Microglia and amyloid precursor protein coordinate control of transient Candida cerebritis with memory deficits | Nature Communications

Bloodborne infections with Candida albicans are an increasingly
recognized complication of modern medicine. Here, we present a mouse
model of low-grade candidemia to determine the effect of disseminated
infection on cerebral function and relevant immune determinants. We show
that intravenous injection of 25,000 C. albicans cells causes a
highly localized cerebritis marked by the accumulation of activated
microglial and astroglial cells around yeast aggregates, forming
fungal-induced glial granulomas. Amyloid precursor protein accumulates
within the periphery of these granulomas, while cleaved amyloid beta
(Aβ) peptides accumulate around the yeast cells. CNS-localized C. albicans
further activate the transcription factor NF-κB and induce production
of interleukin-1β (IL-1β), IL-6, and tumor necrosis factor (TNF), and Aβ
peptides enhance both phagocytic and antifungal activity from BV-2
cells. Mice infected with C. albicans display mild memory
impairment that resolves with fungal clearance. Our results warrant
additional studies to understand the effect of chronic cerebritis on
cognitive and immune function.