Role of Fas and TNF in the apoptosis of CD4 T lymphocyte and CD8 T lymphocyte in dogs with visceral leishmaniasis

Abstract

The Canine visceral leishmaniasis (CVL) is one of the most important emerging diseases with high prevalence in Latin America, caused largely by the Leishmania (L.) chagasi. The LVC has a major impact on public health, because domestic dogs are the most important reservoirs of the disease, both in urban as in peri-urban areas. So the dog is an important target for the adoption of control measures. Symptomatic infected dogs show a suppression of cell-mediated immunity, apoptosis of T lymphocytes has been associated with suppression of cellular response in experimental infection. To investigate whether apoptosis of T lymphocytes is involved in suppression of cellular response in dogs naturally infected apoptosis of CD4 and CD8 peripheral blood and spleen of dogs naturally infected with L. (L.) chagasi with clinical manifestations will be quantified and compared to healthy dogs. The mechanisms that induce apoptosis are also evaluated. Fifteen symptomatic adult dogs infected with L. (L.) chagasi and six healthy dogs from non endemic area (controls) will be included in the study. Samples from spleen and peripheral blood will be used for quantification of apoptosis and investigate the possible mechanisms that induce the process. In dogs naturally infected immune suppression observed may be related to the mechanism of apoptosis in T-lymphocyte stimulation due to the constant feature of chronic infection can trigger apoptosis and cooperate in the failure of cellular immunity, the definition of what population is undergoing apoptosis and characterization of the inducing mechanisms may be important for understanding the factors responsible for suppression of cellular immunity. The understanding of this mechanism in infected dogs may allow future therapeutic interventions to reduce the depletion of lymphocytes. (AU)