Co-expression of nectin-4 receptor and canine distemper viral antigen in naturally infected dogs

Abstract

Canine distemper virus (CDV) is a virulent infected virus which threatens many mammalian species rendering multisystemic symptoms. The crucial cellular receptor for this virus is signaling lymphocyte activation molecule (SLAM) which expressed on immune cells. It can infect in silencing SLAM expression cells including epithelium and central nervous system. The newly cellular receptor for Measles virus (MV), the closely related morbillivirus, has been investigated so-called nectin-4 receptor. The aims of this study were to investigate the distribution of nectin-4 receptor in canine tissues and to exhibit the co-localization of nectin-4 receptors and CDV in naturally infected canine tissues by double immunohistochemistry and immunofluorescence. The 20 paraffin-embedded canine tissues were collected from Thailand and Vietnam. The routine histopatological process and CDV immunochemistry staining were done in various infected organs. For brain, the double immunohistochemistry between CDV and several brain markers were performed. Subsequently, the dual immunohistochemistry of nectin-4 receptor with CDV and several brain markers were processed. The pathognomonic lesions especially eosinophillic intranuclear or intracytoplasmic inclusion bodies were seen in various organs. The CDV immuno-labeling cells were also noticed abundantly. In brain, the different cell infection was seen. There were co-harboring CDV and nectin-4 cells in glandular cells, various epithelium and neuron using both methods. The brain markers confirmed that nectin-4 expressed in neurons. The co-expression was also seen as same organs by immunofluorescence method. In conclusion, CDV also utilize the nectin-4 as an alternative potential cellular receptor through host cells especially various epithelial cells and neuronal cells. These findings might play a key role to elucidate the pathogenesis of canine distemper infection in depth.