Pneumococcal LytR Protein Is Required for the Surface Attachment of Both Capsular Polysaccharide and Teichoic Acids: Essential for Pneumococcal Virulence.
Pneumococcal LytR Protein Is Required for the Surface Attachment of Both Capsular Polysaccharide and Teichoic Acids: Essential for Pneumococcal Virulence.
复制标题
肺炎球菌 LytR 蛋白是荚膜多糖和磷壁酸表面附着所必需的：对于肺炎球菌毒力至关重要
DOI：
10.3389/fmicb.2018.01199
复制
发表时间：
2018
影响因子：
5.2
通讯作者：
Wu K
中科院分区：
文献类型：
--
作者：
Ye W;Zhang J;Shu Z;Yin Y;Zhang X;Wu K
LytR-Cps-Psr家族蛋白通常存在于革兰氏阳性细菌中，其已被证明与将细胞壁相关的糖共聚物锚定至肽聚糖有关。在这里，我们报告SPD_1741（LytR）在肺炎链球菌中的细胞功能及其在肺炎球菌毒力中的作用。通过将肺炎球菌ΔlytR基因替换为p53表达盒，已成功构建了肺炎球菌ΔlytR突变体。通过生长实验确定LytR在肺炎球菌生长中的作用，并使用流式细胞术分析LytR蛋白的表面可及性。透射电子显微镜（TEM）和免疫印迹法显示荚膜多糖（CPS）的变化。采用斑点杂交和ELISA法测定磷壁酸（TA）的含量。使用体外吞噬测定和感染实验评估LytR对细菌毒力的贡献。与野生型菌株相比，ΔlytR突变体显示出生长缺陷，其在液体培养基中仅生长至最大OD 620为0.2。在培养基中添加重组ΔTM-LytR蛋白可以以剂量依赖的方式恢复ΔlytR突变体的生长。透射电镜结果表明，D39ΔlytR突变体在CPS表面的附着能力受到了破坏。lytR基因的缺失也损害了TA在肺炎球菌表面的保留。使用斑点印迹和ELISA测定法证实了结肠癌细胞上CPS和TA的减少。与野生型D39相比，ΔlytR突变体更容易被吞噬。动物实验表明，lytR基因的损伤会影响肺炎球菌在鼻咽的定植能力和毒力。总的来说，这些结果表明肺炎球菌LytR参与将CPS和TA锚定到细胞壁，这对于肺炎球菌的毒力是重要的。
The LytR-Cps-Psr family proteins are commonly present in Gram-positive bacteria, which have been shown to implicate in anchoring cell wall-related glycopolymers to the peptidoglycan. Here, we report the cellular function of SPD_1741 (LytR) in Streptococcus pneumoniae and its role in virulence of pneumococci. Pneumococcal ΔlytR mutants have been successfully constructed by replacing the lytR gene with erm cassette. The role of LytR in pneumococcal growth was determined by growth experiments, and surface accessibility of the LytR protein was analyzed using flow cytometry. Transmission electron microscopy (TEM) and immunoblotting were used to reveal the changes in capsular polysaccharide (CPS). Dot blot and ELISA were used to quantify the amount of teichoic acids (TAs). The contribution of LytR on bacterial virulence was assessed using in vitro phagocytosis assays and infection experiments. Compared to the wild-type strain, the ΔlytR mutant showed a defect in growth which merely grew to a maximal OD620 of 0.2 in the liquid medium. The growth of the ΔlytR mutant could be restored by addition of recombinant ΔTM-LytR protein in culture medium in a dose-dependent manner. TEM results showed that the D39ΔlytR mutant was impaired in the surface attachment of CPS. Deletion of lytR gene also impaired the retention of TAs on the surface of pneumococci. The reduction of CPS and TAs on the pneumocccal cells were confirmed using Dot blot and ELISA assays. Compared to wild-type D39, the ΔlytR mutant was more susceptible to the phagocytosis. Animal studies showed that the ability to colonize the nasophaynx and virulence of pneumococci were affected by impairment of the lytR gene. Collectively, these results suggest that pneumococcal LytR is involved in anchoring both the CPS and TAs to cell wall, which is important for virulence of pneumococci.
登录
查看更多内容
影响因子：
3.1
作者：
Wu, Kaifeng;Zhang, Xuemei;Yin, Yibing
通讯作者：
Yin, Yibing
在超临界温度和各种压力下纳米多孔材料中的甲烷储存
影响因子：
4.6
作者：
Wu K;Chen Z;Li X;Dong X
通讯作者：
Dong X
影响因子：
15.3
作者：
Llull, D;Munoz, R;Lopez, R;Garcia, E
通讯作者：
Garcia, E
影响因子：
14.8
作者：
Schaefer K;Matano LM;Qiao Y;Kahne D;Walker S
通讯作者：
Walker S
DOI：
10.1084/jem.188.11.2047
发表时间：
1998-12-07
期刊：
The Journal of experimental medicine
影响因子：
--
作者：
Mollerach M;López R;García E
通讯作者：
García E