has role protective antigen role protective antigen Actinobacillus pleuropneumoniae protein ApxIIA Protegen ID: 360; NCBI Protein GI: 52630374; NCBITaxon: 715 Allen Xiang The levels of local and systemic antibodies specific to the Apx antigens were investigated in mice orally immunized with Apx antigen-expressing yeast. Specific IgA responses to ApxIA or ApxIIA in the intestines and lungs from mice immunized with yeast expressing Apx antigens were significantly higher than those in the control groups after the second and third immunizations, respectively (p < 0.05). All mice were monitored for up to 72 h after challenge with the MLD of an A. pleuropneumoniae field isolate. Overall, the final survival rates of the vaccinated groups were higher than those of the control groups at each time point [PubMed: 17993753]. Oliver He protein