重组白介素18抗小鼠系统性白念珠菌感染的研究

目的 探讨重组白介素18在抗小鼠系统性白念珠菌感染中的作用。方法 建立环磷酰胺诱导的免疫抑制小鼠系统性白念珠菌感染动物模型，设置对照组（单纯白念珠菌感染组）与处理组（白念珠菌感染前注射重组白介素18）。用平皿稀释法检测肾脏、脾脏组织菌落形成单位（cfu）数目；制作肾、脾脏组织病理学标本，评估其病理学分级；并通过酶联免疫吸附试验（ELISA）检测脾脏干扰素γ分泌水平。结果 感染后2，3，7天，处理组肾脏cfu分别为4.996 ± 0.063，4.765 ± 0.188，3.985 ± 0.133，对照组肾脏cfu分别为5.786 ± 0.110，6.097 ± 0.079，5.996 ± 0.082，处理组显著低于对照组（P < 0.01）；脾脏组织cfu值也低于对照组，但两组差异无统计学意义（P > 0.05）。肾脏组织病理学评分处理组低于对照组，处理组较对照组感染程度减轻，差异有统计学意义（P < 0.05）；脾脏组织病理学评分处理组也低于对照组，但差异无统计学意义（P > 0.05）。同时检测脾脏干扰素γ分泌水平，感染后2，3，7天，处理组分别为73.529 ± 6.070，92.181 ± 7.820，108.564 ± 9.802 pg/mL，对照组分别为40.511 ± 4.456，59.414 ± 5.041，64.455 ± 5.272 pg/mL，处理组明显高于对照组，差异具有统计学意义（P < 0.01）。结论 重组白介素18在小鼠系统性白念珠菌感染中具有保护作用。

Effect of recombinant interleukin-18 on systemic Candida albicans infection in mice

Objective To investigate the effect of recombinant interleukin-18 （rIL-18） on systemic Candida albicans infection in mice. Methods A cyclophosphamide-induced immunosuppressed mouse model of systemic Candida albicans infection was established. The mice were divided into two groups, the treatment group injected with rIL-18 before infection with C. albicans , and the control group infected with C. albicans but not given rIL-18 injection. Both groups included 15 mice, and 5 mice were killed for exami-nation respectively at 2, 3 and 7 days after the infection. Colony forming units （cfu） of C. albicans were counted in the kidney and spleen with plating dilution method.The histopathological changes and degree of infection were graded in the kidney and spleen. The levels of interferon gamma （IFN-γ） was measured in the spleen by enzyme-linked immunosorbent assay （ELISA）. Results The number of cfu in the kidney was significantly lower in the treatment group than in the control group at 2, 3 and 7 days after the infection （4.996 ± 0.063 vs 5.786 ± 0.110, 4.765 ± 0.188 vs 6.097 ± 0.079, 3.984 ± 0.133 vs 5.996 ± 0.082, all P < 0.01）. Compared with the control group, the scores of histopathological changes in the kidney were lower, and the degree of infection was milder in the treatment group （both P < 0.05）. After infection, both the cfu number and score of histopathological changes were lower in the spleen of treatment group than in that of control group, but no statistical difference was observed for the difference （both P > 0.05）. The IFN-γlevels in the spleen were significantly higher in the treatment group than in the control group at the three time points （73.5292 ± 6.0701 pg/mL vs 40.5109 ± 4.4556 pg/mL, 92.1807 ± 7.8196 pg/mL vs 59.4145 ± 5.0410 pg/mL, 108.5638 ± 9.8024 pg/mL vs 108.5638 ± 9.8024 pg/mL, all P < 0.01）. Conclusion It is demonstrated that rIL-18 has a protective effect against systemic Candida albicans infection in mice.