title: Leishmania mexicana: promastigotes and amastigotes secrete protein phosphatases and this correlates with the production of inflammatory cytokines in macrophages.
abstract: Phosphatase activity of Leishmania spp. has been shown to deregulate the signalling pathways of the host cell. We here show that Leishmania mexicana promastigotes and amastigotes secrete proteins with phosphatase activity to the culture medium, which was higher in the Promastigote Secretion Medium (PSM) as compared with the Amastigote Secretion Medium (ASM) and was not due to cell lysis, since parasite viability was not affected by the secretion process. The biochemical characterization showed that the phosphatase activity present in PSM was higher in dephosphorylating the peptide END (pY) INASL as compared with the peptide RRA (pT)VA. In contrast, the phosphatase activity in ASM showed little dephosphorylating capacity for both peptides. Inhibition assays demonstrated that the phosphatase activity of both PSM and ASM was sensible only to protein tyrosine phosphatases inhibitors. An antibody against a protein phosphatase 2C (PP2C) of Leishmania major cross-reacted with a 44·9 kDa molecule in different cellular fractions of L. mexicana promastigotes and amastigotes, however, in PSM and ASM, the antibody recognized a protein about 70 kDa. By electron microscopy, the PP2C was localized in the flagellar pocket of amastigotes. PSM and ASM induced the production of tumor necrosis factor alpha, IL-1β, IL-12p70 and IL-10 in human macrophages.
authors.affiliation: Facultad de Medicina,Unidad de Investigación en Medicina Experimental, Universidad Nacional Autónoma de México,México, DF,México.
authors.forename: A R
authors.initials: AR
authors.lastname: Escalona-Montaño
authors.affiliation: Facultad de Medicina,Unidad de Investigación en Medicina Experimental, Universidad Nacional Autónoma de México,México, DF,México.
authors.forename: D M
authors.initials: DM
authors.lastname: Ortiz-Lozano
authors.affiliation: Facultad de Medicina,Unidad de Investigación en Medicina Experimental, Universidad Nacional Autónoma de México,México, DF,México.
authors.forename: A
authors.initials: A
authors.lastname: Rojas-Bernabé
authors.affiliation: Facultad de Medicina,Unidad de Investigación en Medicina Experimental, Universidad Nacional Autónoma de México,México, DF,México.
authors.forename: A A
authors.initials: AA
authors.lastname: Wilkins-Rodriguez
authors.affiliation: Facultad de Medicina,Unidad de Investigación en Medicina Experimental, Universidad Nacional Autónoma de México,México, DF,México.
authors.forename: H
authors.initials: H
authors.lastname: Torres-Guerrero
authors.affiliation: Departamento de Bioquímica,Centro de Investigación y Estudios Avanzados (CINVESTAV-IPN),Av. Instituto Politécnico Nacional No. 2508,Col. San Pedro Zacatenco,México, DF,México.
authors.forename: R
authors.initials: R
authors.lastname: Mondragón-Flores
authors.affiliation: Departamento de Genética y Biología Molecular,Centro de Investigación y Estudios Avanzados (CINVESTAV-IPN),Av. Instituto Politécnico Nacional No. 2508,Col. San Pedro Zacatenco,México, DF,México.
authors.forename: R
authors.initials: R
authors.lastname: Mondragón-Gonzalez
authors.affiliation: Facultad de Medicina,Unidad de Investigación en Medicina Experimental, Universidad Nacional Autónoma de México,México, DF,México.
authors.forename: I
authors.initials: I
authors.lastname: Becker
authors.affiliation: Facultad de Medicina,Unidad de Investigación en Medicina Experimental, Universidad Nacional Autónoma de México,México, DF,México.
authors.forename: L
authors.initials: L
authors.lastname: Gutiérrez-Kobeh
authors.affiliation: Facultad de Medicina,Unidad de Investigación en Medicina Experimental, Universidad Nacional Autónoma de México,México, DF,México.
authors.forename: M M
authors.initials: MM
authors.lastname: Aguirre-Garcia
mesh_terms: D000818:Animals; D001692:Biological Transport; D003470:Culture Media / Q000737:chemistry; D016207:Cytokines / Q000096:biosynthesis / Q000276:immunology*; D006790:Host-Parasite Interactions; D006801:Humans; D016753:Interleukin-10 / Q000096:biosynthesis / Q000276:immunology; D007894:Leishmania mexicana / Q000201:enzymology* / Q000235:genetics / Q000276:immunology / Q000648:ultrastructure; D008264:Macrophages / Q000276:immunology*; D051379:Mice; D008854:Microscopy, Electron; D000071636:Protein Phosphatase 2C / Q000276:immunology / Q000378:metabolism*; D017027:Protein Tyrosine Phosphatases / Q000037:antagonists & inhibitors; D015800:Protozoan Proteins / Q000276:immunology / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D003470:Culture Media; D016207:Cytokines; C508609:IL10 protein, human; D015800:Protozoan Proteins; D016753:Interleukin-10; D000071636:Protein Phosphatase 2C; D017027:Protein Tyrosine Phosphatases
keywords: Leishmania mexicana; inflammatory cytokines; protein phosphatase PP2C; protein tyrosine phosphatase