Species: Mus musculus Strain/breeder: SJL/JHanHsd / Harlan Winkelmann Sex: Female Age: 11 weeks Study type: Experimental infection Treatment: None Animal status: Normal Clinical findings: None Organ(s): Spinal cord Gross finding(s): None Staining: H&E Literature: Theiler, M (1934). Science 80: 122-123 Lipton HL (1975). Infect Immun 11: 1147-1155 McGavern DB et al. (1999). Exp. Neurol 158: 171-181

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Abstract

W. Baumgärtner¹, R. Ulrich², F. Seeliger¹, and S. Alldinger²

¹ Department of Pathology, School of Veterinary Medicine Hannover, Hannover, Germany
² Institute of Veterinary Pathology, Justus-Liebig University, Giessen, Germany

Key words: CNS, demyelination, encephalomyelitis, TMEV

Theiler's murine encephalomyelitis (TME) is caused by TME virus (TMEV), a cardiovirus of the Picornaviridae family and is an important model for human demyelinating diseases like multiple sclerosis.

TMEV strains are categorized into two subgroups. GDVII and FA strains cause a fatal polioencephalitis, while members of the second group, like the BeAn strain, persist in the central nervous system (CNS) and induce a demyelinating encephalitis after intracerebral infection.

To study the impact of a TMEV infection on the CNS extracellular matrix, female SJL/JHanHsd mice were injected with 2.7x106 PFU of BeAn viral inoculum intracerebrally and killed at various timepoints post infection (d.p.i.). The case presented here was killed at 42 d.p.i.. Clinically, the animal showed no behavioral changes. Histologically, neuropathological findings were most prominent in the ventromedial segments of the spinal cord. Lesions were characterized by thick perivascular cuffs composed of mononuclear cells, vacuolations, active demyelination with scavenging gitter cells, and a moderate gliosis. Summarized, this case represents the classical chronic TME.