Avaliação dos mecanismos de proteção do probiótico Lactobacillus delbrueckii UFV-H2b20 durante a inflamação alérgica pulmonar

Abstract

Lung inflammation is the most common hallmark of allergic asthma. Asthma is a heterogeneous disorder characterized by variable degree of airflow obstruction, inflammation and declining airway function, bronchial hyperresponsiveness and tissue remodeling. CD39 and CD73 are membrane proteins with enzymatic activities, which play a role in calibrating the purinergic signals delivered to immune cells through the conversion of ADP and ATP to AMP and AMP to adenosine, respectively. This drives a shift from an ATP-driven pro-inflammatory environment to an anti-inflammatory milieu induced by adenosine. The growing awareness about the involvement of purinergic signaling in shaping immune and inflammatory responses during allergic reactions has fostered scientific interest in the roles of CD39 and CD73 in this context. The term probiotic is defined as “live microorganisms which, when administered in adequate amounts, confer a health benefit on the host”. The use of probiotics is becoming increasingly studied and recent evidence has suggested that probiotics may provide therapeutic benefits not only in asthma but also in other atopic diseases. The microorganism L. delbrueckii UFV-H2b20 can be considered a probiotic because it fulfills the basic requirements that a microbial strain needs to be classified as such. Some studies have already shown the ability of L. delbrueckii UFV-H2b20 to stimulate the host's immune system, but its mechanisms of action remain unknown. Therefore, the objective of this study was to evaluate the mechanisms of action by which L. delbrueckii UFV-H2b20 exerts its protective effect during experimental lung inflammation induced by OVA in mice, analyzing the possible participation of CD39 and CD73 molecules in the production of this effect. Our results show that oral treatment with L. delbrueckii UFV-H2b20 inhibits the inflammatory response in the lungs of treated mice, decreasing number of inflammatory monocytes, eosinophils and alveolar macrophages. Our results also suggest that its mechanism of action is related to T CD4 + , T regulatory and T CD8 + lymphocytes stimuli and increased expression of CD39 and CD73 in these cells. Finally, we observed that the metabolites produced by L. delbrueckii UFV-H2b20 might be responsible for generating the anti-inflammatory response in treated animals.