Aerosols transmit prions to immunocompetent and immunodeficient mice

• Published in: PLoS pathogens 2011-01, Vol.7 (1), p.e1001257
• Main Authors: Haybaeck, Johannes, Heikenwalder, Mathias, Klevenz, Britta, Schwarz, Petra, Margalith, Ilan, Bridel, Claire, Mertz, Kirsten, Zirdum, Elizabeta, Petsch, Benjamin, Fuchs, Thomas J, Stitz, Lothar, Aguzzi, Adriano
• Format: Article
• Language: English
• Subjects: Aerosols; Airborne infection; Animals; Animals, Newborn; Blood; Brain; Brain - immunology; Brain - metabolism; Brain - pathology; Brain research; Dendritic cells; Development and progression; Disease transmission; Experiments; Feces; Female; Food; Food contamination & poisoning; Immune system; Immunocompetence - immunology; Immunocompromised Host - immunology; Immunodeficiency; Inbreeding; Infection; Infections; Inhalation Exposure; Longevity; Lymphocytes T; Lymphotoxin; Male; Medical research; Mice; Mice, Inbred Strains; Mice, Knockout; Mice, SCID; Mice, Transgenic; Milk; Neurodegeneration; Neurodegenerative diseases; Neurons; Neurons - immunology; Neurons - metabolism; Neurons - pathology; Neuroscience; Pathogens; Pathology/Neuropathology; Physiological aspects; Prion diseases; Prion protein; Prions; Prions - pathogenicity; Saliva; Scrapie; Scrapie - immunology; Scrapie - metabolism; Scrapie - transmission; Signal transduction; Species Specificity; Spongiform encephalopathies; Transgenic mice; Transmissible spongiform encephalopathy; Urine; Vectors
• ISSN: 1553-7374; 1553-7366; 1553-7374
• DOI: 10.1371/journal.ppat.1001257

Prions, the agents causing transmissible spongiform encephalopathies, colonize the brain of hosts after oral, parenteral, intralingual, or even transdermal uptake. However, prions are not generally considered to be airborne. Here we report that inbred and crossbred wild-type mice, as well as tga20 transgenic mice overexpressing PrP(C), efficiently develop scrapie upon exposure to aerosolized prions. NSE-PrP transgenic mice, which express PrP(C) selectively in neurons, were also susceptible to airborne prions. Aerogenic infection occurred also in mice lacking B- and T-lymphocytes, NK-cells, follicular dendritic cells or complement components. Brains of diseased mice contained PrP(Sc) and transmitted scrapie when inoculated into further mice. We conclude that aerogenic exposure to prions is very efficacious and can lead to direct invasion of neural pathways without an obligatory replicative phase in lymphoid organs. This previously unappreciated risk for airborne prion transmission may warrant re-thinking on prion biosafety guidelines in research and diagnostic laboratories.