Efeito imunomodulador do Ácido Palmitoleico 16:1 n-9 na infecção experimental por Klebsiella pneumoniae

Abstract

Klebsiella pneumonia is a pathogenic and opportunistic Gram-negative bacterium, which can cause pneumonia, consequently lung injury and mortality according to the exacerbation of inflammatory response. Therefore, many efforts have been made to discovery alternative therapies to control the events involved in inflammation, increasing resolution and reducing the risk of tissue injury. Recently studies described such as potential anti-inflammatory the isomer of palmitoleic acid 16:1 n-9 in humans circulating monocytes and in macrophages derived from monocytes in humans. Thus, we investigated the immunomodulatory effect of 16:1 n-9 on experimental infection with K. pneumoniae. In this study, we performed in vitro LPS stimulation and 16:1 n-9 treatment using AMJ2-C11 lineage macrophages and bone marrow derived macrophages (BMDM). Although both macrophages presented different biology, we observed for BMDM the decrease production of inflammatory mediators such as NO, IL-6, KC, MCP-1 after the treatment with 16:1 n-9. In efferocytosis process of neutrophils infected with K. pneumoniae, the treatment with 16:1 n-9 increased phagocytosis by MDMO and IL-1β production, and decreased IL-10. In vivo experiments, mice infected with lethal dose of K. pneumoniae and treated with 16: 1 n-9 (100 μg/mL) had increased survival. The immunomodulatory effects of 16:1 n-9 during the experimental infection by K. pneumoniae were characterized for decrease in neutrophil recruitment in the acute phase of infection, and increased mononuclear cells in the chronic phase, indicating action on resolution of inflammation. The effect on the production of inflammatory, proteic and lipid mediators has also been described, and the data contribute to the resolution effect, however it is not efficient in eliminating the infectious agent. In addition, treatment with 16:1 n-9 had a great influence on the metabolism of eicosanoids. Thereby, we suggest that 16:1 n-9 treatment in pneumonia is potential in resolving an inflammatory process, without immunosuppressive effects, and can be used only as an adjuvant of other pharmacological therapies.