Seong S Y, Huh M S, Jang W J, Park S G, Kim J G, Woo S G, Choi M S, Kim I S, Chang W H
Department of Microbiology, Seoul National University College of Medicine, Republic of Korea.
Infect Immun. 1997 Apr;65(4):1541-5. doi: 10.1128/iai.65.4.1541-1545.1997.
Although the 56-kDa protein of Rickettsia tsutsugamushi has been presumed to play important roles in generating protective immunity against scrub typhus, studies of this protein have been impeded. We used the recombinant 56-kDa protein of R. tsutsugamushi Boryong fused with the maltose-binding protein of Escherichia coli (MBP-Bor56) to analyze its ability to induce protective immunity in a C3H/HeDub murine model. Intraperitoneal immunization of mice with MBP-Bor56 resulted in an increase in the 50% minimal lethal dose of more than 160 times compared with that for the control mice. Splenic mononuclear cells from the mice immunized with MBP-Bor56 showed a dose-dependent pattern of lymphocyte proliferation response and secreted gamma interferon and interleukin-2 when stimulated with irradiated R. tsutsugamushi Boryong, which is a cytokine profile of Th1 cells. High titers of antibody to R. tsutsugamushi were also demonstrated by indirect immunofluorescent-antibody testing. These findings suggest that the 56-kDa protein of R. tsutsugamushi is one of the candidates for a vaccine against scrub typhus.
尽管普遍认为恙虫病东方体的56-kDa蛋白在产生针对恙虫病的保护性免疫中发挥重要作用，但对该蛋白的研究一直受到阻碍。我们使用与大肠杆菌麦芽糖结合蛋白（MBP-Bor56）融合的恙虫病东方体保荣株重组56-kDa蛋白，在C3H/HeDub小鼠模型中分析其诱导保护性免疫的能力。与对照小鼠相比，用MBP-Bor56对小鼠进行腹腔免疫导致50%最小致死剂量增加了160倍以上。用MBP-Bor56免疫的小鼠的脾单核细胞表现出淋巴细胞增殖反应的剂量依赖性模式，并且在用经辐照的恙虫病东方体保荣株刺激时分泌γ干扰素和白细胞介素-2，这是Th1细胞的细胞因子谱。间接免疫荧光抗体检测也显示出针对恙虫病东方体的高滴度抗体。这些发现表明，恙虫病东方体的56-kDa蛋白是恙虫病疫苗的候选之一。
