Design of new therapeutic strategies, based on the carbohydrate recognition, against cryptococcosis

Abstract

Cryptococcus gattii is found in tropical climatic zones, subtropical and temperate; cause cryptococcosis in immunocompetent host, including children. C. gattii infection is caused by the inhalation of spores and yeast. This pathogen has a predilection for the lung, and can spread to CNS. The pathogenesis of the cryptococcosis is influenced by virulence factors, mainly the polysaccharide capsule. C. gattii capacity to subvert the response of innate immunity reduces the microbicidal activity of phagocytes and impairs the Th1 and Th17 immune response, which act in effector response against cryptococcosis. Antifungal drugs are used as treatment and was reported the toxicity activity and limited to eliminate the C. gattii infection. Immunotherapy was proposed as an alternative form to subvert the regulation the immune response by C. gattii. Immunomodulatory agents induce an appropriate immune response, which the innate immunity receptors are potential mediators. This immumomodulatory effect could be promoted by lectins that interact with N-glycans of Toll-like receptors (TLRs) and trigger activation. Our group described this mechanism for lectins, which induce the Th1 and Th17 immune response that protects against P. brasiliensis and Candida albicans infection. This evidence support the lectins ability to modulate the immune response in fungal infections, which is a therapeutic strategies to treat the cryptococcosis. Therefore, we propose as therapeutic strategie against C. gattii infection based on the lectins recognition by N-glycans linked to receptors of immune cells. So, ArtinM, Paracoccin, ConA, L-PHA and WGA, which will be used to assay the immunomodulatory effect in vitro and in vivo models infections. After, the following parameters will be analyzed: phagocytic activity and killing of innate immune cells; levels of cytokines and chemokines; measurement of reactive oxygen and nitrogen species; expression of costimulatory molecules; relative expression of markers of polarization of macrophages and CD4+ T cells; molecules phosphorylated of the TLR signaling pathway, expression levels of virulence factors of C. gattii; GXM levels; histopathology; cellular profile of inflammatory infiltrate; fungal burden in organs; survival curve. To innovate, T cells will be modified to express the chimeric antigenic receptor (CAR) containing the CRDs, fact that allows the interaction with glycotargets promoting the activation of innate and adaptive immune cells. This proposal will be evaluate in vitro after infection with C. gattii, in the presence of macrophages and genetically modified T cells. After, the following parameters will be analyzed: fungal burden in immune cells, levels of cytokines and chemokines, production of reactive oxygen and nitrogen species, release of perforin and granzyme, expression levels of virulence factors of C. gattii. These results to open new perspectives and to support the application in vivo models infection with C. gattii. (AU)