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H Senpuku

Publications and source records attributed to H Senpuku.

35 records · Page 2Linked to original sources
PubMed1998

Identification of Streptococcus mutans PAc peptide motif binding with human MHC class II molecules (DRB1*0802, *1101, *1401 and *1405).

A surface protein antigen (PAc) of Streptococcus mutans, in particular the A-region of this PAc molecule, has been noted as a possible target in research for an effective dental caries vaccine. To identify the antigenic peptide binding to major histocompatibility complex (MHC) class II (HLA-DR) molecules in the A-region, we prepared a panel of overlapping synthetic peptides in the second unit of the A-region, and established that a simple enzyme-linked immunosorbent assay (ELISA) binding assay could be achieved by incubating the DR-crude. Binding to DR molecules of these peptides from nine donors was investigated by using the ELISA binding assay. It was revealed that the PAc(316-334) peptide bound more strongly to the HLA-DR molecule in seven out of nine subjects. In particular, DR8 (DRB1*0802), DR5 (DRB1*1101) and DR6 (DRB1*1402 and *1405), which bound strongly to PAc(316-334) peptide, were identified. Moreover, we synthesized glycine-substituted peptide analogues of the peptide and examined the binding motif of the binding region. As a result, the multiple binding motif in DR8, DR5 and DR6 was found in L-RV-K-A. It is suggested that a peptide vaccine for dental caries that is more effective for humans, with fewer adverse side-effects, could be designed by combining the multiple binding motif with the B-cell epitope to produce only the inhibiting antibody against dental caries. The peptide could therefore be useful for peptide vaccine development in the general human population.

Adult↗
PubMed1998

Purification of immunosuppressive factor from Capnocytophaga ochracea.

Capnocytophaga, one of the genera of oral bacteria, has been implicated in the pathogenesis of several diseases, including endocarditis, septicaemia and disorders of the oral cavity such as abscesses and periodontal disease. This study examined sonic extracts (SE) of Capnocytophaga strains for their ability to alter lymphocyte function. The SE of tested Capnocytophaga caused dose-dependent suppression of spleen cells in response to mitogen. This suppressive effect was heat-labile and sensitive to the proteolytic enzyme pronase E. The suppressive factor (SF) was purified from SE of C. ochrasea by a combination of ultrogel-AcA34, high-pressure liquid DEAE ion-exchange chromatography and hydroxyapatite columns, which revealed a single band of 14 kDa by SDS-PAGE. Rabbit anti-serum against the purified SF inhibited the immunosuppression induced by SE of C. ochracea with the recovery of lymphocyte proliferation.

Animals↗
PubMed1996

Interaction of lysozyme with a surface protein antigen of Streptococcus mutans.

The interaction of salivary lysozyme with the surface protein antigen (PAc) of Streptococcus mutans and the interaction of lysozyme with the pathogen were examined by ELISA using S. mutans MT8148 (PAc+) and the PAc-defective mutant EM-2 (PAc-). The lysozyme clearly bound to the S. mutans wild type but not to the S. mutans mutant. Furthermore, lysozyme bound directly in the fluid phase to the rPAc, of which the binding kinetics were determined (Kon = 3.63 +/- 0.04 x 10(3) M-1 s-1, K(off) = 1.72 +/- 0.04 x 10-5 s-1 and Kon/K(off) = 2.11 x 10(8) M-1) using surface plasmon resonance. The kinetics of both association and dissociation were relatively slow. In addition, anti-lysozyme antibody significantly inhibited the binding of salivary components to the rPAc. The present findings indicate that lysozyme is one of the major salivary components interacting with S. mutans PAc.

Adult↗
PubMed1996

Immunogenicity of peptides coupled with multiple T-cell epitopes of a surface protein antigen of Streptococcus mutans.

A surface protein antigen (PAc) of Streptococcus mutans, in particular the A-region of the molecule, has been noted as a possible target of effective dental caries vaccine. We have previously shown that two peptides of 19 amino acids (residues 361-379, NAKATYEAALKQYEADLAA, and residues 301-319, ANAANEADYQAKLTAYQTE), which correspond to parts of the A-region, contain both T- and B-cell epitopes for the induction of cross-reacting antibodies to the PAc. In this study, for development of an appropriate antigen as a peptide vaccine for use in prophylactic dentistry, we analysed in detail the localization of the T- and B-cell epitopes of PAc(361-379) peptide and the T-cell epitope of PAc(301-319) peptide in B10 congenic mice. In four murine major histocompatibility complex (MHC) haplotypes (H-2f,d,a and k), PAc(361-377) peptide showed T- and B-cell epitopes forming a cluster. It was found that the antibody which was induced by the immunization with the peptide was strongly cross-reactive with recombinant (r)PAc. Meanwhile, PAc(305-318) peptide, recognised by five strains of mice of different MHC haplotypes (H-2f,d,a,k and s), also bore multiple T-cell epitopes. PAc(361-377) peptide coupled to PAc(305-318) significantly elevated cross-reacting antibody levels compared to immunization with PAc(361-377) only in four H-2 haplotypes. Moreover, a peptide with PAc(305-318) coupled to the N-terminal region of PAc(361-377) produced significant cross-reacting antibody against rPAc, even in B10.S mice which had not responded to immunization with PAc(361-379) peptide. Therefore, it was suggested that coupling among the peptides forming a cluster might be effective in increasing immunogenicity. These results may provide us with a useful strategy for the design of peptide-based vaccines for S. mutans in the future.

Amino Acid Sequence↗
PubMed1996

Identification of human antigenic epitopes in an alanine-rich repeating region using sera from hu-PBL-SCID mice immunized with a surface protein antigen of Streptococcus mutans.

A 190-kDa surface protein antigen (PAc) of Streptococcus mutans is considered to play an important role in dental caries. To identify antigenic epitopes of the PAc in humans, we immunized severe combined immunodeficient (SCID) mice with recombinant PAc that was transplanted with human peripheral blood mononuclear cells (PBMC). The reactivities of the sera from the immunized hu-PBL-SCID mice to the recombinant PAc and 24 19-mer synthetic peptides covering the alanine-rich repeating region (A-region) presented in the PAc molecule were then examined. The results showed that the immunized mice produced a significant recombinant PAc-specific human antibody, and among 24 19-mer peptides, 6 19-mer peptides showed a strong reaction with the antibodies. In addition, 4 19-mer peptides containing human antigenic epitope in a donor were identified with enzyme-linked immunosorbent assay (ELISA) inhibition assays using the recombinant PAc protein. In this study, the SCID mouse was useful in identifying human antigenic epitopes.

Adult↗
PubMed1996

Identification of a repeated epitope recognized by human serum antibodies in a surface protein antigen of Streptococcus mutans.

This study determined the antigen determinants of a 190-kDa protein antigen of Streptococcus mutans that is involved in the initial attachment to the tooth surface. In 5 subjects, the reactivities of serum antibodies to 7 overlapping surface protein antigen fragments covering the entire antigen molecule and 19 sequential overlapping synthetic 19-mer peptides covering the entire A-region of the surface protein antigen were examined with enzyme-linked immunosorbent assay (ELISA). The study showed that the A-region of the antigen is strongly immunogenic in humans and contains several widely distributed epitopes. In addition, an amino acid sequence of the one of dominant epitopes in a certain subject was identified as LTAENTAI with ELISA inhibition assays using the relevant truncated peptides. This epitope was located both at the positions from L-346 to I-364 and L-430 to E-437 of the antigen molecule, and serum antibodies against the epitope were found in 3 of the 5 subjects.

Adult↗
PubMed1995

An antigenic peptide inducing cross-reacting antibodies inhibiting the interaction of Streptococcus mutans PAc with human salivary components.

A 190-kDa surface protein antigen (PAc) of Streptococcus mutans, in particular the A region of this molecule, may be implicated in the induction of dental caries via an interaction with salivary components. For this reason, it was probably used successfully as an antigenic component for experimental vaccination to prevent dental caries in animals. While developing a synthetic peptide vaccine for dental caries, as reported herein, we have identified a unique peptide, TYEAALKQYEADL, as a candidate vaccinal immunogen. The amino acid sequence of this peptide completely corresponds to the sequence of a B-cell epitope in the A region of PAc and additionally contains its own T-cell epitope for B10.D2 mice within the molecule. This peptide strongly induces the production of only cross-reacting antibodies against PAc. In addition, as demonstrated by surface plasmon resonance analysis using the BIAcore system, these cross-reacting antibodies inhibit approximately 50% of the binding of fluid-phase salivary components to immobilized recombinant PAc.

Adult↗
PubMed1995

Membrane-associated interleukin-1 on macrophages stimulated with Actinobacillus actinomycetemcomitans lipopolysaccharide induces osteoclastic bone resorption in vivo.

The effect of paraformaldehyde-fixed murine macrophage P388D1 cells stimulated with Actinobacillus actinomycetemcomitans Y4 lipopolysaccharide (membrane-associated interleukin-1) on osteoclastic bone resorption was investigated. Both the number of osteoclasts and the bone resorption surfaces increased considerably along the inside of the marrow space of mouse calvaria when membrane-associated interleukin-1 mediated by A. actinomycetemcomitans Y4 lipopolysaccharide were injected into the subcutaneous tissues overlying the central calvaria of 4-week-old C3H/HeJ mice. Membrane-associated interleukin-1 caused hypercalcaemia when injected into C3H/HeJ mice twice a day for 2 days. The calvaria of C3H-HeJ mice injected with membrane-associated interleukin-1 contained less mineral than those of the control mice. These results suggest that membrane-associated interleukin-1 on macrophages stimulated with A. actinomycetemcomitans Y4 lipopolysaccharide plays an important role in inflammatory osteoclastic bone resorption in periodontal diseases.

Aggregatibacter actinomycetemcomitans↗
PubMed1994

Membrane-associated interleukin-1 promotes osteoclast-like cell formation in vitro.

The effect of paraformaldehyde-fixed murine macrophage P388D1 cells on osteoclast-like cell formation was investigated in mouse marrow cultures. When mouse marrow cells were cocultured for 8 days with paraformaldehyde-fixed P388D1 cells stimulated with lipopolysaccaride (LPS), many tartrate-resistant acid phosphatase (TRACP)-positive multinucleated cells were formed. Non-stimulated, and paraformaldehyde-fixed P388D1 cells did not induce the formation of TRACP-positive multinucleated cells. Salmon calcitonin and indomethacin strongly inhibited the paraformaldehyde-fixed, LPS-stimulated P388D1 cells-induced TRACP-positive multinucleated cell formation. Monospecific anti-mouse recombinant IL-1 alpha serum inhibited TRACP-positive multinucleated cell formation in the presence of paraformaldehyde-fixed P388D1 cells stimulated with LPS. These results suggest that membrane-associated IL-1 on macrophages is responsible for the resorptive effect of paraformaldehyde-fixed P388D1 cells stimulated with LPS.

3T3 Cells↗
PubMed1993

Identification of antigenic epitopes in an alanine-rich repeating region of a surface protein antigen of Streptococcus mutants.

A surface protein antigen (PAc) of Streptococcus mutans with a molecular mass of 190 kDa is considered to play an important role in the initial attachment of this streptococcus to the tooth surface. Two internal repeating amino acid sequences are present in the PAc molecule. One repeating region located in the N-terminal region is rich in alanine (A-region), and the other, located in the central region, is rich in proline (P-region). To identify antigenic epitopes on the A-region of the PAc protein, 82 sequential overlapping synthetic decapeptides covering one of the repetitive units of the A-region were synthesized. In the epitope scanning analyses using murine antisera raised against recombinant PAc (rPAc), multiple antigenic epitopes were found in the repetitive unit of the A-region, and some of them reacted with antisera to rPAc from BALB/c, B10, B10.D2, and B10.BR mice. In particular, a peptide YEAALKQY (residues 366 to 373) was recognized by anti-rPAc sera from all four strains of mice. The reactivities of anti-rPAc sera in the epitope scanning were confirmed by using a purified synthetic peptide, NAKATYEAALKQYEADLAA (corresponding to residues 361 to 379). Furthermore, antisera against a surface protein antigen PAg (SpaA) of Streptococcus sobrinus from BALB/c mice reacted strongly to residues 330 to 337, 362 to 369, and 366 to 373 of the PAc protein by the epitope scanning analysis. An AKATYEAALKQY (residues 362 to 373 of the PAc protein)-like sequence, AKANYEAKLAQY, was found within the A-region of S. sobrinus PAg, suggesting that the amino acid sequences AKA-YEA and YEA-L-QY may be major cross-reactive epitopes of the S. mutans PAc protein and the S. sobrinus PAg protein.

Amino Acid Sequence↗
PubMed1990

Monoclonal antibody-coated latex agglutination assay for identification of Actinobacillus actinomycetemcomitans.

Three monoclonal antibodies (MAbs) to lipopolysaccharide of Actinobacillus actinomycetemcomitans strain Y4 (serotype b) and eight MAbs to a serotype b-specific polysaccharide antigen of strain Y4 were obtained. Latex particles sensitized with an MAb to the Y4 lipopolysaccharide produced a positive agglutination with whole cells of all three serotypes of A. actinomycetemcomitans, but not with Haemophilus aphrophilus, Haemophilus paraphrophilus, Haemophilus influenzae, Porphyromonas (Bacteroides) gingivalis, "Bacteroides" intermedius, Fusobacterium nucleatum and Escherichia coli. On the other hand, latex particles sensitized with an MAb to the serotype b-specific polysaccharide antigen agglutinated with whole cells of serotype b A. actinomycetemcomitans and P. gingivalis, but not with heated and trypsinized cells of P. gingivalis. The simple and rapid latex agglutination assay using MAbs may be useful for the identification of A. actinomycetemcomitans.

Actinobacillus↗
PubMedDate not supplied

Inhibitory effects of MoAbs against a surface protein antigen in real-time adherence in vitro and recolonization in vivo of Streptococcus mutans.

A surface protein antigen (PAc) of Streptococcus mutans, particularly the A-region of the molecule, has been reported to interact with salivary components on the tooth surface. It might be a candidate antigen inducing the production of antibodies against the adherence of S. mutans to the tooth surface. We investigated the effects of monoclonal antibodies (MoAbs) obtained by immunization of synthetic PAc peptides that completely correspond to the amino acid sequence of part of the A-region. These MoAbs recognize several core B-cell epitopes in the sequence. Two (KH5 and SH2) of these antibodies reacted with both S. mutans and Streptococcus sobrinus, but not with Streptococcus sanguis, Streptococcus salivarius, Porphyromonas gingivalis or Lactobacillus casei. They clearly inhibited the real-time adherence of S. mutans to salivary components in a biosensor. KH5, which showed a real-time inhibition (71%), also significantly prevented the recolonization of S. mutans on the tooth surface in rats. These results suggested that the core B-cell epitope (-Y---L--Y----) recognized by KH5 was the essential sequence in the antigenic epitopes of PAc protein recognized specifically by the inhibitory antibody. Therefore, the amino acid residues were found to be important in the initial attachment of S. mutans to the tooth surface. These results provide for the mechanism of PAc molecule in the initial attachment of S. mutans on the tooth surface and more effective designs for the removal of S. mutans and S. sobrinus from the oral cavity.

Adhesins, Bacterial↗
PubMedDate not supplied

Systemic diseases in association with microbial species in oral biofilm from elderly requiring care.

BACKGROUND: The oral cavity is a reservoir for colonization and infection of systemic organs by pathogenic bacteria. It is understood that aging, tooth eruption, hormonal changes, active disease, oral hygiene, and other factors have an influence on biofilm formation and bacterial accumulation in the oral cavity. OBJECTIVE: To understand the influence of systemic health care on microfloral changes, we conducted epidemiological studies of nursing home residents in an attempt to elucidate the relationship between underlying systemic diseases and the isolation frequency of oral opportunistic pathogens. METHODS: The prevalence of bacteria and fungi causing pneumonia in association with oral biofilm bacteria were determined using detection culture plates. The influences of gender, age, denture-wearing status, number of teeth, and bedridden status in the patients residing in nursing homes were then analyzed. RESULTS: The isolation frequency rates of Candida albicans, Pseudomonadaceae, Staphylococcus spp., and some strains of Enterobacteriaceae in plaque samples, as well as C. albicans and Xanthomonas maltophilia in samples from the pharynx, were significantly higher in those requiring systemic care (mean age 83.9 years) than in those who did not require such care (mean 71.0 years). In particular, the frequencies of Pseudomonas spp., C. albicans, and Serratia marcescens in plaque were significantly higher in those who were bedridden. Furthermore, the isolation of Pseudomonas spp. and Klebsiella pneumoniae, and/or C. albicans in plaque was significantly associated with heart disease. CONCLUSION: The coexistence of Pseudomonas spp. and C. albicans in elderly with 10-19 teeth is a potential indicator of high risk for pneumonia and heart disease. Therefore, attention to oral hygiene and professional care for removing the indicators may diminish the occurrence of systemic disease in the elderly requiring systemic care.

Age Factors↗
PubMedDate not supplied

Post-operative infection by pathogenic micro-organisms in the oral cavity of patients with prostatic carcinoma.

The aim of this study was to analyse the change in the oral cavity microflora of 14 patients who had undergone a radical prostatectomy for prostatic carcinoma. The detection of micro-organisms in the oral cavity was compared before and after the surgical procedure. Post-operative infection, defined as those patients who had increased Candida species counts and/or pathogenic bacteria only at the post-operative examination, was observed in 10 patients. Six patients showed increased Candida species counts at the post-operative examination compared with the pre-operative examination. In five patients, pathogenic bacterial species were detected at the post-operative examination but not at the pre-operative examination. One patient had detectable pathogenic bacterial species only at the post-operative examination along with increased Candida species counts. Our findings suggest that pre-operative oral hygiene to remove bacterial and Candida species from patients who are scheduled for surgical procedures is important for satisfactory clinical outcomes.

Aged↗
PubMedDate not supplied

Identification of core B cell epitope in the synthetic peptide inducing cross-inhibiting antibodies to a surface protein antigen of Streptococcus mutans.

A surface protein antigen (PAc) of Streptococcus mutans, in particular, A-region of the molecule, has been considered as a possible target for the development of an effective anticaries vaccine. This region might be implicated in the induction of dental caries via interaction with salivary components. We have recently specified a unique peptide, TYEAALKQYEADL, as one of the minimum peptides that completely corresponds to the amino acid sequence of a part of the A-region. The unique peptide contains both T and B cell epitopes for the induction of cross-reacting antibodies to the PAc. In this study, we synthesized valine or glycine-substituted peptide analogs of this peptide and examined core B cell epitopes of this unique peptide by using ELISA inhibition assay. As a result, the core amino acid residues of -Y------Y---- for B cell recognition were found to likely be not only important amino acids stabilizing the structure, but also might be essential for induction of the cross-inhibiting antibodies against PAc. These results will hopefully provide us with useful information for the design of an effective anticaries peptide vaccine.

Amino Acid Sequence↗