Effect of the PB2 and M Genes on the Replication of H6 Influenza Virus in Chickens

Hiroichi Ozaki,Robert Webster,Richard Webby,Ayato Takada,Malik Peiris,Yi Guan

doi:10.1155/2014/547839

Abstract

H6 subtype influenza viruses are commonly isolated from wild aquatic birds. However, limited information is available regarding H6 influenza virus isolated from chickens. We compared the viral genome segment between A/chicken/Hong Kong/W312/97 (H6N1), which was able to grow in chicken trachea, and A/duck/Shantou/5540/01 (H6N2), which was isolated from wild aquatic duck, to explore the factors for effective replication in chicken. When chickens were inoculated with 7 + 1 reassortants (W312 background), the replication of viruses with PB2 and M genes derived from the duck strain was significantly reduced. Chimeras of PB2 and M proteins, encoding the C-terminal region of the PB2 protein and the M2 protein from W312, were required for efficient replication in canine-derived (MDCK) cells and in chicken trachea. These results indicate that host range may be determined by some types of internal proteins such as PB2 and M2, as well as by surface glycoprotein like hemagglutinin.

Highlights

Avian influenza viruses (AIVs) are member of the family Orthomyxoviridae, genus Influenzavirus A [1]
H6 influenza viruses are frequently isolated from wild aquatic birds and domestic ducks, and most of them are nonpathogenic to avian
We previously reported that the H6 isolate from ducks replicates poorly in chicken trachea and that the viruses recovered were W312-like viruses [16]

Summary

Introduction

Avian influenza viruses (AIVs) are member of the family Orthomyxoviridae, genus Influenzavirus A [1]. Influenza viruses are normally nonpathogenic in their natural hosts in which they remain in evolutionary stasis [2, 3]. H6 influenza viruses are frequently isolated from wild aquatic birds and domestic ducks, and most of them are nonpathogenic to avian. They have a broader host range than any other subtype [5, 6]. H6 viruses continue to circulate worldwide including North America and South Africa [6,7,8,9,10], as well as Asian countries including southern China and Taiwan [11, 12]. A/teal/Hong Kong/W312/97 (H6N1) (W312)like virus has been endemic in southern China since the late

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