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W Sugiura

Publications and source records attributed to W Sugiura.

At least 19 recordsLinked to original sources
PubMed2006

Bayesian network analysis of resistance pathways against HIV-1 protease inhibitors.

Interpretation of Human Immunodeficiency Virus 1 (HIV-1) genotypic drug resistance is still a major challenge in the follow-up of antiviral therapy in infected patients. Because of the high degree of HIV-1 natural variation, complex interactions and stochastic behaviour of evolution, the role of resistance mutations is in many cases not well understood. Using Bayesian network learning of HIV-1 sequence data from diverse subtypes (A, B, C, F and G), we could determine the specific role of many resistance mutations against the protease inhibitors (PIs) nelfinavir (NFV), indinavir (IDV), and saquinavir (SQV). Such networks visualize relationships between treatment, selection of resistance mutations and presence of polymorphisms in a graphical way. The analysis identified 30N, 88S, and 90M for nelfinavir, 90M for saquinavir, and 82A/T and 46I/L for indinavir as most probable major resistance mutations. Moreover we found striking similarities for the role of many mutations against all of these drugs. For example, for all three inhibitors, we found that the novel mutation 89I was minor and associated with mutations at positions 90 and 71. Bayesian network learning provides an autonomous method to gain insight in the role of resistance mutations and the influence of HIV-1 natural variation. We successfully applied the method to three protease inhibitors. The analysis shows differences with current knowledge especially concerning resistance development in several non-B subtypes.

Bayes Theorem↗
PubMed2001

Immunogenicity and protective efficacy of oligomeric human immunodeficiency virus type 1 gp140.

The biologically active form of the human immunodeficiency virus type 1 (HIV-1) envelope (Env) glycoprotein is oligomeric. We previously described a soluble HIV-1 IIIB Env protein, gp140, with a stable oligomeric structure composed of uncleaved gp120 linked to the ectodomain of gp41 (P. L. Earl, C. C. Broder, D. Long, S. A. Lee, J. Peterson, S. Chakrabarti, R. W. Doms, and B. Moss, J. Virol. 68:3015-3026, 1994). Here we compared the antibody responses of rabbits to gp120 and gp140 that had been produced and purified in an identical manner. The gp140 antisera exhibited enhanced cross-reactivity with heterologous Env proteins as well as greater neutralization of HIV-1 compared to the gp120 antisera. To examine both immunogenicity and protective efficacy, we immunized rhesus macaques with oligomeric gp140. Strong neutralizing antibodies against a homologous virus and modest neutralization of heterologous laboratory-adapted isolates were elicited. No neutralization of primary isolates was observed. However, a substantial fraction of the neutralizing activity could not be blocked by a V3 loop peptide. After intravenous challenge with simian-HIV virus SHIV-HXB2, three of the four vaccinated macaques exhibited no evidence of virus replication.

AIDS Vaccines↗
PubMed2000

Molecular cloning and characterization of the gene coding for azoreductase from Bacillus sp. OY1-2 isolated from soil.

Azo dyes are regarded as pollutants because they are not readily reduced under aerobic conditions. Bacillus sp. OY1-2 transforms azo dyes into colorless compounds, and this reduction is mediated by a reductase activity for the azo group in the presence of NADPH. A 1.2-kbp EcoRI fragment containing the gene that encodes azoreductase was cloned by screening the genomic library of Bacillus sp. OY1-2 with digoxigenin-labeled probe designed from the N-terminal amino acid sequence of the purified enzyme. An open reading frame encoding the azoreductase, consisting of 178 amino acids, was predicted from the nucleotide sequence. In addition, because only a Bacillus subtillis hypothetical protein was discovered in the public databases (with an amino acid identity of 52.8%), the gene encoding the azoreductase cloned in this study was predicted to be a member of a novel family of reductases. Southern blot analysis revealed that the azoreductase gene exists as a single copy gene on a chromosome. Escherichia coli-expressing recombinant azoreductase gave a ten times greater reducing activity toward azo dyes than the original Bacillus sp. OY1-2. In addition, the expressed azoreductase purified from the recombinant E. coli lysate by Red-Sepharose affinity chromatography showed a similar activity and specificity as the native enzyme. This is the first report describing the sequencing and characterization of a gene encoding the azo dye-reducing enzyme, azoreductase, from aerobic bacteria and its expression in E. coli.

Amino Acid Sequence↗
PubMed2000

Suppression of furylfuramide-induced SOS response by acetophenones using Salmonella typhimurium TA1535/pSK1002 umu test.

The recently isolated paeonol (2-hydroxy-4-methoxyacetophenone), as one of the antimutagenic compounds from Discorea japonica, was used as a lead compound for detailed structure-activity relationship studies. Nine acetophenones (2-hydroxy-4-methoxy, 2-hydroxy-5-methoxy, 2-hydroxy-6-methoxy, 4-hydroxy-3-methoxy, o-methoxy, m-methoxy, p-methoxy, and 2,5-dimethoxyacetophenone and acetophenone) were investigated for their ability of suppression of furylfuramide-induced SOS response using Salmonella typhimurium TA1535/pSK1002 in the umu test, against the mutagen, 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide (furylfuramide). The results showed that 2-hydroxy-6-methoxyacetophenone displayed the strongest activity (EC(50) = 0.6 micromol/mL), and a hydroxyl group at C-2 is necessary feature for acetophenone derivatives to show the suppressive effects of furylfuramide-induced SOS response.

Acetophenones↗
PubMed2000

Polymorphism in the interleukin-4 promoter affects acquisition of human immunodeficiency virus type 1 syncytium-inducing phenotype.

The emergence of syncytium-inducing (SI) variants of human immunodeficiency virus type 1 (HIV-1) in infected individuals is an indicator of poor prognosis and is often correlated with faster CD4(+) cell depletion and rapid disease progression. Interleukin-4 (IL-4) is a pleiotropic cytokine with various immune-modulating functions including induction of immunoglobulin E (IgE) production in B cells, down-regulation of CCR5 (a coreceptor for HIV-1 non-SI [NSI] strains), and up-regulation of CXCR4 (a coreceptor for HIV-1 SI variants). Here we show that homozygosity of a polymorphism in the IL-4 promoter region, IL-4 -589T, is correlated with increased rates of SI variant acquisition in HIV-1-infected individuals in Japan. This mutation was also shown to be associated with elevated serum IgE levels in HIV-1-infected individuals, especially in those at advanced stages of disease. In contrast, neither a triallele polymorphism in IL-10, another Th2 cytokine, nor a biallele polymorphism in the RANTES promoter affected acquisition of the SI phenotype. This finding suggested that IL-4-589T increases IL-4 production in the human body and thus accelerates the phenotypic switch of HIV-1 from NSI to SI and possibly disease progression of AIDS.

Alleles↗
PubMed1999

Characterization of conformation-dependent anti-gp120 murine monoclonal antibodies produced by immunization with monomeric and oligomeric human immunodeficiency virus type 1 envelope proteins.

Twenty-five conformation-dependent monoclonal antibodies (MAbs) produced by immunization of mice with oligomeric forms of the human immunodeficiency virus type 1 (HIV-1) envelope (env) glycoprotein were used to map exposed, immunogenic regions on oligomeric env. Based on MAb cross-competition, reactivity with diverse env proteins, and reactivity with a panel of gp120 mutants, seven distinct epitope clusters were identified. These include the classic CD4 binding site, V1/V2, and V3. in addition, several novel epitope clusters, including one mapping to the N- and C-termini of gp120, were identified. The locations of the seven epitope clusters on the gp120 core structure are proposed.

Animals↗
PubMed1999

Isolation of azo-dye-degrading microorganisms and their application to white discharge printing of fabric.

Three bacterial strains, which degraded azo dyes, were isolated from soil and sewage samples. The strains were identified as Bacillus sp. OY1-2, Xanthomonas sp. NR25-2 and Pseudomonas sp. PR41-1. The bacteria produced azo-dyes-degrading enzymes. That catalyzed the reduction of methyl red and produced dimethyl p-phenylenediamine and o-aminobenzoic acid. The enzymes could thus be applied to white discharge printing of azo-dyed fabric by owing to there.

Journal Article↗
PubMed1999

Moscatilin from Dendrobium nobile, a naturally occurring bibenzyl compound with potential antimutagenic activity.

A bibenzyl compound that possesses antimutagenic activity was isolated from the storage stem of Dendrobium nobile. The isolated compound suppressed the expression of the umu gene following the induction of SOS response in Salmonella typhimurium TA1535/pSK1002 that have been treated with various mutagens. The suppressive compound was mainly localized in the n-hexane extract fraction of the processed D. nobile. This n-hexane fraction was further fractionated by silica gel column chromatography, which resulted in the purification and subsequent identification of the suppressive compound. EI-MS and (1)H and (13)C NMR spectroscopy were then used to delineate the structure of the compound that confers the observed antimutagenic activity. Comparison of the obtained spectrum with that found in the literature indicated that moscatilin is the secondary suppressive compound. When using 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide (furylfuramide) as the mutagen, moscatilin suppressed 85% of the umu gene expression compared to the controls at <0.73 micromol/mL, with an ID(50) value of 0.41 micromol/mL. Additionally, moscatilin was tested for its ability to suppress the mutagenic activity of other well-known mutagens such as 4-nitroquinoline-1-oxide (4NQO), N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), UV irradiation, 3-amino-1,4-dimethyl-5H-pyrido[4,3b]indole (Trp-P-1), benzo[a]pyrene (B[a]P), and aflatoxin B(1) (AFB(1)). With all of the aforementioned chemicals or treatments, moscatilin showed a dramatic reduction in their mutagenic potential. Interestingly, moscatilin almost completely suppressed (97%) the AFB(1)-induced SOS response at concentrations <0.73 micromol/mL, with an ID(50) of 0.08 micromol/mL. Finally, the antimutagenic activities of moscatilin against furylfuramide and Trp-P-1 were assayed by the Ames test using the S. typhimurium TA100 strain. The results those experiments indicated that moscatilin demonstrated a dramatic suppression of the mutagenicity of only Trp-P-1 but not furylfuramide.

Antimutagenic Agents↗
PubMed1995

Protective immune responses induced by secretion of a chimeric soluble protein from a recombinant Mycobacterium bovis bacillus Calmette-Guérin vector candidate vaccine for human immunodeficiency virus type 1 in small animals.

A recombinant Mycobacterium bovis bacillus Calmette-Guérin (BCG) vector-based vaccine that secretes the V3 principal neutralizing epitope of human immunodeficiency virus (HIV) could induce immune response to the epitope and prevent the viral infection. By using the Japanese consensus sequence of HIV-1, we successfully constructed chimeric protein secretion vectors by selecting an appropriate insertion site of a carrier protein and established the principal neutralizing determinant (PND)-peptide secretion system in BCG. The recombinant BCG (rBCG)-inoculated guinea pigs were initially screened by delayed-type hypersensitivity (DTH) skin reactions to the PND peptide, followed by passive transfer of the DTH by the systemic route. Further, immunization of mice with the rBCG resulted in induction of cytotoxic T lymphocytes. The guinea pig immune antisera showed elevated titers to the PND peptide and neutralized HIVMN, and administration of serum IgG from the vaccinated guinea pigs was effective in completely blocking the HIV infection in thymus/liver transplanted severe combined immunodeficiency (SCID)/hu or SCID/PBL mice. In addition, the immune serum IgG was shown to neutralize primary field isolates of HIV that match the neutralizing sequence motif by a peripheral blood mononuclear cell-based virus neutralization assay. The data support the idea that the antigen-secreting rBCG system can be used as a tool for development of HIV vaccines.

AIDS Vaccines↗
PubMed1995

Induction of MHC class II antigens on rat bronchial epithelial cells by interferon-gamma and its effect on antigen presentation.

Recent studies have found aberrant expression of class II antigens by bronchial epithelial cells (BECs), suggesting that these cells may also be involved in airway mucosal immunity. However, the regulation of class II antigen expression on BECs by cytokines and the functional capacity of such cells bearing class II molecules remain unknown. We investigated the effect of IFN-gamma on class II antigen expression by cultured rat BECs, as well as the ability of these cells to present intact protein antigens to specifically sensitized T cells. Although primary BECs did not express class II antigens, IFN-gamma readily induced their expression in a dose-dependent manner. More than 85% of the BECs treated with 1000 U/ml of IFN-gamma were positive for class II antigens. In addition, when IFN-treated BECs bearing class II molecules were pulsed with ovalbumin (OVA), they significantly stimulated the proliferation of OVA-sensitized T cells, whereas cells that were not treated with IFN-gamma but were pulsed with OVA did not do so. Our findings indicate that BECs bearing class II molecules are capable of presenting OVA to OVA-sensitized T cells. These results suggest that various pathological conditions causing the local production of IFN-gamma may increase class II antigen expression on BECs, which in turn may modulate the airway mucosal immune response by the presentation of antigens to T cells.

Animals↗