目的观察重组融合蛋白IL-18对金黄色葡萄球菌(SA)感染后小鼠体内免疫相关炎症因子表达的影响,探讨IL-18在体内防御SA感染的可能机制。方法将40只SPF级雌性BLAB/c小鼠随机分为对照组、SA感染组、免疫组和干预组。采用鼻腔接种SA液建立SA感染小鼠模型,免疫组和干预组均在建模前以IL-18滴鼻,但免疫组不予SA接种,对照组以PBS进行替代处理。采用ELISA法测定各组小鼠血液及支气管肺泡灌洗液(BALF)中IL-4、干扰素-γ(IFN-γ)、肿瘤坏死因子(TNF)、粒细胞集落刺激因子(G-CSF)、Ig M的浓度。实时荧光定量PCR技术检测各组小鼠肺组织中巨噬细胞炎性蛋白(MIP)-1α和MIP-2βm RNA表达水平。结果与对照组相比,SA感染组和免疫组小鼠血清及BALF中IL-4、G-CSF、Ig M浓度,以及肺组织中MIP-1α、MIP-2βm RNA含量均升高(P<0.05);SA感染组小鼠血清及BALF中IFN-γ水平降低,TNF水平升高(P<0.05);免疫组小鼠血清及BALF中IFN-γ水平升高(P<0.05)。与SA感染组相比,干预组小鼠血清及BALF中IL-4、IFN-γ、G-CSF、Ig M浓度,以及肺组织中MIP-1αm RNA含量均升高,血清及BALF中TNF水平,以及肺组织中MIP-2βm RNA含量均降低(P<0.05)。除血清IFN-γ水平外,其余上述指标在干预组小鼠中均高于对照组(P<0.05)。结论重组融合蛋白IL-18经黏膜免疫小鼠,可改变SA感染后小鼠血清及BALF中炎症因子,以及肺组织中MIP-1α、MIP-2βm RNA的表达水平,从而促进机体的抗感染免疫反应,增强了机体清除病原体的能力。 Objective To investigate the effect of recombinant fusion protein IL-18 on the expression of immune-related inflammatory cytokines in mice infected with Staphylococcus aureus (SA) and to explore the possible mechanism of IL-18 in preventing SA infection in vivo. Methods Forty SPF female BLAB / c mice were randomly divided into control group, SA-infected group, immunized group and intervention group. The SA-infected mice were established by intranasal inoculation of SA solution. IL-18 was given intranasally before immunization and in the intervention group, but the SA group was not vaccinated in the immunized group. The control group was treated with PBS instead. The levels of IL-4, IFN-γ, TNF, G-CSF in blood and bronchoalveolar lavage fluid (BALF) , Ig M concentration. Real-time fluorescence quantitative PCR was used to detect the expression of MIP-1α and MIP-2βmRNA in the lungs of mice in each group. Results Compared with the control group, the levels of IL-4, G-CSF and IgM in sera and BALF of SA-infected and immunized groups were significantly increased as well as the contents of MIP-1α and MIP-2βmRNA in lung tissues (P < 0.05). The level of IFN-γ in serum and BALF of SA-infected mice decreased and the level of TNF increased (P <0.05). The level of IFN-γ in serum and BALF increased in SA-infected mice (P <0.05). Compared with SA group, the levels of IL-4, IFN-γ, G-CSF and IgM in serum and BALF of mice in the intervention group were increased, and the levels of MIP-1αmRNA in lung tissue were increased. The level of TNF in serum and BALF , And the content of MIP-2βmRNA in lung tissue decreased (P <0.05). Except for serum IFN-γ, the above indexes were higher in the intervention group than in the control group (P <0.05). Conclusions The recombinant fusion protein IL-18 can change the expression of MIP-1α and MIP-2βmRNA in sera and BALF of mice after SA infection, and promote the anti-infective immunity Reaction, enhance the body’s ability to clear pathogens.