title: Comparison of the neuropathology induced by two West Nile virus strains.
abstract: Some strains of West Nile virus (WNV) are neuroinvasive and may induce fatal encephalitis/meningitis in a variety of animal species including humans. Whether, however, there is a strain-specific signature in the brain is as yet unknown. Here we investigated the neuropathogenesis induced by two phylogenetically distant WNV strains of lineage 1, WNV(IS98) and WNV(KUN35 911). While four-week old C57Bl/6J mice were susceptible to both strains and succumbed rapidly after intraperitoneal inoculation, differences were observed in virulence and clinical disease. WNV(KUN35 911), the less virulent strain as judged by determination of LD50, induced typical signs of encephalitis. Such signs were not observed in WNV(IS98)-infected mice, although they died more rapidly. Histological examination of brain sections also revealed differences, as the level of apoptosis and inflammation was higher in WNV(KUN35 911)- than WNV(IS98)-infected mice. Moreover, staining for cleaved caspase 3 showed that the two WNV strains induced apoptotic death through different molecular mechanisms in one particular brain area. Finally, the two strains showed similar tropism in cortex, striatum, brainstem, and cerebellum but a different one in hippocampus. In summary, our data show that, upon peripheral administration, WNV(IS98) and WNV(KUN35 911) strains induce partially distinct lesions and tissue tropism in the brain. They suggest that the virulence of a WNV strain is not necessarily correlated with the severity of apoptotic and inflammatory lesions in the brain.
authors.affiliation: Virology (UMR1161), French National Institute for Agricultural Research (INRA), Maisons-Alfort, France ; Virology (UMR1161), French Agency for Food, Environmental and Occupational Health and Safety (ANSES), Maisons-Alfort, France ; Virology (UMR1161), Paris-Est University, National Veterinary School of Alfort, Maisons-Alfort, France.
authors.forename: Emilie
authors.initials: E
authors.lastname: Donadieu
authors.affiliation: Virology (UMR1161), French National Institute for Agricultural Research (INRA), Maisons-Alfort, France ; Virology (UMR1161), French Agency for Food, Environmental and Occupational Health and Safety (ANSES), Maisons-Alfort, France ; Virology (UMR1161), Paris-Est University, National Veterinary School of Alfort, Maisons-Alfort, France.
authors.forename: Steeve
authors.initials: S
authors.lastname: Lowenski
authors.affiliation: French National Institute for Agricultural Research (INRA), Nouzilly, France ; Histology and Pathological Anatomy, Paris-Est University, National Veterinary School of Alfort, Maisons-Alfort, France.
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Servely
authors.affiliation: Histology and Pathological Anatomy, Paris-Est University, National Veterinary School of Alfort, Maisons-Alfort, France.
authors.forename: Eve
authors.initials: E
authors.lastname: Laloy
authors.affiliation: Biomedical Research Center, Paris-Est University, National Veterinary School of Alfort, Maisons-Alfort, France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Lilin
authors.affiliation: Institute of Virology, University of Veterinary Medicine, Vienna, Austria ; Department of Microbiology and Immunology, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, Oman.
authors.forename: Norbert
authors.initials: N
authors.lastname: Nowotny
authors.affiliation: Virology (UMR1161), French National Institute for Agricultural Research (INRA), Maisons-Alfort, France ; Virology (UMR1161), French Agency for Food, Environmental and Occupational Health and Safety (ANSES), Maisons-Alfort, France ; Virology (UMR1161), Paris-Est University, National Veterinary School of Alfort, Maisons-Alfort, France.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Richardson
authors.affiliation: Virology (UMR1161), French National Institute for Agricultural Research (INRA), Maisons-Alfort, France ; Virology (UMR1161), French Agency for Food, Environmental and Occupational Health and Safety (ANSES), Maisons-Alfort, France ; Virology (UMR1161), Paris-Est University, National Veterinary School of Alfort, Maisons-Alfort, France.
authors.forename: Stéphan
authors.initials: S
authors.lastname: Zientara
authors.affiliation: Virology (UMR1161), French National Institute for Agricultural Research (INRA), Maisons-Alfort, France ; Virology (UMR1161), French Agency for Food, Environmental and Occupational Health and Safety (ANSES), Maisons-Alfort, France ; Virology (UMR1161), Paris-Est University, National Veterinary School of Alfort, Maisons-Alfort, France.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Lecollinet
authors.affiliation: Virology (UMR1161), French National Institute for Agricultural Research (INRA), Maisons-Alfort, France ; Virology (UMR1161), French Agency for Food, Environmental and Occupational Health and Safety (ANSES), Maisons-Alfort, France ; Virology (UMR1161), Paris-Est University, National Veterinary School of Alfort, Maisons-Alfort, France.
authors.forename: Muriel
authors.initials: M
authors.lastname: Coulpier
mesh_terms: D000818:Animals; D017209:Apoptosis; D001921:Brain / Q000473:pathology* / Q000821:virology*; D007249:Inflammation / Q000821:virology; D051379:Mice; D008810:Mice, Inbred C57BL; D013045:Species Specificity; D014902:West Nile virus / Q000472:pathogenicity* / Q000502:physiology