title: Apoptosis in T lymphocytes from spleen tissue and peripheral blood of L. (L.) chagasi naturally infected dogs.
abstract: Dogs are the main domestic reservoirs of L. (L.) chagasi. Once in the vertebrate host, the parasite may cause visceral leishmaniasis, which can also be transmitted to humans. Infected symptomatic dogs show disorganization in the white pulp in spleen tissue and a reduction in T lymphocytes in peripheral blood. To investigate whether apoptosis is involved in white pulp disorganization and diminished T cell counts in peripheral blood, apoptotic T cells from the spleen and peripheral blood of dogs naturally infected with L. (L.) chagasi and presenting clinical manifestations were quantified and compared with healthy dogs. Thirteen symptomatic adult dogs infected by L. (L.) chagasi and six healthy dogs from a nonendemic area (controls) were included in the study. Samples from spleen and peripheral blood were used to quantify apoptosis in CD3 lymphocytes by flow cytometry using Anexin V and Multicaspase kits; the results were compared using the Mann Whitney test. The percentage of total T cells was lower in Leishmania infected dogs compared to healthy controls (P<0.05). Apoptosis levels in T cells from PBMC and spleen were higher in infected dogs than in controls (P<0.05). The least squares method test was used to determine the effect between the degree of structural organization of spleen white pulp and the percentage of apoptosis in the spleen. A significant effect on the level of white pulp morphological disorganization and percentage of apoptosis in spleen T cells was observed (F=20.45; P=0.0014). These data suggest that apoptosis is an important for the immunopathogenesis of canine visceral leishmaniasis.
authors: Departamento de Clinica, Cirurgia e Reprodução Animal, Faculdade de Medicina Veterinária, Universidade Estadual Paulista, Rua Clóvis Pestana, 793, ZIP 16050-400 Araçatuba, São Paulo, Brazil. vmflima@fmva.unesp.br
authors: Valéria Marçal Felix
authors: VM
authors: de Lima
authors: Karina Reinaldo
authors: KR
authors: Fattori
authors: Fausto
authors: F
authors: de Souza
authors: Flavia Rezende
authors: FR
authors: Eugênio
authors: Paulo Sérgio Patto
authors: PS
authors: dos Santos
authors: Daniele Bernadete
authors: DB
authors: Rozza
authors: Gisele Fabrino
authors: GF
authors: Machado
mesh_terms: D000818:Animals; D017209:Apoptosis; D004283:Dog Diseases / Q000473:pathology*; D004285:Dogs; D005260:Female; D007150:Immunohistochemistry; D018314:Leishmania infantum; D007898:Leishmaniasis, Visceral / Q000473:pathology / Q000662:veterinary*; D008297:Male; D013154:Spleen / Q000166:cytology / Q000473:pathology; D013601:T-Lymphocytes / Q000473:pathology*