title: [Anti-phagocytosis mechanism of SalK/SalR, a two-component regulatory system of Streptococcus suis serotype 2].
abstract: OBJECTIVE
  To determine the role of the two-component regulatory system (TCS) SalK/SalR in the resistance of Streptococcus suis serotype 2 (SS2) phagocytosed by THP-1-derived macrophages (THP-Mphi).
  
  
  METHODS
  Using transmission electron microscopy (TEM), the capsular differences between the wild-type strain 05ZYH33 and the mutant δsalKR were observed. The interactions of SS2 with THP-Mphi were monitored by Gram staining and immunofluorescence cytochemistry. The anti-phagocytic activity of SS2 was evaluated by the construction of phagocytosis model of THP-Mphi.
  
  
  RESULTS
  The TEM showed that in the mutant δsalKR, the capsule was lost; the Gram staining and immunofluorescence imaging revealed that the absence of salKR caused more SS2 were engulfed by THP-Mphi. The phagocytosis model of THP-Mphi cells further demonstrated that the mutant δsalKR was easier to be phagocytosed by THP-1 cells than the wild-type strain.
  
  
  CONCLUSIONS
  The SalK/SalR regulatory system resists the phagocytosis by THP- Mphi through the capsular formation, but the mechanism of how it regulates the formation of the capsule needs further elucidation.
authors.affiliation: College of Biological Science and Technology, Shenyang Agricultural University, Shenyang 110866, China. fuzhonglin219@163.com
authors.forename: Zhonglin
authors.initials: Z
authors.lastname: Fu
authors.forename: Yaya
authors.initials: Y
authors.lastname: Pian
authors.forename: Xueqin
authors.initials: X
authors.lastname: Li
authors.forename: Yuling
authors.initials: Y
authors.lastname: Zheng
authors.forename: Shiliang
authors.initials: S
authors.lastname: Ma
authors.forename: Yuan
authors.initials: Y
authors.lastname: Yuan
authors.forename: Chunyue
authors.initials: C
authors.lastname: Huo
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008264:Macrophages / Q000276:immunology / Q000382:microbiology; D009154:Mutation; D010587:Phagocytosis / Q000502:physiology*; D017011:Streptococcus suis / Q000235:genetics / Q000276:immunology* / Q000378:metabolism*; D014774:Virulence / Q000235:genetics
chemical_list: D001426:Bacterial Proteins