科研之友
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<jats:title>Abstract</jats:title><jats:p>Whereas studies have extensively examined the ability of bacteria to influence <jats:italic>Plasmodium</jats:italic> infection in the mosquito, the tripartite interactions between non-entomopathogenic fungi, mosquitoes and <jats:italic>Plasmodium</jats:italic> parasites remain largely uncharacterized. Here we report the isolation of a common mosquito-associated ascomycete fungus, <jats:italic>Penicillium chrysogenum</jats:italic>, from the midgut of field-caught <jats:italic>Anopheles</jats:italic> mosquitoes. Although the presence of <jats:italic>Pe. chrysogenum</jats:italic> in the <jats:italic>Anopheles gambiae</jats:italic> midgut does not affect mosquito survival, it renders the mosquito significantly more susceptible to <jats:italic>Plasmodium</jats:italic> infection through a secreted heat-stable factor. We further provide evidence that the mechanism of the fungus-mediated modulation of mosquito susceptibility to <jats:italic>Plasmodium</jats:italic> involves an upregulation of the insect’s ornithine decarboxylase gene, which sequesters arginine for polyamine biosynthesis. Arginine plays an important role in the mosquito’s anti-<jats:italic>Plasmodium</jats:italic> defense as a substrate of nitric oxide production and its availability therefore has a direct impact on the mosquito’s susceptibility to the parasite. While this type of immunomodulatory mechanism has already been demonstrated in other host-pathogen interaction systems, this is the first report of a mosquito-associated fungus that can suppress the mosquito’s innate immune system in a way that would favor <jats:italic>Plasmodium</jats:italic> infection and possibly malaria transmission.</jats:p>
- 出版日期2016-9-28
