The role of interleukins in vitiligo: a systematic review.

Vitiligo is a disorder of the skin that causes depigmentation and asymptomatic macules whose exact cause is still unclear. Although its aetiology is not fully elucidated, the main theory of its pathomechanism is that it is associated with the autoimmune process. There is few summarized information about the role of inflammatory mediators, as interleukins, in vitiligo, so our aim was to present a systematic review of the role of interleukins in vitiligo, focusing on interleukins. In this review, we included all studies assessing interleukin levels in vitiligo patients conducted up to June 2017. Quality assessment of these studies was performed using the Newcastle-Ottawa Scale (NOS). The interleukins mainly involved were IL-2, IL-4, IL-6, IL-10 and IL-17. The studies highlight the crucial role of IL-17 in the onset and progression of the disease, and its synergistic action with IL-2, IL-6 and IL-33. Dysregulated levels of the interleukins were also correlated with the stage of disease, the affected skin surface area, and indicated as the main factor for lymphocyte infiltration found in depigmented regions. These findings illustrate the growing need for new therapies targeting vitiligo and further research into the role of interleukins as an area of particular interest.

Leishmania chagasi naturally resistant to nitric oxide isolated from humans and dogs with visceral leishmaniasis in Brazil.

Nitric oxide (NO) plays an important role as a leishmanicidal agent in murine macrophages. NO resistant Escherichia coli and Mycobacterium tuberculosis have been associated with poor outcomes of their resulting diseases. NO resistant Leishmania braziliensis has also been identified and exacerbates the clinical course of human leishmaniasis. We report, for the first time, natural resistance of Leishmania chagasi promastigotes to NO. These parasites were isolated from humans and dogs with visceral leishmaniasis. We also demonstrate that this resistance profile was associated with a greater survival capacity and a greater parasite burden in murine macrophages, independent of activation and after activation by IFN-γ and LPS.

Protective immunity against Trypanosoma cruzi provided by oral immunization with Phytomonas serpens: role of nitric oxide.

We have previously demonstrated that Phytomonas serpens, a tomato parasite, shares antigens with Trypanosoma cruzi, the protozoa that causes Chagas' disease. These antigens are recognized by human sera and induce protective immunity in Balb/c mice. In the present study, inducible nitric oxide synthase (iNOS) knockout (KO) mice and C57BL/6 mice treated with the nitric oxide inhibitor, aminoguanidine (AG, 50 mg kg(-1)) infected with T. cruzi, were used to demonstrate the role of nitric oxide (NO) to host protection against T. cruzi infection achieved by oral immunization with live P. serpens. A reduction in parasitaemia and an increase in survival were observed in C57BL/6 infected mice and previously immunized with P. serpens, when compared to non-immunized mice. iNOS (KO) mice immunized and C57BL/6 immunized and treated with AG presented parasitaemia and mortality rates comparable to those of infected and non-immunized mice. By itself, immunization with P. serpens did not induce inflammation in the myocardium, but C57BL/6 mice so immunized showed fewer amastigotes nests in the heart following an acute T. cruzi infection than those in non-immunized mice. These results suggest that protective immunity against T. cruzi infection induced by immunization with P. serpens is dependent upon enhanced NO production during the acute phase of T. cruzi infection.