Isolamento e purificação de exossomos de indivíduos não-atópicos e sua influência no perfil de citocinas secretadas in vitro por leucócitos de indivíduos atópicos

Abstract

Allergy is a public health problem that affects children and adults. Its prevalence has increased dramatically in many countries. Nowadays, many studies have shown that nanovesicles membranous, called exosomes, are secreted by a large number of cells implicated in allergy, including mast cells, dendritic cells, T and B lymphocyte. These nanovesicles have endosomal origin, are produced under physiological and pathological conditions, when the secretion appears to be increased. The aim of this study was to isolate exosomes from healthy subjects, non-atopic, and to evaluate their influence in cytokine profile secreted in vitro by leukocytes of atopic subjects. Exosomes were isolated from peripheral blood mononuclear cells from healthy subjects and characterized by protein electrophoretic profile by staining with specific proteins (transferin receptor 2 - TFR2, CD63 and CD81) and by ultrastructural analysis. These exosomes were then used to stimulate in vitro peripheral blood mononuclear cells of atopic subjects. Quantitative analysis was made of the production of cytokines in culture supernatants. The exosomes were able to modulate negatively the production of proinflammatory cytokines such as IFN- _ and IL-17 by peripheral blood mononuclear cells, but were not able to inhibit Th2 immune responses. The immune response obtained from stimulation with exosomes was shown immunomodulatory effect rather than immunosuppressive effect, as expected.