title: Hybrid- and complex-type N-glycans are not essential for Newcastle disease virus infection and fusion of host cells.
abstract: N-linked glycans are composed of three major types: high-mannose (Man), hybrid or complex. The functional role of hybrid- and complex-type N-glycans in Newcastle disease virus (NDV) infection and fusion was examined in N-acetylglucosaminyltransferase I (GnT I)-deficient Lec1 cells, a mutant Chinese hamster ovary (CHO) cell incapable of synthesizing hybrid- and complex-type N-glycans. We used recombinant NDV expressing green fluorescence protein or red fluorescence protein to monitor NDV infection, syncytium formation and viral yield. Flow cytometry showed that CHO-K1 and Lec1 cells had essentially the same degree of NDV infection. In contrast, Lec2 cells were found to be resistant to NDV infection. Compared with CHO-K1 cells, Lec1 cells were shown to more sensitive to fusion induced by NDV. Viral attachment was found to be comparable in both lines. We found that there were no significant differences in the yield of progeny virus produced by both CHO-K1 and Lec1 cells. Quantitative analysis revealed that NDV infection and fusion in Lec1 cells were also inhibited by treatment with sialidase. Pretreatment of Lec1 cells with Galanthus nivalis agglutinin specific for terminal α1-3-linked Man prior to inoculation with NDV rendered Lec1 cells less sensitive to cell-to-cell fusion compared with mock-treated Lec1 cells. Treatment of CHO-K1 and Lec1 cells with tunicamycin, an inhibitor of N-glycosylation, significantly blocked fusion and infection. In conclusion, our results suggest that hybrid- and complex-type N-glycans are not required for NDV infection and fusion. We propose that high-Man-type N-glycans could play an important role in the cell-to-cell fusion induced by NDV.
authors.affiliation: Animal Infectious Disease Laboratory, School of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu 225009, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Sun
authors.forename: Lixiang
authors.initials: L
authors.lastname: Zhao
authors.forename: Qingqing
authors.initials: Q
authors.lastname: Song
authors.forename: Zheng
authors.initials: Z
authors.lastname: Wang
authors.forename: Xusheng
authors.initials: X
authors.lastname: Qiu
authors.forename: Wenjun
authors.initials: W
authors.lastname: Zhang
authors.forename: Mingjun
authors.initials: M
authors.lastname: Zhao
authors.forename: Guo
authors.initials: G
authors.lastname: Zhao
authors.forename: Wenbo
authors.initials: W
authors.lastname: Liu
authors.forename: Haiyan
authors.initials: H
authors.lastname: Liu
authors.forename: Yunsen
authors.initials: Y
authors.lastname: Li
authors.forename: Xiufan
authors.initials: X
authors.lastname: Liu
mesh_terms: D000818:Animals; D001483:Base Sequence; D016466:CHO Cells; D002236:Carbohydrate Conformation; D002459:Cell Fusion; D002642:Chick Embryo; D003001:Cloning, Molecular; D006224:Cricetinae; D017930:Genes, Reporter; D005818:Genetic Engineering; D015726:Giant Cells / Q000821:virology; D054884:Host-Pathogen Interactions; D008164:Luminescent Proteins / Q000096:biosynthesis / Q000235:genetics; D008358:Mannose / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000378:metabolism*; D009521:Newcastle Disease / Q000821:virology*; D009522:Newcastle disease virus / Q000235:genetics / Q000502:physiology*; D011134:Polysaccharides / Q000378:metabolism*; D012794:Sialic Acids / Q000378:metabolism; D019562:Viral Load; D053585:Virus Attachment; D014779:Virus Replication; D000097573:Red Fluorescent Protein
chemical_list: D008164:Luminescent Proteins; D008358:Mannose; D008562:Membrane Glycoproteins; D011134:Polysaccharides; D012794:Sialic Acids; D000097573:Red Fluorescent Protein