title: A PLGA-encapsulated chimeric protein protects against adherence and toxicity of enterotoxigenic Escherichia coli.
abstract: Enterotoxigenic Escherichia coli (ETEC) are the most common cause of diarrhea among children. Colonization factors and enterotoxins are the major ETEC candidate vaccines. Since protection against ETEC mostly occurs by induction of IgA antibodies, much effort is focused on the development of oral vaccines. In this study oral immunogenicity of a poly(lactic-co-glycolic acid) (PLGA) encapsulated chimeric protein containing CfaB, CstH, CotA and LTB (Heat-labile B subunit) was investigated. The protein was encapsulated in PLGA by double emulsion method and nanoparticles were characterized physicochemically. Immunogenicity was assessed by evaluating IgG1, IgG2 and IgA titers after BALB/c mice vaccination. Non aggregated nanoparticles had a spherical shape with an average particle size of 252.7±23 nm and 91.96±4.4% of encapsulation efficiency. Western blotting showed maintenance of the molecular weight and antigenicity of the released protein. Oral immunization of mice induced serum IgG and fecal IgA antibody responses. Immunization induced protection against ETEC binding to Caco-2 cells. The effect of LT toxin on fluid accumulation in ileal loops was neutralized by inhibition of enterotoxin binding to GM1-ganglosides. Delivery of the chimeric protein in PLGA elicited both systemic and mucosal immune responses. The findings could be exploited to development of oral multi-component ETEC prophylactic measures.
authors.affiliation: Department of Biology, Shahed University, Tehran, Iran.
authors.forename: Shahram
authors.initials: S
authors.lastname: Nazarian
authors.affiliation: Department of Biology, Shahed University, Tehran, Iran. Electronic address: slmousavi@shahed.ac.ir.
authors.forename: Seyed Latif Mousavi
authors.initials: SL
authors.lastname: Gargari
authors.affiliation: Department of Biology, Shahed University, Tehran, Iran.
authors.forename: Iraj
authors.initials: I
authors.lastname: Rasooli
authors.affiliation: Tarbiat Modares University, Faculty of Biological Sciences, Tehran, Iran.
authors.forename: Sadegh
authors.initials: S
authors.lastname: Hasannia
authors.affiliation: Faculty of Science, Department of Biology, University of Guilan, Rasht, Iran.
authors.forename: Nazanin
authors.initials: N
authors.lastname: Pirooznia
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology; D001422:Bacterial Adhesion; D018938:Caco-2 Cells; D054307:Enterotoxigenic Escherichia coli / Q000276:immunology / Q000502:physiology*; D004768:Enterotoxins / Q000737:chemistry / Q000276:immunology / Q000633:toxicity; D004927:Escherichia coli Infections / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control*; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000276:immunology* / Q000633:toxicity; D005260:Female; D006801:Humans; D019344:Lactic Acid / Q000737:chemistry*; D051379:Mice; D008807:Mice, Inbred BALB C; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer
chemical_list: D000907:Antibodies, Bacterial; D004768:Enterotoxins; D029968:Escherichia coli Proteins; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid
keywords: Biodegradable PLGA; Enterotoxigenic E. coli; Nanoparticles; Oral immunization