Isolation of a Novel Swine Influenza Virus from Oklahoma in 2011 Which Is Distantly Related to Human Influenza C Viruses

PLoS Pathogens

Zizhang Sheng¹  Bryan Kaplan¹  Randy R. Simonson²  Feng Li²  Suvobrata Chakravarty²  Emily A. Collin³  Richard J. Webby³  Runxia Liu⁴  Anibal Armien⁴  Mariette Ducatez⁴  Zhiguang Ran⁵  Ben M. Hause⁵  Adam D. Hoppe⁶ 

[1] Department of Biology and Microbiology, South Dakota State University, Brookings, South Dakota, United States of America;Department of Chemistry and Biochemistry, South Dakota State University, Brookings, South Dakota, United States of America;Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, Tennessee, United States of America;Department of Veterinary and Biomedical Sciences, South Dakota State University, Brookings, South Dakota, United States of America;Newport Laboratories, Worthington, Minnesota, United States of America;Veterinary Diagnostic Laboratory, University of Minnesota, St. Paul, Minnesota, United States of America

关键词: Influenza C virus;    Influenza A virus;    Influenza;    Influenza B virus;    Swine;    Ferrets;    Orthomyxoviruses;    Viral replication;   

DOI  :  10.1371/journal.ppat.1003176

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

Of the Orthomyxoviridae family of viruses, only influenza A viruses are thought to exist as multiple subtypes and has non-human maintenance hosts. In April 2011, nasal swabs were collected for virus isolation from pigs exhibiting influenza-like illness. Subsequent electron microscopic, biochemical, and genetic studies identified an orthomyxovirus with seven RNA segments exhibiting approximately 50% overall amino acid identity to human influenza C virus. Based on its genetic organizational similarities to influenza C viruses this virus has been provisionally designated C/Oklahoma/1334/2011 (C/OK). Phylogenetic analysis of the predicted viral proteins found that the divergence between C/OK and human influenza C viruses was similar to that observed between influenza A and B viruses. No cross reactivity was observed between C/OK and human influenza C viruses using hemagglutination inhibition (HI) assays. Additionally, screening of pig and human serum samples found that 9.5% and 1.3%, respectively, of individuals had measurable HI antibody titers to C/OK virus. C/OK virus was able to infect both ferrets and pigs and transmit to naive animals by direct contact. Cell culture studies showed that C/OK virus displayed a broader cellular tropism than a human influenza C virus. The observed difference in cellular tropism was further supported by structural analysis showing that hemagglutinin esterase (HE) proteins between two viruses have conserved enzymatic but divergent receptor-binding sites. These results suggest that C/OK virus represents a new subtype of influenza C viruses that currently circulates in pigs that has not been recognized previously. The presence of multiple subtypes of co-circulating influenza C viruses raises the possibility of reassortment and antigenic shift as mechanisms of influenza C virus evolution.

【 授权许可】

CC BY