Latent Herpes Simplex Virus Type 1 (HSV-1) in the Central Nervous System (CNS) of Immune Competant Mice Reactivates Spontaneously (P05.110)

Abstract

Objective: To determine if HSV-1 can spontaneously reactivate in the CNS of mice developing recurrent demyelinating lesions throughout the brain. Background We previously reported SJL/J, A/J, and PL/J mice develop lesions, characterized by demyelination, relative preservation of axons, and a mononuclear cell infiltrate, in the CNS following infection of the oral mucosa with HSV-1. In the early stage ( 3 months) of demyelination. Design/Methods: To determine if latent HSV-1 exists in the brains of A/J and PL/J mice, solution phase PCR was performed on [female] 10-12 week old mice infected with HSV-1 strain 2 via the oral mucosa. Immunohistochemistry (IHC) studies were also performed on the brains of these mice using α-HSV polyclonal antibody/ABC staining. Results: Using solution phase PCR, viral DNA was identified in the brains of both A/J and PL/J mice at 10 and 25 weeks PI. Further, a number of cells, with the morphology of neurons, stained positive with α-HSV antibody in the brainstems of A/J and PL/J but not C57BL/6 and Balb/c mice beyond 4 weeks PI. Conclusions: The results suggest that latent HSV-1 can reactivate spontaneously in the CNS of immune competent mice but is mouse strain dependent. The results raise the possibility that an immune response directed at reactivated virus could be responsible for the development of recurrent CNS demyelination in A/J and PL/J mice. Disclosure: Dr. Kastrukoff has nothing to disclose. Dr. Lau has nothing to disclose. Dr. Thomas has nothing to disclose.