γ-干扰素对免疫低下小鼠结核分支杆菌感染的影响

目的　观察、评价γ干扰素(IFNγ)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IFNγ或IFNγ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(51.5±17.5)×10³cfu/mL、(106.3±41.0)×10³cfu/mL。免疫低下组8只死亡,菌落数分别为(163.7±61.7)×10³cfu/mL、(768.3±206.5)×10³cfu/mL,免疫低下+IFNγ组3只死亡,菌落数分别为(54.2±21.3)×10³cfu/mL、(212.7±80.7)×10³cfu/mL,免疫低下组与免疫低下+IFNγ组比较有显著性差异。免疫正常小鼠给予IFNγ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 IFNγ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。

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

Objective To study the effects of IFN-γ on immunocompromised mice infected withMycobacterium tuberculosis.Methods 90 DBA/2 mice infected withMycobacterium 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)×10³ cfu/mL,(106.3±41.0)×10³ cfu/mL respectively.In immunocompromised groups, 8 mice were dead. The numbers of viable bacteria were (163.7±61.7)×10³ cfu/mL,(768.3±206.5)×10³ cfu/mL respectively.In immunocompromised treated with IFN-γ group, 3 mice were dead. The numbers of viable bacteria were(54.2±21.3)×10³ cfu/mL,(212.7±80.7)×10³ 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.