Heparin interacts with elongation factor 1α of Cryptosporidium parvum and inhibits invasion.

Atsuko Inomata,Kentaro Kato,Frances Cagayat Recuenco,Tatsuki Sugi,Akiko Ishiwa,Hitoshi Takemae,Fumi Murakoshi,Taisuke Horimoto,Ryo Takano

doi:10.1038/srep11599

Abstract

Cryptosporidium parvum is an apicomplexan parasite that can cause serious watery diarrhea, cryptosporidiosis, in human and other mammals. C. parvum invades gastrointestinal epithelial cells, which have abundant glycosaminoglycans on their cell surface. However, little is known about the interaction between C. parvum and glycosaminoglycans. In this study, we assessed the inhibitory effect of sulfated polysaccharides on C. parvum invasion of host cells and identified the parasite ligands that interact with sulfated polysaccharides. Among five sulfated polysaccharides tested, heparin had the highest, dose-dependent inhibitory effect on parasite invasion. Heparan sulfate-deficient cells were less susceptible to C. parvum infection. We further identified 31 parasite proteins that potentially interact with heparin. Of these, we confirmed that C. parvum elongation factor 1α (CpEF1α), which plays a role in C. parvum invasion, binds to heparin and to the surface of HCT-8 cells. Our results further our understanding of the molecular basis of C. parvum infection and will facilitate the development of anti-cryptosporidial agents.

Highlights

Cryptosporidium parvum is an apicomplexan parasite that can cause serious watery diarrhea, cryptosporidiosis, in human and other mammals
Our data reveal that sulfated polysaccharides differ in their invasion inhibitory effects, with heparin having the highest and dose-dependent inhibitory effect on C. parvum invasion of HCT-8 cells among the sulfated polysaccharides tested
We evaluated the inhibitory effect of sulfated polysaccharides on the invasion of HCT-8 cells by C. parvum, and found that heparin was the most effective inhibitor of C. parvum invasion among the five sulfated polysaccharides tested

Summary

Introduction

Cryptosporidium parvum is an apicomplexan parasite that can cause serious watery diarrhea, cryptosporidiosis, in human and other mammals. Nitazoxanide is only the drug approved by the FDA7 for the treatment of cryptosporidiosis; it effectively eradicates C. parvum oocysts from stool and resolves the diarrhea of both immuno-competent and -compromised individuals[8]. Lasalocid is an ionophorous antibiotic that reduces oocyst excretion in cattle[9,10] All of these agents have limited effects on parasite growth, highlighting the urgent need for novel effective anti-cryptosporodial drugs. The oocysts undergo excystation and release sporozoites while passing through the stomach and duodenum due to the rise of temperature, bile salt, and digestive enzymes[12] These sporozoites attach to intestinal epithelial cells, subsequently are embraced by the host cell membrane and develop into trophozoites in epicellular space[13]. This invasion is a critical step for the development of disease caused by C. parvum, yet there have been www.nature.com/scientificreports/

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