Nanoparticulated Heat-Stable(STa)and Heat-Labile B Subunit(LTB)Recombinant Toxin Improves Vaccine Protection Against Enterotoxigenic Escherichia coli Challenge in Mouse

摘要

Enterotoxigenic Escherichia coli (ETEC)remains a major cause of diarrheic disease in developing areas,for which there is no effective vaccine available.In this study,we genetically engineered a recombinant heat-stable enterotoxin (STa)coupled to the subunit B of heat-labile enterotoxin (LTB ).This fusion protein,STa-LTB,possesses a single amino acid substitution at position 14 of STa.Our data demonstrates that the enterotoxicity of STa in STa-LTB was dramatically reduced.A gelatin nanovaccine candidate was prepared using the purified STa-LTB fusion protein characterized with an entrapment efficiency of 84.88％±6.37％ and smooth spheres size ranges of 80e200 nm.