title: Mast cells phagocyte Candida albicans and produce nitric oxide by mechanisms involving TLR2 and Dectin-1.
abstract: Candida albicans (C. albicans) is a fungus commonly found in the human mucosa, which may cause superficial and systemic infections, especially in immunosuppression. Until now, the main actors in the defense against this fungus are the epithelial cells, neutrophils, macrophages/monocytes and dendritic cells. However, mast cells are strategically located to play a first line of anti-Candida defense and it has appropriate mechanisms to do it. As with other cells, the recognition of C. albicans occurs meanly via TLR2 and Dectin-1. We assess the TLR2/Dectin-1 involvement in phagocytosis and production of nitric oxide (NO) and reactive oxygen species (ROS) by mast cells challenged with C. albicans. Bone marrow-derived mast cells (MC) from wild type (Wt) or knockout (TLR2-/-) mice C57BL/6 were subjected to in vitro Dectin-1 blockade. After challenged with FITC-labeled C. albicans or zymosan, phagocytosis was analyzed by microscopy. The intracellular production of NO and ROS was measured by DAF-FM diacetate and CellROX Deep/Red Reagent kits. The nitrite formation and hydrogen peroxide release were analyzed by Griess reaction and Amplex Red Hydrogen Peroxide/Peroxidase Assay Kit. Wt/MC phagocytose C. albicans with production of intracellular NO, but not ROS. Moreover, increased levels of nitrite were also observed. The absence and/or blockade of TLR2/Dectin-1 caused significant decreased in C. albicans phagocytosis and NO production. Our results showed that mast cells are able to phagocytose and produce NO against C. albicans via TLR2/Dectin-1. Therefore, mast cells could be important during the course of Candida infection and as a therapeutic target.
authors.affiliation: Department of Stomatology, Bauru School of Dentistry, University of São Paulo: Al. Dr. Octávio Pinheiro Brisola, 9-75, Vila Universitária, 17012-901 Bauru, São Paulo, Brazil. Electronic address: vanessa@fob.usp.br.
authors.forename: Karen Henriette
authors.initials: KH
authors.lastname: Pinke
authors.affiliation: Department of Stomatology, Bauru School of Dentistry, University of São Paulo: Al. Dr. Octávio Pinheiro Brisola, 9-75, Vila Universitária, 17012-901 Bauru, São Paulo, Brazil.
authors.forename: Heliton Gustavo de
authors.initials: HG
authors.lastname: Lima
authors.affiliation: Department of Pharmacology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Fernando Queiroz
authors.initials: FQ
authors.lastname: Cunha
authors.affiliation: Department of Stomatology, Bauru School of Dentistry, University of São Paulo: Al. Dr. Octávio Pinheiro Brisola, 9-75, Vila Universitária, 17012-901 Bauru, São Paulo, Brazil.
authors.forename: Vanessa Soares
authors.initials: VS
authors.lastname: Lara
mesh_terms: D000818:Animals; D057134:Antibodies, Neutralizing / Q000494:pharmacology; D002176:Candida albicans / Q000276:immunology*; D005786:Gene Expression Regulation; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D037181:Lectins, C-Type / Q000037:antagonists & inhibitors / Q000235:genetics / Q000276:immunology*; D008297:Male; D008407:Mast Cells / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009569:Nitric Oxide / Q000096:biosynthesis* / Q000276:immunology; D009573:Nitrites / Q000378:metabolism; D010587:Phagocytosis / Q000187:drug effects; D061251:Primary Cell Culture; D015398:Signal Transduction; D051195:Toll-Like Receptor 2 / Q000172:deficiency / Q000235:genetics / Q000276:immunology*; D015054:Zymosan / Q000494:pharmacology; D000099181:Dectin-1
chemical_list: D057134:Antibodies, Neutralizing; D006861:Hydrogen Peroxide; D037181:Lectins, C-Type; D009569:Nitric Oxide; D009573:Nitrites; D051195:Toll-Like Receptor 2; D015054:Zymosan; D000099181:Dectin-1; C493486:Tlr2 protein, mouse
keywords: C. albicans; Dectin-; Mast cells; Nitric oxide; Phagocytosis; Reactive oxygen species; TLR2