Inhibitory effect of 1,25-dihydroxyvitamin D on Porphyromonas gingivalis-induced inflammation and bone resorption in vivo.

Objective: To investigate whether intragastric administration of 1,25-dihydroxyvitamin D (1,25(OH)D) could inhibit the bone resorption and inflammation in a mouse calvarial model infected by Porphyromonas gingivalis (P. gingivalis).

Design: Live P.

CCL17 combined with CCL19 as a nasal adjuvant enhances the immunogenicity of an anti-caries DNA vaccine in rodents.

Aim: CCL19 and its receptor CCR7 are essential molecules for facilitating the trafficking of mature dendritic cells (DCs) and helping to establish a microenvironment in lymphoid tissues to initiate primary immune responses, whereas CCL17 is required in the CCR7-CCL19-dependent migration of DCs. In this study we examined whether co-administration of CCL17 and CCL19 could enhance the immunogenicity of an anti-caries DNA vaccine, pCIA-P, in rodents.

Methods: Plasmids encoding CCL17 (pCCL17/VAX) and CCL19 (pCCL19/VAX) were constructed.

Effects of 1,25-dihydroxyvitamin D on Macrophage Cytokine Secretion Stimulated by Porphyromonas gingivalis.

Vitamin D is known to be closely associated with periodontitis; however, its exact mechanisms remain to be clarified. The present study aimed to investigate the influence of 1,25-dihydroxyvitamin D (1,25(OH)D) on Porphyromonas gingivalis (Pg)-stimulated cytokine production and the involved signaling pathways in macrophages. The main observation was that 1,25(OH)D inhibited Pg-induced interleukin (IL)-6 cytokine expression but up-regulated the expression of anti-inflammatory cytokine IL-10.

Intranasal co-delivery of IL-6 gene enhances the immunogenicity of anti-caries DNA vaccine.

Aim: To investigate the effects of co-delivering IL-6 expressing plasmid pCI-IL-6 on the immunogenicity of the anti-caries DNA vaccine pCIA-P, which encodes the surface protein antigen PAc of Streptococcus mutans.

Methods: Plasmid pCI-IL-6 was constructed by inserting the murine IL-6 gene into the pCI vector. Expression of IL-6 in vitro was assessed using Western blot analysis.

[Application of case-based learning in clinical internship teaching of conservative dentistry and endodontics].

Purpose: To investigate the education effect of case-based learning (CBL) pattern on clinical internship of conservative dentistry and endodontics.

Methods: Forty-one undergraduates were randomly assigned into CBL group and traditional teaching group. After clinical internship in the department of conservative dentistry and endodontics for 11 weeks, each student in the 2 groups underwent comprehensive examinations including medical record writing, case analysis, academic knowledge, professional skills and the ability of winning the trust of the patients.

A new gcrR-deficient Streptococcus mutans mutant for replacement therapy of dental caries.

Background: gcrR gene acts as a negative regulator related to sucrose-dependent adherence in S. mutans. It is constructive to test the potential capacity of mutans with gcrR gene deficient in bacteria replacement therapy.

Co-delivery of ccl19 gene enhances anti-caries DNA vaccine pCIA-P immunogenicity in mice by increasing dendritic cell migration to secondary lymphoid tissues.

Aim: To investigate how co-delivery of the gene encoding C-C chemokine ligand-19 (CCL-19) affected the systemic immune responses to an anti-caries DNA vaccine pCIA-P in mice.

Methods: Plasmid encoding CCL19-GFP fusion protein (pCCL19/GFP) was constructed by inserting murine ccl19 gene into GFP-expressing vector pAcGFP1-N1. Chemotactic effect of the fusion protein on murine dendritic cells (DCs) was assessed in vitro and in vivo using transwell and flow cytometric analysis, respectively.

Anti-caries DNA vaccine-induced secretory immunoglobulin A antibodies inhibit formation of Streptococcus mutans biofilms in vitro.

Aim: To investigate the effects of anti-caries DNA vaccine-induced salivary secretory immunoglobulin A (S-IgA) antibodies on Streptococcus mutans (S. mutans) adherence and biofilms formation in vitro.

Methods: Adult female Wistar rats were intranasally immunized with the anti-caries DNA vaccine pGJA-P/VAX.

A targeted fimA DNA vaccine prevents alveolar bone loss in mice after intra-nasal administration.

Aim: To construct a dendritic cell (DC)-targeted DNA vaccine against FimA of Porphyromonas gingivalis and evaluate the immunogenicity and protection in mice.

Materials And Methods: A targeted DNA plasmid pCTLA4-FimA, which encodes the signal peptide and extracellular regions of mouse cytotoxic T lymphocyte-associated antigen 4 (CTLA4), the hinge and Fc regions of human Igγ1 and FimA of P. gingivalis, was constructed.

[Protective efficacy of a new fusion anti-caries DNA vaccine encoding antigens of both Streptococcus mutans and Streptococcus sobrinus].

Objective: To construct a new fusion anti-caries DNA vaccine pGJGAC/VAX encoding antigens of both S. mutans and S. sobrinus so as to enhance the protective effect of DNA vaccine against S.

A new strategy for the replacement therapy of dental caries.

The rationale of bacterial replacement therapy against dental caries is that relatively avirulent strains of Mutans Streptococi (MS) are most likely to occupy the same ecological niche in plaque as their more cariogenic counterparts. As known, lactate dehydrogenase (LDH) deficiency has been proposed as one aspect of a strategy to construct an effector strain because LDH-deficient mutants could affect acid production by MS so as to reduce their cariogenicity. Glucan-binding lectin (GBL) plays a very important role in the formation of dental plaque biomembrane and the adherence of S.

Protective efficacy of two new anti-caries DNA vaccines.

As we know, the catalytic region of glucosyltransferases (GTFs) is a key region responsible for sucrose-dependent adherence of cariogenic bacteria to teeth. In this study, we evaluate the potential of the catalytic region to enhance the immunogenicity of the anti-caries DNA vaccine. We construct two new anti-caries DNA plasmids pGJGAC/VAX and pGJGA-5C/VAX by cloning different styles of the catalytic regions of GTFs into the previous plasmid pGJA-P/VAX.

Analysis of the molecular mechanisms of targeted anti-caries DNA plasmid enhancing antibody responses by gene arrays.

Background: The cytotoxic T lymphocyte antigen 4 (CTLA4) represents an attractive ligand for use in the targeting of antigens to dendritic cells (DCs). Studies have shown that CTLA4 targeted DNA vaccines induced accelerated and increased antibody responses compared to nontargeted vaccines. However, little is known about the molecular events on DCs after transfection with targeted DNA vaccines.

CTLA4 targeting strategy in DNA vaccination against periodontitis.

Periodontitis are among the most frequent infectious diseases affecting children and adolescents. The primary etiology of periodontal diseases is the bacterial plaque. Studies have demonstrated the feasibility of inducing immune responses by DNA vaccines against Porphyromonas gingivalis, the major aetiological agent of chronic periodontitis, and the subsequent development of periodontitis in animal models.

Enhanced efficacy of CTLA-4 fusion anti-caries DNA vaccines in gnotobiotic hamsters.

Aim: To evaluate the comparative immunogenicity and protective efficacy of the cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) fusion anti-caries DNA vaccines pGJA-P/VAX1, pGJA-P, and non-fusion anti-caries DNA construct pGLUA-P in hamsters. In addition, the ability of CTLA-4 to target pGJA-P/VAX1-encoding antigen to dendritic cells was tested in vitro.

Methods: All DNA constructs contain genes encoding the A-P regions of a cell surface protein (PAc) and the glucan binding (GLU) domain of glucosyltransferases (GTFs) of cariogenic organism Streptococcus mutans.

Immunogenicity of CTLA4 fusion anti-caries DNA vaccine in rabbits and monkeys.

Enhancement of mucosal and systemic immune responses is still a challenge for the application of DNA vaccine. Here, we show anti-caries DNA vaccines, pGJA-P and pGJA-P/VAX, encoding Streptococcus mutans antigens fused to cytotoxic T lymphocyte antigen-4 (CTLA4), which binds to B7 molecule expressed on the surfaces of antigen-presenting cells. Rabbits and monkeys were immunized via intranasal or intramuscular routes.

Immunogenicity and protective efficacy of a targeted fusion DNA construct against dental caries.

Targeting antigens to antigen-presenting cells by fusion to cytotoxic T lymphocyte-associated antigen 4 (CTLA4) has been shown to be a highly efficient method to enhance the efficacy of DNA vaccines. The purpose of this study was to determine the immunogenicity and protective efficacy of the targeted fusion DNA construct pGJA-P, which contains the signal peptide and extracellular regions of human CTLA4 gene, the hinge and Fc regions of human Iggamma1 gene, the glucan-binding domain of the Streptococcus mutans gtfB gene and the A-P fragment of the S. mutans pac gene, compared with the fusion DNA construct pGLUA-P, which contains only the glucan-binding domain of the S.

[Immunization of rats with a targeted fusion anticaries DNA vaccine].

Objective: To observe the expression of a targeted fusion anticaries DNA vaccine pGJA-P in situ. To compare the levels of specific antibodies and anticaries efficacy generated by pGJA-P and pGLUA-P, a fusion anticaries DNA vaccine.

Methods: pGJA-P was administrated intramuscularly or intranasally to rats, and the expression of recombinant protein was detected by immunohistochemistry technique.

[Immunization with targeted fusion anticaries DNA vaccine via intramuscular route:experiment with murine].

Objectives: To observe the expression of a targeted fusion anticaries DNA vaccine pGJA-P in muscular in vivo. To compare the levels of specific antibodies and anticaries efficacy generated by pGJA-P and fusion anticaries DNA vaccine pGLUA-P in gnotobiotic rats, and observe the kinetics of antibody responses in BALB/c mice.

Methods: (1) Twelve 28-day-old female Wistar rats were randomly divided into 2 groups of 6 rats to be injected with the plasmid pGJA-P containing the signal peptide and extracellular regions of human CTLA(4), hinge and Fc regions of human IgG, the glu sequence of gtfB gene and A-P fragment of pac gene of Streptococcus mutans or the eukaryotic expression plasmid pCI into the quadriceps muscle of thigh respectively.