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Publication Abstract from PubMed

Talaromyces (Penicillium) marneffei is one of the leading causes of systemic mycosis in immunosuppressed or AIDS patients in Southeast Asia. How this intracellular pathogen evades the host immune defense remains unclear. We provide evidence that T. marneffei depletes levels of a key proinflammatory lipid mediator arachidonic acid (AA) to evade the host innate immune defense. Mechanistically, an abundant secretory mannoprotein Mp1p, shown previously to be a virulence factor, does so by binding AA with high affinity via a long hydrophobic central cavity found in the LBD2 domain. This sequesters a critical proinflammatory signaling lipid, and we see evidence that AA, AA's downstream metabolites, and the cytokines interleukin-6 and tumor necrosis factor alpha are downregulated in T. marneffei-infected J774 macrophages. Given that Mp1p-LBD2 homologs are identified in other fungal pathogens, we expect that this novel class of fatty-acid-binding proteins sequestering key proinflammatory lipid mediators represents a general virulence mechanism of pathogenic fungi.

Talaromyces marneffei Mp1p Is a Virulence Factor that Binds and Sequesters a Key Proinflammatory Lipid to Dampen Host Innate Immune Response.,Sze KH, Lam WH, Zhang H, Ke YH, Tse MK, Woo PC, Lau SK, Lau CC, Cai JP, Tung ET, Lo RK, Xu S, Kao RY, Hao Q, Yuen KY Cell Chem Biol. 2017 Feb 16;24(2):182-194. doi: 10.1016/j.chembiol.2016.12.014., Epub 2017 Jan 19. PMID:28111099^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.