title: Impact of Leishmania mexicana infection on dendritic cell signaling and functions.
abstract: Leishmania parasites have the ability to modify macrophage signaling pathways in order to survive and multiply within its mammalian host. They are also known to invade other cells including neutrophils, fibroblasts and dendritic cells (DCs). DCs have an important role in immunity as the link between innate and adaptive immunity, necessary for the development of an effective response; however, the impact of Leishmania mexicana infection on DCs has been poorly studied. Herein, we report that Leishmania infection rapidly induced DC protein tyrosine phosphatases activity, leading to MAP kinases inactivation. In line with this, L. mexicana was found to decrease the nuclear translocation of transcription factors such as AP-1 and NF-κB. Concomitantly, L. mexicana-infected DCs showed reduced expression of several surface antigen-presenting and co-stimulatory molecules upon LPS stimulation. Leishmania-induced interference on DC maturation was further reflected by their reduced capacity to present OVA antigen to OVA-specific T cells, as shown by abrogation of IL-2 production by the T cells. Collectively, our data revealed that DC infection by L. mexicana appears to affect the cellular and immunological mechanisms necessary for the development of an effective and protective immune response, therefore favouring the survival and propagation of the parasite within its host.
authors.affiliation: Department of Microbiology and Immunology, McGill University, Montréal, Quebec, Canada; Neurochemistry Laboratory, Faculty of Medicine. Universidad Autónoma del Estado de México, Toluca, Estado de México, México.
authors.forename: Irazú
authors.initials: I
authors.lastname: Contreras
authors.affiliation: Department of Microbiology and Immunology, McGill University, Montréal, Quebec, Canada; Neurochemistry Laboratory, Faculty of Medicine. Universidad Autónoma del Estado de México, Toluca, Estado de México, México.
authors.forename: José A
authors.initials: JA
authors.lastname: Estrada
authors.affiliation: Department of Microbiology and Immunology, McGill University, Montréal, Quebec, Canada.
authors.forename: Hannah
authors.initials: H
authors.lastname: Guak
authors.affiliation: Department of Microbiology and Immunology, McGill University, Montréal, Quebec, Canada.
authors.forename: Caroline
authors.initials: C
authors.lastname: Martel
authors.affiliation: Department of Microbiology and Immunology, McGill University, Montréal, Quebec, Canada.
authors.forename: Alborz
authors.initials: A
authors.lastname: Borjian
authors.affiliation: Department of Microbiology and Immunology, McGill University, Montréal, Quebec, Canada.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Ralph
authors.affiliation: Department of Microbiology and Immunology, McGill University, Montréal, Quebec, Canada.
authors.forename: Marina T
authors.initials: MT
authors.lastname: Shio
authors.affiliation: Department of Microbiology and Immunology, McGill University, Montréal, Quebec, Canada.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Fournier
authors.affiliation: Department of Microbiology and Immunology, McGill University, Montréal, Quebec, Canada.
authors.forename: Connie M
authors.initials: CM
authors.lastname: Krawczyk
authors.affiliation: Department of Microbiology and Immunology, McGill University, Montréal, Quebec, Canada; McGill TB International Centre and the Research Institute of the McGill University Health Centre, Montréal, Quebec, Canada.
authors.forename: Martin
authors.initials: M
authors.lastname: Olivier
mesh_terms: D000818:Animals; D018122:B7-1 Antigen / Q000276:immunology; D051940:B7-2 Antigen / Q000276:immunology; D019013:CD40 Antigens / Q000276:immunology; D002460:Cell Line; D003713:Dendritic Cells / Q000201:enzymology / Q000276:immunology* / Q000469:parasitology*; D018799:Intercellular Adhesion Molecule-1 / Q000276:immunology; D007376:Interleukin-2 / Q000096:biosynthesis / Q000276:immunology; D007894:Leishmania mexicana / Q000276:immunology*; D007896:Leishmaniasis / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D017027:Protein Tyrosine Phosphatases / Q000378:metabolism; D015398:Signal Transduction / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D018122:B7-1 Antigen; D051940:B7-2 Antigen; D019013:CD40 Antigens; D007376:Interleukin-2; D018799:Intercellular Adhesion Molecule-1; D020928:Mitogen-Activated Protein Kinases; D017027:Protein Tyrosine Phosphatases