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Editor, Senior Moderator
J. Virol. doi:10.1128/JVI.05038-11
Emergence of Mammalian Species-infectious and -pathogenic Avian Influenza H6N5 Virus with No Evidence of Adaptation
Jeong-Hyun Nam1,2, Eun-Ha Kim1, Daesub Song1,2, Young Ki Choi3, Jeong-Ki Kim1,2,*, and Haryoung Poo1,2,*
1 Korea Research Institute of Bioscience and Biotechnology, Daejeon, Republic of Korea
2 University of Science and Technology, Daejeon, Republic of Korea
3 College of Medicine and Medical Research Institute, Chungbuk National University, Cheongju, Chungbuk, Republic of Korea
* Corresponding authors: Jeong-Ki Kim. Korea Research Institute of Bioscience and Biotechnology, 125 Gwahak-ro, Yuseong-gu, Daejeon 305-806, Republic of Korea. Phone: +82-42-879-8272. Fax: +82-42-879-8498. E-mail: jkim{at}kirbb.re.kr; Haryoung Poo. Korea Research Institute of Bioscience and Biotechnology, 125 Gwahak-ro, Yuseong-gu, Daejeon 305-806, Republic of Korea. Phone: +82-42-860-4157. Fax: +82-42-879-8498. E-mail: haryoung{at}kribb.re.kr
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ABSTRACT
The migratory waterfowl of the world are considered to be the natural reservoir of influenza A viruses. Of the 16 hemagglutinin subtypes of avian influenza viruses, the H6 subtype is commonly perpetuated in its natural hosts and is of concern due to its potential to be a precursor of highly pathogenic influenza viruses by reassortment. During routine influenza surveillance, we isolated an unconventional H6N5 subtype of avian influenza virus. Experimental infection of mice revealed that this isolate efficiently replicated in the lungs, subsequently spread systemically, and caused fetal lethality. The isolate also productively infected ferrets with direct evidence of contact transmission, but no disease or transmission was seen in pigs. Although the isolate possessed the conserved receptor-binding site sequences of avian influenza viruses, it exhibited relatively low replication efficiencies in ducks and chickens. Our genetic and molecular analyses of the isolate revealed that its PB1 sequence showed the highest evolutionary relationship to those of highly pathogenic H5N1 avian influenza viruses and that its PA protein had an isoleucine residue at position 97 (a representative virulence marker). Further studies will be required to examine why our isolate has the virologic characteristics of mammalian influenza viruses but the archetypal receptor binding profiles of avian influenza viruses, and to determine whether its potential virulence markers (PB1 analogous to those of H5N1 viruses or isoleucine residue at position 97 within PA) could render it highly pathogenic in mice.
http://jvi.asm.org/cgi/content/short/JVI.05038-11v1
Emergence of Mammalian Species-infectious and -pathogenic Avian Influenza H6N5 Virus with No Evidence of Adaptation
Jeong-Hyun Nam1,2, Eun-Ha Kim1, Daesub Song1,2, Young Ki Choi3, Jeong-Ki Kim1,2,*, and Haryoung Poo1,2,*
1 Korea Research Institute of Bioscience and Biotechnology, Daejeon, Republic of Korea
2 University of Science and Technology, Daejeon, Republic of Korea
3 College of Medicine and Medical Research Institute, Chungbuk National University, Cheongju, Chungbuk, Republic of Korea
* Corresponding authors: Jeong-Ki Kim. Korea Research Institute of Bioscience and Biotechnology, 125 Gwahak-ro, Yuseong-gu, Daejeon 305-806, Republic of Korea. Phone: +82-42-879-8272. Fax: +82-42-879-8498. E-mail: jkim{at}kirbb.re.kr; Haryoung Poo. Korea Research Institute of Bioscience and Biotechnology, 125 Gwahak-ro, Yuseong-gu, Daejeon 305-806, Republic of Korea. Phone: +82-42-860-4157. Fax: +82-42-879-8498. E-mail: haryoung{at}kribb.re.kr
arrow
ABSTRACT
The migratory waterfowl of the world are considered to be the natural reservoir of influenza A viruses. Of the 16 hemagglutinin subtypes of avian influenza viruses, the H6 subtype is commonly perpetuated in its natural hosts and is of concern due to its potential to be a precursor of highly pathogenic influenza viruses by reassortment. During routine influenza surveillance, we isolated an unconventional H6N5 subtype of avian influenza virus. Experimental infection of mice revealed that this isolate efficiently replicated in the lungs, subsequently spread systemically, and caused fetal lethality. The isolate also productively infected ferrets with direct evidence of contact transmission, but no disease or transmission was seen in pigs. Although the isolate possessed the conserved receptor-binding site sequences of avian influenza viruses, it exhibited relatively low replication efficiencies in ducks and chickens. Our genetic and molecular analyses of the isolate revealed that its PB1 sequence showed the highest evolutionary relationship to those of highly pathogenic H5N1 avian influenza viruses and that its PA protein had an isoleucine residue at position 97 (a representative virulence marker). Further studies will be required to examine why our isolate has the virologic characteristics of mammalian influenza viruses but the archetypal receptor binding profiles of avian influenza viruses, and to determine whether its potential virulence markers (PB1 analogous to those of H5N1 viruses or isoleucine residue at position 97 within PA) could render it highly pathogenic in mice.
http://jvi.asm.org/cgi/content/short/JVI.05038-11v1