Rotavirus , Genética , Fisiologia , Toxinas Biológicas , Genética , Carga Viral , Genética , Proteínas não Estruturais Virais , Genética , Replicação Viral , GenéticaRESUMO
Interferon a gene was cloned from genomic DNA of Chinese Luxi yellow cattle by PCR, and the PCR product was inserted into vector pET32a( + ) to make a recombinant plasmid pET32a( + )/BoIFN-alpha. The expression of BoIFN-alpha in Escherichia coli was induced by addition of IPTG. Sequence analysis showed that the Chinese Luxi yellow cattle IFN-alpha gene is composed of 498 nucleotides, encoding a mature polypeptide of 166 amino acids. Compared with other BoIFN-alpha subtypes, it shares the highest identity of 97.6% to the C-subtype. SDS-PAGE results showed that recombinant proteins were expressed in inclusion bodies in Escherichia coli with molecular weight of 40 kD and the recombinant proteins accounted for 26.7% of the whole proteins.The expressed product was purified by affinity chromatography with immobilized nickel chelating NTA (Ni-NTA) and its antiviral activities were tested on MDBK/VSV cell system. Its antiviral activities were 5 x 10(5) u/mg on MDBK/VSV cell system. The results showed that the expression plasmid was successfully constructed and BoIFN-alpha C2 protein was expressed in Escherichia coli. Moreover the purification had good effects on antiviral activities.