Association and Virulence Gene Expression Vary among Serotype III Group B Streptococcus Isolates following Exposure to Decidual and Lung Epithelial Cells
Association and Virulence Gene Expression Vary among Serotype III Group B Streptococcus Isolates following Exposure to Decidual and Lung Epithelial Cells
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DOI：
10.1128/iai.02181-14
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发表时间：
2014-11-01
影响因子：
3.1
通讯作者：
Manning, Shannon D.
中科院分区：
文献类型：
--
作者：
Korir, Michelle L.;Knupp, David;Manning, Shannon D.
B群链球菌（GBS）在新生儿、老年人和免疫功能低下的个体中引起严重疾病。GBS种类多样，可根据血清型和多位点序列分型进行分类。序列17型（ST-17）菌株比其他STs菌株更容易引起侵袭性新生儿疾病。宿主细胞的附着和侵袭是GBS发病的关键步骤。我们研究了代表ST-17（2株）、ST-19和ST-23的4种血清III型菌株在附着和侵袭蜕细胞和肺上皮细胞的能力上是否存在差异。宿主细胞关联和暴露于羊膜细胞后的毒力基因表达也进行了测试。ST-17菌株在附着和侵袭蜕细胞的能力上存在差异，而在肺上皮细胞上没有差异。而ST-19和ST-23菌株对蜕膜细胞的附着和侵袭程度低于ST-17菌株。虽然ST-23菌株对肺上皮细胞的附着性优于ST-17和st -19菌株，但没有菌株能有效侵袭肺上皮细胞。值得注意的是，与宿主细胞的关联导致了几种毒力基因相对于基础表达水平的差异表达。无论使用何种细胞类型，都观察到一些基因的相似表达模式。总的来说，这些结果表明GBS菌株在附着不同宿主细胞类型和表达与疾病过程相关的关键毒力基因的能力方面存在差异。加强我们对致病机制的理解有助于确定新的治疗靶点或候选疫苗，从而有可能降低与新生儿感染相关的发病率和死亡率。
Group B Streptococcus (GBS) causes severe disease in neonates, the elderly, and immunocompromised individuals. GBS species are highly diverse and can be classified by serotype and multilocus sequence typing. Sequence type 17 (ST-17) strains cause invasive neonatal disease more frequently than strains of other STs. Attachment and invasion of host cells are key steps in GBS pathogenesis. We investigated whether four serotype III strains representing ST-17 (two strains), ST-19, and ST-23 differ in their abilities to attach to and invade both decidual cells and lung epithelial cells. Virulence gene expression following host cell association and exposure to amnion cells was also tested. The ST-17 strains differed in their abilities to attach to and invade decidual cells, whereas there were no differences with lung epithelial cells. The ST-19 and ST-23 strains, however, attached to and invaded decidual cells less than both ST-17 strains. Although the ST-23 strain attached to lung epithelial cells better than ST-17 and -19 strains, none of the strains effectively invaded the lung epithelial cells. Notably, the association with host cells resulted in the differential expression of several virulence genes relative to basal expression levels. Similar expression patterns of some genes were observed regardless of cell type used. Collectively, these results show that GBS strains differ in their abilities to attach to distinct host cell types and express key virulence genes that are relevant to the disease process. Enhancing our understanding of pathogenic mechanisms could aid in the identification of novel therapeutic targets or vaccine candidates that could potentially decrease morbidity and mortality associated with neonatal infections.