Poster Presentation International Veterinary Immunology Symposium 2016

Nasal immunization with M cell-targeting ligand-conjugated antigen induces protective immunity in a murine model of porcine pleuropneumonia (#128)

Jisang Park 1 , Bum Seok Kim 2 , Han Sang Yoo 3 , Yong Seob Jeong 4 , Yong-Suk Jang 1 5 , Beom-Tae Kim 1
  1. Department of Bioactive Material Sciences and Research Center of Bioactive Materials, Chonbuk National University, Jeonju, Jeonbuk, Korea
  2. Department of Pathology, College of Veterinary Medicine, Chonbuk National University, Iksan, Jeonbuk, Korea
  3. Department of Infectious Diseases, College of Veterinary Medicine, Seoul National University, Seoul, Korea
  4. Department of Food Science and Technology, Chonbuk National University, Jeonju, Jeonbuk, Korea
  5. Department of Molecular Biology and the Institute for Molecular Biology and Genetics, Chonbuk National University, Jeonju, Jeonbuk, Korea

Actinobacillus pleuropneumoniae is the causative agent of porcine pleuropneumonia and severe economic loss in the swine industry has been caused by the infection. Therefore, the development of an effective vaccine against the bacteria is necessary. ApxII toxin, among several virulence factors expressed by the bacteria, is considered to be a promising vaccine candidate because ApxII toxin not only accompanies cytotoxic and hemolytic activities, but is also expressed in all 15 serotypes of bacteria except serotypes 10 and 14. In this study, we identified the peptide ligand capable of targeting the ligand-conjugated ApxIIA#5 fragment antigen to nasopharynx-associated lymphoid tissue. It was found that nasal immunization with ligand-conjugated ApxIIA#5 induced efficient mucosal and systemic immune responses measured at the levels of antigen-specific antibodies, cytokine-secreting cells after antigen exposure, and antigen-specific lymphocyte proliferation. More importantly, the nasal immunization induced protective immunity against nasal challenge infection of the bacteria, which was confirmed by histopathological studies and bacterial clearance after challenge infection. Collectively, we confirmed that the ligand capable of targeting the ligand-conjugated antigen to nasopharynx-associated lymphoid tissue can be used as an effective nasal vaccine adjuvant to induce protective immunity against Actinobacillus pleuropneumoniae infection. (Dr. B.-T. Kim carried out this work with the support of “Cooperative Research Program for Agricultural Science & Technology Development (Project No. PJ009998022016)”, Rural Development Administration, Republic of Korea.)

(This study was supported by 2014K1B1A1073861 through the National Research Foundation (NRF) funded by the Korean Ministry of Science, ICT & Future Planning.)