Papel da obesidade na imunomodulação da infecção experimental por Mycobacterium bovis BCG

Abstract

Obesity is a huge world health problem and with the habits and lifestyles of these days, it’s important only tend to grown. Today obesity is associated with a bad prognosis of a large number of diseases , like cancer, diabetes and light self-immune diseases, and besides that, its also associated with an uncompleted response to several pathogens, like some virus and bacteria. The tuberculosis is an infect-contagious disease, commonly pulmonary, caused by Mycobacterium tuberculosis (or, Koch bacillus), and other members of the Mycobacterium tuberculosis complex. This illness cause about 1,4 million deaths per year, being registered 8 million new cases per year, being only behind AIDS on the mortality ratio by infectious diseases in the world and ur success can be related to your capacity to live from months to decades on the host , in a asymptomatic state. In this work, we evaluated the relationship between the obesity and the development of tuberculosis, by using the experimental infection model by Mycobacterium bovis BCG. C57/BL6 mice, male, with about 4 to 6 weeks of life, had being fed with standard ration (control group) or hiperglicidic ration (obese group), for 0, 2 or 3 months. The body weight was monitored during this period, and the fat gain and glucose tolerance was measured at the end, so the state of obesity could be characterized. At the end of these periods, this animals received a intraperitoneal inoculation of 100 mL of saline solution (infection control) or 100 mL of BCG solution (infected group) and characteristic processes of this infection were observed, like leukocitary recruitment , lipid bodies formation on these cells, the production of pro and anti-inflammatory cytokines, eicosanoids (PGE2) and adipokines. Was observed then, that the obese animals, presented a lower leukocitary recruitment , among then, less influx of neutrophils and eosinophils, lower formation of lipid bodies and production of PGE2 , higher production of anti-inflammatory mediators (IL-10 and adipokine) and lower production of pro-inflammatory mediators (leptin) . Overall , our data points to a more anti-inflammatory profile on the obese animals , occurring in a minor expression of factors that are important to the pathogen survival , like the formation of lipid bodies and eosinophilia , indicating that, the obesity, on the early stages of the infection, may be representing a disadvantaging factor to the disease.