Induction of protective immune responses against the challenge of Actinobacillus pleuropneumoniae by the oral administration of transgenic tobacco plant expressing ApxIIA toxin from the bacteria.
Actinobacillus pleuropneumoniae is the causative agent of porcine pleuropneumonia. Among the virulence factors, ApxIIA, a bacterial exotoxin, is reportedly expressed in many serotypes and is considered as a candidate for the development of a vaccine against the bacterial infection. Previously, we isolated a field strain of A. pleuropneumoniae serotype 2 in Korea and characterized its exotoxins to develop an oral vaccine. In this study, we initially confirmed the immunogenicity of ApxIIA expressed in Escherichia coli. We then developed transgenic tobacco expressing ApxIIA and tested its efficacy to induce a protective immune response against A. pleuropneumoniae infection after oral administration of the plant powder. We observed that protective immune responses were induced in mice after oral administration of the plant powder once a week for 4 weeks. Immunoassays revealed that the levels of antigen-specific immunoglobulin G against ApxIIA increased in mice that were fed a powder made from the transgenic plant, but not in mice fed a powder made from wild-type tobacco. Additionally, mice fed the transgenic plant powder were protected from an injection of a lethal dose of A. pleuropneumoniae. These results support that the transgenic plant may be a suitable candidate for an oral vaccine that could be used effectively against A. pleuropneumoniae infection.
Lee
Kyung-Yeol
KY
Department of Oral Microbiology, School of Dentistry, Chonbuk National University, Chonju, Korea.
Kim
Dong-Heon
DH
Kang
Tae-Jin
TJ
Kim
Ju
J
Chung
Gook-Hyun
GH
Yoo
Han-Sang
HS
Arntzen
Charles J
CJ
Yang
Moon-Sik
MS
Jang
Yong-Suk
YS
D000189:Actinobacillus Infections / Q000276:immunology / Q000517:prevention & control*; D016977:Actinobacillus pleuropneumoniae / Q000276:immunology*; D000284:Administration, Oral; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D004195:Disease Models, Animal; D005098:Exotoxins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D006460:Hemolysin Proteins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D051379:Mice; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism / Q000382:microbiology*; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism / Q000382:microbiology*; D014612:Vaccines; D014614:Vaccines, Synthetic / Q000096:biosynthesis / Q000382:microbiology
C085361:ApxII toxin, bacteria; D001426:Bacterial Proteins; D005098:Exotoxins; D006460:Hemolysin Proteins; D014612:Vaccines; D014614:Vaccines, Synthetic