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S Kusumoto

Publications and source records attributed to S Kusumoto.

At least 19 recordsLinked to original sources
PubMed2006

The CCR4 as a novel-specific molecular target for immunotherapy in Hodgkin lymphoma.

Here, we report that tumor cells from some patients (23.8%) with Hodgkin lymphoma (HL) are positive for CC chemokine receptor 4 (CCR4). We therefore tested the chimeric anti-CCR4 monoclonal antibody (mAb), KM2760, the Fc region of which is defucosylated to enhance antibody-dependent cellular cytotoxicity (ADCC), as a novel immunotherapy for refractory HL. KM2760 demonstrated a promising antitumor activity in the CCR4-positive HL-bearing mouse model in the therapeutic setting. Although KM2760 did not induce any ADCC mediated by mouse natural killer (NK) cells, it significantly enhanced phagocytosis mediated by mouse monocytes/macrophages against the CCR4-positive HL cell line in vitro. Together with the findings that KM2760 did not exhibit any complement-dependent cytotoxicity or direct antiproliferation activity in vitro, these data indicated that KM2760 exerted its robust in vivo antitumor activity via monocytes/macrophages in mice. In the human system, KM2760 enhanced phagocytic activity mediated by monocytes/macrophages. Furthermore, it induced robust ADCC mediated by NK cells against the CCR4-positive HL cell line in vitro. Thus, it is conceivable that KM2760 would have much more potent antitumor activity in humans than in mice. Collectively, this study strongly indicates that anti-CCR4 mAb could be a novel treatment modality for patients with CCR4-positive HL.

Animals↗
PubMed2006

Toll-like receptors, NOD1, and NOD2 in oral epithelial cells.

Oral epithelium might be the first barrier against oral bacteria in periodontal tissue. We hypothesized that oral epithelium is endowed with innate immune receptors for bacterial components, which play roles in host defense against bacterial infection without being accompanied by excessive inflammatory responses. We found clear expression of Toll-like receptor (TLR)4 as well as TLR2, and strong expression of NOD1 and NOD2 in normal oral epithelial tissues by immunohistochemical analysis. We also showed that primary oral epithelial cells in culture expressed these molecules using PCR, flow cytometry, and immunostaining. In inflamed oral epithelium, cell-surface localizations of TLR2 and TLR4 were more clearly observed than in healthy tissue. Upon stimulation with synthetic ligands for these receptors, the expression of beta-defensin 2 was markedly up-regulated. These findings indicate that these molecules in oral epithelial cells are functional receptors that induce antibacterial responses.

Adaptor Proteins, Signal Transducing↗
PubMed2005

Muramyldipeptide and diaminopimelic acid-containing desmuramylpeptides in combination with chemically synthesized Toll-like receptor agonists synergistically induced production of interleukin-8 in a NOD2- and NOD1-dependent manner, respectively, in human monocytic cells in culture.

Two types of synthetic peptidoglycan fragments, diaminopimelic acid (DAP)-containing desmuramylpeptides (DMP) and muramyldipeptide (MDP), induced secretion of interleukin (IL)-8 in a dose-dependent manner in human monocytic THP-1 cells, although high concentrations of compounds are required as compared with chemically synthesized Toll-like receptor (TLR) agonists mimicking bacterial components: TLR2 agonistic lipopeptide (Pam3CSSNA), TLR4 agonistic lipid A (LA-15-PP) and TLR9 agonistic bacterial CpG DNA. We found marked synergistic IL-8 secretion induced by MDP or DAP-containing DMP in combination with synthetic TLR agonists in THP-1 cells. Suppression of the mRNA expression of nucleotide-binding oligomerization domain (NOD)1 and NOD2 by RNA interference specifically inhibited the synergistic IL-8 secretion induced by DMP and MDP with these TLR agonists respectively. In accordance with the above results, enhanced IL-8 mRNA expression and the activation of nuclear factor (NF)-kappaB induced by MDP or DMP in combination with synthetic TLR agonists were markedly suppressed in NOD2- and NOD1-silenced cells respectively. These findings indicated that NOD2 and NOD1 are specifically responsible for the synergistic effects of MDP and DMP with TLR agonists, and suggested that in host innate immune responses to invading bacteria, combinatory dual signalling through extracellular TLRs and intracellular NODs might lead to the synergistic activation of host cells.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed2005

Chemically synthesized pathogen-associated molecular patterns increase the expression of peptidoglycan recognition proteins via toll-like receptors, NOD1 and NOD2 in human oral epithelial cells.

Peptidoglycan recognition proteins (PGRPs), a novel family of pattern recognition molecules (PRMs) in innate immunity conserved from insects to mammals, recognize bacterial cell wall peptidoglycan (PGN) and are suggested to act as anti-bacterial factors. In humans, four kinds of PGRPs (PGRP-L, -Ialpha, -Ibeta and -S) have been cloned and all four human PGRPs bind PGN. In this study, we examined the possible regulation of the expression of PGRPs in oral epithelial cells upon stimulation with chemically synthesized pathogen-associated molecular patterns (PAMPs) in bacterial cell surface components: Escherichia coli-type tryacyl lipopeptide (Pam3CSSNA), E. coli-type lipid A (LA-15-PP), diaminopimelic acid containing desmuramyl peptide (gamma-D-glutamyl-meso-DAP; iE-DAP), and muramyldipeptide (MDP). These synthetic PAMPs markedly upregulated the mRNA expression of the four PGRPs and cell surface expression of PGRP-Ialpha and -Ibeta, but did not induce either mRNA expression or secretion of inflammatory cytokines, in oral epithelial cells. Suppression of the expression of Toll-like receptor (TLR)2, TLR4, nucleotide-binding oligomerization domain (NOD)1 and NOD2 by RNA interference specifically inhibited the upregulation of PGRP mRNA expression induced by Pam3CSSNA, LA-15-PP, iE-DAP and MDP respectively. These PAMPs definitely activated nuclear factor (NF)-kappaB in the epithelial cells, and suppression of NF-kappaB activation clearly prevented the induction of PGRP mRNA expression induced by these PAMPs in the cells. These findings suggested that bacterial PAMPs induced the expression of PGRPs, but not proinflammatory cytokines, in oral epithelial cells, and the PGRPs might be involved in host defence against bacterial invasion without accompanying inflammatory responses.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed2003

Dual mutations in the AML1 and FLT3 genes are associated with leukemogenesis in acute myeloblastic leukemia of the M0 subtype.

Point mutations of the transcription factor AML1 are associated with leukemogenesis in acute myeloblastic leukemia (AML). Internal tandem duplications (ITDs) in the juxtamembrane domain and mutations in the second tyrosine kinase domain of the Fms-like tyrosine kinase 3 (FLT3) gene represent the most frequent genetic alterations in AML. However, such mutations per se appear to be insufficient for leukemic transformation. To evaluate whether both AML1 and FLT3 mutations contribute to leukemogenesis, we analyzed mutations of these genes in AML M0 subtype in whom AML1 mutations were predominantly observed. Of 51 patients, eight showed a mutation in the Runt domain of the AML1 gene: one heterozygous missense mutation with normal function, five heterozygous frameshift mutations and two biallelic nonsense or frameshift mutations, resulting in haploinsufficiency or complete loss of the AML1 activities. On the other hand, a total of 10 of 49 patients examined had the FLT3 mutation. We detected the FLT3 mutation in five of eight (63%) patients with AML1 mutation, whereas five of 41 (12%) without AML1 mutation showed the FLT3 mutation (P=0.0055). These observations suggest that reduced AML1 activities predispose cells to the acquisition of the activating FLT3 mutation as a secondary event leading to full transformation in AML M0.

Cell Transformation, Neoplastic↗
PubMed2002

Prognostic significance of the null genotype of glutathione S-transferase-T1 in patients with acute myeloid leukemia: increased early death after chemotherapy.

We investigated the prognostic significance of genetic polymorphism in glutathione-S transferase mu 1 (GSTM1), glutathione-S transferase theta 1 (GSTT1), NAD(P)H:quinone oxidoreductase (NQO1) and myeloperoxidase (MPO), the products of which are associated with drug metabolism as well as with detoxication, in 193 patients with de novo acute myeloid leukemia (AML) other than M3. Of the patients, 64.2% were either homozygous or heterozygous for GSTT1 (GSTT1(+)), while 35.8% showed homozygous deletions of GSTT1 (GSTT1(-)). The GSTT1(-) group had a worse prognosis than the GSTT1(+) group (P = 0.04), whereas other genotypes did not affect the outcome. Multivariate analysis revealed that GSTT1(-) was an independent prognostic factor for overall survival (relative risk: 1.53; P = 0.026) but not for disease-free survival of 140 patients who achieved complete remission (CR). The rate of early death after the initiation of chemotherapy was higher in the GSTT1(-) group than the GSTT1(+) group (within 45 days after initial chemotherapy, P = 0.073; within 120 days, P = 0.028), whereas CR rates and relapse frequencies were similar. The null genotype of GSTT1 might be associated with increased toxicity after chemotherapy.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2001

Multicenter prospective study of interferon-alpha versus bone marrow transplantation for newly diagnosed patients with chronic myelogenous leukemia: a preliminary analysis.

Interferon-alpha (IFN-alpha) therapy was compared with bone marrow transplantation (BMT) in patients with chronic myelogenous leukemia (CML) in a multicenter, prospective study. Of 254 evaluable patients, 175 received IFN-alpha and 79 received allogeneic BMT, 50 of whom received transplants from human leukocyte antigen (HLA)-identical related donors and 29 from HLA-matched unrelated donors. Complete hematologic response was achieved by 148 patients (89%) in the IFN-alpha group and 53 (78%) in the BMT group. In the IFN-alpha group, a complete cytogenetic response was induced in 25 patients (15%), a partial cytogenetic response in 37 (23%), and a minor cytogenetic response in 41 (25%). At a median follow-up of 38 months, in the IFN-alpha group the predicted 5-year survival rate was 79%, and the predicted 5-year rate of remaining in chronic phase was 66%. In the BMT group the predicted 5-year survival rate was 72% for related-donor BMT and 67% for unrelated-donor BMT. Among low Sokal-risk patients, 5-year survival did not differ between IFN-alpha therapy and BMT, irrespective of age. In higher Sokal-risk patients, survival for related-donor BMT and unrelated-donor BMT tended to be better than that with IFN-alpha therapy in younger patients. On the other hand, in older patients, survival in the BMT group, especially for those receiving unrelated-donor BMT, appeared to be inferior to that in the IFN-alpha group. Unrelated-donor BMT can be recommended for high-risk younger patients. However, for older patients, it should be performed after careful consideration of prognostic factors such as age, Sokal score, and response to IFN-alpha.

Adolescent↗
PubMed2001

Structural elucidation of a capsular polysaccharide from a clinical isolate of Bacteroides vulgatus from a patient with Crohn's disease.

The structure of a capsular polysaccharide (CPS) from a clinical isolate of Bacteroides vulgatus was elucidated. B. vulgatus IMCJ 1204 was isolated from feces of a patient with Crohn's disease. CPS was prepared by phenol/water extraction of the bacterial cells followed by hydrophobic interaction chromatography and then gel filtration chromatography of the extract. The structure of CPS was determined by chemical analysis and NMR spectroscopy including DQF-COSY, TOCSY, ROESY, HSQC-TOCSY, HMQC and HMBC to be a polysaccharide composed of the following repeating unit: -->3)beta-D-Glcp(1-->6)[alpha-D-GalpNAc(1-->2)beta-D-Galp(1-->4)]beta-D-GlcpNAc(1-->3)alpha-D-Galp(1-->4)beta-D-Manp(1-->.

Bacterial Capsules↗
PubMed2001

Heparin modulates integrin function in human platelets.

PURPOSE: Heparin binds to human platelets and can cause activation and aggregation, although the mechanisms are unknown. To determine how heparin alters platelet function, we identified platelet-binding sites for heparin and measured heparin's influence on the function of platelet integrin alpha(IIb)beta(3) (glycoprotein IIb/IIIa). METHODS: Photoaffinity cross-linking and affinity chromatography experiments were performed to identify platelet membrane proteins that bind heparin. Heparin's effect on fibrinogen binding to platelets was measured with a radioligand-binding assay. The translocation to the cytoskeleton of Rap2, a guanosine triphosphate-binding protein, was measured from platelets aggregating in response to heparin and other agonists. RESULTS: Cross-linking and affinity chromatographic experiments positively identified the integrin alpha(IIb)beta(3) as a heparin-binding site. Heparin aggregation was calcium dependent. Low concentrations of unfractionated porcine mucosal heparin (2-5 U/mL) significantly increased fibrinogen I 125 binding to activated platelets, whereas higher doses did not. Heparin-mediated platelet aggregation was completely blocked by GRGDS peptide (5 mmol/L), a competitive inhibitor of fibrinogen binding, and was blocked by EDTA (2 mmol/L), which dissociates the functional integrin complex. Aggregation was associated with Rap2 translocation to the cytoskeleton, a sign of outside-in signaling. CONCLUSIONS: Heparin binds to the alpha(IIb)beta(3) integrin in vitro and ex vivo, and heparin increases fibrinogen binding to the integrin. Heparin-mediated aggregation requires an intact integrin and ligand and leads to Rap2 translocation to the cytoskeleton-an outside-in signal of ligand engagement. Heparin may directly modulate platelet integrin function, most likely through direct binding and modulation of integrin function.

Binding Sites↗
PubMed2001

Human MD-2 confers on mouse Toll-like receptor 4 species-specific lipopolysaccharide recognition.

Toll-like receptor 4 (TLR4) recognizes lipopolysaccharide (LPS). MD-2 is associated with TLR4 and imparts LPS responsiveness to it. Little is known, however, as to whether MD-2 directly regulates LPS recognition by TLR4. To address the issue, we took advantage of a species-specific pharmacology of lipid IVa, an analogue of lipid A. Lipid IVa acted agonistically on mouse (m) TLR4/MD-2 but not on human (h) TLR4/MD-2. Lipid IVa antagonized the agonistic effect of lipid A on hTLR4/MD-2. We examined the chimeric complex consisting of mTLR4 and hMD-2 to ask whether species specificity is conferred by TLR4 or MD-2. hMD-2 was clearly distinct from mMD-2 in the way of influencing LPS recognition by mTLR4. hMD-2 conferred on mTLR4 responsiveness to lipid A but not to lipid IVa. Moreover, lipid IVa acted as a lipid A antagonist on mTLR4 that is associated with hMD-2. Collectively, MD-2 directly influences the fine specificity of TLR4.

Adjuvants, Immunologic↗
PubMed2001

Chemical structure and biological activity of a lipid A component from Helicobacter pylori strain 206.

The chemical structure of a lipid A, which was obtained as a minor component from lipopolysaccharide of Helicobacter pylori strain 206-1, was determined to be a glucosamine beta-(1 -6) disaccharide 1-(2-aminoethyl)phosphate acylated by (R)-3-hydroxyoctadecanoic acid, (R)-3- hydroxyhexadecanoic acid, and (R)-3-(octadecanoyloxy)octadecanoic acid at the 2-, 3- and 2'-positions, respectively. Compared with the other major lipid A from the same strain, which was previously reported [Suda Y, Ogawa T, Kashihara W et al. Chemical structure of lipid A from Helicobacter pylori strain 206-1 lipopolysaccharide. J Biochem 1997; 121: 1129--1133], the structure was very similar with one exception. An (R)-3-hydroxyhexadecanoic acid was present at the 3-position of the novel lipid A component. The structure is apparently identical to one of the proposals by Moran et al. [Moran AP, Lindner B, Walsh EJ. Structural characterization of the lipid A component of Helicobacter pylori rough- and smooth-form lipopolysaccharides. J Bacteriol 1997; 179: 6453--6463], who concluded the same structure as the so-called major lipid A from the H. pylori strain NCTC 11637 but without isolating a homogeneous component. The endotoxic properties and pro-inflammatory cytokine-inducing activities of this novel tetra-acyl type lipid A were lower than those of previously reported major tri-acyl type lipid A.

Animals↗
PubMed2001

[CD7(+) acute myeloid leukemia (M0) associated with a mediastinal bulky mass lesion].

A 41-year-old man visited his doctor in May 2000 because of a sore throat and high fever. His symptoms did not improve, despite administration of antibiotics and nonsteroidal anti-inflammatory drugs. Since a chest X-ray examination revealed an anterior mediastinal bulky tumor, he was referred and admitted to our hospital on June 21, 2000. The peripheral white blood cell count was 44,540/microliter with 74% myeloblasts. Bone marrow aspiration revealed a hypercellular marrow with 82% myeloblasts, which were negative for peroxidase and alpha-naphthyl butylate esterase staining. Blast cells were positive for CD7, CD13, CD33, CD34, and HLA-DR, and negative for CD56. A needle biopsy specimen of the mediastinal tumor consisted of myeloblasts. We diagnosed the patient as having CD7 (+) acute myeloid leukemia (AML) (M0) with a bulky mediastinal mass based on the surface marker analysis, although the clinical features resembled myeloid/NK precursor acute leukemia. The patient achieved a complete remission after two courses of induction therapy. We are planning an allogeneic stem cell transplantation during his first remission because of the high risk of relapse.

Adult↗
PubMed2000

Cytokine-inducing macromolecular glycolipids from Enterococcus hirae: improved method for separation and analysis of its effects on cellular activation.

Previously, we showed that several minor macromolecular glycolipids accounting for less than 5% of the lipoteichoic acid (LTA) fraction from Enterococcus hirae ATCC 9790 possess cytokine-inducing activity, whereas the purified LTA does not. In other words, the immunobiological activity of the LTA fraction reported in the 1980s was not attributable to LTA itself, but to other glycolipids coexisting in the fraction. In the present study, we improved the procedure of separation of the active glycolipids and evaluated their effects on cellular activation. The immunobiologically active glycolipids were separated from the crude glycolipid fraction obtained by hot phenol-water extraction of the cells. The total yield of active glycolipids was about fivefold higher than that separated by the previous method. Interleukin-6-inducing activities of the active glycolipids from 1,25-dihydroxy vitamin D(3)-differentiated human monocytic leukemia cells, THP-1, were inhibited by anti-CD14 mAbs in a dose-dependent manner. Macrophages from Toll-like receptor (TLR)-2-deficient or -4-deficient mice completely lacked the ability to produce tumor necrosis factor-alpha on stimulation with active glycolipids. These observations indicated that the cellular activation by the active glycolipids from E. hirae is mediated by CD14 and by both TLR2 and TLR4.

Animals↗
PubMed2000

Prognostic value of p53 gene mutations and the product expression in de novo acute myeloid leukemia.

In acute myeloid leukemia (AML), p53 mutations are reportedly infrequent but associated with a poor prognosis. The majority of mutations are missense mutations, which generally lead to accumulation of nuclear p53 protein. However, the prognostic significance of the accumulation remains unknown in AML. In this study, we compared the prognostic value of p53 mutations versus accumulation of the product. p53 mutations were found in 9 (4.5%) of 200 patients with de novo AML. The p53 mutation detectable (mutation+) group had a worse prognosis (p = 0.0009) than the mutation not detectable (mutation-) group. Multivariate analysis showed that the p53 mutation was an independent factor (p = 0.005) for short overall survival as well as 60 yr or older (p = 0.001) and unfavorable karyotypes (p = 0.001). In 79 of the 200 patients, the expression of p53 was studied by immunocytochemistry (ICC) using anti-p53 monoclonal antibody (DO-7). All samples carrying missense mutations (N = 6) were positive for ICC in over 15% of nuclei of each sample, chosen as the optimized cutoff value of p53 accumulation. Accumulation was thus found in 14 of the 79 patients. However, there was no prognostic difference according to the accumulation, because the mutation-/accumulation+ group (N = 8) tended to have a good prognosis. These findings indicate that molecular detection of p53 mutations yields better prognostic information than ICC. In a subset of AML, p53 protein might be accumulated without mutation presumably due to upstream signals of p53.

Acute Disease↗
PubMed2000

Intrinsic conformation of lipid A is responsible for agonistic and antagonistic activity.

Lipopolysaccharides (LPS, endotoxin) represent a major virulence factor of Gram-negative bacteria, which can cause septic shock in mammals, including man. The lipid anchor of LPS to the bacterial outer membrane, lipid A, exhibits a peculiar chemical structure, harbours the 'endotoxic principle' of LPS and is also responsible for the expression of pathophysiological effects. Chemically modified lipid A can be endotoxically inactive, but may express strong antagonistic activity against endotoxically active LPS. By applying orientation measurements with attenuated total reflectance (ATR) infrared spectroscopy on hydrated lipid A samples, we show here that these different biological activities are directly correlated to the intrinsic conformation of lipid A. Bisphosphoryl-hexaacyl lipid A molecules with an asymmetric (4/2) distribution of the acyl chains linked to the diglucosamine backbone have a large tilt angle (> 45 degrees ) of the diglucosamine backbone with respect to the membrane surface, a conical molecular shape (larger cross-section of the hydrophobic than the hydrophilic moiety), and are endotoxically highly active. Monophosphoryl hexaacyl lipid A has a smaller tilt angle, and the conical shape is less expressed in favour of a more cylindrical shape. This correlates with decreasing endotoxic activity. Penta- and tetraacyl lipid A or hexaacyl lipid A with a symmetric acyl chain distribution (3/3) have a small tilt angle (< 25 degrees ) and a cylindrical shape and are endotoxically inactive, but may be antagonistic.

Carbohydrate Conformation↗
PubMed2000

Toll-like receptor 4 imparts ligand-specific recognition of bacterial lipopolysaccharide.

Lipopolysaccharide (LPS) is the main inducer of shock and death in Gram-negative sepsis. Recent evidence suggests that LPS-induced signal transduction begins with CD14-mediated activation of 1 or more Toll-like receptors (TLRs). The lipid A analogues lipid IVa and Rhodobacter sphaeroides lipid A (RSLA) exhibit an uncommon species-specific pharmacology. Both compounds inhibit the effects of LPS in human cells but display LPS-mimetic activity in hamster cells. We transfected human TLR4 or human TLR2 into hamster fibroblasts to determine if either of these LPS signal transducers is responsible for the species-specific pharmacology. RSLA and lipid IVa strongly induced NF-kappaB activity and IL-6 release in Chinese hamster ovary fibroblasts expressing CD14 (CHO/CD14), but these compounds antagonized LPS antagonists in CHO/CD14 fibroblasts that overexpressed human TLR4. No such antagonism occurred in cells overexpressing human TLR2. We cloned TLR4 from hamster macrophages and found that human THP-1 cells expressing the hamster TLR4 responded to lipid IVa as an LPS mimetic, as if they were hamster in origin. Hence, cells heterologously overexpressing TLR4 from different species acquired a pharmacological phenotype with respect to recognition of lipid A substructures that corresponded to the species from which the TLR4 transgene originated. These data suggest that TLR4 is the central lipid A-recognition protein in the LPS receptor complex.

Animals↗