title: Impairment of Interleukin-17A Expression in Canine Visceral Leishmaniosis is Correlated with Reduced Interferon-γ and Inducible Nitric Oxide Synthase Expression.
abstract: Dogs are the primary urban reservoir of Leishmania infantum and play a crucial role in the transmission of this parasite to man via sandflies. The spleen and liver are the main target organs of L. infantum infection, but few studies have evaluated the immune response to this infection in the canine liver. To identify the immunological mediators involved in resistance and/or susceptibility to canine visceral leishmaniosis (CVL), we selected 21 dogs naturally infected by L. infantum and classified as asymptomatic or symptomatic. Immunological parameters were analysed and correlations with clinical signs were determined. Symptomatic dogs showed higher numbers of parasites and less leucocyte infiltration in the liver compared with asymptomatic dogs. The progression of this disease was characterized not only by the down regulation of T helper (Th) 1-related cytokines, such as interferon (IFN)-γ and tumour necrosis factor (TNF)-α, but also by the down regulation of genes encoding interleukin (IL)-17A, inducible nitric oxide synthase (iNOS) and IL-10 in the spleen and liver in symptomatic dogs compared with asymptomatic dogs. Importantly, IL-17A gene transcription level was positively correlated with mRNA expression for iNOS and IFN-γ. Th1- and Th17-related cytokines therefore appear to play a role in restricting parasite growth via iNOS activation and decrease susceptibility of dogs to CVL.
authors.affiliation: Department of Biochemistry and Immunology, Medical School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil.
authors.forename: M S L
authors.initials: MS
authors.lastname: Nascimento
authors.affiliation: Department of Microbiology and Parasitology, Federal University of Rio Grande do Norte, Natal, Brazil.
authors.forename: T D R
authors.initials: TD
authors.lastname: Albuquerque
authors.affiliation: Department of Biological Sciences/NUPEB, Federal University of Ouro Preto, Ouro Preto, Brazil.
authors.forename: A F S
authors.initials: AF
authors.lastname: Nascimento
authors.affiliation: Department of Biological Sciences/NUPEB, Federal University of Ouro Preto, Ouro Preto, Brazil.
authors.forename: I S
authors.initials: IS
authors.lastname: Caldas
authors.affiliation: Laboratory of Cellular Ultrastructure, Oswaldo Cruz Institute/FIOCRUZ, Rio de Janeiro, Brazil.
authors.forename: M A
authors.initials: MA
authors.lastname: Do-Valle-Matta
authors.affiliation: Department of Microbiology and Parasitology, Federal University of Rio Grande do Norte, Natal, Brazil.
authors.forename: J T
authors.initials: JT
authors.lastname: Souto
authors.affiliation: Department of Biological Sciences/NUPEB, Federal University of Ouro Preto, Ouro Preto, Brazil.
authors.forename: A
authors.initials: A
authors.lastname: Talvani
authors.affiliation: Department of Biological Sciences/NUPEB, Federal University of Ouro Preto, Ouro Preto, Brazil.
authors.forename: M T
authors.initials: MT
authors.lastname: Bahia
authors.affiliation: Department of Parasitology, Federal University of Minas Gerais, Belo Horizonte, Brazil.
authors.forename: L M C
authors.initials: LM
authors.lastname: Galvão
authors.affiliation: Department of Clinical and Toxicological Analyses, Federal University of Rio Grande do Norte, Natal, Brazil.
authors.forename: A C J
authors.initials: AC
authors.lastname: Câmara
authors.affiliation: Department of Microbiology and Parasitology, Federal University of Rio Grande do Norte, Natal, Brazil. Electronic address: pauloguedes@cb.ufrn.br.
authors.forename: P M M
authors.initials: PM
authors.lastname: Guedes
mesh_terms: D000818:Animals; D016207:Cytokines / Q000032:analysis / Q000096:biosynthesis; D004283:Dog Diseases / Q000276:immunology* / Q000378:metabolism; D004285:Dogs; D004797:Enzyme-Linked Immunosorbent Assay; D007371:Interferon-gamma / Q000096:biosynthesis*; D020381:Interleukin-17 / Q000096:biosynthesis*; D007898:Leishmaniasis, Visceral / Q000276:immunology / Q000378:metabolism / Q000662:veterinary*; D052247:Nitric Oxide Synthase Type II / Q000096:biosynthesis*; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D016207:Cytokines; D020381:Interleukin-17; D007371:Interferon-gamma; D052247:Nitric Oxide Synthase Type II
keywords: canine visceral leishmaniosis; inducible nitric oxide synthase; interleukin-17; liver