Resposta imune na infecção mista por Leishmania amazonensis e Leishmania chagasi em macrófagos

Abstract

Leishmaniasis is endemic in several regions of the world, being considered a major public health problem. In this context, mixed infection by different Leishmania species in the same individual, especially in areas of overlapping LTA and LV species, may be more prevalent than previously reported, affecting the clinical course, diagnosis and treatment of the disease. In this research, a review was carried out on the panorama of mixed infection, presented as chapter 1, which aimed to identify the work already carried out on this topic. Many case reports and a scarcity of experimental works were identified. But the results of the studies revealed that in a shared environment, different species can show different behaviors and compromise the course of the infection. In chapter 2, the work carried out, which aimed to evaluate the immune response and behavior of parasites in mixed infection by Leishmania amazonensis and Leishmania chagasi. For this, the macrophages were infected by L. amazonensis and L. chagasi, at times of 24 and 48 hours, then the infection rate, production of nitric oxide, hydrogen peroxide, production of inflammatory cytokines, in addition to the morphometric analysis were evaluated. of the parasitophorous vacuoles. The initial results related to the infection rate showed an overlap of L. chagasi in the mixed infection, suggesting the occurrence of an uneven proliferation and competition. Regarding the production of hydrogen peroxide, the mixed infection group showed a production similar to that seen in the single infection by L. chagasi, and this species may be influencing the production of this reactive in the mixed infection. The production of cytokine TNF mixed infection was similar to that observed in the single infection by L. amazonensis, so it is believed that the presence of this species may be relevant for the production of this cytokine in the shared environment. The MCP-1 chemokine was a parameter that showed no difference between the groups, even though it is an important chemokine linked to the recruitment of monocytes and the increase in the number of macrophages during the single and mixed infection. After evaluating the amount of parasitophorous vacuoles, a smaller amount of these structures in the mixed infection group was observed within 48 hours, a result that may be related to the strategy of sharing vacuoles by the parasites, which has already been analyzed in other studies with other species. Regarding the area of the vacuole, an increase in extension was noted only in the group with single infection by L. chagasi, within 48 hours. In view of the results, it was possible to observe that in a shared environment, the influence of species occurs differently, with changes in the behavior of vacuoles and the action of the cytokine TNF- e protozoan in the host and compromise the clinical course of infection