Análise do potencial imunomodulador do extrato antigênico de Pythium insidiosum utilizando modelo murino de leishmaniose tegumentar.

Abstract

The effective immune response in Cutaneous Leishmaniasis is the cell type Th1. Pithyum insidiosum´s immunomodulators antigens (VPI) appears to stimulate this phenotype, according to cell profiles found before and after immunotherapy in humans and animals with pythiosis. In this study, we evaluated the potential of the VPI act as immunotherapy or vaccine agent in cutaneous infection caused by L. major in BALB/c mice. Furthermore, it determined the phenotype of splenic cells after Immunization with VPI, intracytoplasmic cytokines in murine splenocytes were quantified as well as those present in the supernatant of the cell culture and the humoral immune response was evaluated. The results showed that the VPI revealed a stable electrophoretic profile and not degraded and that despite not having prevented the appearance of lesions in animals, there was a reduction in the size and in the development time of them. In the analysis by flow cytometry, it was observed on the "ex vivo" assay of spleen cells that in the immunized group the number of lymphocytes was higher in the control group, as well as the phenotypes CD4+ e CD8+. The intracytoplasmic cytokine of splenocytes cultured for 72 hours under antigenic stimulation revealed, qualitatively, IFNã higher production compared to IL-10, and that the primary source of IFNã was CD8 T cells. The in vitro dosage of cytokine in the cell culture supernatant of stimulated cells showed greater production of INFã , followed by IL-4, IL - 2 and IL - 10, revealing a mixed cytokine profile, tending to Th1 polarization. The humoral response assessed by IgG dosage of plasma in the immunized animals revealed low titers, suggesting a minor importance of it in infection control. This immunological profile was partly described in other effective vaccine protection studies. The success of therapy in animals and patients with the use of VPI in cases of Pythiosis provide sufficient evidence for further investigations of its immunomodulatory role in leishmaniasis as well as in other types of infections caused by intracellular pathogens.