title: Direct visualization of fungal infection in brains from patients with Alzheimer's disease.
abstract: Recently, we have reported the presence of fungal infections in patients with Alzheimer's disease (AD). Accordingly, fungal proteins and DNA were found in brain samples, demonstrating the existence of infection in the central nervous system. In the present work, we raised antibodies to specific fungal species and performed immunohistochemistry to directly visualize fungal components inside neurons from AD patients. Mice infected with Candida glabrata were initially used to assess whether yeast can be internalized in mammalian tissues. Using polyclonal rabbit antibodies against C. glabrata, rounded immunopositive cells could be detected in the cytoplasm of cells from liver, spleen, and brain samples in infected, but not uninfected, mice. Immunohistochemical analyses of tissue from the frontal cortex of AD patients revealed the presence of fungal material in a small percentage (~10%) of cells, suggesting the presence of infection. Importantly, this immunopositive material was absent in control samples. Confocal microscopy indicated that this fungal material had an intracellular localization. The specific morphology of this material varied between patients; in some instances, disseminated material was localized to the cytoplasm, whereas small punctate bodies were detected in other patients. Interestingly, fungal material could be revealed using different anti-fungal antibodies, suggesting multiple infections. In summary, fungal infection can only be observed using specific anti-fungal antibodies and only a small percentage of cells contain fungi. Our findings provide an explanation for the hitherto elusive detection of fungi in AD brains, and are consistent with the idea that fungal cells are internalized inside neurons.
authors.affiliation: Centro de Biología Molecular "Severo Ochoa", Universidad Autónoma de Madrid, Cantoblanco, Madrid, Spain.
authors.forename: Diana
authors.initials: D
authors.lastname: Pisa
authors.affiliation: Centro de Biología Molecular "Severo Ochoa", Universidad Autónoma de Madrid, Cantoblanco, Madrid, Spain.
authors.forename: Ruth
authors.initials: R
authors.lastname: Alonso
authors.affiliation: Departamento de Biología, Universidad Autónoma de Madrid, Cantoblanco, Madrid, Spain.
authors.forename: Angeles
authors.initials: A
authors.lastname: Juarranz
authors.affiliation: Department of Neuropathology and Tissue Bank, Unidad de Investigación Proyecto Alzheimer, Fundación CIEN, Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: Alberto
authors.initials: A
authors.lastname: Rábano
authors.affiliation: Centro de Biología Molecular "Severo Ochoa", Universidad Autónoma de Madrid, Cantoblanco, Madrid, Spain.
authors.forename: Luis
authors.initials: L
authors.lastname: Carrasco
mesh_terms: D000544:Alzheimer Disease / Q000150:complications* / Q000473:pathology*; D000818:Animals; D000908:Antibodies, Fungal / Q000097:blood; D001921:Brain / Q000473:pathology*; D041221:Candida glabrata / Q000235:genetics / Q000378:metabolism; D004195:Disease Models, Animal; D005260:Female; D005656:Fungal Proteins / Q000378:metabolism; D006801:Humans; D007211:Indoles; D008099:Liver / Q000473:pathology; D008297:Male; D051379:Mice; D008819:Mice, Nude; D009181:Mycoses / Q000150:complications* / Q000473:pathology*; D013154:Spleen / Q000473:pathology; D014404:Tubulin / Q000378:metabolism; D016875:tau Proteins / Q000378:metabolism
chemical_list: D000908:Antibodies, Fungal; D005656:Fungal Proteins; D007211:Indoles; D014404:Tubulin; D016875:tau Proteins; C007293:DAPI
keywords: Candida; fungal infection; intracellular infection; neurodegenerative disease