Trimeric autotransporter adhesins contribute to Actinobacillus pleuropneumoniae pathogenicity in mice and regulate bacterial gene expression during interactions between bacteria and porcine primary alveolar macrophages.
Actinobacillus pleuropneumoniae is an important pathogen that causes respiratory disease in pigs. Trimeric autotransporter adhesin (TAA) is a recently discovered bacterial virulence factor that mediates bacterial adhesion and colonization. Two TAA coding genes have been found in the genome of A. pleuropneumoniae strain 5b L20, but whether they contribute to bacterial pathogenicity is unclear. In this study, we used homologous recombination to construct a double-gene deletion mutant, ΔTAA, in which both TAA coding genes were deleted and used it in in vivo and in vitro studies to confirm that TAAs participate in bacterial auto-aggregation, biofilm formation, cell adhesion and virulence in mice. A microarray analysis was used to determine whether TAAs can regulate other A. pleuropneumoniae genes during interactions with porcine primary alveolar macrophages. The results showed that deletion of both TAA coding genes up-regulated 36 genes, including ene1514, hofB and tbpB2, and simultaneously down-regulated 36 genes, including lgt, murF and ftsY. These data illustrate that TAAs help to maintain full bacterial virulence both directly, through their bioactivity, and indirectly by regulating the bacterial type II and IV secretion systems and regulating the synthesis or secretion of virulence factors. This study not only enhances our understanding of the role of TAAs but also has significance for those studying A. pleuropneumoniae pathogenesis.
College of Veterinary Medicine, Jilin University, Changchun, People's Republic of China.
Wanhai
W
Qin
College of Veterinary Medicine, Jilin University, Changchun, People's Republic of China.|College of Animal Science, Henan Institute of Science and Technology, Xinxiang, People's Republic of China.
Lei
L
Wang
College of Veterinary Medicine, Jilin University, Changchun, People's Republic of China.
Ruidong
R
Zhai
College of Veterinary Medicine, Jilin University, Changchun, People's Republic of China.
Qiuyue
Q
Ma
College of Veterinary Medicine, Jilin University, Changchun, People's Republic of China.
Jianfang
J
Liu
College of Veterinary Medicine, Jilin University, Changchun, People's Republic of China.
Chuntong
C
Bao
School of Public Health, Jilin University, Changchun, People's Republic of China.
Hu
H
Zhang
College of Veterinary Medicine, Jilin University, Changchun, People's Republic of China.
Changjiang
C
Sun
College of Veterinary Medicine, Jilin University, Changchun, People's Republic of China.
Xin
X
Feng
College of Veterinary Medicine, Jilin University, Changchun, People's Republic of China.
Jingmin
J
Gu
College of Veterinary Medicine, Jilin University, Changchun, People's Republic of China.
Chongtao
C
Du
College of Veterinary Medicine, Jilin University, Changchun, People's Republic of China.
Wenyu
W
Han
Section of Paediatrics, Imperial College London, London, UK.
P R
PR
Langford
College of Veterinary Medicine, Jilin University, Changchun, People's Republic of China. leiliancheng@163.com.
Liancheng
L
Lei
D000189:Actinobacillus Infections / Q000382:microbiology; D016977:Actinobacillus pleuropneumoniae / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity* / Q000502:physiology; D018829:Adhesins, Bacterial / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D001422:Bacterial Adhesion / Q000235:genetics / Q000502:physiology; D005260:Female; D017353:Gene Deletion; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D016676:Macrophages, Alveolar / Q000382:microbiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D020411:Oligonucleotide Array Sequence Analysis; D061251:Primary Cell Culture; D013552:Swine; D000069320:Type V Secretion Systems / Q000235:genetics / Q000378:metabolism; D037521:Virulence Factors / Q000096:biosynthesis / Q000235:genetics
D018829:Adhesins, Bacterial; D000069320:Type V Secretion Systems; D037521:Virulence Factors
Actinobacillus pleuropneumoniae; Gene expression profiles; Trimeric autotransport adhesin