Viral envelope protein glycosylation is a molecular determinant of the neuroinvasiveness of the New York strain of West Nile virus

Abstract

Two New York (NY) strains of the West Nile (WN) virus were plaque-purified and four variants that had different amino acid sequences at the N-linked glycosylation site in the envelope (E) protein sequence were isolated. The E protein was glycosylated in only two of these strain variants. To determine the relationship between E protein glycosylation and pathogenicity of the WN virus, 6-week-old mice were infected subcutaneously with these variants. Mice infected with viruses that carried the glycosylated E protein developed lethal infection, whereas mice infected with viruses that carried the non-glycosylated E protein showed low mortality. In contrast, intracerebral infection of mice with viruses carrying either the glycosylated or non-glycosylated forms of the E protein resulted in lethal infection. These results suggested that E protein glycosylation is a molecular determinant of neuroinvasiveness in the NY strains of WN virus.

Requirement of Glycosylation of West Nile Virus Envelope Protein for Infection of, but Not Spread within, Culex quinquefasciatus Mosquito Vectors

“…However, other groups have used several different amino acid mutations to remove the E protein glycosylation site and have obtained similar results in vitro and in mice. 16,20,29 Therefore, would not expect that our results were caused solely by the presence of an isoleucine at anino acid position 154, rather than the lack of the E protein glycan. Additionally, if an isoleucine at amino acid position 154 was universally detrimental to the virus, we would expect to see reversion to the wild-type asparagine in Cx.…”

“…16,17 In vivo studies have demonstrated that E protein glycosylation enhances WNV virulence in mice and chickens. [18][19][20] Additionally, we have previously found that WNV lacking the E protein glycan replicated less efficiently in vivo and was almost completely defective in spread beyond the mosquito midgut in two important Culex vector species ( Cx. pipiens and Cx.…”

N-glycosylation of the premembrane protein of Japanese encephalitis virus is critical for folding of the envelope protein and assembly of virus-like particles

“…E proteins in the family Flaviviridae are N-glycosylated, but the site and number of sugar chains differ in flavivirus E proteins (Chambers et al, 1990). The glycosylation site in E protein is known to be critical for viral propagation, infectivity, virulence, and neuroinvasion (Beasley et al, 2005;Bryant et al, 2007;Lee et al, 2010;Li et al, 2006;Shirato et al, 2004). How the glycosylation site in E is affecting the phenotypes of JEV is not clear.…”

“…N-glycosylation of E protein is known to be important in viral propagation, infectivity, secretion, and neuroinvasion (Beasley et al, 2005;Bryant et al, 2007;Lee et al, 2010;Shirato et al, 2004;Vorndam et al, 1993). However, little attention had been paid to the roles of the N-glycosylation in prM protein until Kim et al (2008) reported that glycosyla-tion of JEV prM protein was associated with viral release and pathogenesis.…”

Rab8b Regulates Transport of West Nile Virus Particles from Recycling Endosomes

“…WT, Rab8b KO, and Rab8aϩb double knock-out (DKO) mouse embryonic fibroblasts (MEFs) were grown in DMEM supplemented with 10% heat-inactivated FBS and 2 mM L-glutamine (Sigma) as described previously (20). The WNV 6-LP strain, previously established by plaque purification of the WNV NY99 -6922 strain isolated from mosquitoes in 1999 (21,22), was kindly provided by Dr. Takashima (Hokkaido University, Japan). All experiments with WNV were performed at the Biosafety Level 3 facility at Hokkaido University in accordance with institutional guidelines.…”