title: Induction of protective immune responses against challenge of Actinobacillus pleuropneumoniae by oral administration with Saccharomyces cerevisiae expressing Apx toxins in pigs.
abstract: Actinobacillus pleuropneumoniae is a causative agent of porcine pleuropneumonia, a highly contagious endemic disease of pigs worldwide, inducing significant economic losses worldwide. Apx toxins, which are correlated with the virulence of A. pleuropneumoniae, were expressed in Saccharomyces cerevisiae and its possible use as an oral vaccine has been confirmed in our previous studies using a murine model. The present study was undertaken to test the hypothesis that oral immunization using S. cerevisiae expressing either ApxI or ApxII could protect pigs against A. pleuropneumoniae as an effective way of inducing both mucosal and systemic immune responses. The surface-displayed ApxIIA#5 expressing S. cerevisiae was selected as an oral vaccine candidate by finding on induction of higher immune responses in mice after oral vaccination. The surface-displayed ApxIIA#5 expressing S. cerevisiae and the ApxIA expressing S. cerevisiae were developed to serve as an oral vaccine in pigs. The vaccinated pigs showed higher specific IgG- and IgA-related antibody activities than the non-treated control and vector control pigs. Additionally, the induced immune responses were found to protect pigs infected with A. pleuropneumoniae according to the analysis of clinical signs and the gross and microscopic pulmonary lesions. These results suggested that the surface-displayed ApxIIA#5 and ApxIA in S. cerevisiae might be a potential oral vaccine to protect pigs against porcine pleuropneumonia. Thus the present study is expected to contribute to the development of a live oral vaccine against porcine pleuropneumonia as an alternative to current conventional vaccines.
authors.affiliation: Department of Infectious Disease, College of Veterinary Medicine and Brain Korea 21 Program for Veterinary Science, Seoul National University, Seoul, Republic of Korea.
authors.forename: Min-Kyoung
authors.initials: MK
authors.lastname: Shin
authors.forename: Mi Lan
authors.initials: ML
authors.lastname: Kang
authors.forename: Myung Hwan
authors.initials: MH
authors.lastname: Jung
authors.forename: Seung-Bin
authors.initials: SB
authors.lastname: Cha
authors.forename: Won-Jung
authors.initials: WJ
authors.lastname: Lee
authors.forename: Jung-Mi
authors.initials: JM
authors.lastname: Kim
authors.forename: Dae-Hyuk
authors.initials: DH
authors.lastname: Kim
authors.forename: Han Sang
authors.initials: HS
authors.lastname: Yoo
mesh_terms: D000189:Actinobacillus Infections / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control / Q000662:veterinary*; D016977:Actinobacillus pleuropneumoniae / Q000235:genetics / Q000276:immunology* / Q000472:pathogenicity; D000284:Administration, Oral; D000595:Amino Acid Sequence; D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis; 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; D001483:Base Sequence; D004269:DNA, Bacterial / Q000235:genetics; D005260:Female; D006460:Hemolysin Proteins / Q000008:administration & dosage* / Q000235:genetics / Q000276:immunology; D008168:Lung / Q000276:immunology / Q000382:microbiology / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D011002:Pleuropneumonia, Contagious / Q000276:immunology* / Q000382:microbiology / Q000517:prevention & control*; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000276:immunology; D034421:Sus scrofa; D013552:Swine; D013553:Swine Diseases / Q000276:immunology* / Q000382:microbiology / Q000517:prevention & control*; D014611:Vaccination / Q000662:veterinary; D014614:Vaccines, Synthetic / Q000008:administration & dosage
chemical_list: D000907:Antibodies, Bacterial; C085361:ApxII toxin, bacteria; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D001428:Bacterial Vaccines; D004269:DNA, Bacterial; D006460:Hemolysin Proteins; D011994:Recombinant Proteins; D014614:Vaccines, Synthetic