title: Nasal immunization with major epitope-containing ApxIIA toxin fragment induces protective immunity against challenge infection with Actinobacillus pleuropneumoniae in a murine model.
abstract: Actinobacillus pleuropneumoniae is an infective agent that leads to porcine pleuropneumonia, a disease that causes severe economic losses in the swine industry. Based on the fact that the respiratory tract is the primary site for bacterial infection, it has been suggested that bacterial exclusion in the respiratory tract through mucosal immune induction is the most effective disease prevention strategy. ApxIIA is a vaccine candidate against A. pleuropneumoniae infection, and fragment #5 (aa. 439-801) of ApxIIA contains the major epitopes for effective vaccination. In this study, we used mice to verify the efficacy of intranasal immunization with fragment #5 in the induction of protective immunity against nasal challenge with A. pleuropneumoniae and compared its efficacy with that of subcutaneous immunization. Intranasal immunization of the fragment induced significantly higher systemic and mucosal immune responses measured at the levels of antigen-specific antibodies, cytokine-secreting cells after antigen exposure, and antigen-specific lymphocyte proliferation. Intranasal immunization not only efficiently inhibited the bacterial colonization in respiratory organs, but also prevented alveolar tissue damage in infectious condition similar to that of a contaminated pig. Moreover, intranasal immunization with fragment #5 provided acquired protective immunity against intranasal challenge with A. pleuropneumoniae serotype 2. In addition, it conferred cross-protection against serotype 5, a heterologous pathogen that causes severe disease by ApxI and ApxII secretion. Collectively, intranasal immunization with fragment #5 of ApxIIA can be considered an efficient protective immunization procedure against A. pleuropneumoniae infection.
authors.affiliation: Department of Molecular Biology and The Institute for Molecular Biology and Genetics, Chonbuk National University, Jeonju 561-756, Republic of Korea.
authors.forename: Ki-Weon
authors.initials: KW
authors.lastname: Seo
authors.forename: Sae-Hae
authors.initials: SH
authors.lastname: Kim
authors.forename: Jisang
authors.initials: J
authors.lastname: Park
authors.forename: Youngok
authors.initials: Y
authors.lastname: Son
authors.forename: Han Sang
authors.initials: HS
authors.lastname: Yoo
authors.forename: Kyung-Yeol
authors.initials: KY
authors.lastname: Lee
authors.forename: Yong-Suk
authors.initials: YS
authors.lastname: Jang
mesh_terms: D000189:Actinobacillus Infections / Q000276:immunology* / Q000382:microbiology / Q000473:pathology / Q000517:prevention & control*; D016977:Actinobacillus pleuropneumoniae / Q000276:immunology; D000281:Administration, Intranasal; D000818:Animals; D000942:Antigens, Bacterial / Q000008:administration & dosage / Q000235:genetics; D001426:Bacterial Proteins / Q000008:administration & dosage* / Q000235:genetics / Q000276:immunology*; D001427:Bacterial Toxins / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D001428:Bacterial Vaccines / Q000008:administration & dosage / Q000235:genetics; D004195:Disease Models, Animal; D000939:Epitopes / Q000008:administration & dosage / Q000235:genetics; D005260:Female; D006460:Hemolysin Proteins / Q000008:administration & dosage* / Q000235:genetics / Q000276:immunology*; D018928:Immunity, Mucosal; D007071:Immunoglobulin A, Secretory / Q000096:biosynthesis; D007279:Injections, Subcutaneous; D008168:Lung / Q000276:immunology / Q000382:microbiology / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D010446:Peptide Fragments / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D011002:Pleuropneumonia, Contagious / Q000276:immunology / Q000517:prevention & control; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D013552:Swine; D013553:Swine Diseases / Q000276:immunology / Q000517:prevention & control
chemical_list: D000942:Antigens, Bacterial; C085361:ApxII toxin, bacteria; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D001428:Bacterial Vaccines; D000939:Epitopes; D006460:Hemolysin Proteins; D007071:Immunoglobulin A, Secretory; D010446:Peptide Fragments; D011994:Recombinant Proteins