Avaliação dos extratos total salino e de excreção e secreção de Strongyloides venezuelensis em células trofoblásticas humanas infectadas com Toxoplasma gondii

Abstract

Toxoplasmosis is a cosmopolitan infection caused by the protozoan Toxoplasma gondii. Vertical transmission can result in congenital toxoplasmosis, a condition with potentially serious implications for the fetus. Human strongyloidiasis is an intestinal parasitosis caused by the nematode Strongyloides stercoralis with worldwide distribution and predominance in tropical and subtropical areas. During an invasion of the host, helminths create an environment conducive to their survival, modulating the host immune response. Helminth antigen products are being explored in parasitic co-infections. However, despite the growing interest in understanding the complex effects of overlapping infections, studies investigating the impact of co-infection/co-stimulation by Strongyloides and T. gondii antigens are still scarce. The aim of this study was to evaluate the stimuli of total saline extracts (TS) and excretion/secretion (ES) antigens of S. venezuelensis in human trophoblastic cells (BeWo lineage) infected with T. gondii regarding to cellular proteins, parasite therapy and cytokine production. Initially, the cytotoxicity of treatment with TS or ES of S. venezuelensis at serial concentrations (64; 32; 16; 8; 4; 2; 1; 0.5; 0.25 and 0.125 μg/ml) was evaluated by MTT assay. The results revealed that the different concentrations of the compounds did not present toxicity when compared to the control. Subsequently, the intracellular replication index of T. gondii was evaluated by β-galactosidase presence. In this assay, we treated BeWo cells infected with T. gondii at concentrations of 32, 8, 2, 0.5, and 0.125 μg/ml for both stimuli. It was found the treatment with different concentrations of the extracts did not affect the cells, as well as no difference was observed between the antigenic preparations , at the same concentrations, for T. gondii proliferation. Finally, the cytokines IL-4, IL-6, IL-8, IL-10 and MIF were measured in cell culture supernatants (TS + T. gondii) by ELISA. At the highest concentration of TS tested (32 μg/mL) there is a greater production of IL-4 and no change in the pattern of decreased IL-6 production in TS + T. gondii infected cells. Stimulation with different concentrations of TS also induced similar levels of MIF production, independent of T. gondii infection. Our results, indicate explaining processes underlying these relationships in neglected diseases is essential for a more complete understanding of the responses and implications of Strongyloides in protozoa co-infection