Rapid Cytopathic Effects of Clostridium perfringens Beta-Toxin on Porcine Endothelial Cells

Abstract

Clostridium perfringens type C isolates cause fatal, segmental necro-hemorrhagic enteritis in animals and humans. Typically, acute intestinal lesions result from extensive mucosal necrosis and hemorrhage in the proximal jejunum. These lesions are frequently accompanied by microvascular thrombosis in affected intestinal segments. In previous studies we demonstrated that there is endothelial localization of C. perfringens type C ␤-toxin (CPB) in acute lesions of necrotizing enteritis. This led us to hypothesize that CPB contributes to vascular necrosis by directly damaging endothelial cells. By performing additional immunohistochemical studies using spontaneously diseased piglets, we confirmed that CPB binds to the endothelial lining of vessels showing early signs of thrombosis. To investigate whether CPB can disrupt the endothelium, we exposed primary porcine aortic endothelial cells to C. perfringens type C culture supernatants and recombinant CPB. Both treatments rapidly induced disruption of the actin cytoskeleton, cell border retraction, and cell shrinkage, leading to destruction of the endothelial monolayer in vitro. These effects were followed by cell death. Cytopathic and cytotoxic effects were inhibited by neutralization of CPB. Taken together, our results suggest that CPB-induced disruption of endothelial cells may contribute to the pathogenesis of C. perfringens type C enteritis.

Toxin Plasmids of Clostridium perfringens

“…Histologically, the hallmark of type C infection is necrosis of the intestinal wall, which starts in the mucosa but usually progresses to affect all layers of the intestine. Fibrin thrombi occluding superficial arteries and veins of the lamina propria and submucosa are characteristic of this condition (207), and it was postulated (although not yet definitely proven) that vascular damage by CPB is an early event in type C infections (211,212).…”

The p38 MAPK and JNK Pathways Protect Host Cells against Clostridium perfringens Beta-Toxin

“…In addition, the toxin was toxic to primary porcine and human endothelial cells (12,13). Gurtner et al (12) reported that beta-toxin-induced endothelial damage plays a role in the necrotizing enteritis caused by C. perfringens type C strains.…”

Endothelial Binding of Beta Toxin to Small Intestinal Mucosal Endothelial Cells in Early Stages of Experimentally Induced Clostridium Perfringens Type C Enteritis in Pigs

“…We recently provided evidence that small intestinal microvascular endothelial cells could be directly targeted by CPB; however, results were based on in vitro studies and analysis of end-stage lesions of naturally affected piglets. 2,3 Experimental infections in rabbits and mice indicated that species differences in the reaction to this enteric infection exist. 5,9 The goal of this limited study was (1) to modify an experimental porcine intestinal loop infection model to reproduce early lesions of NE and (2) to determine CPB binding to potential target cells in the small intestine during early stages of NE in a naturally affected animal species.…”