Over-expression of mammalian sialidase NEU3 reduces Newcastle disease virus entry and propagation in COS7 cells.
The paramyxovirus Newcastle Disease Virus (NDV) binds to sialic acid-containing glycoconjugates, sialoglycoproteins and sialoglycolipids (gangliosides) of host cell plasma membrane through its hemagglutinin-neuraminidase (sialidase) HN glycoprotein. We hypothesized that the modifications of the cell surface ganglioside pattern determined by over-expression of the mammalian plasma-membrane associated, ganglioside specific, sialidase NEU3 would affect the virus-host cell interactions. Using COS7 cells as a model system, we observed that over-expression of the murine MmNEU3 did not affect NDV binding but caused a marked reduction in NDV infection and virus propagation through cell-cell fusion. Moreover, since GD1a was greatly reduced in COS7 cells following NEU3-over-expression, we added [(3)H]-labelled GD1a to COS7 cells under conditions that block intralysosomal metabolic processing, and we observed a marked increase of GD1a cleavage to GM1 during NDV infection, indicating a direct involvement of the virus sialidase and host cell GD1a in NDV infectivity. Therefore, the decrease of GD1a in COS7 cell membrane upon MmNEU3 over-expression is likely to be instrumental to NDV reduced infection. Evidence was also provided for the preferential association of NDV-HN at 4 degrees C to detergent resistant microdomains (DRMs) of COS7 cells plasma membranes.
D000818:Animals; D015153:Blotting, Western; D019556:COS Cells; D002459:Cell Fusion; D002462:Cell Membrane / Q000821:virology; D002522:Chlorocebus aethiops; D002855:Chromatography, Thin Layer; D005677:G(M1) Ganglioside / Q000031:analogs & derivatives / Q000378:metabolism; D015870:Gene Expression; D015726:Giant Cells / Q000821:virology; D015707:HN Protein / Q000378:metabolism; D009439:Neuraminidase / Q000235:genetics* / Q000378:metabolism; D009521:Newcastle Disease / Q000821:virology; D009522:Newcastle disease virus / Q000502:physiology*; D053586:Virus Internalization; D014779:Virus Replication
D015707:HN Protein; C064020:ganglioside GD1alpha; D005677:G(M1) Ganglioside; C511796:Neu3 protein, mouse; D009439:Neuraminidase