Relação entre a expressão de genes de imunidade inata e grau de sobrevivência intracelular de Leishmania infantum em macrófagos caninos experimentalmente infectados

Abstract

Canine visceral leishmaniasis is an important zoonosis caused by Leishmania infantum, transmitted by sand flies. Despite the advance in the understanding of the immune mechanisms against Leishmania infection in recent years, there are few studies about the establishment of the immune response in dogs, especially on the mechanisms of innate immunity. In this context, aiming future control measures of canine and human cases, immunotherapy has emerged as a viable option. This way, the aim of this study was to determine the gene expression of the receptors TLR9, NOD1 and NOD2 in canine macrophages and evaluate their correlation with the intracellular survival of L. infantum. After screening tests and confirmation of negative diagnosis for the disease, 43 clinically healthy animals were selected for blood collection for cell culture. After monocytes differentiation into macrophages, part of the culture supernatant was collected and stored at - 80°C for subsequent RNA extraction and real-time PCR, for evaluation of the expression of innate immunity genes. The other part was experimentally infected with L. infantum, with further evaluation of the intracellular survival of the parasite. It was observed the low expression of these receptors and a positive correlation between the expression of NOD2 and intracellular survival of L. infantum. These results highlight the importance of studies that aim to describe, in a more detailed manner, the function of these and other receptors, both in experimental infection as in naturally infected animals.