Enzymatic Cleavage of Stx2a in the Gut and Identification of Pancreatic Elastase and Trypsin as Possible Main Cleavers

被引：2

作者：

Kellnerova, Sara ^{[1
]}

Huber, Silke ^{[1
]}

Massri, Mariam ^{[1
]}

Fleischer, Verena ^{[1
]}

Losso, Klemens ^{[2
,3
]}

Sarg, Bettina ^{[4
]}

Kremser, Leopold ^{[4
]}

Talasz, Heribert ^{[4
]}

He, Xiaohua ^{[5
]}

Varrone, Elisa ^{[6
]}

Brigotti, Maurizio ^{[6
]}

Ardissino, Gianluigi ^{[7
]}

Orth-Hoeller, Dorothea ^{[1
,8
]}

Wuerzner, Reinhard ^{[1
]}

机构：

[1] Med Univ Innsbruck, Inst Hyg & Med Microbiol, A-6020 Innsbruck, Austria

[2] Univ Innsbruck, Inst Analyt Chem & Radiochem, A-6020 Innsbruck, Austria

[3] MCI Entrepreneurial Sch, Dept Food Technol & Nutr, A-6020 Innsbruck, Austria

[4] Med Univ Innsbruck, Inst Med Biochem, Ctr Chem & Biomed, Prot Core Facil, A-6020 Innsbruck, Austria

[5] ARS, Western Reg Res Ctr, USDA, Albany, CA 94710 USA

[6] Univ Bologna, Sch Med, Dept Med & Surg Sci, I-40126 Bologna, Italy

[7] Osped Maggiore Policlin, Fdn IRCCS Ca Granda, Ctr HUS Prevent Control & Management, Pediat Nephrol Dialysis & Transplant Unit, I-20122 Milan, Italy

[8] MB LAB Clin Microbiol Lab, A-6020 Innsbruck, Austria

来源：

MICROORGANISMS | 2023年 / 11卷 / 10期

基金：

奥地利科学基金会;

关键词：

enterohemorrhagic Escherichia coli (EHEC); EHEC-associated hemolytic uremic syndrome (eHUS); Shiga toxin 2a (Stx2a); trypsin; furin; chymotrypsin-like elastase 3B (CELA3B); ENTEROHEMORRHAGIC ESCHERICHIA-COLI; HEMOLYTIC-UREMIC SYNDROME; FURIN-INDUCED CLEAVAGE; SHIGA-TOXIN; CYTOTOXICITY; ACTIVATION; CELLS; TISSUE; RESPONSES; SUBUNIT;

D O I：

10.3390/microorganisms11102487

中图分类号：

Q93 [微生物学];

学科分类号：

071005 ; 100705 ;

摘要：

Shiga toxins (Stxs), especially the Stx2a subtype, are the major virulence factors involved in enterohemorrhagic Escherichia coli (EHEC)-associated hemolytic uremic syndrome (eHUS), a life-threatening disease causing acute kidney injury, especially in children. After oral transmission and colonization in the gut, EHEC release Stx. Intracellular cleavage of the Stx A subunit, when followed by reduction, boosts the enzymatic activity that causes damage to targeted cells. This cleavage was assumed to be mostly mediated by furin during Stx intracellular trafficking. To investigate whether this cleavage could occur in the intestine, even prior to entering target cells, Stx2a A subunit structure (intact or cleaved) was characterized after its exposure to specific host factors present in human stool. The molecular weight of Stx2a A subunit/fragments was determined by immunoblotting after electrophoretic separation under reducing conditions. In this study, it was demonstrated that Stx2a is cleaved by certain human stool components. Trypsin and chymotrypsin-like elastase 3B (CELA3B), two serine proteases, were identified as potential candidates that can trigger the extracellular cleavage of Stx2a A subunit directly after its secretion by EHEC in the gut. Whether the observed cleavage indeed translates to natural infections and plays a role in eHUS pathogenesis has yet to be determined. If so, it seems likely that a host's protease profile could affect disease development by changing the toxin's biological features.

引用

页数：15