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United States Department of Agriculture

Agricultural Research Service

Research Project: CHARACTERIZATION OF PROTECTIVE HOST RESPONSES TO AVIAN INFLUENZA VIRUS INFECTIONS IN AVIAN SPECIES

Location: Exotic and Emerging Avian Viral Diseases Research Unit

Title: Difference in susceptibility to highly pathogenic avian influenza virus following interferon alpha application in chickens expressing polymorphism in the chicken Mx gene

Authors
item Kapczynski, Darrell
item Zsak, Aniko
item Ewald, Sandra -
item Suarez, David

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: January 12, 2012
Publication Date: April 4, 2012
Citation: Kapczynski, D.R., Zsak, A., Ewald, S., Suarez, D.L. 2012. Difference in susceptibility to highly pathogenic avian influenza virus following interferon alpha application in chickens expressing polymorphism in the chicken Mx gene [abstract]. 8th International Symposium on Avian Influenza. Available: http://vla.defra.gov.uk/news/new_isai12.htm

Technical Abstract: Type I interferons, including interferon alpha (IFN-a), represent a first line of defense initiated by the innate immune response following viral infection. Induction of IFN-a results in an antiviral state which can decrease morbidity and mortality. In response to IFN-a, host cells produce a myriad of anti-viral proteins, including Mx, which has been shown to confer protection against influenza in mammalian studies. Chickens have a single Mx gene with multiple alleles. In previous experiments, transfecting cDNAs of various alleles into mouse 3T3 cells, a single nucleotide polymorphism encoding an Asn631Ser dimorphism in the chicken Mx protein determined antiviral activity against highly pathogenic avian influenza virus (HPAIV). Mx-Asn631 was antivirally positive in transfection experiments, whereas the Mx-Ser631 alleles lacked antiviral activity. We have previously demonstrated the protective potential of IFN-a applied to poultry against low pathogenic avian influenza viruses. In those studies, intranasal application of IFN-a during infection reduced clinical signs of disease and the incidence of viral shedding. In these studies, we evaluated the Mx-631 dimorphism on pathogenesis of HPAIV H5N1 in specific pathogen free (SPF) chickens that segregate for Mx-631 alleles during IFN-a application. We observed >90 percent protection from mortality that was dependent on Mx-631 allele. Birds with the Mx-Asn631 (White Leghorn) were resistant to disease whereas Mx-Ser631 birds (White Rock) were susceptible to HPAIV. Results of virus shedding and antibody responses will be discussed. Taken together, these studies show that IFN-a can protect chickens from disease associated with HPAIV and that Mx may contribute to that protection.

Last Modified: 7/24/2014
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