Interaction between the levels of ROS, NO and activity of HO-1 with apoptosis of mononuclear cells from peripheral blood and spleen of dogs with visceral leishmaniasis

Abstract

Leishmaniasis are diseases caused by flagellate protozoa of the genus Leishmania and have been found in about 90 countries, predominantly visceral form of the disease. The main reservoir of this parasite are dogs, and out of the wild environment, performs the important function of maintaining epidemiological cycle of the disease. The resistance of animals with LVC infection is associated with low levels of specific antibodies and the presence of cellular immunity is the principal cells involved in CD4 and CD8. Recent work suggests apoptosis as a regulatory mechanism in visceral leishmaniasis. Among the various factors that induce the apoptosis process includes the species of reactive oxygen and high levels of nitric oxide. Mononuclear cells from symptomatic dogs with visceral leishmaniasis have high rates of production of reactive oxygen species, but not investigated whether such production may be associated with apoptosis. Moreover, high levels of iNOS enzyme production of NO are observed in the spleen tissue, suggesting that high levels of NO may be present and contribute to the previously observed apoptosis. In addition to these elements the enzyme heme oxygenase -1 can also act immunity by inhibiting the proliferation and / or function of T cells, appears to be involved in the apoptotic process, it may act by inhibiting pro -oxidant effect of free heme in the body which is damaging to cells and tissues by inducing oxidative stress, cytotoxicity and inflammation. The objective of this study is to investigate in vitro how these parameters interact, contributing or inhibiting the apoptotic process, as observed in canine visceral leishmaniasis. Knowledge of these mechanisms may contribute to the understanding of the immunopathology of dogs with leishmaniasis and thus collaborate in the development of therapies for disease. (AU)