Author :
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ISBN 13 :
Total Pages : 160 pages
Book Rating : 4.:/5 (888 download)
Book Synopsis Subversion of Innate Immunity by Blastomyces Dermatitidis by :
Download or read book Subversion of Innate Immunity by Blastomyces Dermatitidis written by and published by . This book was released on 2014 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our understanding of the innate immune response to the dimorphic fungus, Blastomyces dermatitidis, is very limited. Blastomycosis is a challenging disease from a clinical perspective due to the long incubation time and difficulty in diagnosis. B. dermatitidis is widely believed to be an extracellular pathogen. We found that pulmonary instillation of spores (the infectious particle) leads to rapid and efficient internalization within leukocytes, particularly alveolar macrophages. The harsh intracellular environment of alveolar macrophages is normally fatal to microorganisms. However, using live imaging we found that B. dermatitidis is able to survive this attack, transition from spores to the pathogenic yeast form, and replicate within alveolar macrophages. We found that depleting alveolar macrophages curtailed infection and delayed phase transition. Additionally, spores cultured in vitro converted to yeast faster in the presence of macrophages than in medium alone. This research reveals B. dermatitidis as facultative intracellular pathogen of alveolar macrophages able to respond to host factors to establish disease. B. dermatitidis also subverts the innate immune response through the production of the aminopeptidase DppIV. Gene silencing in B. dermatitidis revealed that DppIV is essential for virulence, and acts in part by blunting recruitment of Ly6ChiCCR2+ inflammatory monocytes to the lung, and their differentiation into TipDCs as well as impairing activation of neutrophils and killing of yeast mediated by these cells and macrophages. Mammalian DppIV regulates the immune response through cleavage and inactivation of cytokines and chemokines. B. dermatitidis likewise dampens innate immunity by producing DppIV. This serves as an example of a pathogen exploiting molecular mimicry. Collectively, this work identifies early mechanisms of pathogenesis through innate immune evasion and alteration by B. dermatitidis.