Trypanosoma cruzi Mexican Strains Differentially Modulate Surface Markers and Cytokine Production in Bone Marrow-Derived Dendritic Cells from C57BL/6 and BALB/c Mice.

Dendritic cells (DCs) are a type of antigen-presenting cells that play an important role in the immune response against Trypanosoma cruzi, the causative agent of Chagas disease. In vitro and in vivo studies have shown that the modulation of these cells by this parasite can directly affect the innate and acquired immune response of the host in order to facilitate its biological cycle and the spreading of the species. Many studies show the mechanisms by which T. cruzi modulates DCs, but the interaction of these cells with the Mexican strains of T. cruzi such as Ninoa and INC5 has not yet been properly investigated. Here, we evaluated whether Ninoa and INC5 strains evaded the immunity of their hosts by modulating the biology and function of murine DCs. The CL-Brener strain was used as the reference strain. Herein, it was demonstrated that Ninoa was more infective toward bone marrow-derived dendritic cells (BMDCs) than INC5 and CL-Brener strains in both BMDCs of BALB/c and C57BL/6 mice. Mexican strains of T. cruzi induced different cytokine patterns. In BMDCs obtained from BALB/c mice, Ninoa strain led to the reduction in IL-6 and increased IL-10 production, while in C57BL/6 mice Ninoa strain considerably increased the productions of TNF-α and IL-10. Also, Ninoa and INC5 differentially modulated BMDC expressions of MHC-II, TLR2, and TLR4 in both BALB/c and C57BL/6 mice compared to Brazilian strain CL-Brener. These results indicate that T. cruzi Mexican strains differentially infect and modulate MHC-II, toll-like receptors, and cytokine production in DCs obtained from C57BL/6 and BALB/c mice, suggesting that these strains have developed particular modulatory strategies to disrupt DCs and, consequently, the host immune responses.

In vitro antifungal activity of Morinda citrifolia (noni) extract against Candida albicans.

INTRODUCTION: Candida albicans is the main agent of the most common fungal infection, Candidiasis. It is an opportunistic and dangerous pathogen, especially in immunosuppressed patients. The biological properties of Morinda citrifolia (noni) make it a potent antifungal. In this study, antifungal effect of M. citrifolia was evaluated to verify its effect on human cells. METHODOLOGY: Extract of M. citrifolia was used against strains of C. albicans (cEC 1291). Glucose consumption in C. albicans biofilm was determined at different concentrations of M. citrifolia, and germ tube formation was evaluated in the presence and absence of M. citrifolia. Fungicidal activity was determined by the kinetics of fungal cell death. THP-1 and HeLa cells were used for cell viability and apoptosis, and cell proliferation assays, respectively. RESULTS: Cells treated with M. citrifolia maintained higher concentration of glucose than the control group (p < 0.05). Germ tube formation was inhibited in cells treated with M. citrifolia (p < 0.05). M. citrifolia exerted a cytotoxic effect on C. albicans cells with 99.99% lethality after 6.82 h (1:1 and 1:2), and reduced the viability of THP-1 cells by 25% and 67% after 12 and 36 h, respectively. Annexin V expression in THP-1 increased in groups that received higher concentrations of M. citrifolia (p < 0.05), reducing the proliferation of THP-1 and HeLa cells (2.8-fold). A greater cytotoxic effect was observed in fungal cells. CONCLUSIONS: These results indicate that M. citrifolia exerts biological activity against C. albicans and reduces the viability and proliferation of human cells.

Role of Cytokines, Chemokines and IFN-γ+ IL-17+ Double-Positive CD4+ T Cells in Patients with Multiple Sclerosis.

Multiple sclerosis is mediated by self-reactive myelin T and B cells that lead to axonal and myelin damage. The immune response in multiple sclerosis involves the participation of CD4+ T cells that produce cytokines and chemokines. This participation is important to find markers for the diagnosis and progression of the disease. In our work, we evaluated the profile of cytokines and chemokines, as well as the production of double positive CD4+ T cells for the production of IFNγ IL-17 in patients with multiple sclerosis, at different stages of the disease and undergoing different treatments. We found that relapsing-remitting patients had a significant increase in IL-12 production. About IL-5, its production showed significantly higher levels in secondarily progressive patients when compared to relapsing-remitting patients. IFN-γ production by PBMCs from secondarily progressive patients showed significantly higher levels. This group also had a higher percentage of CD4+ IFNγ+ IL-17+ T cells. The combination of changes in certain cytokines and chemokines together with the presence of IFNγ+ IL-17+ double positive lymphocytes can be used to better understand the clinical forms of the disease and its progression.

In Silico Identification of New Targets for Diagnosis, Vaccine, and Drug Candidates against Trypanosoma cruzi.

Chagas disease is a neglected tropical disease caused by the parasite Trypanosoma cruzi. Despite the efforts and distinct methodologies, the search of antigens for diagnosis, vaccine, and drug targets for the disease is still needed. The present study is aimed at identifying possible antigens that could be used for diagnosis, vaccine, and drugs targets against T. cruzi using reverse vaccinology and molecular docking. The genomes of 28 T. cruzi strains available in GenBank (NCBI) were used to obtain the genomic core. Then, subtractive genomics was carried out to identify nonhomologous genes to the host in the core. A total of 2630 conserved proteins in 28 strains of T. cruzi were predicted using OrthoFinder and Diamond software, in which 515 showed no homology to the human host. These proteins were evaluated for their subcellular localization, from which 214 are cytoplasmic and 117 are secreted or present in the plasma membrane. To identify the antigens for diagnosis and vaccine targets, we used the VaxiJen software, and 14 nonhomologous proteins were selected showing high binding efficiency with MHC I and MHC II with potential for in vitro and in vivo tests. When these 14 nonhomologous molecules were compared against other trypanosomatids, it was found that the retrotransposon hot spot (RHS) protein is specific only for T. cruzi parasite suggesting that it could be used for Chagas diagnosis. Such 14 proteins were analyzed using the IEDB software to predict their epitopes in both B and T lymphocytes. Furthermore, molecular docking analysis was performed using the software MHOLline. As a result, we identified 6 possible T. cruzi drug targets that could interact with 4 compounds already known as antiparasitic activities. These 14 protein targets, along with 6 potential drug candidates, can be further validated in future studies, in vivo, regarding Chagas disease.