RESUMEN
Studies suggested that some aspects of asthma exacerbation by Spn infection remain unclear. Objective: to evaluate possible mechanism that worsen inflammation caused by Spn in an experimental model of chronic allergic inflammation. Methods: 30 BALB/c mice were divided in 4 groups: SAL (non-sensitized group), STREP (animals challenged with Spn), OVA (ovalbumin sensitized group), OVAST (OVA sensitized and challenged with Spn). OVA and OVAST groups received intraperitoneal injections of ovalbumin (OVA) solution (days 1 and 14). OVA challenges were performed on days 22, 24, 26, and 28. Afterwards, animals were challenged with pneumococcal strains M10 (11A)(50ul/bacteria in saline). After 12h, lung mechanics and bronchoalveolar lavage (BAL) were performed. Animals were euthanized, lungs removed for immunohistochemistry and morphometric analysis. Results: Challenge with Spn in OVA sensitized group induces an increase in of total cells (46.33±13.22x104cells/mL), neutrophils (23.70±14.39x104cells/mL), macrophages (7.70±2.03x104cells/mL) and eosinophils (14.52±13.88x104cells/mL) in BALF as well as increasing in polymorphonuclear cells (0.152±0.06mm2) and expression of IL-17 (12.12±2.67mm2) in peribronchovascular area in lung compared to OVA group (p<0.05). There were an increase in tissue damping (27.01±7.25cmH2O/mL/s(1-a)); expression of IL-5 (10.15±3.39mm2) and IL-13 (8.85±3.56mm2) in peribronchovascular area were observed in OVA groups compared to other groups (p<0.05). Conclusion: Challenge with Spn, in this model induces an increasing in lung inflammation by increasing IL-17 without changes in Th2 profile.
RESUMEN
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.
RESUMEN
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.