title: Immunization with Salmonella Enteritidis secreting mucosal adjuvant labile toxin confers protection against wild type challenge via augmentation of CD3+CD4+T-cell proliferation and enhancement of IFN-γ, IL-6 and IL-10 expressions in chicken.
abstract: The protective efficacy and immunological profiles of chickens immunized with an attenuated Salmonella Enteritidis (SE) constitutively secreting double mutant heat labile enterotoxin (dmLT) were investigated. The dmLT is a detoxified variant of Escherichia coli heat labile toxin and is a potent mucosal adjuvant capable of inducing both humoral and cell-mediated immunity. In this study, four-week-old chickens were inoculated with SE-dmLT strain JOL1641, parental SE strain JOL1087 or phosphate buffered saline control. Peripheral blood mononuclear cells of SE-dmLT inoculated birds showed significant proliferation upon stimulation with SE antigens as compared to the control and JOL1087 groups (P⩽0.05). One week post-challenge, the ratio of CD3+CD4+to CD3+CD8+T-cells showed a significant increase in the immunized groups. Significant increases in IFN-γ levels were observed in JOL1641 birds immunized via oral and intramuscular routes. While immunizations with the JOL1087 strain via the intramuscular route also induced significant increases in IFN-γ, immunization via the oral route did not trigger significant changes. Pro-inflammatory cytokine IL-6 was also elevated significantly in immunized birds; a significant elevation of IL-10 was observed only in oral immunization with JOL1641 (P⩽0.05). JOL1641 immunized birds showed significant reduction of challenge bacterial-organ recovery as compared to JOL1087 and non-immunized birds. Collectively, our results revealed that immunization with the adjuvant-secreting S. Enteritidis confers protection against wild type SE challenge via induction of strong cell proliferative response, augmentation of CD3+CD4+: CD3+CD8+T-cells ratio and enhancement of IFN-γ, IL-6 and IL-10 cytokine secretion.
authors.affiliation: College of Veterinary Medicine, Chonbuk National University, Iksan Campus, 54596, Republic of Korea.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Lalsiamthara
authors.affiliation: College of Veterinary Medicine, Chonbuk National University, Iksan Campus, 54596, Republic of Korea. Electronic address: johnhlee@jbnu.ac.kr.
authors.forename: John Hwa
authors.initials: JH
authors.lastname: Lee
mesh_terms: D000276:Adjuvants, Immunologic / Q000378:metabolism / Q000494:pharmacology*; D000284:Administration, Oral; D000818:Animals; D015703:Antigens, CD / Q000235:genetics / Q000276:immunology; D001427:Bacterial Toxins / Q000494:pharmacology*; D049109:Cell Proliferation / Q000187:drug effects; D002645:Chickens; D004768:Enterotoxins / Q000378:metabolism / Q000494:pharmacology*; D029968:Escherichia coli Proteins / Q000378:metabolism / Q000494:pharmacology*; D015870:Gene Expression; D007111:Immunity, Cellular / Q000187:drug effects; D056724:Immunity, Humoral / Q000187:drug effects; D018928:Immunity, Mucosal / Q000187:drug effects; D007273:Injections, Intramuscular; D007371:Interferon-gamma / Q000235:genetics / Q000276:immunology; D016753:Interleukin-10 / Q000235:genetics / Q000276:immunology; D015850:Interleukin-6 / Q000235:genetics / Q000276:immunology; D011201:Poultry Diseases / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control*; D020033:Protein Isoforms / Q000378:metabolism / Q000494:pharmacology; D012481:Salmonella Infections, Animal / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control*; D022562:Salmonella Vaccines / Q000008:administration & dosage*; D012477:Salmonella enteritidis / Q000187:drug effects* / Q000276:immunology / Q000472:pathogenicity; D013601:T-Lymphocytes / Q000187:drug effects* / Q000276:immunology / Q000382:microbiology; D014613:Vaccines, Attenuated
chemical_list: D000276:Adjuvants, Immunologic; D015703:Antigens, CD; D001427:Bacterial Toxins; D004768:Enterotoxins; D029968:Escherichia coli Proteins; D015850:Interleukin-6; D020033:Protein Isoforms; D022562:Salmonella Vaccines; D014613:Vaccines, Attenuated; D016753:Interleukin-10; D007371:Interferon-gamma; C027538:heat-labile enterotoxin, E coli
keywords: Chickens; Cytokines; Flow cytometry; RT-qPCR; Salmonella Enteritidis; dmLT