title: Phagocytic receptors on macrophages distinguish between different Sporothrix schenckii morphotypes.
abstract: Sporothrix schenckii is a human pathogen that causes sporotrichosis, a cutaneous subacute or chronic mycosis. Little is known about the innate immune response and the receptors involved in host recognition and phagocytosis of S. schenckii. Here, we demonstrate that optimal phagocytosis of conidia and yeast is dependent on preimmune human serum opsonisation. THP-1 macrophages efficiently ingested opsonised conidia. Competition with D-mannose, methyl α-D-mannopyranoside, D-fucose, and N-acetyl glucosamine blocked this process, suggesting the involvement of the mannose receptor in binding and phagocytosis of opsonised conidia. Release of TNF-α was not stimulated by opsonised or non-opsonised conidia, although reactive oxygen species (ROS) were produced, resulting in the killing of conidia by THP-1 macrophages. Heat inactivation of the serum did not affect conidia internalization, which was markedly decreased for yeast cells, suggesting the role of complement components in yeast uptake. Conversely, release of TNF-α and production of ROS were induced by opsonised and non-opsonised yeast. These data demonstrate that THP-1 macrophages respond to opsonised conidia and yeast through different phagocytic receptors, inducing a differential cellular response. Conidia induces a poor pro-inflammatory response and lower rate of ROS-induced cell death, thereby enhancing the pathogen's survival.
authors: Departamento de Microbiología en Investigación, Instituto Nacional de Enfermedades Respiratorias Ismael Cosio Villegas, Calzada de Tlalpan 4502, Col. Sección XVI, México DF, Mexico.
authors: Silvia
authors: S
authors: Guzman-Beltran
authors: Armando
authors: A
authors: Perez-Torres
authors: Cristina
authors: C
authors: Coronel-Cruz
authors: Haydee
authors: H
authors: Torres-Guerrero
mesh_terms: D002460:Cell Line; D003165:Complement System Proteins / Q000276:immunology; D006801:Humans; D037181:Lectins, C-Type / Q000378:metabolism; D008264:Macrophages / Q000276:immunology*; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins / Q000378:metabolism; D009895:Opsonin Proteins / Q000276:immunology; D010587:Phagocytosis; D017382:Reactive Oxygen Species / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000378:metabolism; D013172:Spores, Fungal / Q000276:immunology; D013175:Sporothrix / Q000166:cytology* / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D037181:Lectins, C-Type; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins; D009895:Opsonin Proteins; D017382:Reactive Oxygen Species; D011956:Receptors, Cell Surface; D014409:Tumor Necrosis Factor-alpha; D003165:Complement System Proteins