title: A low-toxic site-directed mutant of Clostridium perfringens ε-toxin as a potential candidate vaccine against enterotoxemia.
abstract: Clostridium perfringens epsilon toxin (ETX), one of the most potent toxins known, is a potential biological weapon; therefore, the development of an effective vaccine is important for preventing intoxication or disease by ETX. In this study, genetically detoxified epsilon toxin mutants were developed as candidate vaccines. We used site-directed mutagenesis to mutate the essential amino acid residues (His106, Ser111 and Phe199). Six site-directed mutants of ETX (mETX (H106P) , mETX (S111H) , mETX (S111Y) , mETX (F199H) , mETX (F199E) , mETX (S111YF199E) ) were generated and then expressed in Escherichia coli. Both mETX (F199E) and mETX (H106P) with low or non-cytotoxicity that retained their immunogenicity were selected to immunize mice 3 times, and the mouse survival data were recorded after challenging with recombinant wild-type ETX. mETX (F199E) induces the same protection as mETX (H106P) , which was reported previously as a promising toxin mutant for vaccine, and both of them could protect immunized mice against a 100× LD₅₀ dose of active wild-type recombinant ETX. This work showed that mETX (F199E) is another promising candidate vaccine against enterotoxemia and other diseases caused by ETX.
authors.affiliation: Anhui Medical University; Hefei, Anhui, PR China; State Key Laboratory of Pathogen and Biosecurity; Institute of Microbiology and Epidemiology; Academy of Military Medical Sciences; Beijing, PR China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Li
authors.forename: Wenwen
authors.initials: W
authors.lastname: Xin
authors.forename: Shan
authors.initials: S
authors.lastname: Gao
authors.forename: Lin
authors.initials: L
authors.lastname: Kang
authors.forename: Jinglin
authors.initials: J
authors.lastname: Wang
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000235:genetics / Q000276:immunology / Q000633:toxicity; D001427:Bacterial Toxins / Q000235:genetics / Q000276:immunology* / Q000633:toxicity; D001428:Bacterial Vaccines / Q000008:administration & dosage / Q000009:adverse effects / Q000235:genetics / Q000276:immunology*; D003016:Clostridium perfringens / Q000235:genetics / Q000276:immunology*; D004195:Disease Models, Animal; D004285:Dogs; D004926:Escherichia coli / Q000235:genetics; D005260:Female; D015870:Gene Expression; D006801:Humans; D061985:Madin Darby Canine Kidney Cells; D008807:Mice, Inbred BALB C; D016297:Mutagenesis, Site-Directed; D050505:Mutant Proteins / Q000235:genetics / Q000276:immunology / Q000633:toxicity; D016019:Survival Analysis; D014115:Toxemia / Q000517:prevention & control*; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000009:adverse effects / Q000235:genetics / Q000276:immunology
chemical_list: D000942:Antigens, Bacterial; D001427:Bacterial Toxins; D001428:Bacterial Vaccines; C039811:Clostridium perfringens epsilon-toxin; D050505:Mutant Proteins; D014614:Vaccines, Synthetic
keywords: Clostridium perfringens; cytotoxicity; enterotoxemia; site-directed mutagenesis; toxin mutant; vaccine; Îµ-toxin