Neutrophil dysfunction varies with the stage of canine visceral leishmaniosis

Canine visceral leishmaniosis (CVL) causes a dependent-stage alteration in neutrophil oxidative metabolism. When production of reactive oxygen species (ROS) exceeds the antioxidant capacity of neutrophils, apoptosis is triggered, impairing the viability and function of these cells, which can predispose dogs to infection. However, the uremic condition observed in late-stage CVL can also alter the viability and function of human neutrophils. To more clearly understand this relationship, the apoptosis rate and oxidative metabolism of neutrophils from control dogs (n= 20) were compared to dogs in moderate (n= 15) and very severe (n= 15) stage CVL, classified according to LeishVet Consensus. To assess neutrophil oxidative metabolism, superoxide production was measured using the nitroblue tetrazolium reduction test (NBT) in isolated neutrophils. The apoptosis rate of neutrophils was estimated using the morphological method. Moderate-stage dogs presented increased superoxide production, while dogs with very severe stage CVL presented decreased superoxide production and an increase neutrophil apoptosis rate. Leishmaniosis causes differential neutrophil dysfunction according to disease stage. In moderate stage CVL, increased superoxide production is observed with no change in neutrophil viability. However, in very severe stage CVL, decreased superoxide production and increased apoptosis occur associated with uremia. © 2013 Elsevier B.V.

Leishmaniasis causes oxidative stress and alteration of oxidative metabolism and viability of neutrophils in dogs

The aim of the present study was to test the hypothesis that oxidative stress and alteration of oxidative metabolism and apoptosis of neutrophils in dogs vary with the stage of leishmaniasis and to determine the contribution of uremia to such alterations. Dogs with leishmaniasis were classified into two stages: moderate (Leish II, n = 20) or very severe (i.e. with concurrent uremia; Leish IV, n = 20) according to the LeishVet Consensus. The two leishmaniasis groups were compared with uremic dogs without leishmaniasis (Uremic, n = 10) and to healthy dogs (Control, n = 30). To determine oxidative stress, total antioxidant/oxidant capacity, lipid peroxidation, total glutathione and the plasma antioxidants albumin, uric acid and bilirubin were quantified. Superoxide production was determined using the hydroethidine probe and viability and apoptosis were measured using annexin V-PE by capillary flow cytometry. Oxidative stress was present in both uremia and leishmaniasis with reduced total antioxidant capacity and was associated with increased induced production of superoxide and apoptosis. The greatest amount of oxidants was observed in animals with moderate disease only. Neutrophils from uremic dogs with and without leishmaniasis had decreased viability and an increased apoptosis rate in addition to increased lipid peroxidation. In conclusion, oxidative stress occurs in both stages of leishmaniasis with differences in intensity and levels of plasma markers; however, uremia does contribute to the decreased spontaneous viability of neutrophils in dogs in the final stage of the disease. © 2013 Elsevier Ltd. All rights reserved.

CD95 (FAS) and CD178 (FASL) induce the apoptosis of CD4+ and CD8+ cells isolated from the peripheral blood and spleen of dogs naturally infected with Leishmania spp

Infected dogs are urban reservoirs of Leishmania chagasi, which is a causative agent of visceral leishmaniasis (VL). Dogs exhibit immune suppression during the course of this disease, and lymphocyte apoptosis is involved in this process. To investigate apoptosis and the expression levels of FAS-FAS-associated death domain protein (CD95 or APO-1), FASL-FAS ligand protein (CD178), and TRAIL-TNF-related apoptosis-inducing ligand (CD253) receptors in peripheral blood mononuclear cells and spleen leukocytes from 38 symptomatic dogs with moderate VL and 25 healthy dogs were evaluated by flow cytometry. The apoptosis rate of blood and splenic CD4+ and CD8+ cells was higher in infected dogs than in healthy dogs. The expression levels of FAS and FASL in blood and splenic CD4+ cells were lower in infected dogs than in healthy dogs. FAS expression in CD8+ cells was higher in infected dogs than in healthy dogs; in contrast, FASL expression was lower in infected dogs. The expression of the TRAIL receptor increased only in splenic CD8+ cells from infected dogs. The FAS and FAS-L blocking antibodies confirmed the importance of these receptors in apoptosis. Our results enhance the current understanding of the immune response in dogs infected with L. chagasi, facilitating the future development of therapeutic interventions to reduce lymphocyte depletion. © 2013 Elsevier B.V.

Ação da benzocaína e do óleo de cravo sobre parâmetros fisiológicos de tilápia, Oreochromis niloticus

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Uso da Aloe vera L. no manejo de matrinxã (Brycon amazonicus)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Soja crua em dietas para a Tilápia-do-Nilo (Oreochromis niloticus)

Pós-graduação em Aquicultura - FCAV

Correlações comportamentais, fisiológicas e morfológicas da carga parasitária em Rhinella icterica (Anura: Bufonidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Investigação do potencial genotóxico do extrato de Garcinia achachairu in vivo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Investigação do potencial genótóxico e antigenotóxico do extrato de Brassica oleracea in vivo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação do efeito do extrato hidroalcóolico de Myrcia bella cambess na dor aguda e na inflamação em modelos experimentais de roedores

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Caracterização do perfil da ação do ácido gálico e seus derivados sobre processos oxidativos in vitro e ex vivo

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Suplementação dietética de selênio e vitamina E: variáveis fisiológicas e desempenho de juvenis de pacu (Piaractus mesopotamicus)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Validação de anticorpo monoclonal anti-CD45 obtido in house para utilização em citometria de fluxo e imuno-histoquímica

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Avaliação da expressão gênica em leucócitos de eqüinos: análise pela técnica do microarray em modelo ex vivo de endotoxemia

Pós-graduação em Ciência Animal - FMVA

Emprego de membrana de celulose microfibrilar na ceratoplastia lamelar em coelhos (O. cuniculus, Linnaeus, 1758): aspectos clínicos, morfológicos e imunoistoquimicos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)