Submitted to: International Symposium on Emerging and Re-Emerging Pig Diseases
Publication Type: Proceedings
Publication Acceptance Date: 6/29/2003
Publication Date: 6/29/2003
Citation: RICHT, J., LAGER, K.M., JANKE, B.H., GARCIA-SASTRE, A., WEBSTER, R., WEBBY, R.J. ATTENUATION OF AN H3N2 SWINE INFLUENZA VIRUS UTILIZING A REVERSE GENETICS APPROACH. PROCEEDINGS OF INTERNATIONAL SYMPOSIUM ON EMERGING AND RE-EMERGING PIG DISEASES. 2003. p. 264-265. Interpretive Summary:
Technical Abstract: Swine influenza (SI) is an acute respiratory disease of swine caused by type A influenza viruses. Before 1998, mainly Aclassical@ H1N1 SI viruses (SIV) were isolated from swine in the United States. Since then, antigenetically distinct reassortant H1 and H3 SIVs have been identified as causative agents of respiratory disease in pigs on U.S. farms. The H3N2 SIVs currently circulating in U.S. swine populations are triple reassortant viruses containing avian like (PA, PB2), swine like (M, NP, NS) and human like (HA, NA, PB1) gene segments. Genetic characterization of swine influenza viruses isolated in the last 2 years has shown that these H3N2 viruses have undergone further reassortment with the classical H1N1 viruses resulting in novel reassortant H1N2 and H1N1 SIVs. Reverse genetics systems, i.e. systems for the generation of virus entirely from cloned cDNA, have been established in the last decade for many non segmented negative sense RNA viruses. nfluenza virus reverse genetics now has reached a level of sophistication where one can confidently generate influenza viruses entirely from cloned cDNAs. This methodology makes it feasible to study the molecular mechanisms of influenza virus replication and pathogenicity, as well as to generate attenuated live influenza virus vaccines or gene delivery vehicles entirely from cloned cDNAs. The objectives of this study were to establish a swine influenza virus reverse genetics system, and to test the hypothesis that mutations/deletions within the NS1 gene attenuates swine influenza viruses.