Abstract: 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.

Key words: Mycobacterium tuberculosis, interferon-gamma, immunocompromised