早期气道接触细菌抗原对Th1/Th2平衡的影响

Effect of early exposure to bacterial antigen in airway on the balance of Th1/Th2

目的了解早期气道接触细菌抗原对辅助性T淋巴细胞1／辅助性T淋巴细胞2（Th1／Th2）平衡的影响，从而更深入地认识哮喘的发病机制。方法将新生SD大鼠随机分为10^7、10^6、10^5细菌抗原接触组（A、B、C组）、哮喘组（D组）及对照组（E组），每组8例。细菌抗原接触组大鼠分别于出生后第1、3、5、7天鼻咽部给予10^7、10^6、10^5灭活肺炎链球菌及流感嗜血杆菌混合液10μl，D组及E组大鼠则给予磷酸盐缓冲液（PBS）10μl。大鼠饲养至成年后造模，观察5组大鼠血清中白介素4（interleukin-4，IL-4）、γ-干扰素（interferon-γ，IFN-γ）的含量。结果A、B组大鼠血清中IFN-γ水平较哮喘组明显下降（P〈0．05）。结论早期气道接触细菌抗原可加重Th1／Th2失衡。

Objective To investigate the effect of early exposure to bacterial antigen in airway on the balance of T-helper-1 cells/T-helper-2 cells （Th1/Th2） in order to understand the pathogenesis of asthma more deeply. Methods The new born rats were randomly divided into 107 , 106, 105 bacterial antigen exposure groups, asthma group and control group,with 8 rats in each group. The rats in bacterial antigen exposure groups were given 10μl bacterial mixtures （ 107 , 106, 105 concentrations respectively） of inactivated streptococcus pneumoniae and hemophilus inftuenzae via nose respectively on day 1 st,3rd,Std,7td after birth, however, the rats in asthma group and control group were given 10μl phosphate buffered saline （PBS） instead. After the rats grew into adults, they were made into asthmatic models, and the serum levels of interleukin-4 （ IL-4 ） and interferon-γ （ IFN-γ ） were detected for all the rats. Results The serum levels of IFN-γ in group A and group B were significantly lower than those in group D （ P 〈 0.05 ）. Conclusion The early exposure to bacterial antigens in airway can aggravate the imbalance of Th1/Th2.