Department of Microbiology and Applied Microbiology Research Center, Systems Biology and Poisonings Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran.
Department of Immunology, Pasteur Institute of Iran, Tehran, Iran.
Microb Pathog. 2018 Aug;121:100-105. doi: 10.1016/j.micpath.2018.04.050. Epub 2018 Apr 27.
Brucella is a Gram-negative and facultative intracellular organism that causes brucellosis, a common zoonotic disease. Over 500,000 people are annually affected by brucellosis. Brucella is highly infectious through inhalation route; for this reason it is used for biological warfare aims. This study aimed to study the serum bactericidal and splenic activity of Total-OMP-r CagA immunogens from Brucella abortus and Helicobacter pylori in a BALB/c mouse model.
Immunization of BALB/c mice was performed with immunogenic proteins three times subcutaneously (S.C.) at 14-day intervals. The protective effects of two component vaccines with CpG adjuvant were evaluated after mice were challenged with H. pylori ss1 and Brucella abortus strain 544. The specific IgG1 and IgG2a antibodies in sera were assessed using ELISA test. For measuring the antigen-specific IL-4, IL-12 and IFN-γ responses in sera of immunized mice after challenge, RT-PCR technique was applied. Twenty days after the challenge, mice were killed then gastric, splenic and serum samples were assessed and bacterial colony count was measured based on the pour plate count agar.
The results indicated that rCagA + OMP decreased bacterial colonization in these tissues, and significant difference was observed between test and control groups (p value˂0.001).
Our results showed that the combination vaccine was effective against an oral exposure and the bacterial burden in the spleen, serum and gastric tissues were reduced in mice immunized with the Total- OMP-CagA.
布鲁氏菌是一种革兰氏阴性兼性细胞内病原体，可引起布鲁氏菌病，这是一种常见的人畜共患病。每年有超过 50 万人受到布鲁氏菌病的影响。布鲁氏菌通过吸入途径具有高度传染性；因此，它被用于生物战目的。本研究旨在研究布鲁氏菌流产株和幽门螺杆菌的总 OMP-r CagA 免疫原在 BALB/c 小鼠模型中的血清杀菌和脾脏活性。
通过皮下（S.C.）三次免疫 BALB/c 小鼠，每隔 14 天一次。用 CpG 佐剂评估两种成分疫苗的保护作用，然后用 H. pylori ss1 和 Brucella abortus 544 菌株对小鼠进行攻毒。使用 ELISA 试验评估血清中特异性 IgG1 和 IgG2a 抗体。为了测量免疫后攻毒后免疫小鼠血清中抗原特异性 IL-4、IL-12 和 IFN-γ 反应，应用 RT-PCR 技术。攻毒后 20 天，处死小鼠，然后评估胃、脾和血清样本，并根据倾注平板计数琼脂测量细菌菌落计数。
结果表明，rCagA+OMP 降低了这些组织中的细菌定植，实验组和对照组之间存在显著差异（p 值˂0.001）。
我们的结果表明，该联合疫苗对口服暴露有效，用总-OMP-CagA 免疫的小鼠脾脏、血清和胃组织中的细菌负荷减少。
