1. 枯草芽孢杆菌表面幽门螺杆菌尿素酶B的表达研究
J Med Microbiol. 2014 Oct 29. pii: jmm.0.076430-0. doi: 10.1099/jmm.0.076430-0.
Expression of Helicobacter pylori urease B on the surface of Bacillus subtilis spores.
Zhou Z1, Gong S2, Li X3, Yang Y2, Guan R2, Zhou S2, Yao S2, Xie Y2, Ou Z2, Zhao J2, Liu Z4.
幽门螺杆菌是慢性胃炎，消化道溃疡，胃腺癌及淋巴瘤的主要危险因素。由于临床工作中根除幽门螺杆菌药物疗效下降，幽门螺杆菌的疫苗研发重新获得人们的重视。枯草芽孢杆菌具有非致病性及产生芽孢的特点，孢子在极端条件下可存活，从而是将异源抗体抗原传送到诸如消化道这样的极端环境的理想载体。 本研究中，我们采用孢子外壳蛋白CotC作为融合伴侣在枯草芽孢杆菌孢子外壳表达幽门螺杆菌尿素酶B。Western印迹分析验证孢子的尿素酶B表达情况。表达尿素酶B抗原的重组孢子用于口服免疫，在小鼠体内产生了体液免疫反应。口服给药2周后，其粪便尿素酶B特异性分泌型IgA和血清IgG抗体水平显著增高。此外，重组尿素酶B孢子的口服免疫（0.25±0.13×106CFU）与非重组孢子治疗组（0.3×1.56±106CFU，P＜0.01）相比可显著减少胃内细菌负荷（84%）。这份报告显示，枯草芽孢杆菌表达的尿素酶B具有免疫原性且口服尿素酶B孢子可预防幽门螺杆菌感染。
译者点评：通过使枯草芽孢杆菌表达尿素酶获得幽门螺杆菌疫苗的方法具有一定的研究前景。
Abstract
Helicobacter pylori infection is a major risk factor for chronic gastritis, digestive ulcers, gastric adenocarcinoma and lymphoma. Due to the decreasing efficacy of anti-Helicobacter pylori antibiotic therapy in clinical practice, there is renewed interest in the development of anti-Helicobacter pylori vaccines. Bacillus subtilis is nonpathogenic and can produce endospores, which can survive under extreme conditions. These features make the Bacillus subtilis spore an ideal vehicle for delivery of heterologous antigens to extreme environments such as the gastrointestinal tract. In this study, we displayed Helicobacter pylori urease B protein on the Bacillus subtilis spore coat using spore coat protein CotC as a fusion partner. Western blotting analyses were used to verify urease B surface expression on spores. Recombinant spores displaying the urease B antigen were used for oral immunization and were shown to generate humoral response in mice. Urease B-specific secretory IgA in feces and IgG in serum reached significant levels 2 weeks after oral dosing. In addition, oral immunization of recombinant urease B spores induced a significant reduction (84%) in the stomach bacterial load (0.25±0.13 x 106CFU) compared to that in non-recombinant spores treated group (1.56±0.3 x 106CFU, P < 0.01). This report shows that urease B expressed on Bacillus subtilis spores was immunogenic and oral administration of urease B spores can provide protection against Helicobacter pylori infection.