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Apoptosis is associated with resolution of inflammation. However, apoptosis may also occur in active inflammation, balancing inflammatory recruitment instead of a resolution event. To test that hypothesis, we measured apoptosis and chemokines expression, involved in recruitment of inflammatory cells. Clinical affected and subclinically infected dogs with canine leishmaniosis (CanL) and uninfected controls were assessed. Apoptosis in renal tissue (glomeruli, tubules, and inflammatory infiltrate) and cellularity in inflammatory foci were quantified. Messenger RNA of CCL5, CCL4, MCP-1, MCP-2, Caspase (Casp) 3, Casp 8, Casp 9, Bax, Bcl 2 and Fas were quantified by qRT PCR. Clinical affected dogs showed more intense inflammation and higher cellularity in the inflammatory infiltrates than subclinically infected ones, which were higher than controls. Glomerular and tubular cells showed higher apoptotic index in clinical affected dogs when compared to controls. Apoptosis within the inflammatory infiltrates was higher in clinical affected dogs. Bax/Bcl 2 ratio and CCL4 showed higher expression in kidney from clinical affected when compared to subclinically infected dogs. Casp 3/CCL4 ratio expression were higher in subclinically infected dogs than in the clinical affected group. Additionally, results suggest that Casp 3/CCL4 ratio is balancing towards an inflammatory recruitment and CCL4 and Bax/Bcl 2 ratio expression is associated with active inflammation in clinical affected CanL. Data demonstrate that apoptosis was not always correlated with resolution of inflammation, when a morphometric and a molecular evaluation were performed concomitantly. In kidneys of Leishmania infected dogs, apoptosis and chemokines may be balancing inflammatory recruitment. In conclusion, Bax/Bcl 2 ratio, chemokines, Casp 8, Casp 3 and Fas were associated with renal apoptosis, active inflammation and increased inflammatory recruitment observed in clinical affected animals, influencing the clinical presentation of leishmaniosis., (Copyright © 2021 Elsevier B.V. All rights reserved.)

In the present study, Leishmania braziliensis enolase was cloned and the recombinant protein (rEnolase) was evaluated for the serodiagnosis of canine and human visceral leishmaniosis (VL). For the canine VL diagnosis, this study examined serum samples of Leishmania infantum-infected dogs, from non-infected animals living in endemic or non-endemic areas of leishmaniosis, as well as those from Leish-Tec ® -vaccinated dogs and Trypanosoma cruzi or Ehrlichia canis experimentally infected animals. For the human VL diagnosis, this study analyzed serum samples from VL patients, from non-infected subjects living in endemic or non-endemic areas of leishmaniosis, as well as those from T. cruzi-infected patients. In the results, an indirect ELISA method using rEnolase showed diagnostic sensitivity and specificity values of 100% and 98.57%, respectively, for canine VL serodiagnosis, and of 100% and 97.87%, respectively, for human VL diagnosis. These results showed rEnolase with an improved diagnostic performance when compared to the recombinant A2 protein, the crude soluble Leishmania antigenic preparation, and the recombinant K39-based immunochromatographic test. In conclusion, preliminary results suggest that the detection of antibodies against rEnolase improves the serodiagnosis of human and canine visceral leishmaniosis., (Copyright © 2017 Elsevier B.V. All rights reserved.)

The development of new therapeutic strategies to treat leishmaniasis has become a priority. In the present study, the antileishmanial activity of 8-hydroxyquinoline (8-HQN) was investigated against in vitro promastigotes and in vivo intra-macrophage amastigotes of three Leishmania species: Leishmania amazonensis, Leishmania infantum and Leishmania braziliensis. Studies were performed to establish the 50% Leishmania inhibitory concentration (IC50) of 8-HQN, as well as its 50% cytotoxic concentration (CC50) on murine macrophages and in human red blood cells. The inhibition of macrophages infection was also evaluated using parasites that were pre-treated with 8-HQN. The effects of this compound on nitric oxide (NO) production and in the mitochondrial membrane potential were also evaluated. Finally, the therapeutic efficacy of 8-HQN was assessed in a known murine model, L. amazonensis-chronically infected BALB/c mice. Our results showed that 8-HQN was effective against promastigote and amastigote stages of all tested Leishmania species, presenting a selectivity index of 328.0, 62.0 and 47.0 for L. amazonensis, L. infantum and L. braziliensis, respectively. It was effective in treating infected macrophages, as well as in preventing the infection of these cells using pre-treated parasites. In addition, 8-HQN caused an alteration in the mitochondrial membrane potential of the parasites. When administered at 10mg/kg body weight/day by subcutaneous route, this product was effective in reducing the lesion diameter, as well as the parasite load in evaluated tissues and organs of infected animals. The results showed the in vitro and in vivo efficacy of 8-HQN against three different Leishmania species causing tegumentary and/or visceral leishmaniasis, and it could well be used for future therapeutic optimization studies to treat leishmaniasis., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Serological diagnostic tests for canine and human leishmaniasis present problems related with their sensitivity and/or specificity. Recently, an immunoproteomic approach performed with Leishmania infantum proteins identified new parasite antigens. In the present study, the diagnostic properties of two of these proteins, cytochrome c oxidase and IgE-dependent histamine-releasing factor, were evaluated for the serodiagnosis of canine visceral (CVL) and human tegumentary (HTL) leishmaniasis. For the CVL diagnosis, sera samples from non-infected dogs living in an endemic or non-endemic area of leishmaniasis, sera from asymptomatic or symptomatic visceral leishmaniasis (VL) dogs, from Leish-Tec(®)-vaccinated dogs, and sera from animals experimentally infected by Trypanosoma cruzi or Ehrlichia canis were used. For the HTL diagnosis, sera from non-infected subjects living in an endemic area of leishmaniasis, sera from active cutaneous or mucosal leishmaniasis patients, as well as those from T. cruzi-infected patients were employed. ELISA assays using the recombinant proteins showed both sensitivity and specificity values of 100% for the serodiagnosis of both forms of disease, with high positive and negative predictive values, showing better diagnostic properties than the parasite recombinant A2 protein or a soluble Leishmania antigen extract. In this context, the two new recombinant proteins could be considered to be used in the serodiagnosis of CVL and HTL., (Copyright © 2015 Elsevier B.V. All rights reserved.)

The role of interleukin IL-4, IL-10 and interferon gamma cytokines on natural Fasciola hepatica infection was investigated by quantifying the mRNA levels in liver tissue from chronically infected cattle. IL-4 and IL-10 had higher expression relative to interferon gamma in the liver tissue of infected animals when compared with the control group. The higher levels of IL-10 and IL-4 observed in the present study suggest a synergism between these cytokines, as well as involvement in the suppression of TH1 cell responses and a consequent induction of decreased interferon gamma expression in chronic cattle fascioliasis. The cytokine ratios were positively correlated, indicating a predominance of IL-4 in the chronic phase of infection with respect to interferon gamma and IL-10. Interferon gamma was predominant expressed in the controls, suggesting the involvement of IL-10 in modulating the immune response in favor of IL-4 in infected animals. Our results suggest that the TH2 polarized host immune response previously observed in experimental infection may also be responsible for establishing chronic phase and the maintenance of the natural infection of cattle from endemic areas that are in continuous contact with parasite., (Copyright © 2013 Elsevier B.V. All rights reserved.)

The immune response in the skin of dogs infected with Leishmania chagasi and its association with distinct levels of tissue parasitism and clinical progression of canine visceral leishmaniasis (CVL) are poorly understood and limited studies are available. A detailed analysis of the profiles of cytokines (IFN-γ, IL-4, IL-5, IL-10, IL-12, IL-13, TGF-β1 and TNF-α) and transcription factors (T-bet, GATA-3 and FOXP3) in the skin of 35 naturally infected dogs was carried out using real-time PCR alongside determinations of skin parasite density and the clinical status of CVL. A mixed cytokine profile with high levels of expression of IFN-γ, TNF-α and IL-13 was determined in asymptomatic dogs. Additionally, the levels of transcription factors GATA-3 and FOXP3 were correlated with the asymptomatic disease. A mixed cytokine profile was also observed during active CVL. Moreover, high levels of IL-10 and TGF-β1, concomitant with the low expression of IL-12, may represent a key condition that allows persistence of parasite replication in the skin. The results obtained indicate that in asymptomatic disease or lower levels of skin parasite density, a mixed inflammatory, regulatory immune response profile may be of major relevance for both the maintenance of the clinical status of the dogs as well as for parasite persistence and replication at low levels., (Copyright © 2010 Elsevier B.V. All rights reserved.)