Gregorius J Sips, Andrew Pekosz, Anke Huckriede, Diane E Griffin, and Jan C Wilschut
Background: Influenza virus is a highly prevalent respiratory virus responsible for annual epidemics as well as occasional pandemics. Extra respiratory complications have been described, including neurological as well as ocular complications. This study examines the permissiveness of a panel of human neuronal and ocular cells to infection with the recent influenza A/H1N1pdm virus and cellular expression of α2,3- and α2,6-linked sialic acids. Methods: Studied cells included the human neuroblastoma cell lines SH-SY5YplkOB1 and SK-N-SH, a glioblastoma patient isolate GBM847a, the human uveal melanoma cell lines OCM3, OMM1.5 and 92-1, and, as controls, Madin-Darby canine kidney (MDCK) and 16HBE human bronchial epithelial cells. Cells were infected with influenza A/H1N1pdm virus and their permissiveness was assessed via nucleoprotein (NP) staining analyzed by fluorescence microscopy. Additionally, cells were stained for the presence of α2,3- and α2,6-linked sialic acids and examined by fluorescence microscopy as well. Results: All tested human cell types were permissive for influenza A/H1N1pdm infection. Furthermore, selected neuronal and ocular cells expressed α2,3- and/or α2,6-linked sialic acids. Discussion: This study demonstrates the permissiveness of a panel of human neuronal and ocular cells for the recent influenza A/H1N1pdm virus and expression of α2,3-and α2,6-linked sialic acids. These data contribute to clinical as well as experimental evidence indicating that, apart from respiratory cells; influenza virus can infect other cells and, thus, may give rise to extra respiratory complications.