title: Differential roles of Porphyromonas gingivalis lipopolysaccharide and Escherichia coli lipopolysaccharide in maturation and antigen-presenting functions of dentritic cells.
abstract: OBJECTIVE
  The aim of this research is to study the roles of Porphyromonas gingivalis-lipopolysaccharide (P. gingivalis-LPS) and Escherichia coli-lipopolysaccharide (E. coli-LPS) on maturation and antigen-presenting functions of dendritic cells (DCs), and to provide experimental evidences to explore the possible mechanism of DCs in periodontitis.
  
  
  METHODS
  Flow cytometry was used to detect CD11c, MHC-II, CD80, CD86 and CD40 expression on DCs which were stimulated by P. gingivalis-LPS or E. coli-LPS and ELISA was used to detect IL-12, IFN-γ, IL-10 and IL-13 secreted by DCs. CCK8 was used to assay CD4+T cells proliferation after co-cultured with DCs stimulated by P. gingivalis-LPS or E. coli-LPS and ELISA was used to detect IL-2, IFN-γ, IL-10 and IL-13 secreted by T cells. TLR4 inhibitor (polymyxin B) or TLR2 and TLR4 inhibitor (OxPAPC) was added to P. gingivalis-LPS group and E. coli-LPS group to observe the effects of these two TLR inhibitors on the maturation and antigen-presenting functions of DCs.
  
  
  RESULTS
  The capacity of P. gingivalis-LPS to stimulate DCs maturation was similar to that of E. coli-LPS. The amount of IL-12 and IFN-γ secreted by DCs in P. gingivalis-LPS group was significantly lower than that of E. coli-LPS group (p < 0.05), meanwhile, IL-10 and IL-13 secreted by DCs in P. gingivalis-LPS group was significantly higher than that of E. coli-LPS group (p < 0.05). DCs stimulated by both P. gingivalis-LPS and E. coli-LPS could promote the proliferation of CD4+T cells. The amount of IL-2 and IFN-γ secreted by T cells stimulated by DCs in P. gingivalis-LPS group was significantly lower than that of E. coli-LPS group (p < 0.05), meanwhile, IL-10 secreted by T cells stimulated by DCs in P. gingivalis-LPS group was significantly higher than that of E. coli-LPS group (p < 0.05). When TLR4 inhibitor was added to E. coli-LPS group, maturation and antigen-presenting functions of DCs were significantly inhibited. When TLR4 inhibitor was added to P. gingivalis-LPS group, maturation and antigen-presenting functions of DCs were not significantly inhibited. When TLR2 and TLR4 inhibitor was added to P. gingivalis-LPS group, maturation and antigen-presenting functions of DCs were significantly inhibited.
  
  
  CONCLUSIONS
  P. gingivalis-LPS could prime DCs maturation and antigen-presenting functions. DCs stimulated by P. gingivalis-LPS are prone to induce a stronger Th2 cell responses while DCs stimulated by E. coli-LPS are prone to induce a stronger Th1 cell responses. P. gingivalis-LPS triggers DCs through TLR2 pathway while E. coli-LPS triggers DCs through TLR4 pathway.
authors.affiliation: Department of Stomatology, Jinling Hospital, Clinical School, Medical College, Nanjing University, Nanjing, China. njuniv@126.com.
authors.forename: H
authors.initials: H
authors.lastname: Su
authors.forename: X
authors.initials: X
authors.lastname: Yan
authors.forename: Z
authors.initials: Z
authors.lastname: Dong
authors.forename: W
authors.initials: W
authors.lastname: Chen
authors.forename: Z-T
authors.initials: ZT
authors.lastname: Lin
authors.forename: Q-G
authors.initials: QG
authors.lastname: Hu
mesh_terms: D000818:Animals; D017951:Antigen Presentation / Q000187:drug effects / Q000502:physiology*; D049109:Cell Proliferation / Q000187:drug effects / Q000502:physiology; D018920:Coculture Techniques; D003713:Dendritic Cells / Q000187:drug effects / Q000502:physiology*; D004926:Escherichia coli / Q000502:physiology*; D008070:Lipopolysaccharides / Q000494:pharmacology / Q000502:physiology*; D008297:Male; D016966:Porphyromonas gingivalis / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D013601:T-Lymphocytes / Q000187:drug effects / Q000502:physiology
chemical_list: D008070:Lipopolysaccharides