No abstract available.
Biofilms* ; Porphyromonas gingivalis

The present study was done to evaluate the environmental factors responsible for the expression of Porphyromonas gingivalis heat shock protein. The intensity of the heat shock protein gene expression was comparable to those seen by the heat shock ptreatment of the bacteria (44 degrees C) when the bacteria was grown as a mixed culture or biofilm state at 37degrees C.
Bacteria ; Biofilms ; Gene Expression ; Heat-Shock Proteins* ; Hot Temperature* ; Porphyromonas gingivalis* ; Porphyromonas* ; Shock

No abstract available.
Fusobacterium nucleatum* ; Fusobacterium* ; Immunization* ; Porphyromonas gingivalis* ; Porphyromonas*

No abstract available.
Humans

The present study has been performed to develop a PCR technology to identify human immunoglobulin(Ig) allotypes with restriction fragment length polymorphism(RFLP) using a probe. Genomic DNA were ampilified with PCR tecnology using primers from peripheral blood lymphocytes of 10 periodontal patiens, whose Ig allotypes have been pre-determined by serological tecnique using heagglutination technique. The result indicated that the RFLP patterns could successfully differentiate the Ig allotypes, which suggests that this technology can be developed as a tool useful for population genetics studies.
DNA ; Genetics, Population ; Humans ; Immunoglobulin Allotypes* ; Immunoglobulins* ; Lymphocytes ; Polymerase Chain Reaction* ; Polymorphism, Restriction Fragment Length

The aim of the study was to see the total IgG and IgG subclass responses against Aa and Pg in the four early onset periodontitis (EOP) subforms or adult periodontitis (AP). 6 patients consisting of 3 patients from subform I (distinctive LJP pattern), 19 from subform II (post-juvenile periodontitis pattern), 16 from subform III ( LJP pattern but rapidly progressing), 24 from age-matched AP (20-40 years of age) have been selected for the measurements of the total IgG and each IgG subclass against to Pg and the IgG subclass against Aa, respectively. The total IgG titers against to Pg of the subforms I & III had a significantly higher values than subforms II and IV (P<0.05). Among the IgG subclasses, only the lgG3 levels were significantly higher in the subform I than the subform IV(P <0.05). Wide ranges of the antibody titers were noted in all of the EOP subforms and the AP. Except for the subform I, which was typical of localized form, the IgG2 subclass levels to Pg gradually became higher in accordance with the subforms II, III and IV. Both of IgG2 and the IgG4 antibody levels of the EOP were significantly higher than those of AP, while other subclasses were not. All of the four IgG subclass levels to Pg were consistently found to be higher in the younger age group around 20. The levels found to be low around the thirties and then gradually became higher at the ages of late thirties. The IgG2 titer to Aa in the subform I was significantly higher than those of any other subforms. Combinations of IgG1+2+4 were the most frequently found to be elevated followed by the IgG4 only, the IgG2 only, the IgG2+4, the IgG2+3+4, and the IgG1 only, in the descending order.
Aggregatibacter actinomycetemcomitans ; Aggressive Periodontitis* ; Chronic Periodontitis ; Humans ; Immunoglobulin G* ; Periodontitis ; Porphyromonas gingivalis

No abstract available.
Dental Occlusion ; Dental Restoration, Permanent ; Education, Dental, Continuing ; Dental Care

In the study presented here, identification, purification, and partial characterization of a hemin-regulated protein in Prevotella nigrescens were carried out. The results of this study confirm that the availability of hemin influences the expression of a selected membrane protein as well as the growth rate of P. nigrescens ATCC 33563. The 50 kDa cell envelope associated protein, whose expression is hemin regulated, is considered to be a putative hemin-binding protein from P. nigrescens. Disulfide bonds were not present in this protein, and N'-terminal amino acid sequence analysis revealed that this protein belongs to a new, so far undescribed protein. The 50 kDa protein was found to be rich in hydrophilic amino acids, with glycine comprising approximately 60% of the total amino acids. The study described here is the first to identify, purify, and biochemically characterize a putative hemin-binding protein from P. nigrescens. Work is in progress to further characterize the molecular structure of this protein.
Amino Acids ; Glycine ; Hemin ; Membrane Proteins ; Molecular Structure ; Prevotella nigrescens* ; Prevotella* ; Sequence Analysis, Protein

Antigen-specific T cell clones were obtained from mice immunized with Fusobacterium nucleatum ATCC 10953(F. nucleatum) and/or Porphyromonas gingivalis 381(P. gingivalis). 10 Balb/c mice per group were immunized with F. nucleatum followed by P. gingivalis, or with P. gingivalis alone by intraperitoneal injection of viable microorganisms. Spleen T cells were isolated and stimulated in vitro with viable P. gingivalis cells to establish P. gingivalis-specific T cell clones. T cell phenotypes and cytokine profiles were determined along with T cell responsiveness to F. nucleatum or P. gingivalis. Serum IgG antibody titers to F. nucleatum or P. gingivalis were also determined by ELISA. All the T cell clones derived from mice immunized with F. nucleatum followed by P. gingivalis demonstrated Th2 subsets, while those from mice immunized with P. gingivalis alone demonstrated Th1 subsets based on the flow cytometric analysis and cytokine profiles, All T cells clones from both groups were cross-reactive to both P. gingivalis and F. nucleatum antigens. Phenotypes of T cell clones were all positive for CD4. Mean post-immune serum IgG antibody levels to F. nucleatum or P. gingivalis were significantly higher than the preimmune levels(p<0.01, respectively). There were no significant differences in the antibody titers between the two groups. It was concluded that P. gingivalis-specific T cells initially primed by cross-reactive F. nucleatum antigens were polarized to Th2 subsets, while T cells stimulated with P. gingivalis alone maintained the profile of Th1 subset.
Animals* ; Clone Cells ; Enzyme-Linked Immunosorbent Assay ; Fusobacterium nucleatum ; Immunity, Humoral* ; Immunization* ; Immunoglobulin G ; Injections, Intraperitoneal ; Mice ; Models, Animal* ; Phenotype ; Porphyromonas gingivalis ; Spleen ; T-Lymphocytes

Multiple periodontal pathogens sequentially colonize the subgingival niche during the conversion from gingivitis to destructive periodontal disease. An animal model of sequential immunization with key periodontal pathogens has been developed to determine whether T and B lymppocyte effector functions are skewed and fail to protect the host from pathogenic challenge. The present study was performed to evaluate immunomodulatory effect of exposure to Fusobacterium nucleatum(F. nucleatum) prior to Porphyromonas gingivalis(P.gingivalis). Group 1(control) mice were immunized with phosphate-buffered saline, Group 2 were immunized with F. nucleatum prior to P. gingivalis, while Group 3 were immunized P. gingivalis alone. All the T cell clones derived from Group 2 demonstrated type 2 helper T cell clone(Th2 subsets), while those from Group 3 mice demonstrated Th1 subsets. Exposure of mice to F. nucleatum prior to P. gingivalis interfered with opsonophagocytosis function of sera against P. gingivalis. In adoptive T cell transfer experiments, in vivo protective capacity type 2 helper T cell clones(Th2) from Group 2 was significantly lower than type 1 helper T cell clones(Th1) from Group 3 against the lethal dose infection of P. gingivalis. Western blot analysis indicated the different pattern of recognition of P. gingivalis fimbrial proteins between sera from Group 2 and Group 3. In conclusion, these study suggest that colonization of the subgingival niche by F. nucleatum prior to the periodontal pathogen, P. gingivalis, modulates the host immune responses to P. gingivalis at humoral, cellular and molecular levels.
Animals ; Blotting, Western ; Clone Cells ; Colon ; Fusobacterium nucleatum* ; Fusobacterium* ; Gingivitis ; Immunization ; Mice* ; Models, Animal ; Periodontal Diseases ; Porphyromonas gingivalis* ; Porphyromonas*