Analysis of exosome profile in patients with brucellosis

Brucellosis is a worldwide zoonotic infection caused by a type of bacteria from the genus Brucella. Exosomes are small lipid vesicles derived from multi-vesicular bodies released by many cell types. The exosomal cell cargo reflects the type of cell from which it originated. In this study, we aimed to perform immunophenotyping of exosomes isolated from serum samples from acute, chronic brucellosis and healthy controls using Flow Cytometry, determine from which cell groups exosomes originate in different groups, reveal the effect of exosomes in the chronicity of brucellosis, and contribute to the literature on the potential roles of exosomes in the immunopathogenesis of brucellosis. Our study included 10 acute and 10 chronic patients diagnosed with brucellosis and 10 healthy controls. Exosomes from serum samples were extracted using a commercial isolation kit. In the pre-designated panel, after staining with monoclonal antibodies (mAbs), the exosomes were immunophenotyped using Flow Cytometry. Confirmation of the presence of exosome was performed by staining of exosome-specific mAbs CD9, CD63 and CD81 and electron microscopy (SEM) evaluations. According to the results of the evaluation, granulocyte and G-MDSC (granulocyte-like myeloid derived suppressor cells) derived exosomes (%) were significantly higher in the acute group compared to the chronic and healthy groups. On the other hand, a significant difference was observed between the chronic group and the healthy control in exosome values (%) originating from G-MDSC. In this study, we found that granulocyte and G-MDSC-derived exosomes may play a role in the acute phase responses of brucellosis. The significant differences between granulocyte and G-MDSC-derived exosomes at different phases of brucellosis may contribute to the immunopathology of the disease with new studies.