The M1Matrix Protein Affect The Morphology Phenotype Of Inlfuenza Virus And The Cloning And Prokaryotic Expression Of Inlfuenza Virus NS2Protein

Since1997, highly pathogenic avain influenza viruses(HPAI) of the H5N1subtype have causednumerous outbreaks in poultry in Southeast Asia that have led to the death or depopulation of significantnumbers of chickens. These outbreaks are accompanied by the occasional transmission of HPAI H5N1viruses to humans, resulting in a case fatality rate of more than50%.Influenza virus particles can display different morphologies,which are ranging from small sphericalparticles80—120nm in diameter to long filamentous particles up to several micrometres in length. It isintreasting to find that the early passages of human isolates are predominance of filamentous particles.The filamentous morphology are advantageous in cell-to-cell transmission of the virus in the respiratorymucosa,which may pose more serious threat to humans.M1protein are recognized as the main factor forthe control of morphology phenotype. Yet the detailed role that M1protein may play in the formation offilamentous virus morphology is still unknown.In this study, we found that the changes of two amino acids at position30and215of M1contributed to the morphology difference of the influenza virus. We futher demonstrated that the variantfrom spherical paticles to long filamentous particles is the result of the different expression level of M1protein. The different expression level of M1protein is not the result of M1gene itself but may be theresult of the interactions between virus proteins and host proteins.To study the relationship between NS2protein and the avian influenza virus replication, we alsocloned NS2gene into expression vector pET-28a，then the positive plasmid was transformed to E.coliBL21(DE3).After induction by IPTG, we got the His-NS2recombinant protein successfully. Thepolyclonal antibody was produced from the immunized rabbit with purified protein. At last, Westernblot and IFA assays confirmed the polyclonal antibody react specially with influenza virus NS2protein.Our research expressed the soluble NS2recombinant protein in protokaryon system, and prepared thepolyclonal antibody successfully. The results make the basis for further explanation of the NS2function.