Studies on the nitric oxide radical-based system for prevention of malaria infection in gene knockout mice

基于一氧化氮自由基的系统预防基因敲除小鼠疟疾感染的研究

• 批准号: 11670238
• 负责人: SAITO Susumu
• 金额: $ 2.05万
• 依托单位: Yamagata University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11670238/
• 关键词: IFN-γR gene knockout mice; iNOS gene knockout mice; Plasmodium chabaudi chabaudi AS; survival rate; parasitemia; prevention of infection; monoclonal anti-mouse granulocyte antibodies; neutrophil-depleted mice; IFN-γR KO マウス; iNOS KO マウス; 赤血球数

To investigate the role of the nitric oxide radical (NO-) in the prevention of infection by erythrocytic malaria parasite, murine malaria parasite (Plasmodium chabaudi chabaudi AS) was injected into the abdominal cavity of interferon-γ receptor gene knockout mice (IFN-γ R-/-) and inducible Nitric Oxide Synthase gene knockout mice (iNOS-/-) to compare survival rate, peripheral red blood cell (RBC) counts, and parasitemia between the knockout mice and wild type mice (IFN-γ R+/+, iNOS+/+). Such infection experiments were also carried out with neutrophil-depleted mice which had been treated with monoclonal anti-mouse granulocyte antibodies (RB6-8C5) for depletion. Results did not show any significant difference in the changes of RBC counts nor parasitemia between them. On the other hand, as for the survival rate of the infected mice, the Logrank (Mantel-Cox) test of the Kaplan-Meter method of Nonmetric Survival Analysis suggested the following results. 1) Male mice of IFN-γ R+/+ lived loner than IFN-γ R-/- male mice when neutrophils were depleted and self-healing was observed with some of the neutrophil-depleted IFN-γ R-/- mice (P=0.0614). 2) The neutrophil-depleted IFN-γ R+/+ mice lived longer and self-healing was observed more often than in the neutrophil-depleted IFN-γ R-/- mice, namely, P=0.0148 for female and P=0.0236 for male mice. 3) When 2.5×10^5-10^6 of infected RBC were administered to iNOS-/- and iNOS+/+ mice, the iNOS+/+ mice lived longer and self-healing was observed more often than in the iNOS-/- mice. 4) The results of the neutrophil-depletion experiment did not differ between the iNOS-/- mice and the iNOS+/+ mice. The results suggested that the NO- did not directly nor significantly prevent infection of the erythrocytic malaria parasite, while the survival rate of the infected mice appeared to be somehow influenced by IFN-γ, neutrophil related various cytokines, the NO-, active oxygen, etc.

为了研究一氧化氮自由基（NO-）在预防红细胞疟原虫感染中的作用，将小鼠疟原虫（chabaudi chabaudi AS）注射到干扰素-γ受体基因敲除小鼠（IFN-γ R-/-）和诱导型一氧化氮合酶基因敲除小鼠（iNOS-/-）腹腔，比较敲除小鼠和野生型小鼠（IFN-γ R+/+、iNOS+/+）的存活率、外周血红细胞（RBC）计数和寄生虫血症。这种感染实验也用中性粒细胞耗尽的小鼠进行，这些小鼠用单克隆抗小鼠粒细胞抗体（RB6-8C5）处理以消耗。结果显示，红细胞计数和寄生虫率的变化在两组间无显著差异。另一方面，对于感染小鼠的存活率，非计量生存分析的Kaplan-Meter法的Logrank （Mantel-Cox）试验显示如下结果。1)中性粒细胞缺失时，IFN-γ R+/+雄性小鼠比IFN-γ R-/-雄性小鼠寿命更长，部分中性粒细胞缺失的IFN-γ R-/-小鼠出现自愈现象（P=0.0614）。2)中性粒细胞缺失的IFN-γ R+/+小鼠比中性粒细胞缺失的IFN-γ R-/-小鼠寿命更长，自愈率更高，雌性P=0.0148，雄性P=0.0236。3) iNOS-/-和iNOS+/+小鼠注射2.5×10^5-10^6感染红细胞，iNOS+/+小鼠比iNOS-/-小鼠寿命更长，自愈率更高。4) iNOS-/-小鼠和iNOS+/+小鼠的中性粒细胞耗竭实验结果无差异。结果表明，NO-对红细胞疟原虫的感染没有直接或显著的预防作用，而感染小鼠的存活率可能受到IFN-γ、中性粒细胞相关的各种细胞因子、NO-、活性氧等的影响。