M1 protein from group A Streptococcus affects fibrin clot formation, structure, and fibrinolytic potential

Blood Vessels, Thrombosis & Hemostasis Pub Date : 2025-07-18 DOI:10.1016/j.bvth.2025.100094

Sophie Cherrington , Lewis J. Hardy , Azhar Maqbool , Helen Philippou , Craig Thelwell

{"title":"M1 protein from group A Streptococcus affects fibrin clot formation, structure, and fibrinolytic potential","authors":"Sophie Cherrington , Lewis J. Hardy , Azhar Maqbool , Helen Philippou , Craig Thelwell","doi":"10.1016/j.bvth.2025.100094","DOIUrl":null,"url":null,"abstract":"<div><h3>Abstract</h3><div>M1 protein is a major virulence determinant of group A <em>Streptococcus</em> (GAS). During infection, M1 is cleaved from the cell surface by host and bacterial proteases resulting in soluble M1 at the site of infection. M1 forms a supramolecular complex with host fibrinogen. We hypothesize that this supramolecular complex affects the formation of fibrin clots. Fibrin formation is an essential part of innate immunity, sealing off infections to limit bacteria spreading. The effects of recombinant M1 (rM1) were assessed in fibrin clots made from whole blood, plasma, or purified fibrinogen incubated in thrombin by a semiautomated coagulation analyzer, permeation studies, confocal microscopy, and scanning electron microscopy. Clotting and lysis profiles (with plasminogen activators and plasminogen) were investigated using microtiter plate assays and kinetically with rotational thromboelastography. Factor XIII crosslinking was quantified using commercial kits and sodium dodecyl sulfate–polyacrylamide gel electrophoresis densitometry analysis. This study demonstrated that rM1-bound (0.47-60 μg/mL) fibrinogen produced clots with remarkably different structures and properties compared with clots without rM1. Inclusion of rM1 formed heterogeneous clots with irregular fiber bundles and compacted fibrin. Formation of the protective fibrin film was disrupted by rM1. Furthermore, mechanical strength of fibrin clots was reduced, and the fibrin networks were more porous with increased fluid permeability. Fibrin clots formed using whole blood incorporating rM1 were more susceptible to lysis by plasmin. GAS strains of M1 type are often associated with invasive infections; the impact of M1 on fibrin structure could contribute to the severity of GAS infection by compromising the fibrin barrier that limits bacterial proliferation and migration.</div></div>","PeriodicalId":100190,"journal":{"name":"Blood Vessels, Thrombosis & Hemostasis","volume":"2 4","pages":"Article 100094"},"PeriodicalIF":0.0000,"publicationDate":"2025-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Blood Vessels, Thrombosis & Hemostasis","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2950327225000518","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}

引用次数: 0

Abstract

M1 protein is a major virulence determinant of group A Streptococcus (GAS). During infection, M1 is cleaved from the cell surface by host and bacterial proteases resulting in soluble M1 at the site of infection. M1 forms a supramolecular complex with host fibrinogen. We hypothesize that this supramolecular complex affects the formation of fibrin clots. Fibrin formation is an essential part of innate immunity, sealing off infections to limit bacteria spreading. The effects of recombinant M1 (rM1) were assessed in fibrin clots made from whole blood, plasma, or purified fibrinogen incubated in thrombin by a semiautomated coagulation analyzer, permeation studies, confocal microscopy, and scanning electron microscopy. Clotting and lysis profiles (with plasminogen activators and plasminogen) were investigated using microtiter plate assays and kinetically with rotational thromboelastography. Factor XIII crosslinking was quantified using commercial kits and sodium dodecyl sulfate–polyacrylamide gel electrophoresis densitometry analysis. This study demonstrated that rM1-bound (0.47-60 μg/mL) fibrinogen produced clots with remarkably different structures and properties compared with clots without rM1. Inclusion of rM1 formed heterogeneous clots with irregular fiber bundles and compacted fibrin. Formation of the protective fibrin film was disrupted by rM1. Furthermore, mechanical strength of fibrin clots was reduced, and the fibrin networks were more porous with increased fluid permeability. Fibrin clots formed using whole blood incorporating rM1 were more susceptible to lysis by plasmin. GAS strains of M1 type are often associated with invasive infections; the impact of M1 on fibrin structure could contribute to the severity of GAS infection by compromising the fibrin barrier that limits bacterial proliferation and migration.

查看原文本刊更多论文

来自A群链球菌的M1蛋白影响纤维蛋白凝块的形成、结构和纤溶电位

摘要m1蛋白是a群链球菌（GAS）的主要毒力决定因子。在感染过程中，M1被宿主和细菌蛋白酶从细胞表面切割，在感染部位产生可溶性M1。M1与宿主纤维蛋白原形成超分子复合物。我们假设这种超分子复合物影响了纤维蛋白凝块的形成。纤维蛋白的形成是先天免疫的重要组成部分，它可以封闭感染，限制细菌的传播。重组M1 （rM1）的作用通过半自动化凝血分析仪、渗透研究、共聚焦显微镜和扫描电子显微镜，在由全血、血浆或纯化的纤维蛋白原在凝血酶中培养的纤维蛋白凝块中进行评估。凝血和溶解谱（与纤溶酶原激活剂和纤溶酶原）研究使用微量滴度板测定和动态旋转血栓弹性成像。采用商品化试剂盒和十二烷基硫酸钠-聚丙烯酰胺凝胶电泳密度分析法对因子十三交联进行定量分析。本研究表明，rM1结合（0.47-60 μg/mL）的纤维蛋白原产生的凝块与不含rM1的凝块相比，具有显著不同的结构和性质。rM1的包涵形成了不规则纤维束和致密纤维蛋白的异质凝块。保护性纤维蛋白膜的形成被rM1破坏。此外，纤维蛋白凝块的机械强度降低，纤维蛋白网络更多孔，流体渗透率增加。含rM1的全血形成的纤维蛋白凝块更容易被纤溶酶溶解。M1型GAS菌株常与侵袭性感染相关；M1对纤维蛋白结构的影响可能通过破坏限制细菌增殖和迁移的纤维蛋白屏障而导致GAS感染的严重程度。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Blood Vessels, Thrombosis & Hemostasis

自引率

0.00%

发文量