The distribution of sialic acid receptors of avian influenza virus in the reproductive tract of laying hens

摘要

The susceptibility of the host to influenza virus is determined by the distribution of the sialic acid (SA) receptors on host cell membrane. Avian influenza virus (AIV) preferentially binds to SA alpha-2,3-galactose (SA alpha 2,3-gal) linked receptors, while human strains bind to sialic acid alpha 2,6-galactose (SA alpha 2,6-gal) linked receptors. Here, we describe the SA patterns and distributions in the reproductive tract of hens by employing two specific lectins, Maackia amurensis agglutinin (MAA) for SA alpha 2,3-gal and sambucus nigra agglutinin (SNA) for SA alpha 2,6-gal receptors. Our results revealed that both SA alpha 2,3-gal and SA alpha 2,6-gal receptors exist in the reproductive tract of hens, including magnum, isthmus, uterus and vagina except for infundibulum. The distribution of SA alpha-2,3-gal receptor was more abundantly in the columnar epithelium cells of magnum, isthmus and uterus. Only minimal positive results for SA alpha-2,6-gal receptors were detected in the columnar epithelium cells of magnum, isthmus, uterus and vagina. Furthermore, AIV in tissues of the reproductive tract tissues of laying hens were detected by SYBR green-based reverse transcription and polymerase chain reaction (RT-PCR). Results showed that both viral loads and pathological changes in different parts of the reproductive tract were positively correlated with the expression of both receptors. Our results revealed that the reproductive tract of hens may provide an environment for the replication of both avian and human influenza viruses. (C) 2015 Elsevier Ltd. All rights reserved.