灭活卡介苗对哮喘小鼠治疗作用及机制探讨

Efficacy and mechanism of the killed BCG on asthmatic attack mice

目的：探讨灭活卡介苗治疗哮喘小鼠的作用机制。方法：40只Balb／c小鼠随机分4组，模型组：皮下注射卵蛋白（OVA）加氢氧化铝凝胶首次致敏，第7、14天用等量致敏液腹腔注射，第21天后用OVA超声雾化，连续激发7d。对照组：用生理盐水代替OVA氢氧化铝混合液注射，雾化用生理盐水代替OVA，处理同模型组。治疗组：致敏激发同模型组，连续激发7d之后，以灭活卡介苗皮内注射，1次／周，共13周，每隔1月用OVA超声雾化激发3d。治疗对照组处理：激发同治疗组，用生理盐水代替灭活卡介苗皮内注射，时间同治疗组。所有动物均在末次激发后处死，分别行肺组织切片及支气管肺泡灌洗，取灌洗液行细胞分离与计数、细胞因子IL-4、IL-13、IFN-γ测定。结果：模型组较对照组：IFN-γ值减低[（54．44±14．60）pg／ml vs（85．14±18．17）pg／ml]（P〈0．01）；IL-4值增高[（26．96±8．95）pg／ml vs（14．37±4．62）pg／m1]（P〈0．01）；IL-13值增高[（120．52±34．09）pg／ml vs（70．99±22．14）pg／m1]（P〈0．01）。治疗组较治疗对照组IFN-γ值增高[（95．96±26．86）pg／ml vs（48．53±13．89）pg／m1]，（P〈0．01）；IL-4值减低[（16．79±7．58）pg／ml vs（30．53±13．34）pg／m1]（P〈0．05）；IL-13值减低[（95、42±15．17）pg／ml vs（139．25±21．58）pg／m1]（P〈0．05）。结论：灭活卡介苗治疗对哮喘小鼠有治疗作用，其机制可能与调节Th1／Th2型细胞因子平衡、重建Th1免疫反应及抑制Th2免疫反应有关。

Objective To investigate the mechanism and efficacy of the killed BCG on asthmatic attack of mice, Methods Forty Balb/c mice were randomly divided into 4 groups. The model group received hypodermic injection of ovalbumin （OVA） and aluminum hydroxide gel for sensitization, intraperitoneal re-injection with the same drugs on the 7th and the 14th day, After 21 days, OVA were given continually for 7 days by ultrasonic nebulization, The control group was injected and nebulizated with normal saline instead of OVA and aluminum hydroxide. The treating group was processed as model group, but after ultrasonic nebulization the killed BCG was injected intracutaneously for 13 weeks, once per week. During the injections, ultrasonic nebulization of OVA was utilized to continue the stimulation for 3 days per month. The treating control group was processed with normal saline instead of BCG. All mice were sacrificed, lung histological sections, bronchoalveolar lavage （BAL） and bronchoalveolar lavage fluid （BALF） cells were detached and counted, IL-4, IL-13, IFN-γ/were detected. Results The concentrations of Thl type cytokines in model group were lower than that in the control group [ IFN-γ： （54. 44 ±14. 60） pg/ml vs （85. 14 _＋ 18.17）pg/ml, P 〈0. 01] , while the concentrations of Th2 type cytokines in model group were higher than that in the control group [ IL-4 ： （26. 96± 8.95 ） pg/ml vs （ 14.37± 4. 62 ） pg/ml, P 〈 0. 01, IL-13 ： （ 120. 52 ± 34. 09） pg/ml vs （70. 99 ± 22. 14） pg/ ml, P 〈0. 01]. The Th1-type cytokines concentrations in the treating group were higher than that in the treating control group [ IFN-γ in BALF： （95.96 ±26. 86）pg/ml vs （48.53 ± 13. 89）pg/ml, P 〈 0. 01] , while the Th2 type cytokines concentrations in the treating group were lower than that in the treating control group [ IL-4 in BALF ： （ 16. 79 ± 7.58 ） pg/ml vs （30. 53 ± 13.34 ） pg/ml, P 〈 0. 05, IL-13 in BALF ： （95.42 ± 15. 17 ） pg/ml vs （ 139. 25 ± 21.58 ） pg/ml, P 〈 0. 05]. Conclusions The killed BCG actually has therapeutical effect on asthmatic mice. The mechanism may be related to adjust the balance of Th1/Th2 cytokine, rebuild the immune response ability of Th1, and suppress the immune response ability of Th2.