Avaliação funcional de vesículas extracelulares de acanthamoebade diferentes genótipos.

• Ano de defesa: 2021
• Autor(a) principal: Isabela Aurora Rodrigues
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; Brasil; FARMACIA - FACULDADE DE FARMACIA; Programa de Pós-Graduação em Análises Clínicas e Toxicológicas; UFMG
• Palavras-chave em Português: Genótipos; Imunidade inata; Proteases; Interação parasita-hospedeiro
• Link de acesso: http://hdl.handle.net/1843/69566

Amoebas of the genus Acanthamoeba are free-living protozoa widely dispersed in the environment. In some situations, they can adopt a parasitic lifestyle and acts as pathogens that cause serious infections in humans. The ability of Acanthamoeba to cause infectionsinvolves factors as the production of proteases, which can be released freely in the environment or, as shown in recent studies, compartmentalized in extracellular vesicles(EVs). However, the comparative characterization of EVs of different strains has not yet been described.This study aimed to compare EVs produced by Acanthamoeba from different genotypes, evaluating physical features, profile of proteases and of nitric oxide and cytokines production after stimulation of murine macrophages. Four strains with different pathogenic characteristics were used: three from an environmental origin (samples of genotypes T1, T2, T11) and one obtained from a keratitis case (sample of genotype T4). Despite their genotype, all strains released EVs with no differences in size or concentration. EVs exhibited a predominant activity of serine proteases (pH 7.4 and 3.5), with more intense activity in those from T4 and T1 strains. Despite their genotype, all strains released EVs with no differences in size or concentration. EVs exhibited a predominant activity of serine proteases (pH 7.4 and 3.5), with more intense activity in those from T4 and T1 strains. Compared with pathogenic (T4 and T1) and moderately pathogenic (T2) strains, EVs from the environmental, nonpathogenic T11 strain exhibited a more proinflammatory profile, inducing higher levels of NO, tumor necrosis, and interleukin-6 via TLR4/TLR2. Preincubation with EVs treated with protease inhibitors or heating drastically decreased nitrite concentration production in macrophages. Altogether, these data indicated that EVs from Acanthamoeba exhibit immunomodulatory effects related to their pathogenic potential and dependent on the integrity of the proteases.