title: Plasmodium falciparum-derived uric acid precipitates induce maturation of dendritic cells.
abstract: Malaria is characterized by cyclical fevers and high levels of inflammation, and while an early inflammatory response contributes to parasite clearance, excessive and persistent inflammation can lead to severe forms of the disease. Here, we show that Plasmodium falciparum-infected erythrocytes contain uric acid precipitates in the cytoplasm of the parasitophorous vacuole, which are released when erythrocytes rupture. Uric acid precipitates are highly inflammatory molecules that are considered a danger signal for innate immunity and are the causative agent in gout. We determined that P. falciparum-derived uric acid precipitates induce maturation of human dendritic cells, increasing the expression of cell surface co-stimulatory molecules such as CD80 and CD86, while decreasing human leukocyte antigen-DR expression. In accordance with this, uric acid accounts for a significant proportion of the total stimulatory activity induced by parasite-infected erythrocytes. Moreover, the identification of uric acid precipitates in P. falciparum- and P. vivax-infected erythrocytes obtained directly from malaria patients underscores the in vivo and clinical relevance of our findings. Altogether, our data implicate uric acid precipitates as a potentially important contributor to the innate immune response to Plasmodium infection and may provide a novel target for adjunct therapies.
authors: Division of Parasitology, Department of Microbiology, New York University School of Medicine, New York, New York, United State of America.
authors: Diana L
authors: DL
authors: van de Hoef
authors: Isabelle
authors: I
authors: Coppens
authors: Thomas
authors: T
authors: Holowka
authors: Choukri
authors: C
authors: Ben Mamoun
authors: OraLee
authors: O
authors: Branch
authors: Ana
authors: A
authors: Rodriguez
mesh_terms: D002450:Cell Communication; D003713:Dendritic Cells / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D004912:Erythrocytes / Q000276:immunology* / Q000378:metabolism / Q000469:parasitology; D005455:Fluorescent Antibody Technique; D006801:Humans; D007249:Inflammation / Q000276:immunology* / Q000378:metabolism / Q000469:parasitology; D008213:Lymphocyte Activation; D016778:Malaria, Falciparum / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D016253:Microscopy, Immunoelectron; D010963:Plasmodium falciparum / Q000502:physiology*; D014527:Uric Acid / Q000378:metabolism*
chemical_list: D014527:Uric Acid