Intracellular NOD2 activation promotes maturation and ... · Porphyromonas gingivalis (P....
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Intracellular NOD2 activation promotes maturation and antigen-presenting functions of dendritic cells exposed to Porphyromonas gingivalis lipopolysaccharide. Han Su 1 , Xiang Yan 2 , Wei Chen 1 , Ting Guo 1 , Zi-Tong Lin 2 , Qin-Gang Hu 2* 1 Department of Stomatology, Jinling Hospital, Clinical School, Medical College, Nanjing University, Nanjing, PR China 2 Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, PR China Abstract Objective: This study aimed to study the roles of Muramyl Dipeptide (MDP) which is an agonist of NOD2 in Dendritic Cells (DCs) exposed to Porphyromonas gingivalis lipopolysaccharide (P. gingivalis- LPS) on maturation and antigen-presenting functions of DCs 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 and ELISA was used to detect IL-12, IFN-γ, IL-10, and IL-13 secreted by DCs which were stimulated by MDP and P. gingivalis-LPS, respectively or in synergism. RT-PCR analysis was used to detect NOD2, TLR2, and TLR4 mRNA expression in DCs stimulated by MDP and P. gingivalis-LPS, respectively or in synergism. CCK8 was used to assess CD4+ T cells proliferation after co-cultured with DCs stimulated by MDP and P. gingivalis-LPS, respectively or in synergism and ELISA was used to detect IL-2, IFN-γ, IL-10 and IL-13 secreted by these T cells. Results: MDP had weak ability to stimulate DCs maturation but MDP could promote DCs maturation stimulated by P. gingivalis-LPS. MDP was NOD2 agonist to DCs and P. gingivalis- LPS was TLR2 but not TLR4 agonist to DCs. MDP could facilitate TLR2 mRNA expression in DCs exposed to P. gingivalis- LPS. The ability of MDP to promote DCs secreting cytokines was far below P. gingivalis-LPS but MDP could promote the functions of Th2 cell-promoting DCs induced by P. gingivalis-LPS. MDP could promote CD4 + T cells proliferation primed by DCs exposed to P. gingivalis-LPS and elevate the ability of DCs exposed to P. gingivalis-LPS to prime Th0 cells to Th2 cells. Conclusion: Intracellular NOD2 in DCs could be activated by MDP and this activation could promote maturation and the ability to prime Th0 cells to Th2 cells of DCs exposed to P. gingivalis-LPS. Keywords: Muramyl dipeptide, P. gingivalis-LPS, Dendritic cells, Maturation, Antigen-presenting. Accepted on November 15, 2017 Introduction Dendritic Cells (DCs) are widely distributed in tissues and organs and they are the body's most efficient Antigen- Presenting Cells (APCs) [1]. Immature DCs uptake antigens and mature DCs present antigens to naive T-lymphocytes, then stimulate naive T cells to differentiate to be effector T cells [2], thus, DCs are important key mediators between innate and acquired immune responses [3]. Priming DCs with microbial compounds up-regulates the expression of costimulatory molecules and the production of proinflammatory cytokines, which drives T-helper (Th) cells to differentiate to Th1 or Th2 cells [4]. The first step of the process is that DCs identify various antigenic materials which are called Pathogen- Associated Molecular Patterns (PAMP) by Pattern Recognition Receptors (PRRs) which are expressed either on the surface or in the cytoplasm of DCs. Thus, PRRs and their ligands have important roles in DCs maturation and antigen-presenting function. Porphyromonas gingivalis (P. gingivalis) is a kind of gram- negative anaerobic rod-shaped bacteria and it is a pathogenic microorganism in the development of Chronic Periodontitis (CP) [5]. The pathogenic components of P. gingivalis include: Lipopolysaccharide (LPS), capsular polysaccharide, fimbrial proteins, and gingipains [6]. P. gingivalis-LPS is one of the main pathogenic factors to periodontitis and P. gingivalis-LPS can elicit various types of immune and inflammatory responses in periodontitis [7]. It is generally accepted that LPS is Toll- Like Receptors (TLR) 4 ligands [8], while there are also many studies declared that different with E. coli-LPS which majorly activated TLR4, P. gingivalis-LPS majorly activated TLR2 [9]. Besides TLRs, there is also another type of important signal transduction PRRs existing in DCs cytoplasm which also play ISSN 0970-938X www.biomedres.info Biomed Res 2018 Volume 29 Issue 4 671 Biomedical Research 2018; 29 (4): 671-679 RETRACTED
Transcript of Intracellular NOD2 activation promotes maturation and ... · Porphyromonas gingivalis (P....
Intracellular NOD2 activation promotes maturation and antigen-presentingfunctions of dendritic cells exposed to Porphyromonas gingivalislipopolysaccharide.
Han Su1, Xiang Yan2, Wei Chen1, Ting Guo1, Zi-Tong Lin2, Qin-Gang Hu2*
1Department of Stomatology, Jinling Hospital, Clinical School, Medical College, Nanjing University, Nanjing, PR China2Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, PR China
Abstract
Objective: This study aimed to study the roles of Muramyl Dipeptide (MDP) which is an agonist ofNOD2 in Dendritic Cells (DCs) exposed to Porphyromonas gingivalis lipopolysaccharide (P. gingivalis-LPS) on maturation and antigen-presenting functions of DCs to provide experimental evidences toexplore the possible mechanism of DCs in periodontitis.Methods: Flow cytometry was used to detect CD11c, MHC-II, CD80, CD86, and CD40 expression onDCs and ELISA was used to detect IL-12, IFN-γ, IL-10, and IL-13 secreted by DCs which werestimulated by MDP and P. gingivalis-LPS, respectively or in synergism. RT-PCR analysis was used todetect NOD2, TLR2, and TLR4 mRNA expression in DCs stimulated by MDP and P. gingivalis-LPS,respectively or in synergism. CCK8 was used to assess CD4+ T cells proliferation after co-cultured withDCs stimulated by MDP and P. gingivalis-LPS, respectively or in synergism and ELISA was used todetect IL-2, IFN-γ, IL-10 and IL-13 secreted by these T cells.Results: MDP had weak ability to stimulate DCs maturation but MDP could promote DCs maturationstimulated by P. gingivalis-LPS. MDP was NOD2 agonist to DCs and P. gingivalis- LPS was TLR2 butnot TLR4 agonist to DCs. MDP could facilitate TLR2 mRNA expression in DCs exposed to P. gingivalis-LPS. The ability of MDP to promote DCs secreting cytokines was far below P. gingivalis-LPS but MDPcould promote the functions of Th2 cell-promoting DCs induced by P. gingivalis-LPS. MDP couldpromote CD4+T cells proliferation primed by DCs exposed to P. gingivalis-LPS and elevate the ability ofDCs exposed to P. gingivalis-LPS to prime Th0 cells to Th2 cells.Conclusion: Intracellular NOD2 in DCs could be activated by MDP and this activation could promotematuration and the ability to prime Th0 cells to Th2 cells of DCs exposed to P. gingivalis-LPS.
Keywords: Muramyl dipeptide, P. gingivalis-LPS, Dendritic cells, Maturation, Antigen-presenting.Accepted on November 15, 2017
IntroductionDendritic Cells (DCs) are widely distributed in tissues andorgans and they are the body's most efficient Antigen-Presenting Cells (APCs) [1]. Immature DCs uptake antigensand mature DCs present antigens to naive T-lymphocytes, thenstimulate naive T cells to differentiate to be effector T cells [2],thus, DCs are important key mediators between innate andacquired immune responses [3]. Priming DCs with microbialcompounds up-regulates the expression of costimulatorymolecules and the production of proinflammatory cytokines,which drives T-helper (Th) cells to differentiate to Th1 or Th2cells [4]. The first step of the process is that DCs identifyvarious antigenic materials which are called Pathogen-Associated Molecular Patterns (PAMP) by Pattern RecognitionReceptors (PRRs) which are expressed either on the surface orin the cytoplasm of DCs. Thus, PRRs and their ligands have
important roles in DCs maturation and antigen-presentingfunction.
Porphyromonas gingivalis (P. gingivalis) is a kind of gram-negative anaerobic rod-shaped bacteria and it is a pathogenicmicroorganism in the development of Chronic Periodontitis(CP) [5]. The pathogenic components of P. gingivalis include:Lipopolysaccharide (LPS), capsular polysaccharide, fimbrialproteins, and gingipains [6]. P. gingivalis-LPS is one of themain pathogenic factors to periodontitis and P. gingivalis-LPScan elicit various types of immune and inflammatory responsesin periodontitis [7]. It is generally accepted that LPS is Toll-Like Receptors (TLR) 4 ligands [8], while there are also manystudies declared that different with E. coli-LPS which majorlyactivated TLR4, P. gingivalis-LPS majorly activated TLR2 [9].
Besides TLRs, there is also another type of important signaltransduction PRRs existing in DCs cytoplasm which also play
ISSN 0970-938Xwww.biomedres.info
Biomed Res 2018 Volume 29 Issue 4 671
Biomedical Research 2018; 29 (4): 671-679
RETRACTED
