title: Immune responses to oral vaccination with Salmonella-delivered avian pathogenic Escherichia coli antigens and protective efficacy against colibacillosis.
abstract: In this study, the immune responses to and protective efficacy of a live attenuated Salmonella-delivered vaccine candidate secreting the papA, papG, iutA, and clpG antigens of Escherichia coli were evaluated against infection with avian pathogenic E. coli (APEC) in layer chickens. Primary vaccination was done at age 7 d and booster vaccination at age 5 wk. The levels of intestinal secretory immunoglobulin A specific to the 4 antigens were significantly higher in the vaccinated group than in the control group. A potent lymphocyte-proliferation response and increased levels of interferon-γ, interleukin-2, and interleukin-6 in the plasma and in culture supernatants of antigen-stimulated lymphocytes from the vaccinated group suggested significant induction of the cell-mediated immune response in this group compared with the control group. Upon challenge with a virulent APEC strain at 8 wk of age, the vaccinated group had no deaths, whereas the control group had a 15% mortality rate. In addition, the morbidity rate was significantly higher in the control group (55%) than in the vaccinated group (15%). Thus, giving primary and booster vaccination with the Salmonella-delivered APEC vaccine candidate significantly elevated both mucosal and cellular immune responses, which protected the chickens against colibacillosis.
authors.affiliation: Department of Bioactive Material Sciences, College of Veterinary Medicine, Chonbuk National University, Jeonju 561-756, Republic of Korea.
authors.forename: John Hwa
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Bioactive Material Sciences, College of Veterinary Medicine, Chonbuk National University, Jeonju 561-756, Republic of Korea.
authors.forename: Atul A
authors.initials: AA
authors.lastname: Chaudhari
authors.affiliation: Department of Bioactive Material Sciences, College of Veterinary Medicine, Chonbuk National University, Jeonju 561-756, Republic of Korea.
authors.forename: In Gyoung
authors.initials: IG
authors.lastname: Oh
authors.affiliation: Department of Bioactive Material Sciences, College of Veterinary Medicine, Chonbuk National University, Jeonju 561-756, Republic of Korea.
authors.forename: Seong Kug
authors.initials: SK
authors.lastname: Eo
authors.affiliation: Department of Bioactive Material Sciences, College of Veterinary Medicine, Chonbuk National University, Jeonju 561-756, Republic of Korea.
authors.forename: Sang-Youel
authors.initials: SY
authors.lastname: Park
authors.affiliation: Department of Bioactive Material Sciences, College of Veterinary Medicine, Chonbuk National University, Jeonju 561-756, Republic of Korea.
authors.forename: Chetan V
authors.initials: CV
authors.lastname: Jawale
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial; D001428:Bacterial Vaccines / Q000276:immunology*; D049109:Cell Proliferation; D002645:Chickens; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000276:immunology*; D004927:Escherichia coli Infections / Q000382:microbiology / Q000517:prevention & control / Q000662:veterinary*; D005786:Gene Expression Regulation / Q000276:immunology; D008214:Lymphocytes / Q000502:physiology; D011201:Poultry Diseases / Q000382:microbiology / Q000517:prevention & control*; D012475:Salmonella / Q000378:metabolism*
chemical_list: D000942:Antigens, Bacterial; D001428:Bacterial Vaccines; D016207:Cytokines