title: Toxoplasma gondii Chitinase Induces Macrophage Activation.
abstract: Toxoplasma gondii is an obligate intracellular protozoan parasite found worldwide that is able to chronically infect almost all vertebrate species, especially birds and mammalians. Chitinases are essential to various biological processes, and some pathogens rely on chitinases for successful parasitization. Here, we purified and characterized a chitinase from T. gondii. The enzyme, provisionally named Tg_chitinase, has a molecular mass of 13.7 kDa and exhibits a Km of 0.34 mM and a Vmax of 2.64. The optimal environmental conditions for enzymatic function were at pH 4.0 and 50 °C. Tg_chitinase was immunolocalized in the cytoplasm of highly virulent T. gondii RH strain tachyzoites, mainly at the apical extremity. Tg_chitinase induced macrophage activation as manifested by the production of high levels of pro-inflammatory cytokines, a pathogenic hallmark of T. gondii infection. In conclusion, to our knowledge, we describe for the first time a chitinase of T. gondii tachyzoites and provide evidence that this enzyme might influence the pathogenesis of T. gondii infection.
authors.affiliation: Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, SP, 14049-900, Brasil.
authors.forename: Fausto
authors.initials: F
authors.lastname: Almeida
authors.affiliation: Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, SP, 14049-900, Brasil.
authors.forename: Aline
authors.initials: A
authors.lastname: Sardinha-Silva
authors.affiliation: Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, SP, 14049-900, Brasil.
authors.forename: Thiago Aparecido
authors.initials: TA
authors.lastname: da Silva
authors.affiliation: Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, SP, 14049-900, Brasil.
authors.forename: André Moreira
authors.initials: AM
authors.lastname: Pessoni
authors.affiliation: Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, SP, 14049-900, Brasil.
authors.forename: Camila Figueiredo
authors.initials: CF
authors.lastname: Pinzan
authors.affiliation: Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, SP, 14049-900, Brasil.
authors.forename: Ana Claudia Paiva
authors.initials: AC
authors.lastname: Alegre-Maller
authors.affiliation: Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, SP, 14049-900, Brasil.
authors.forename: Nerry Tatiana
authors.initials: NT
authors.lastname: Cecílio
authors.affiliation: Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de Sao Paulo, São Paulo, SP, Brasil.
authors.forename: Nilmar Silvio
authors.initials: NS
authors.lastname: Moretti
authors.affiliation: Departamento de Bioquímica e Biologia Tecidual, Instituto de Biologia, Universidade de Campinas, Campinas, SP, Brasil.
authors.forename: André Ricardo Lima
authors.initials: AR
authors.lastname: Damásio
authors.affiliation: Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, SP, 14040-900, Brasil.
authors.forename: Wellington Ramos
authors.initials: WR
authors.lastname: Pedersoli
authors.affiliation: Laboratorio de Imunoparasitologia, Departamento de Imunologia, Microbiologia e Parasitologia, Universidade Federal de Uberlândia, Av. Pará, 1720, Uberlândia, MG, 38400 902, Brasil.
authors.forename: José Roberto
authors.initials: JR
authors.lastname: Mineo
authors.affiliation: Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, SP, 14040-900, Brasil.
authors.forename: Roberto Nascimento
authors.initials: RN
authors.lastname: Silva
authors.affiliation: Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, SP, 14049-900, Brasil.
authors.forename: Maria Cristina
authors.initials: MC
authors.lastname: Roque-Barreira
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002688:Chitinases / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D002853:Chromatography, Liquid; D016207:Cytokines / Q000276:immunology / Q000378:metabolism; D003593:Cytoplasm / Q000201:enzymology; D006790:Host-Parasite Interactions / Q000276:immunology; D006863:Hydrogen-Ion Concentration; D018836:Inflammation Mediators / Q000276:immunology / Q000378:metabolism; D007700:Kinetics; D008262:Macrophage Activation / Q000276:immunology*; D017737:Macrophages, Peritoneal / Q000276:immunology* / Q000378:metabolism / Q000469:parasitology; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D018613:Microscopy, Confocal; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary; D015800:Protozoan Proteins / Q000737:chemistry / Q000276:immunology*; D053719:Tandem Mass Spectrometry; D013696:Temperature; D014122:Toxoplasma / Q000201:enzymology / Q000276:immunology* / Q000502:physiology
chemical_list: D016207:Cytokines; D018836:Inflammation Mediators; D015800:Protozoan Proteins; D002688:Chitinases