微卡对致敏小鼠气道炎症和Th1/Th2比例变化的影响

目的　观察母牛分支杆菌菌苗 (微卡 )对致敏小鼠抗原攻击后气道炎症、Th1和Th2细胞因子的比例变化 ,评估微卡防治哮喘的药理作用。方法　小鼠分 9组 ,每组 7～ 1 0只。采用皮肤划痕、气管滴入、肌肉注射三种给药途径单次给药 ,观察比较微卡菌苗对致敏小鼠吸入抗原后支气管肺泡灌洗液 (BALF)中炎症细胞 ,γ干扰素 (IFN γ)和白细胞介素 4(IL 4)水平变化的影响和作用强度。结果　经皮肤划痕 (2 .2 5μg)、气管内滴入 (2 .2 5μg)、肌肉注射 (2 2 .5μg)后BALF中炎症细胞总数分别为 (6± 6)× 1 0 8/L、(7± 6)× 1 0 8/L、(8± 5)× 1 0 8/ml,与模型组 (1 5± 8)× 1 0 8/L比较 (P <0 .0 5) ;嗜酸细胞 :皮肤划痕组 (2 2 5μg)为 0 7± 0 5、气管内滴入 (2 2 5μg)为 1 6± 1 9、肌肉注射 (7 5μg)为 2 6±1 3、肌肉注射组 (2 2 .5μg)为 1 .40± 1 .2 0 ,与模型组 (4.90± 4 .60 )比较 (P <0 .0 5或 <0 .0 1 ) ;皮肤划痕组 (2 .2 5μg)BALF中IFN γ水平为 (2 89± 57)pg/ml、气管滴入组 (2 .2 5μg)为 (335± 57)pg/ml、肌肉注射组 (2 2 .5μg)为 (31 3± 49)pg/ml,与模型组 (2 1 6± 42 )pg/ml比较 (P <0 .0 5或 0 .0 1 ) ;皮肤划痕组(2 .2 5μg) BALF中IL 4水平为 (63± 1 9)pg/ml、气管滴入组

Effects of vaccae on airway inflammation and Th1/Th2 cytokines in sensitized mice

OBJECTIVE: To study the inhibitory effect of Mycobacterium vaccae (M. vaccae) on the accumulation of airway inflammatory cells and its regulatory effect on IFN-gamma/IL-4 balance in bronchoalveolar lavage fluids (BALF) from ovalbumin (OVA)-challenged and sensitized mice, therefore to provide experimental evidence for the application of M. vaccae in the treatment of asthma. METHODS: Sensitized mice were given a single dose of M. vaccae 3 days before inhaled OVA-challenge by one of the three routes: intramuscularly (i.m.), by intratracheal (i.t) instillation or by cutaneous scarification (c.s). Accumulation of inflammatory cells, IFN-gamma and IL-4 levels in BALF were determined. RESULTS: The total numbers of the inflammatory cells in BALF from the M. vaccae 2.25 micro g (per mouse) c.s group (6 +/- 6) x 10(8)/L, the 2.25 microgram i.t group (7 +/- 6) x 10(8)/L and the 22.5 micro g i.m group (8 +/- 5) x 10(8)/L, were significantly lower than that of the model control (15 +/- 8) x 10(8)/L (P < 0.05). Eosinophils in the 2.25 microgram c.s group 0.7 +/- 0.5, the 2.25 microgram i.t group 1.6 +/- 1.9, the 7.5 micro g i.m group 2.6 +/- 1.3 and the 22.5 microgram i.m group 1.40 +/- 1.20, were significantly lower than those in the model group 4.90 +/- 4.60 (P < 0.05 and P < 0.01). IFN-gamma levels in the 2.25 microgram c.s group (289 +/- 57) pg/ml, the 2.25 micro g i.t group (335 +/- 57) pg/ml and the 22.5 micro g i.m group (313 +/- 49) pg/ml, were significantly higher than that in the model group (216 +/- 42) pg/ml (P < 0.05 and P < 0.01). IL-4 levels in the 2.25 microgram c.s group (63 +/- 19) pg/ml, the 2.25 microgram i.t group (8 +/- 5) pg/ml and the 22.5 micro g i.m group (13 +/- 6) pg/ml, were significantly lower than that in the model group (93 +/- 25) pg/ml (P < 0.05 and P < 0.01). The inhibitory effect on eosinophil accumulation by i.t or c.s M. vaccae was 10 times stronger than that by i.m M. vaccae. i.t M. vaccae was the most effective in regulating the IFN-gamma/IL-4 ratio. CONCLUSION: M. vaccae inhibited airway inflammation via regulating Th1/Th2 balance, suggesting that it may be beneficial in the treatment of asthma.