1. Alzheimer’s disease-associated β-amyloid does not protect against herpes simplex virus 1 infection in the mouse brain
- Author
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Kara Molesworth, Olga Mychko, Ilia V. Baskakov, Natallia Makarava, Olga V. Bocharova, Narayan P. Pandit, and Aidan Fisher
- Subjects
0301 basic medicine ,Aβ, β-amyloid ,microglia ,amyloid precursor protein ,medicine.disease_cause ,Biochemistry ,Mice ,Multiplicity of infection ,Genotype ,Amyloid precursor protein ,5XFAD mice ,MOI, multiplicity of infection ,Plaque-forming unit ,PS1, presenilin 1 ,Microglia ,Editors' Pick ,Amyloidosis ,HHV6 and HHV7, human herpesviruses 6 and 7 ,medicine.anatomical_structure ,LD, lethal dose ,herpes simplex virus 1 ,HSV-1, herpes simplex virus 1 ,Alzheimer’s disease ,Research Article ,Biology ,AD, Alzheimer’s disease ,CNS, central nervous system ,Presenilin ,03 medical and health sciences ,APP, amyloid precursor protein ,Alzheimer Disease ,HSE, herpes simplex encephalitis ,medicine ,Animals ,Molecular Biology ,Amyloid beta-Peptides ,030102 biochemistry & molecular biology ,IC, intracranially ,Wild type ,Aβ aggregates ,astrocytes ,GFAP, glial fibrillary acidic protein ,Herpes Simplex ,Cell Biology ,Virology ,WT, wild-type ,030104 developmental biology ,Herpes simplex virus ,biology.protein ,PFU, plaque-forming unit - Abstract
Alzheimer’s disease (AD) is a devastating fatal neurodegenerative disease. An alternative to the amyloid cascade hypothesis is that a viral infection is key to the etiology of late-onset AD, with β-amyloid (Aβ) peptides playing a protective role. In the current study, young 5XFAD mice that overexpress mutant human amyloid precursor protein with the Swedish, Florida, and London familial AD mutations were infected with one of two strains of herpes simplex virus 1 (HSV-1), 17syn+ and McKrae, at three different doses. Contrary to previous work, 5XFAD genotype failed to protect mice against HSV-1 infection. The region- and cell-specific tropisms of HSV-1 were not affected by the 5XFAD genotype, indicating that host–pathogen interactions were not altered. Seven- to ten-month-old 5XFAD animals in which extracellular Aβ aggregates were abundant showed slightly better survival rate relative to their wild-type (WT) littermates, although the difference was not statistically significant. In these 5XFAD mice, HSV-1 replication centers were partially excluded from the brain areas with high densities of Aβ aggregates. Aβ aggregates were free of HSV-1 viral particles, and the limited viral invasion to areas with a high density of Aβ aggregates was attributed to phagocytic activity of reactive microglia. In the oldest mice (12–15 months old), the survival rate did not differ between 5XFAD and WT littermates. While the current study questions the antiviral role of Aβ, it neither supports nor refutes the viral etiology hypothesis of late-onset AD.
- Published
- 2021