title: Spinal Cord Ventral Horns and Lymphoid Organ Involvement in Powassan Virus Infection in a Mouse Model.
abstract: Powassan virus (POWV) belongs to the family Flaviviridae and is a member of the tick-borne encephalitis serogroup. Transmission of POWV from infected ticks to humans has been documented in the USA, Canada, and Russia, causing fatal encephalitis in 10% of human cases and significant neurological sequelae in survivors. We used C57BL/6 mice to investigate POWV infection and pathogenesis. After footpad inoculation, infected animals exhibited rapid disease progression and 100% mortality. Immunohistochemistry and immunofluorescence revealed a very strong neuronal tropism of POWV infection. The central nervous system infection appeared as a meningoencephalitis with perivascular mononuclear infiltration and microglial activation in the brain, and a poliomyelitis-like syndrome with high level of POWV antigen at the ventral horn of the spinal cord. Pathological studies also revealed substantial infection of splenic macrophages by POWV, which suggests that the spleen plays a more important role in pathogenesis than previously realized. This report provides a detailed description of the neuroanatomical distribution of the lesions produced by POWV infection in C57BL/6 mice.
authors.affiliation: Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555, USA. roimarqu@utmb.edu.|Galveston National Laboratory, University of Texas Medical Branch, Galveston, TX 77555, USA. roimarqu@utmb.edu.
authors.forename: Rodrigo I
authors.initials: RI
authors.lastname: Santos
authors.affiliation: Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555, USA. meherman@UTMB.EDU.
authors.forename: Meghan E
authors.initials: ME
authors.lastname: Hermance
authors.affiliation: Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555, USA. bgelman@UTMB.EDU.
authors.forename: Benjamin B
authors.initials: BB
authors.lastname: Gelman
authors.affiliation: Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555, USA. sathanga@UTMB.EDU.|Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX 77555, USA. sathanga@UTMB.EDU.|Galveston National Laboratory, University of Texas Medical Branch, Galveston, TX 77555, USA. sathanga@UTMB.EDU.
authors.forename: Saravanan
authors.initials: S
authors.lastname: Thangamani
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004669:Encephalitis Viruses, Tick-Borne / Q000302:isolation & purification* / Q000472:pathogenicity* / Q000502:physiology; D004675:Encephalitis, Tick-Borne / Q000473:pathology*; D007150:Immunohistochemistry; D008297:Male; D008810:Mice, Inbred C57BL; D008856:Microscopy, Fluorescence; D066151:Spinal Cord Ventral Horn / Q000473:pathology*; D013154:Spleen / Q000473:pathology*; D016019:Survival Analysis; D056189:Viral Tropism
keywords: Poliomyelitis-like syndrome; Powassan virus; lymphoid organs infection