Inflammatory response to Streptococcus pneumoniae was attenuated by moderate aerobic exercise training

Moderate aerobic exercise training may alter immune system. Studies suggested that S. pneumoniae remained an important cause of mortality. Objective: To study mechanisms for attenuating inflammatory process involving pneumococcal infection by moderate aerobic exercise. Methods: 38Balb/C mice were divided into 4 groups: Control (C), Moderate Aerobic Exercise Training (MAT), S. pneumonia infection (IF), MAT+IF groups. Moderate intensity treadmill training was performed over 4weeks, 5x/week, 60min/session in MAT groups. After 72h of last exercise training, IF groups were challenged with pneumococcal strains M10 (11A; 50ul/bacteria in saline) and 12h after, lung function and bronchoalveolar lavage (BAL) were performed. Afterwards, animals were euthanized, lungs removed to proceed immunohistochemistry and morphometric analysis in lung parenchyma. Results: Bacterial inoculation resulted in increase in: total cells (77.66±54.02x104cells/mL), neutrophils (73.78±50.88x104cells/mL), resistance (0.77±0.08cmH2O.mL-1.s;) and elastance (31.86±8.16cmH2O.mL-1.s) of respiratory system and expression of IL-17 (817.88±217.59mm2)(p<0.05). MAT in animals submitted to bacterial challenge presented a decrease of these parameters (p<0.05). MAT+IF group showed an increase in expression of IL-1ra (886.04±274.07mm2), TLR2 (708.28±161.48mm2) and TLR4 (1444.11±723.92mm2) compared to IF group (p<0.05). Conclusion: These results suggest that MAT attenuated inflammatory process in an animal model of bacterial infection by increasing anti-inflammatory mediators, increasing Toll-like receptors that anticipated host defense, helping in resolution of inflammation.

High intensity interval training control inflammation in mice exposed to Streptococus pneumoniae

S.pneumoniae is an important cause of pneumonia. Exercise training is a stimulator of immune system. High Intensity Interval Training (HIIT) have been gain adepts, although their benefits remain unclear. Objective: Evaluate if HIIT prior to S.pneumoniae infection in mice alters lung inflammation. Methods: 38Balb/C mice were divided into 4 groups: Sedentary (SED),HIIT (HIIT), Infection (IF),HIIT+infection (HIIT/IF). HIIT was performed in a treadmill altering 26 session: 1min of 75%¨maximum capacity training and 30s of 50% maximum capacity training, over 4w, 5x/w. 72h after last training, IF groups were challenged with pneumococcal strains M10 (11A)(50 ul/bacteria in saline).Lung function and bronchoalveolar lavage (BAL) were performed 12h after challenge. Afterwards, animals were euthanized, lungs removed to immunohistochemistry and morphometric analysis in lung parenchyma. Results: Pneumococcal inoculation induces an increase in lung resistance (0.74±0.07cmH2O.mL-1.s) and elastance (31.86±8.16 cmH2O.mL-1.s) of respiratory system, in total cells (77.66±54.02x104cells/mL) and neutrophils (73.47±50.88x104cells/mL) in BALF, expression of IL-17 (817.88±217.59mm2) and collagen fibers content in lung parenchyma (17.24±4.54%) (p<0.05). HIIT in inoculated animals resulted in a reduction of all parameters (p<0.05), except for lung resistance. HIIT groups presented increasing expression of IL-1ra (698.64±432.42mm2), CuZnSOD (576.42±138.18mm2), IL-33 (990.07±212.47mm2)(p<0.001). Conclusion: HIIT attenuated inflammatory process induced by S.pneumoniae, increasing antiinflammatory mediators and antioxidant enzymes, reducing proinflammatory mediators.