title: Intragastric immunization of mice with enterohemorrhagic Escherichia coli O157:H7 bacterial ghosts reduces mortality and shedding and induces a Th2-type dominated mixed immune response.
abstract: A bacterial ghost (BG)-based vaccine was developed against enterohemorrhagic Escherichia coli O157:H7 infection. The aim of this study was to evaluate the protective effect of E. coli O157:H7 BGs in a mouse model and to reveal the mechanism of the immune response. Booster immunization provided a higher protection rate (84%) than single-dose immunization (56%). Intragastric immunization of E. coli O157:H7 BGs induced both humoral and cellular immune responses. The proliferative response of CD4+ T cells was mediated by the antigen-presenting cells. The humoral immune response dominated the immune response, while the cellular immune response developed later. Inflammatory reaction was balanced by the mixed Th1/Th2 immune response. The immune sera anti-adhesion effect was confirmed by the inhibition effect, which could inhibit >90% of the adhesion of E. coli O157:H7 to Hep-2 target cells in vitro. Antibody titer specific for intimin, a molecule important for adhesion of E. coli O157:H7 to target cells, correlated with specific immunoglobulin A or G antibody titer. Therefore, it might be feasible to clinically test BG vaccines in the future.
authors.affiliation: State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Microbiology and Epidemiology, No. 20 Dongdajie, Fengtai District, Beijing 100071, P.R. China.
authors.forename: Kun
authors.initials: K
authors.lastname: Cai
authors.forename: Xiang
authors.initials: X
authors.lastname: Gao
authors.forename: Tao
authors.initials: T
authors.lastname: Li
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Hou
authors.forename: Qin
authors.initials: Q
authors.lastname: Wang
authors.forename: Hao
authors.initials: H
authors.lastname: Liu
authors.forename: Le
authors.initials: L
authors.lastname: Xiao
authors.forename: Wei
authors.initials: W
authors.lastname: Tu
authors.forename: Yuenan
authors.initials: Y
authors.lastname: Liu
authors.forename: Jing
authors.initials: J
authors.lastname: Shi
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
mesh_terms: D018829:Adhesins, Bacterial / Q000276:immunology; D000818:Animals; D001428:Bacterial Vaccines / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D019453:Escherichia coli O157 / Q000276:immunology*; D029968:Escherichia coli Proteins / Q000276:immunology; D007111:Immunity, Cellular / Q000276:immunology; D056724:Immunity, Humoral / Q000276:immunology; D007117:Immunization, Secondary; D007070:Immunoglobulin A / Q000276:immunology; D007074:Immunoglobulin G / Q000276:immunology; D051379:Mice; D013601:T-Lymphocytes / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology*
chemical_list: D018829:Adhesins, Bacterial; D001428:Bacterial Vaccines; D029968:Escherichia coli Proteins; D007070:Immunoglobulin A; D007074:Immunoglobulin G; C073819:eaeA protein, E coli