Structure-Function Characterization of Streptococcus intermedius Surface Antigen Pas.
Structure-Function Characterization of Streptococcus intermedius Surface Antigen Pas.
复制标题
中间链球菌表面抗原的结构-功能表征。
DOI：
10.1128/jb.00175-21
复制
发表时间：
2021
影响因子：
3.2
通讯作者：
Deivanayagam,Champion
中科院分区：
文献类型：
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作者：
Mieher,JoshuaL;Schormann,Norbert;Wu,Ren;Patel,Manisha;Purushotham,Sangeetha;Wu,Hui;Scoffield,Jessica;Deivanayagam,Champion
中间链球菌是一种口腔共生细菌，存在于不同部位，包括龈下牙菌斑、化脓性感染和囊性纤维化肺。口腔链球菌利用其表面的蛋白质粘附到细菌定位的组织和/或表面，随后导致生物膜的形成、定植和感染。在 S. intermedius 上 19 种基因组注释的细胞壁附着表面蛋白中，Pas 是属于抗原 I/II (AgI/II) 家族的粘附素。在这里，我们对 Pas 进行了结构和功能表征，特别关注其微生物与宿主以及微生物与微生物的相互作用。 VPas和C123Pass的晶体结构与变形链球菌AgI/II具有高度相似性。 VPashosts 具有保守的金属结合位点，同样，C123Pas 结构在其三个 DEv-IgG 结构域内保留其保守的金属结合位点和异肽键。 Pas 以纳摩尔亲和力与肺泡糖蛋白 340 (Gp340)、其清道夫受体富含半胱氨酸结构域 (SRCR) 以及纤维蛋白原相互作用。双物种生物膜研究对白色念珠菌和铜绿假单胞菌这两种与中间链球菌共存于 CFTR 患者肺部的机会性病原体进行了研究。 Pas 缺陷突变体 (Δpas) 显示白色念珠菌双生物膜形成显着减少。在铜绿假单胞菌的类似研究中，Pas 不介导急性分离株 (PAO1) 或慢性分离株 (FRD1) 的生物膜形成。然而，分选酶 A 缺陷突变体 (ΔsrtA) 显示白色念珠菌和铜绿假单胞菌 FRD1 的生物膜形成减少。总而言之，我们的研究结果强调了 Pas 在微生物-宿主和界间相互作用中的作用，并揭示了其在疾病结果中的潜在作用。 重要性中间链球菌是一种口腔共生细菌，已在龈下牙菌斑、化脓性感染和肺部囊性纤维化中观察到。在这项研究中，我们 (i) 确定了 Pas V 和 C 区的晶体结构； (ii) 表明其表面蛋白 Pas 粘附在纤维蛋白原上，这可能会通过口腔的血流运送微生物； (iii) 表征了 Pas 对肺泡蛋白 Gp340 的高亲和力粘附，可以将微生物固定在肺上皮细胞上； (iv) 最重要的是，口腔共生中间链球菌上的这些表面蛋白增强了已知病原体白色念珠菌和铜绿假单胞菌的生物膜。
Streptococcus intermedius, an oral commensal bacterium, is found at various sites, including subgingival dental plaque, purulent infections, and cystic fibrosis lungs. Oral streptococci utilize proteins on their surface to adhere to tissues and/or surfaces localizing the bacteria, which subsequently leads to the development of biofilms, colonization, and infection. Among the 19 genomically annotated cell wall-attached surface proteins on S. intermedius, Pas is an adhesin that belongs to the antigen I/II (AgI/II) family. Here, we have structurally and functionally characterized Pas, particularly focusing on its microbial-host as well as microbial-microbial interactions. The crystal structures of VPasand C123Passhow high similarity with AgI/II of Streptococcus mutans. VPashosts a conserved metal binding site, and likewise, the C123Passtructure retains its conserved metal binding sites and isopeptide bonds within its three DEv-IgG domains. Pas interacts with nanomolar affinity to lung alveolar glycoprotein 340 (Gp340), its scavenger receptor cysteine-rich domains (SRCRs), and with fibrinogen. Both Candida albicans and Pseudomonas aeruginosa, the opportunistic pathogens that cohabitate with S. intermedius in the lungs of CFTR patients were studied in dual-species biofilm studies. The Pas-deficient mutant (Δpas) displayed significant reduction in dual-biofilm formation with C. albicans. In similar studies with P. aeruginosa, Pas did not mediate the biofilm formation with either the acute isolate (PAO1) or the chronic isolate (FRD1). However, the sortase A-deficient mutant (ΔsrtA) displayed reduced biofilm formation with both C. albicans and P. aeruginosa FRD1. Taken together, our findings highlight the role of Pas in both microbial-host and interkingdom interactions and expose its potential role in disease outcomes.IMPORTANCEStreptococcus intermedius, an oral commensal bacterium, has been clinically observed in subgingival dental plaque, purulent infections, and cystic fibrosis lungs. In this study, we have (i) determined the crystal structure of the V and C regions of Pas; (ii) shown that its surface protein Pas adheres to fibrinogen, which could potentially ferry the microbe through the bloodstream from the oral cavity; (iii) characterized Pas’s high-affinity adherence to lung alveolar protein Gp340 that could fixate the microbe on lung epithelial cells; and (iv) most importantly, shown that these surface proteins on the oral commensal S. intermedius enhance biofilms of known pathogens Candida albicans and Pseudomonas aeruginosa.