Evaluation of TNF-α, IL-4, and IL-10 and parasite density in spleen and liver ofL. (L.) chagasinaturally infected dogs

Abstract

Dogs are the main domestic reservoirs of L. (L.) chagasi. Once in the vertebrate host, the parasite can cause visceral leishmaniasis, which can also be transmitted to humans. Cytokines are key elements of the host immune response against Leishmania spp. To investigate whether tumor necrosis factor (TNF)-a, interleukin (IL)-4 and IL-10 are associated with pattern infection in dogs, these cytokines were quantified in the spleen and liver of dogs naturally infected with L. (L.) chagasi, with or without clinical manifestations, and their levels were correlated with the parasite load verified in these organs. A total of 40 adult dogs naturally infected with L. (L.) chagasi were assessed, together with 12 uninfected control dogs. Samples from spleen and liver were used to determine the cytokine levels by capture ELISA and for quantifying parasite load by real-time PCR. Statistical analysis was performed using the minimum Chi square method and group means were compared using the Tukey test. TNF-a, IL-4 and IL-10 levels in infected dogs were higher than in control groups; the liver was the main cytokine-producing organ during infection. The level of splenic TNF-a showed correlation with parasite load and may represent an important marker for infection process evolution, with the participation of IL-10. These results may contribute to a clearer understanding of the immune response in dogs infected with L. (L.) chagasi, which may lead to the development of prophylactic or preventive measures for these animals.

Insights on adaptive and innate immunity in canine leishmaniosis

“…Michelin et al . measured TNF- α , IL-4 and IL-10 in the liver and spleen of dogs naturally infected with L. infantum and reported that all cytokines studied were higher in the spleens of symptomatic dogs compared with asymptomatic or non-infected controls (Michelin et al 2011). …”

Induction of haem oxygenase‐1 increases infection of dog macrophages by L. infantum

“…in macrophages . IL‐10 is one of the major suppressor cytokines present in CVL, and a positive correlation between IL‐10 and parasite burden has been established . Moreover, a positive correlation between HO‐1 and IL‐10 has also been described in infected dogs, and inhibition of HO‐1 was found to increase the lymphoproliferative response of these dogs, in association with suppression of IL‐10 production .…”

Exploitation of Interleukin-10 (IL-10) Signaling Pathways: Alternate Roles of Viral and Cellular IL-10 in Rhesus Cytomegalovirus Infection

“…One striking finding of this study is that there are significant correlations between the levels of antigenstimulated cIL-10 production in PBMC and RhCMV genome copy numbers detected in saliva. This is not unique to RhCMV, as cIL-10 levels have been positively associated, either alone or with other biomarkers, with increased burdens of other pathogens, including human papillomavirus, HIV, hepatitis B virus, EpsteinBarr virus (EBV), Mycobacterium tuberculosis, Leishmania spp., dengue virus, and murine and human CMV (45,(55)(56)(57)(58)(59)(60)(61)(62)(63)(64)(65)(66)(67)(68)(69)(70)(71)(72). While the specific cell type(s) responsible for elevated cIL-10 expression in response to RhCMV antigen exposure was not explored, multiple cell types have been implicated for other pathogens, including regulatory B and T cells.…”