Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 45
Filter
1.
Nat Commun ; 8(1): 592, 2017 09 19.
Article in English | MEDLINE | ID: mdl-28928380

ABSTRACT

Immune checkpoint blockers (ICB) have become pivotal therapies in the clinical armamentarium against metastatic melanoma (MMel). Given the frequency of immune related adverse events and increasing use of ICB, predictors of response to CTLA-4 and/or PD-1 blockade represent unmet clinical needs. Using a systems biology-based approach to an assessment of 779 paired blood and tumor markers in 37 stage III MMel patients, we analyzed association between blood immune parameters and the functional immune reactivity of tumor-infiltrating cells after ex vivo exposure to ICB. Based on this assay, we retrospectively observed, in eight cohorts enrolling 190 MMel patients treated with ipilimumab, that PD-L1 expression on peripheral T cells was prognostic on overall and progression-free survival. Moreover, detectable CD137 on circulating CD8+ T cells was associated with the disease-free status of resected stage III MMel patients after adjuvant ipilimumab + nivolumab (but not nivolumab alone). These biomarkers should be validated in prospective trials in MMel.The clinical management of metastatic melanoma requires predictors of the response to checkpoint blockade. Here, the authors use immunological assays to identify potential prognostic/predictive biomarkers in circulating blood cells and in tumor-infiltrating lymphocytes from patients with resected stage III melanoma.

2.
Am J Transplant ; 16(11): 3139-3149, 2016 11.
Article in English | MEDLINE | ID: mdl-27265023

ABSTRACT

B cells play a central role in antibody-mediated rejection and certain autoimmune diseases. However, B cell-targeted therapy such as anti-CD20 B cell-depleting antibody (aCD20) has yielded mixed results in improving outcomes. In this study, we investigated whether an accelerated B cell reconstitution leading to aCD20 depletion resistance could account for these discrepancies. Using a transplantation model, we found that antigen-independent inflammation, likely through toll-like receptor (TLR) signaling, was sufficient to mitigate B cell depletion. Secondary lymphoid organs had a quicker recovery of B cells when compared to peripheral blood. Inflammation altered the pharmacokinetics (PK) and pharmacodynamics (PD) of aCD20 therapy by shortening drug half-life and accelerating the reconstitution of the peripheral B cell pool by bone marrow-derived B cell precursors. IVIG (intravenous immunoglobulin) coadministration also shortened aCD20 drug half-life and led to accelerated B cell recovery. Repeated aCD20 dosing restored B cell depletion and delayed allograft rejection, especially B cell-dependent, antibody-independent allograft rejection. These data demonstrate the importance of further clinical studies of the PK/PD of monoclonal antibody treatment in inflammatory conditions. The data also highlight the disconnect between B cell depletion on peripheral blood compared to secondary lymphoid organs, the deleterious effect of IVIG when given with aCD20 and the relevance of redosing of aCD20 for effective B cell depletion in alloimmunity.


Subject(s)
Antigens, CD20/immunology , B-Lymphocytes/immunology , Graft Rejection/prevention & control , Graft Survival/immunology , Inflammation/immunology , Lymphocyte Depletion , Rituximab/pharmacology , Animals , Female , Graft Rejection/etiology , Heart Transplantation/adverse effects , Immunoglobulins, Intravenous/administration & dosage , Immunologic Factors/pharmacology , Inflammation/pathology , Male , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL
3.
Radiat Prot Dosimetry ; 120(1-4): 461-5, 2006.
Article in English | MEDLINE | ID: mdl-16717112

ABSTRACT

An allyl di-glycol carbonate (ADC) sheet which has been utilised as a neutron detector for personal dosimetry has recently been studied for its application as a device for radiation exposure control for astronauts in space, where protons are the dominant radiation. It is known that the fabrication process, modified by adding some kind of antioxidant to improve the sensitivity of ADC to high energy protons, causes a substantial increase in false tracks, which disturb the automatic counting of proton tracks using the auto-image analyser. This made clear the difficulty of fabricating ADC sheets which have sufficient sensitivity to high energy protons, while maintaining a good surface. In this study, we have tried to modify the fabrication process to improve the sensitivity to high energy protons without causing a deterioration of the surface condition of ADC sheets. We have successfully created fairly good products.


Subject(s)
Carbonates/chemistry , Carbonates/radiation effects , Membranes, Artificial , Protons , Radiation Protection/instrumentation , Thermoluminescent Dosimetry/instrumentation , Dose-Response Relationship, Radiation , Equipment Design , Equipment Failure Analysis , Materials Testing , Radiation Dosage , Reproducibility of Results , Sensitivity and Specificity , Surface Properties , Thermoluminescent Dosimetry/methods
4.
Radiat Prot Dosimetry ; 120(1-4): 470-4, 2006.
Article in English | MEDLINE | ID: mdl-16597695

ABSTRACT

Atomic force microscopy (AFM) has been applied to the analysis of CR-39 nuclear track detectors for high dose neutron dosimetry. As a feasible study to extract the neutron dose, we have employed a (239)Pu-Be neutron source with the traditional track density measurement of recoil proton etch pits from a high density polyethylene (CH(2)) radiator. After very short etching ( approximately 1 microm), etch pit densities were measured as a function of neutron fluence (neutron dose) up to 1.4 x 10(10) cm(-2) (6.6 Sv). Neutron sensitivity was also measured to be 6.6 x 10(-4). Maximum measurable neutron dose was estimated to be approximately 200 Sv by measuring the fraction of the total image area occupied by the etch pits.


Subject(s)
Microscopy, Atomic Force/methods , Polyethylene Glycols/chemistry , Polyethylene Glycols/radiation effects , Radiation Protection/instrumentation , Thermoluminescent Dosimetry/instrumentation , Dose-Response Relationship, Radiation , Equipment Design , Equipment Failure Analysis , Materials Testing , Radiation Dosage , Reproducibility of Results , Sensitivity and Specificity , Surface Properties , Thermoluminescent Dosimetry/methods
5.
Respir Med ; 99(1): 111-7, 2005 Jan.
Article in English | MEDLINE | ID: mdl-15672859

ABSTRACT

Osteopontin (OPN) produced by alveolar macrophages functions as a fibrogenic cytokine in the development of bleomycin (BLM)-induced murine pulmonary fibrosis, and OPN mRNA is expressed on lung tissues from patients with idiopathic pulmonary fibrosis (IPF). The present study investigates plasma OPN levels in human interstitial pneumonia (IP) and their relationships with disease severity by analyzing the correlation between plasma OPN concentrations and pulmonary functions. The concentrations of OPN in plasma were measured in 17 patients with IP, in 9 with sarcoidosis and in 20 healthy controls using an antigen-capture enzyme-linked immunosorbent assay. The concentrations of OPN in plasma were significantly higher in IP patients than in those with sarcoidosis or in controls. Based on a Receiver Operating Characteristic curve analysis, cut-off points between 300 and 380 ng/ml discriminated between IP and control subjects with 100% sensitivity and 100% specificity. In such case, the sensitivity for sarcoidosis decreased (55.5-33.3%) in cut-offs with 100% specificity. Plasma OPN levels inversely and closely correlated with arterial oxygen tension (PaO2) in patients with IP. Immunohistochemically, OPN was localized predominantly in macrophages and airway epithelium. These findings suggest that plasma OPN levels were found to be associated with the presence of IP, and that OPN play an important role in the development of IP.


Subject(s)
Lung Diseases, Interstitial/blood , Sialoglycoproteins/blood , Adult , Aged , Biomarkers/blood , Carbon Monoxide/metabolism , Female , Humans , Immunoenzyme Techniques , Lung Diseases, Interstitial/metabolism , Lung Diseases, Interstitial/physiopathology , Macrophages, Alveolar/metabolism , Male , Middle Aged , Osteopontin , Oxygen/blood , Partial Pressure , Sarcoidosis, Pulmonary/blood , Sensitivity and Specificity , Sialoglycoproteins/metabolism , Sialoglycoproteins/physiology , Vital Capacity
6.
Interv Neuroradiol ; 10 Suppl 2: 35-40, 2004 Dec 24.
Article in English | MEDLINE | ID: mdl-20587247

ABSTRACT

SUMMARY: The purpose of this study was to evaluate the effect of endovascular treatment with Guglielmi detachable coils (GDC) on the outcomes of subarachnoid haemorrhage (SAH) patients of poor grades and high ages for each location of aneurysms. Between 1990 and 2003, 529 SAH cases underwent angiograghy as candidates of early aggressive treatment in our hospital. For the 299 cases in 1990-96 (Group 1), treatment options were early and intensively delayed craniotomy surgery and conservative management, while for the 230 cases in 1997-2003 (Group 2), GDG embolization at acute stage was added to these three treatment options. We compared clinical courses and outcomes of the poor grade (Hunt & Kosnik Grade 4-5) patients and high age (>=70 years old) patients between two groups for each location of aneurysms. Introduction of GDC embolization expanded the indication for early treatment in the poor grade patients with anterior communicating artery aneurysm (A-Comm An), the high age patients with internal carotid artery aneurysm (IC An) and all patients with Basilar bifurcation aneurysm (BA-Top An), and has contributed to improvement of their outcomes. To the poor grade patients with middle cerebral artery aneurysm (MCA An), GDC embolization was hardly indicated, because haematoma evacuation concomitantly performed with aneurysm occlusion would be necessary for those patients. In conclusion, results of treatment with GDC embolization at an acute stage are desirable for poor grade patients with A-Comm An, aged patients with IC An and all patients with BA-Top An. The indication of GDC embolization for the patients with MCA An is limited.

7.
Interv Neuroradiol ; 10 Suppl 1: 147-52, 2004 Mar 30.
Article in English | MEDLINE | ID: mdl-20587291

ABSTRACT

SUMMARY: We have been using the Guglielmi detachable coils (GDC) since 1997 as one choice of cerebral aneurysm treatment.We have, at the present time, two effective radical treatment methods for acutely ruptured cerebral aneurysms, GDC embolization and conventional surgical aneurysmal neck clipping. There ensued questions about the cost and efficacy of the two strategies. Retrospective analysis was done on a GDC group and a clipping group, with each twenty consecutive patients. The features of the GDC group patients were higher age, and poorer Hunt and Kosnik grades than the other group. All MCA aneurysms were treated with surgical neck clipping, while all the posterior circulation aneurysms were embolized with GDC. Based on the Japanese Medical Insurance and Payment System, 477,890 points (1 point = yen 10) as a mean was required with the GDC group, and 456,084 points with the neck clipping group, showing no significant difference between the two groups. In the GDC group, the cost of the implanted medical device seemed to raise the total medical expense. At present, the GDC embolization is the preferred choice of strategies in acutely ruptured cerebral aneurysms, and its preference increases in the surgically difficult cases, very old, or poor grade patients, and in various complicated cases. And, the GDC embolization seems to be satisfactory from the medico-financial viewpoint.

8.
Interv Neuroradiol ; 10 Suppl 1: 173-9, 2004 Mar 30.
Article in English | MEDLINE | ID: mdl-20587296

ABSTRACT

SUMMARY: Ruptured vertebral artery dissecting aneurysms (VADA) re-bleed frequently especially during first 24 hours, which makes the prognosis of the patients with this disease poor. Recently endovascular trapping with detachable platinum coils at an acute stage has been done for preventing re-bleeding. However, for the cases with dissecting aneurysm involving the origin of the posterior inferior cerebellar artery (PICA), these methods are hardly indicated because of the risk of ischemic complication in the PICA territory. We proposed a simple and effective therapeutic method for these cases. We occluded the affected vertebral artery (VA) near its root intending to introduce collateral blood flow from the deep cervical artery into the VA trunk. The controlled antegrade VA flow and retrograde flow from the contralateral VA make a watershed at the dissecting aneurysm, which promotes thrombosis of pseudolumen with preserving the antegrade blood flow of PICA.We treated two cases with ruptured VADA involving PICA, and in both cases thrombosis of aneurysm was obtained without any ischemic complication. This method would be considered as a treatment of choice to the cases with VADA involving PICA.

9.
J Immunol ; 167(11): 6525-32, 2001 Dec 01.
Article in English | MEDLINE | ID: mdl-11714821

ABSTRACT

To elucidate the role of NKT cells in the host defense to cryptococcal infection, we examined the proportion of these cells, identified by the expression of CD3 and NK1.1, in lungs after intratracheal infection with Cryptococcus neoformans. This population increased on day 3 after infection, reached a peak level on days 6-7, and decreased thereafter. In Valpha14 NKT cell-deficient mice, such increase was significantly attenuated. The proportion of Valpha14 NKT cells, detected by binding to alpha-galactosylceramide-loaded CD1d tetramer, and the expression of Valpha14 mRNA increased after infection with a similar kinetics. The delayed-type hypersensitivity response and differentiation of the fungus-specific Th1 cells was reduced in Valpha14 NKT cell-deficient mice, compared with control mice. Additionally, elimination of this fungal pathogen from lungs was significantly delayed in Valpha14 NKT cell-deficient mice. Production of monocyte chemoattractant protein (MCP)-1 in lungs, detected at both mRNA and protein levels, increased on day 1, reached a peak level on day 3, and decreased thereafter, which preceded the increase in NKT cells. Finally, the increase of total and Valpha14(+) subset of NKT cells after infection was significantly reduced in MCP-1-deficient mice. Our results demonstrated that NKT cells, especially Valpha14(+) subset, accumulated in a MCP-1-dependent manner in the lungs after infection with C. neoformans and played an important role in the development of Th1 response and host resistance to this fungal pathogen.


Subject(s)
Chemokine CCL2/physiology , Cryptococcosis/immunology , Killer Cells, Natural/immunology , Lung/cytology , Lung/immunology , Receptors, Antigen, T-Cell, alpha-beta/biosynthesis , T-Lymphocyte Subsets/immunology , Th1 Cells/immunology , Animals , Cell Movement/immunology , Cryptococcosis/pathology , Cryptococcus neoformans/immunology , Immunity, Innate/genetics , Intubation, Intratracheal , Killer Cells, Natural/metabolism , Killer Cells, Natural/pathology , Lung/pathology , Lymphocyte Count , Lymphopenia/genetics , Lymphopenia/immunology , Mice , Mice, Inbred C57BL , Mice, Knockout , Receptors, Antigen, T-Cell, alpha-beta/deficiency , Receptors, Antigen, T-Cell, alpha-beta/genetics , T-Lymphocyte Subsets/metabolism , T-Lymphocyte Subsets/pathology
10.
Infect Immun ; 69(11): 6643-50, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11598033

ABSTRACT

We showed recently that activation of Valpha14(+) natural killer T cells (NKT cells) by alpha-galactosylceramide (alpha-GalCer) resulted in increased gamma interferon (IFN-gamma) production and host resistance to intravenous infection with Cryptococcus neoformans. In other studies, interleukin-18 (IL-18) activated NKT cells in collaboration with IL-12, suggesting the possible contribution of this cytokine to alpha-GalCer-induced IFN-gamma synthesis. Here we examined the role of IL-18 in alpha-GalCer-induced Th1 response by using IL-18KO mice with this infection. In these mice, levels of IFN-gamma in serum and its synthesis in vitro by spleen cells stimulated with live organisms were not reduced, but rather enhanced, compared to those in wild-type (WT) mice, while such production was completely absent in IL-12KO mice. The enhanced production of IFN-gamma correlated with increased IL-12 synthesis but not with reduced production of IL-4, which was rather increased. IFN-gamma synthesis in IL-18KO mice was abolished by neutralizing anti-IL-12 antibody and significantly inhibited by neutralization of endogenous IL-4 with a specific monoclonal antibody. In addition, administration of recombinant IL-4 significantly enhanced the production of IFN-gamma in WT mice. Finally, the enhanced production of IFN-gamma in IL-18KO mice correlated with increased host defense against cryptococcal infection, as indicated by enhancement in alpha-GalCer-related clearance of microorganisms. Our results indicated that in IL-18KO mice, IFN-gamma synthesis was enhanced through overproduction of IL-12 and IL-4 after intravenous infection with C. neoformans and a ligand-specific activation of Valpha14(+) NKT cells.


Subject(s)
Cryptococcosis/immunology , Galactosylceramides/pharmacology , Interferon-gamma/biosynthesis , Interleukin-18/physiology , Killer Cells, Natural/immunology , Lymphocyte Activation/immunology , Receptors, Antigen, T-Cell, alpha-beta/immunology , T-Lymphocytes/immunology , Animals , Cryptococcosis/blood , Cryptococcus neoformans/immunology , Female , Interferon-gamma/blood , Interleukin-12/genetics , Interleukin-12/physiology , Interleukin-18/genetics , Interleukin-4/biosynthesis , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Th1 Cells/cytology
11.
J Mol Biol ; 311(3): 543-8, 2001 Aug 17.
Article in English | MEDLINE | ID: mdl-11493007

ABSTRACT

The 20 S proteasome core particle (CP), a multicatalytic protease, is involved in a variety of biologically important processes, including immune response, cell-cycle control, metabolic adaptation, stress response and cell differentiation. Therefore, selective inhibition of the CP will be one possible way to influence these essential pathways. Recently, a new class of specific proteasome inhibitors, TMC-95s, was investigated and we now present a biochemical and crystallographic characterisation of the yeast proteasome core particle in complex with the natural product TMC-95A. This unusual heterocyclic compound specifically blocks the active sites of CPs non-covalently, without modifying the nucleophilic Thr1 residue. The inhibitor is bound to the CP by specific hydrogen bonds with the main-chain atoms of the protein. Analysis of the crystal structure of the complex has revealed which portions of TMC-95s are essential for binding to the proteasome. This will form the basis for the development of synthetic selective proteasome inhibitors as promising candidates for anti-tumoral or anti-inflammatory drugs.


Subject(s)
Cysteine Endopeptidases/chemistry , Cysteine Endopeptidases/metabolism , Cysteine Proteinase Inhibitors/chemistry , Cysteine Proteinase Inhibitors/metabolism , Multienzyme Complexes/chemistry , Multienzyme Complexes/metabolism , Peptides, Cyclic/chemistry , Peptides, Cyclic/metabolism , Saccharomyces cerevisiae/enzymology , Antibiotics, Antineoplastic/chemistry , Antibiotics, Antineoplastic/metabolism , Binding Sites , Crystallography, X-Ray , Drug Design , Hydrogen Bonding , Models, Molecular , Multienzyme Complexes/antagonists & inhibitors , Oligopeptides/chemistry , Oligopeptides/metabolism , Proteasome Endopeptidase Complex , Protein Conformation , Protein Structure, Secondary , Static Electricity
12.
Infect Immun ; 69(1): 213-20, 2001 Jan.
Article in English | MEDLINE | ID: mdl-11119508

ABSTRACT

We examined the effect of alpha-galactosylceramide (alpha-GalCer) on the synthesis of gamma interferon (IFN-gamma) and local resistance in mice infected intravenously with Cryptococcus neoformans. The level of IFN-gamma in serum increased on day 3, reached a peak level on day 7, and decreased to the basal level on day 14 postinfection in mice treated with alpha-GalCer, while in vehicle-treated mice, no increase was detected at any time points except for a small increase on day 7. Such effects were not observed in NKT-KO mice. In CD4KO mice, minor synthesis of IFN-gamma was detected on day 3 in sera but was completely abolished by day 7. The alpha-GalCer-induced IFN-gamma production on day 3 was partially reduced in mice depleted of NK cells by treatment with anti-asialo-GM(1) antibody (Ab). Spleen cells obtained from infected and alpha-GalCer-treated mice on day 7 produced a large amount of IFN-gamma upon restimulation with live organisms, while only a marginal level of production was detected in splenocytes from infected and vehicle-treated mice. Such effects were abolished in CD4KO and NKT-KO mice. Finally, the fungal loads in the lungs and spleen on days 7 and 14 were significantly reduced in alpha-GalCer-treated mice compared to those in control mice. In NKT-KO mice, local resistance elicited by alpha-GalCer was completely abolished, although no obvious exacerbation of infection was detected. Furthermore, treatment with anti-IFN-gamma monoclonal Ab mostly abrogated the protective effect of this agent. Thus, our results indicated that activation of Valpha14(+) NKT cells resulted in an increased Th1 response and local resistance to C. neoformans through production of IFN-gamma.


Subject(s)
Cryptococcosis/immunology , Galactosylceramides/pharmacology , Killer Cells, Natural/immunology , Lymphocyte Activation , Th1 Cells/immunology , Animals , CD4 Antigens/physiology , Interferon-gamma/biosynthesis , Interleukin-4/biosynthesis , Lung/microbiology , Mice , Mice, Inbred C57BL , Mice, Knockout , Spleen/microbiology
13.
Interv Neuroradiol ; 7(Suppl 1): 57-60, 2001 Dec 22.
Article in English | MEDLINE | ID: mdl-20663379

ABSTRACT

SUMMARY: It is apparent that subarachnoid clots play an important role in the development of delayed vasospasm that is one of the major causes of mortality and morbidity in patients with acutely ruptured cerebral aneurysm. The purpose of this study is to compare the clearance of subarachnoid clots in the acute stage after the treatment with Guglielmi detachable coils (GDC) and after treatment with direct surgery. Forty-nine patients were treated by GDC embolization within four days of the ictus. After GDC embolization, adjunctive therapies, such as ventricular and/or spinal drainage (67%), intrathecal administration of urokinase (41%), continuous cisternal irrigation (16%), and external decompression (16%), were performed. Seventy-four surgically treated patients were subsequently treated by continuous cisternal irrigation with mock-CSF containing ascorbic acid for ten days. The clearance of subarachnoid clots was assessed by the Hounsfield number serial changes on the CT scans taken on days 0, 4, 7, 10 after subarachnoid hemorrhage. The incidence of symptomatic vasospasm was lower in the GDC group (6%) than in the surgery group (12%). The clearance of subarachnoid clots from both the basal cistern and the Sylvian fissure was more rapid in the GDC cases than in the surgery cases in the first four days. Intrathecal administration of urokinase accelerated the clearance significantly. GDC embolization followed by intrathecal administration of thrombolytic agents accelerates the reduction of subarachnoid clots and favorably acts to prevent delayed vasospasm.

15.
J Immunol ; 165(2): 941-7, 2000 Jul 15.
Article in English | MEDLINE | ID: mdl-10878369

ABSTRACT

The aim of this study was to examine the contribution of IL-18 in host defense against infection caused by Cryptococcus neoformans in mice with defective IL-12 production. Experiments were conducted in mice with a targeted disruption of the gene for IL-12p40 subunit (IL-12p40-/- mice). In these mice, host resistance was impaired, as shown by increased number of organisms in both lungs and brains, compared with control mice. Serum IFN-gamma was still detected in these mice at a considerable level (20-30% of that in control mice). The host resistance was moderately impaired in IL-12p40-/- mice compared with IFN-gamma-/- mice. Neutralizing anti-IFN-gamma mAb further increased the lung burdens of organisms. In addition, treatment with neutralizing anti-IL-18 Ab almost completely abrogated the production of IFN-gamma and also impaired the host resistance. Host resistance in IL-12p40-/- IL-18-/- mice was more profoundly impaired than in IL-12p40-/- mice. Administration of IL-12 as well as IL-18 increased the serum levels of IFN-gamma and significantly restored the reduced host resistance. Spleen cells obtained from infected IL-12p40-/- mice did not produce any IFN-gamma upon restimulation with the same organisms, while those from infected and IL-12-treated mice produced IFN-gamma. In contrast, IL-18 did not show such effect. Finally, depletion of NK cells by anti-asialo GM1 Ab mostly abrogated the residual production of IFN-gamma in IL-12p40-/- mice. Our results indicate that IL-18 contributes to host resistance to cryptococcal infection through the induction of IFN-gamma production by NK cells, but not through the development of Th1 cells, under the condition in which IL-12 synthesis is deficient.


Subject(s)
Cryptococcosis/immunology , Interferon-gamma/biosynthesis , Interleukin-12/biosynthesis , Interleukin-12/deficiency , Interleukin-18/physiology , Killer Cells, Natural/immunology , Killer Cells, Natural/metabolism , Adjuvants, Immunologic/administration & dosage , Adjuvants, Immunologic/physiology , Animals , Cryptococcosis/genetics , Cryptococcosis/prevention & control , Cryptococcus neoformans/immunology , Humans , Immunity, Innate/genetics , Injections, Intraperitoneal , Interferon-gamma/physiology , Interleukin-12/genetics , Interleukin-18/administration & dosage , Lymphocyte Activation/genetics , Lymphocyte Activation/immunology , Mice , Mice, Inbred C57BL , Mice, Knockout , Th1 Cells/immunology
16.
J Org Chem ; 65(4): 990-5, 2000 Feb 25.
Article in English | MEDLINE | ID: mdl-10814045

ABSTRACT

Four novel proteasome inhibitors, TMC-95A-D (1-4) have been isolated from the fermentation broth of Apiospora montagnei Sacc. TC 1093, isolated from a soil sample. All of the molecular formulas of 1-4 were established as C(33)H(38)N(6)O(10) by high-resolution FAB-MS. Their planar structures were determined on the basis of extensive analyses of 1D and 2D NMR, and degradation studies. Compounds 1-4 have the same planar structures to each other, and are unique highly modified cyclic peptides containing L-tyrosine, L-aspargine, highly oxidized L-tryptophan, (Z)-1-propenylamine, and 3-methyl-2-oxopentanoic acid units. The absolute configuration at C-11 and C-36 of 1-4 was determined based on chiral TLC and HPLC analyses of their chemical degradation products. The ROESY analysis along with (1)H-(1)H coupling constants clarified the absolute stereochemistry at C-6, -7, -8, and -14 of the cyclic moieties. These studies revealed the relationships of 1-4 to be diastereomers at C-7 and C-36.


Subject(s)
Cysteine Endopeptidases/metabolism , Cysteine Proteinase Inhibitors/chemistry , Fungi/chemistry , Multienzyme Complexes/metabolism , Peptides, Cyclic/chemistry , Cysteine Proteinase Inhibitors/pharmacology , Gas Chromatography-Mass Spectrometry , Magnetic Resonance Spectroscopy , Models, Molecular , Molecular Structure , Peptides, Cyclic/pharmacology , Proteasome Endopeptidase Complex , Protein Conformation
17.
J Antibiot (Tokyo) ; 53(2): 105-9, 2000 Feb.
Article in English | MEDLINE | ID: mdl-10805568

ABSTRACT

In our course of screening for novel proteasome inhibitors, TMC-95A and its diastereomers, TMC-95B to D, were isolated from the fermentation broth of Apiospora montagnei Sacc. TC 1093. TMC-95A inhibited the chymotrypsin-like (ChT-L), trypsin-like (T-L), and peptidylglutamyl-peptide hydrolyzing (PGPH) activities of 20S proteasome with IC50 values of 5.4nM, 200nM, and 60nM, respectively. TMC-95B inhibited these activities to the same extent as TMC-95A, while the inhibitory activities of TMC-95C and D were 20 to 150 times weaker than that of TMC-95A and B. TMC-95A did not inhibit m-calpain, cathepsin L, and trypsin at 30 microM, suggesting its high selectivity for proteasome. Taxonomy of the producing strain is also described.


Subject(s)
Cysteine Endopeptidases/drug effects , Mitosporic Fungi/classification , Mitosporic Fungi/metabolism , Multienzyme Complexes/drug effects , Peptides, Cyclic/pharmacology , Protease Inhibitors/isolation & purification , Protease Inhibitors/pharmacology , Chymotrypsin/metabolism , Colonic Neoplasms/drug therapy , Fermentation , HL-60 Cells/drug effects , Humans , Hydrolysis , Inhibitory Concentration 50 , Peptides/metabolism , Peptides, Cyclic/isolation & purification , Peptides, Cyclic/metabolism , Protease Inhibitors/metabolism , Proteasome Endopeptidase Complex , Trypsin/metabolism , Tumor Cells, Cultured
18.
FEMS Microbiol Lett ; 186(1): 121-6, 2000 May 01.
Article in English | MEDLINE | ID: mdl-10779723

ABSTRACT

Using interleukin (IL)-18 deficient (IL-18(-/-)) mice, we examined the role of IL-18 in the host resistance and Th1 response against infection with Cryptococcus neoformans. Fungal clearance in the lung was reduced in IL-18(-/-) mice, although there was no significant change in the level of dissemination to the brain. The DTH response, as determined by footpad swelling, was also diminished in IL-18(-/-) mice compared to control wild-type (WT) mice. The levels of IL-12 and interferon (IFN)-gamma in the sera were significantly lower in IL-18(-/-) mice than in WT mice. Spleen cells from infected WT mice produced a high level of IFN-gamma upon stimulation with the microbe, while only a low level of IFN-gamma production was detected in spleen cells from infected IL-18(-/-) mice. Administration of IL-18 almost completely restored the reduced response in IL-18(-/-) mice, while IL-12 showed a marginal effect. These results demonstrated the important role of IL-18 in the resistance and Th1 response of mice to C. neoformans by potentiating the production of IFN-gamma.


Subject(s)
Cryptococcosis/immunology , Cryptococcus neoformans/immunology , Interleukin-18/immunology , Th1 Cells/immunology , Animals , Brain/immunology , Brain/microbiology , Colony Count, Microbial , Crosses, Genetic , Cryptococcosis/microbiology , Cryptococcus neoformans/isolation & purification , Cytokines/blood , Hypersensitivity, Delayed/physiopathology , Interferon-gamma/blood , Interleukin-12/blood , Interleukin-18/blood , Lung/immunology , Lung/microbiology , Mice , Mice, Inbred C57BL , Spleen/cytology , Spleen/immunology
20.
FEMS Immunol Med Microbiol ; 27(3): 191-200, 2000 Mar.
Article in English | MEDLINE | ID: mdl-10683463

ABSTRACT

We previously demonstrated that interleukin (IL)-12 protected mice against fatal pulmonary infection with a highly virulent strain of Cryptococcus neoformans, which correlated well with the production of interferon (IFN)-gamma as well as IL-18 in the primary infected site. In the present study, we examined the role of endogenously synthesized IL-18 in IL-12-induced host resistance to this pathogen. There was little or no production of IFN-gamma and IL-18 both at mRNA and protein levels in lungs of mice infected with C. neoformans, while treatment with IL-12 induced a marked production of these cytokines. Caspase-1 mRNA was expressed in infected mice even without IL-12 treatment. Administration of neutralizing anti-IFN-gamma monoclonal antibody (mAb) clearly inhibited production of IFN-gamma and IL-18 induced by IL-12, while control IgG did not show such an effect. However, administration of IFN-gamma did not induce the production of both cytokines in infected mice, although tumor necrosis factor (TNF)-alpha and IFN-gamma-inducible protein (IP)-10 were synthesized by the same treatment. Finally, neutralizing anti-IL-18 antibody (Ab) significantly interfered with the production of IFN-gamma and elimination of the microorganism from the lung induced by IL-12 treatment. Furthermore, both IFN-gamma synthesis and host protection caused by IL-12 were profoundly diminished in IL-18 gene-disrupted mice. Considered collectively, our results indicated that host protection against C. neoformans induced by IL-12 involved endogenously synthesized IL-18 and that the production of IL-18 was mediated at least in part by endogenous IFN-gamma.


Subject(s)
Cryptococcosis/immunology , Interleukin-12/immunology , Interleukin-18/biosynthesis , Interleukin-18/immunology , Lung Diseases, Fungal/immunology , Animals , Bronchoalveolar Lavage Fluid/immunology , Caspase 1/biosynthesis , Caspase 1/genetics , Cryptococcosis/microbiology , Cryptococcus neoformans/immunology , Cryptococcus neoformans/isolation & purification , Female , Humans , Interferon-gamma/biosynthesis , Interferon-gamma/genetics , Interferon-gamma/immunology , Interleukin-12/pharmacology , Interleukin-18/genetics , Lung/microbiology , Lung Diseases, Fungal/microbiology , Mice , Mice, Inbred C57BL , RNA, Fungal/analysis , Rabbits , Reverse Transcriptase Polymerase Chain Reaction
SELECTION OF CITATIONS
SEARCH DETAIL
...