Generation, safety and immunogenicity of an Actinobacillus pleuropneumoniae quintuple deletion mutant SLW07 (ΔapxICΔapxIICΔorf1ΔcpxARΔarcA). Issue 14 (27th March 2018)

• Record Type: Journal Article
• Authors: Yuan, Fangyan; Liu, Jinlin; You, Wujin; Bei, Weicheng; Wang, Chunlai; Zhao, Jin; Tian, Yiongxiang; Liu, Siguo
• Is Part Of: Vaccine. Volume 36:Issue 14(2018)
• Page Start: 1830
• Page End: 1836
• Publication Date: 2018-03-27
• Subjects: Actinobacillus pleuropneumoniae -- Quintuple deletion mutant -- Safety -- Protective efficacy; Vaccines -- Periodicals; 615.372
• DOI: 10.1016/j.vaccine.2018.02.083
• Languages: English
• ISSNs: 0264-410X

Abstract

Highlights: An A. pleuropneumoniae quintuple deletion mutant SLW07 was constructed. ArcA is involved in adherence, invasion and intracellular survival. SLW07 is safer than its parent SLW06 in animals. SLW07 stimulates strong humoral immune responses in mice. SLW07 provides complete protection for animals against virulent challenge. Abstract: We inactivated a virulence determinant, ArcA, in an Actinobacillus pleuropneumoniae quadruple deletion mutant SLW06 (Δ apxIC Δ apxIIC Δ orf 1Δ cpxAR, serovar 1), and a quintuple deletion mutant SLW07 was generated. SLW07 showed decreased adherence to and invasion of host cells, compared to its parent strain SLW06. SLW07 was more sensitive in RAW264.7 macrophage-mediated phagocytosis and clearance. SLW07 was less virulent in mice. An immunization assay indicated that both SLW07 and SLW06 preferentially stimulated T helper cell type 2 response in mice. Live vaccines induced the production of interleukin-6 and tumor necrosis factor-α by splenic lymphocytes. Furthermore, the protective immunity of SLW07 was not affected after ArcA mutation. Immunization with SLW07 could provide a complete protection following virulent A. pleuropneumoniae challenge in mice. Our results suggest that SLW07 is a promising live vaccine candidate, which is further attenuated from and shares similar protective efficacy with its quadruple deletion parent SLW06.