Affiliations: [a] Instituto de Microbiología Clínica, Facultad de Medicina, Universidad Austral de Chile, Valdivia, Chile | [b] Instituto de Anatomía, Histología y Patología, Facultad de Medicina, Universidad Austral de Chile, Valdivia, Chile | [c] Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile | [d] Centro de Investigación Sur-Austral en Enfermedades del Sistema Nervioso (CISNE), Universidad Austral de Chile, Valdivia, Chile
Correspondence:
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Correspondence to: Carola Otth, PhD, Instituto de Microbiología Clínica, Facultad de Medicina, P.O. Box 567, Universidad Austral de Chile, Valdivia, Chile. Tel.: +56 63 2221923; Fax: +56 63 2293300; E-mail: cotth@uach.cl.
Abstract: Background:Currently, it is unclear whether asymptomatic recurrent reactivations of herpes simplex virus type 1 (HSV-1) occur in the central nervous systems of infected people, and if these events could lead to a progressive deterioration of neuronal function. In this context, HSV-1 constitutes an important candidate to be included among the risk factors for the development of neuropathies associated with chronic neuroinflammation. Objective:The aim of this study was to assess in vivo inflammatory and neurodegenerative markers in the brain during productive and latent HSV-1 infection using a mouse model of herpes simplex encephalitis. Methods:Neuroinflammation and neurodegeneration markers were evaluated in mice trigeminal ganglia and cerebral cortex during HSV-1 infection, by immunohistochemistry, western blot, and RT-PCR. Results:Neuronal ICP4 viral antigen expression indicative of a reactivation episode during asymptomatic latency of HSV-1 infection in mice was accompanied by upregulation of neuroinflammatory (toll-like receptor-4, interferon α/β, and p-IRF3) and early neurodegenerative markers (phospho-tau and TauC3). Conclusions:HSV-1 reactivation from latency induced neuroinflammatory and neurodegenerative markers in the brain of asymptomatic mice suggesting that recurrent reactivations could be associated with cumulative neuronal dysfunctions.
