Mutant Brucella abortus Membrane Fusogenic Protein Induces Protection against Challenge Infection in Mice
Mutant Brucella abortus Membrane Fusogenic Protein Induces Protection against Challenge Infection in Mice
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DOI：
10.1128/iai.02790-14
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发表时间：
2015-04-01
影响因子：
3.1
通讯作者：
Oliveira, Sergio Costa
中科院分区：
文献类型：
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作者：
de Souza Filho, Job Alves;Martins, Vicente de Paulo;Oliveira, Sergio Costa
布鲁氏菌属可引起布鲁氏菌病，这是一种人畜共患疾病，会造成严重的牲畜经济损失，并对公共健康构成威胁。布鲁氏菌属的毒力机制。尚未完全了解。因此，识别作为毒力因子的新分子以更好地了解宿主与病原体的相互作用至关重要。在这里，我们评估了布鲁氏菌膜融合蛋白 (Mfp) 和外膜蛋白 19 (Omp19) 在细菌发病机制中的作用。在这项研究中，我们发现流产布鲁氏菌 Delta mfp::kan 和 Delta omp19::kan 缺失突变株在 C57BL/6 和干扰素调节因子 1 (IRF-1) 敲除 (KO) 小鼠体内的持久性降低。此外，表达绿色荧光蛋白 (GFP) 的 Delta mfp::kan 或 Delta omp19::kan 菌株感染巨噬细胞 24 小时后，约 80% 或 65% 的含布鲁氏菌液泡 (BCV) 分别保留了晚期内体/溶酶体标记物 LAMP-1，而约 60% 的含有野生型 S2308 的 BCV 在 LAMP-1 阴性区室中发现。 B. abortus Delta omp19::kan 在体内减毒，但在 C57BL/6 和 IRF-1 KO 小鼠中具有残留毒力，而 Delta mfp::kan 菌株在这些相同的小鼠模型中具有较低的毒力。此外，Delta mfp::kan 和 Delta omp19::kan 菌株被用作活疫苗。攻击实验表明，在 C57BL/6 和 IRF-1 KO 小鼠中，Delta mfp::kan 菌株比疫苗 RB51 诱导了更强的保护作用，并且与疫苗 S19 的保护作用相似。然而，Delta omp19::kan 菌株诱导的保护与 RB51 类似。因此，这些结果表明布鲁氏菌 Mfp 和 Omp19 对于细菌的完整毒力至关重要，并且 Delta mfp::kan 突变体可以作为未来研究中的潜在候选疫苗。
Brucella species can cause brucellosis, a zoonotic disease that causes serious livestock economic losses and represents a public health threat. The mechanism of virulence of Brucella spp. is not yet fully understood. Therefore, it is crucial to identify new molecules that serve as virulence factors to better understand this host-pathogen interplay. Here, we evaluated the role of the Brucella membrane fusogenic protein (Mfp) and outer membrane protein 19 (Omp19) in bacterial pathogenesis. In this study, we showed that B. abortus Delta mfp::kan and Delta omp19::kan deletion mutant strains have reduced persistence in vivo in C57BL/6 and interferon regulatory factor 1 (IRF-1) knockout (KO) mice. Additionally, 24 h after macrophage infection with a Delta mfp::kan or Delta omp19::kan strain expressing green fluorescent protein (GFP) approximately 80% or 65% of Brucella-containing vacuoles (BCVs) retained the late endosomal/lysosomal marker LAMP-1, respectively, whereas around 60% of BCVs containing wild-type S2308 were found in LAMP-1-negative compartments. B. abortus Delta omp19::kan was attenuated in vivo but had a residual virulence in C57BL/6 and IRF-1 KO mice, whereas the Delta mfp::kan strain had a lower virulence in these same mouse models. Furthermore, Delta mfp::kan and Delta omp19::kan strains were used as live vaccines. Challenge experiments revealed that in C57BL/6 and IRF-1 KO mice, the Delta mfp::kan strain induced greater protection than the vaccine RB51 and protection similar that of vaccine S19. However, a Delta omp19::kan strain induced protection similar to that of RB51. Thus, these results demonstrate that Brucella Mfp and Omp19 are critical for full bacterial virulence and that the Delta mfp::kan mutant may serve as a potential vaccine candidate in future studies.