title: Immunogenicity and protective efficacy of a recombinant adenoviral based vaccine expressing heat-stable enterotoxin (STa) and K99 adhesion antigen of enterotoxigenic Escherichia coli in mice.
abstract: The diarrheal disease of domestic animals or in humans caused by enterotoxigenic Escherichia coli (ETEC) infections remains a major issue for public health in developing countries. Unfortunately, there is no effective vaccine available for preventing from an ETEC infection. Therefore, the development of a safe and effective vaccine against ETEC is urgently needed. In the present study, A recombinant adenoviral vector Ad5-STa-K99 that capable of expressing a fusion protein of heat-stable enterotoxin (STa) and K99 adhesion antigen of ETEC was generated and its immunogenicity was evaluated in a murine model. The intestinal mucosal secretory IgA(sIgA), serum anti-STa-K99 antibody responses, antigen-specific CD4(+) and CD8(+) T cells frequencies, as well as T-cell proliferation of mice immunized with the viral vector were determined as immunological indexes. The results demonstrated that Ad5-STa-K99 was able to enhance humoral responses with a dramatically augmented antigen-specific serum IgG antibody, and an elevated production of intestinal sIgA in immunized mice, suggesting the elicitation of both of humoral and mucosal immune responses. In addition, this adenoviral vector could significantly promote splenic T cell proliferation and increase the frequencies of CD4(+) and CD8(+) T cell populations in mice, indicative of a capacity to activate T cell responses. More importantly, vaccination of the Ad5-STa-K99 showed a potential to evoke a protective effect from ETEC challenge in mice. These data indicate that the Ad5-STa-K99 is a highly immunogenic vector able to induce a broad range of antigen-specific immune responses in vivo, and evoke a protective immune response against ETEC infections, implying that it may be a novel vaccine candidate warranted for further investigation.
authors.affiliation: Key Laboratory of Ministry of Education for Conservation and Utilization of Special Biological Resources in the Western, Ningxia University, Yinchuan, Ningxia 750021, China; College of Life Science, Ningxia University, Yinchuan, Ningxia 750021, China.
authors.forename: Guangcun
authors.initials: G
authors.lastname: Deng
authors.affiliation: Key Laboratory of Ministry of Education for Conservation and Utilization of Special Biological Resources in the Western, Ningxia University, Yinchuan, Ningxia 750021, China; College of Life Science, Ningxia University, Yinchuan, Ningxia 750021, China.
authors.forename: Wu
authors.initials: W
authors.lastname: Li
authors.affiliation: Key Laboratory of Ministry of Education for Conservation and Utilization of Special Biological Resources in the Western, Ningxia University, Yinchuan, Ningxia 750021, China; College of Life Science, Ningxia University, Yinchuan, Ningxia 750021, China.
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Wu
authors.affiliation: Key Laboratory of Ministry of Education for Conservation and Utilization of Special Biological Resources in the Western, Ningxia University, Yinchuan, Ningxia 750021, China; College of Life Science, Ningxia University, Yinchuan, Ningxia 750021, China.
authors.forename: Shaowen
authors.initials: S
authors.lastname: Bao
authors.affiliation: Key Laboratory of Ministry of Education for Conservation and Utilization of Special Biological Resources in the Western, Ningxia University, Yinchuan, Ningxia 750021, China; College of Life Science, Ningxia University, Yinchuan, Ningxia 750021, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Zeng
authors.affiliation: Key Laboratory of Ministry of Education for Conservation and Utilization of Special Biological Resources in the Western, Ningxia University, Yinchuan, Ningxia 750021, China; College of Life Science, Ningxia University, Yinchuan, Ningxia 750021, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Zhao
authors.affiliation: Ningxia Key Laboratory of Clinical and Pathogenic Microbiology at the General Hospital of Ningxia Medical University, Yinchuan, Ningxia 750004, China.
authors.forename: Meihui
authors.initials: M
authors.lastname: Luo
authors.affiliation: Key Laboratory of Ministry of Education for Conservation and Utilization of Special Biological Resources in the Western, Ningxia University, Yinchuan, Ningxia 750021, China; College of Life Science, Ningxia University, Yinchuan, Ningxia 750021, China; Ningxia Key Laboratory of Clinical and Pathogenic Microbiology at the General Hospital of Ningxia Medical University, Yinchuan, Ningxia 750004, China.
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Liu
authors.affiliation: Key Laboratory of Ministry of Education for Conservation and Utilization of Special Biological Resources in the Western, Ningxia University, Yinchuan, Ningxia 750021, China; College of Life Science, Ningxia University, Yinchuan, Ningxia 750021, China. Electronic address: yujiongw@126.com.
authors.forename: Yujiong
authors.initials: Y
authors.lastname: Wang
mesh_terms: D000256:Adenoviridae; D000818:Animals; D000954:Antigens, Surface / Q000276:immunology*; D001427:Bacterial Toxins / Q000276:immunology*; D015153:Blotting, Western; D004195:Disease Models, Animal; D054307:Enterotoxigenic Escherichia coli; D004768:Enterotoxins / Q000276:immunology*; D004927:Escherichia coli Infections / Q000276:immunology / Q000517:prevention & control*; D005260:Female; D005822:Genetic Vectors; D008213:Lymphocyte Activation / Q000187:drug effects / Q000276:immunology; D051379:Mice; D008813:Mice, Inbred ICR; D011993:Recombinant Fusion Proteins / Q000276:immunology; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology; D014614:Vaccines, Synthetic / Q000276:immunology*
chemical_list: D000954:Antigens, Surface; D001427:Bacterial Toxins; D004768:Enterotoxins; C031429:K99 antigen; D011993:Recombinant Fusion Proteins; D014614:Vaccines, Synthetic
keywords: Enterotoxigenic Escherichia coli (ETEC); Heat-stable enterotoxin (STa); K99; Recombinant adenovirus; Vaccine