Brucellosis is a worldwide bacterial zoonosis caused by Brucella spp. No approved vaccine is available for human use against the disease. In this study, outer membrane vesicles (OMVs) from a Brucella melitensis biovar 1 human isolate obtained in Iran were used to immunize BALB/c mice (n = 12) by 2 intramuscular injections with a 2-week interval. Another group of 12 mice was used as non-vaccinated controls. Two weeks after the last vaccination, six mice of each group were sacrificed, and proliferation and interferon gamma (IFNγ) production responses of their splenocytes were evaluated following in vitro stimulation with killed Brucella cells. The other mice were challenged with the virulent B. melitensis isolate. Two weeks later, mice were killed and spleens were cultured to determine the number of the challenge strain. The results showed proliferative response and IFNγ production of splenocytes from vaccinated mice (stimulation index: 2.18 ± 0.57, and 1519.35 ± 10.70 pg/mL, respectively) were significantly higher than those of control mice (stimulation index: 1.02 ± 0.02, and 210.01 ± 17.58 pg/mL, respectively). Numbers of the challenge strain in spleens of vaccinated mice were also significantly less than those in the controls with 1.6 units of protection. Our study revealed vaccination with OMVs of the B. melitensis isolate could induce specific immune responses and protection against infection in the mouse model suggesting their potential application for active immunization against brucellosis.

中文翻译：

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通过接种来自布鲁氏菌人分离株的外膜囊泡进行接种，在BALB / c小鼠中诱导特异性细胞介导的免疫反应并提供保护。

布鲁氏菌病是由布鲁氏菌属引起的一种世界性细菌人畜共患病。没有批准的疫苗可用于人类抵抗这种疾病。在这项研究中，来自伊朗的布鲁氏菌biovar 1人类分离株的外膜囊泡（OMV）用于通过两次肌肉注射两次（间隔2周）来免疫BALB / c小鼠（n = 12）。另一组12只小鼠用作未接种的对照。在最后一次疫苗接种后两周，处死每组六只小鼠，并在体外用杀死的布鲁氏菌细胞刺激后评估其脾细胞的增殖和干扰素γ（IFNγ）产生反应。用有毒的B. melitensis分离株攻击其他小鼠。两周后，处死小鼠并培养脾脏以确定攻击株的数目。结果表明，接种小鼠（刺激指数分别为2.18±0.57和1519.35±10.70 pg / mL）的脾细胞的增殖反应和IFNγ的产生显着高于对照小鼠（刺激指数：1.02±0.02和210.01±分别为17.58 pg / mL）。接种小鼠的脾脏中攻击菌株的数量也显着少于具有1.6个保护单位的对照组的数量。我们的研究表明，接种B. melitensis分离株的OMV可以在小鼠模型中诱导特异性免疫反应并防止感染，这表明它们在主动免疫布鲁氏菌病中具有潜在的用途。分别高于对照组（刺激指数：1.02±0.02和210.01±17.58 pg / mL）。接种小鼠的脾脏中攻击菌株的数量也显着少于具有1.6个保护单位的对照组的数量。我们的研究表明，接种B. melitensis分离株的OMV可以在小鼠模型中诱导特异性免疫反应并防止感染，这表明它们在主动免疫布鲁氏菌病中具有潜在的用途。分别高于对照组（刺激指数：1.02±0.02和210.01±17.58 pg / mL）。接种小鼠的脾脏中攻击菌株的数量也显着少于具有1.6个保护单位的对照组的数量。我们的研究表明，接种B. melitensis分离株的OMV可以在小鼠模型中诱导特异性免疫反应并防止感染，这表明它们在主动免疫布鲁氏菌病中具有潜在的用途。