γ-干扰素对免疫低下小鼠结核分支杆菌感染的影响

The effects of interferon-gamma on immunocompromised mice infected with Mycobacterium tuberculosis

目的 观察、评价γ 干扰素 (IFN γ)对免疫功能低下小鼠结核分支杆菌感染的影响和疗效。方法 将DBA/ 2小鼠 90只按免疫功能正常和免疫功能低下 2种状态分别制成小鼠结核分支杆菌感染模型。随机分组给予IFN γ或IFN γ单克隆抗体治疗 ,检测肺组织菌落计数 ,观察治疗后生存率。结果 免疫正常组小鼠无死亡 ,第 2周、第 4周菌落数分别为 (5 1.5± 17.5 )× 10 3cfu/mL、(10 6 .3± 4 1.0 )× 10 3cfu/mL。免疫低下组 8只死亡 ,菌落数分别为 (16 3.7± 6 1.7)× 10 3cfu/mL、(76 8.3± 2 0 6 .5 )× 10 3cfu/mL ,免疫低下 +IFN γ组 3只死亡 ,菌落数分别为 (5 4.2± 2 1.3)× 10 3cfu/mL、(2 12 .7± 80 .7)× 10 3cfu/mL ,免疫低下组与免疫低下 +IFN γ组比较有显著性差异。免疫正常小鼠给予IFN γ抗体后肺组织菌落数增多 ,与对照组比较有显著性差异。结论 IFN γ增强宿主免疫功能 ,对结核分支杆菌感染小鼠产生保护效应 ,适用于免疫功能低下宿主合并结核感染的辅助治疗。

Objective To study the effects of IFN-γ on immunocompromised mice infected with Mycobacterium tuberculosis .Methods 90 DBA/2 mice infected with Mycobacterium tuberculosis were divided randomly into normal control groups and immunocompromised groups, treated with anti-IFN-γ MoAb or IFN-γ respectively. The numbers of viable bacteria in lung were counted. Survival rate after treatment was investigated.Results In control group, none was dead. The numbers of viable bacteria after infection for 14 and 28 days were (51.5±17.5)×10 3 cfu/mL,(106.3±41.0)×10 3 cfu/mL respectively.In immunocompromised groups, 8 mice were dead. The numbers of viable bacteria were (163.7±61.7)×10 3 cfu/mL,(768.3±206.5)×10 3 cfu/mL respectively.In immunocompromised treated with IFN-γ group, 3 mice were dead. The numbers of viable bacteria were(54.2±21.3)×10 3 cfu/mL,(212.7±80.7)×10 3 cfu/mL respectively. There was significant difference between treated and nontreated in immunocompromised. The numbers of viable bacteria in lung were increased in normal mice after treated with anti-IFN-γ MoAb, significant higher than that in the nontreated group.Conclusion IFN-γ improved the host's immunological function,protected the mice against Mycobacterium tuberculosis infection. It can be used as an adjuvant therapy to immunocompromised host with Mycobacterium tuberculosis .