Sialic acid profiles in the respiratory tracts of selected species of raptors: evidence for potential binding sites for human and avian influenza A viruses

作者：Han, Chun-Hua; Lin, Jian; Wang, Xiuqing; Han, Jing-Wen; Duan, Hui-Juan; Pan, Jie; Liu, Yue-Huan^*

来源：Wildlife Research, 2011, 38(8): 647-652.

DOI：10.1071/WR11003

• influenza A virus
• MAA
• raptor
• SNA
• SA alpha 2,3-Gal
• SA alpha 2,6-Gal

Context. The ability of influenza A viruses to recognise and bind to cell surface receptors such as sialic acid linked to galactose by an alpha 2,3 linkage (SA alpha 2,3-gal) and sialic acid linked to galactose by an alpha 2,6 linkage (SA alpha 2,6-gal) is a major determinant of influenza A virus infection. Although the epidemiological surveys of influenza A virus infection in raptors suggest that some raptor species are susceptible to influenza A viruses under natural conditions, the sialic acid profiles in the respiratory and intestinal tracts of raptors are unknown.
Aims. To examine the sialic acid receptor profiles in the respiratory tracts of the selected raptor species and assess the potential susceptibility of raptors to avian and human influenza viruses and the role of raptors in the epidemiology and evolution of influenza A viruses.
Methods. The lectin immunohistochemistry staining method was used to examine the sialic acid profiles in the respiratory tracts of eight different species of raptors.
Key results. A strong staining with Maackia amurensis agglutinin (MAA), specific for sialic acid linked to galactose by an alpha 2,3 linkage (SA alpha 2,3-gal), was observed in the epithelial cells of the respiratory tract of Accipiter nisus and Falco tinnunculus. However, a positive staining for both MAA and Sambucus nigra agglutinin (SNA), specific for sialic acid linked to galactose by an alpha 2,6 linkage (SA alpha 2,6-gal), was detected in the epithelial cells of the upper respiratory tract of Accipiter gularis, Buteo buteo, Otus sunia, Bubo bubo and Asio otus, and in the epithelial cells of the alveoli of Buteo buteo, Falco peregrinus, Otus sunia and Bubo bubo.
Conclusions. Both avian and human influenza A virus receptors are expressed in six species of raptors examined. There are some variations in the type and distribution of sialic acid receptor expression among different raptor species. No correlation between phylogeny of birds and their sialic acid receptor distributions was observed.
Implications. Since SA alpha 2,3-gal and SA alpha 2,6-gal are often considered as the primary receptors for avian influenza A viruses and human influenza A viruses, respectively, our data suggest that raptors could be a potential host for avian and human influenza A viruses.

• 出版日期2011
• 单位北京市农林科学院