Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 52
Filter
2.
Bone Marrow Transplant ; 56(7): 1550-1557, 2021 07.
Article in English | MEDLINE | ID: mdl-33514918

ABSTRACT

Patients with advanced Ewing sarcoma (AES) carry a poor prognosis. Retrospectively, we analyzed 66 AES patients treated with allogeneic stem cell transplantation (allo-SCT) receiving HLA-mismatched (group A, n = 39) versus HLA-matched grafts (group B, n = 27). Median age at diagnosis was 13 years, and 15 years (range 3-49 years) at allo-SCT. The two groups did not differ statistically in distribution of gender, age, remission status/number of relapses at allo-SCT, or risk stratum. 9/39 (23%) group A versus 2/27 (7%) group B patients developed severe acute graft versus host disease (GvHD). Of patients alive at day 100, 7/34 (21%) group A versus 9/19 (47%) group B patients had developed chronic GvHD. In group A, 33/39 (85%) versus 20/27 (74%) group B patients died of disease and 1/39 (3%) versus 1/27 (4%) patients died of complications, respectively. Altogether 12/66 (18%) patients survived in CR. Median EFS 24 months after allo-SCT was 20% in both groups, median OS was 27% (group A) versus 17% (group B), respectively. There was no difference in EFS and OS in AES patients transplanted with HLA-mismatched versus HLA-matched graft in univariate and multivariate analyses. In this analysis, CR at allo-SCT is a condition for survival (p < 0.02).


Subject(s)
Graft vs Host Disease , Hematopoietic Stem Cell Transplantation , Sarcoma, Ewing , Adolescent , Adult , Child , Child, Preschool , Humans , Middle Aged , Neoplasm Recurrence, Local , Retrospective Studies , Sarcoma, Ewing/therapy , Transplantation Conditioning , Young Adult
3.
Br J Cancer ; 109(10): 2523-32, 2013 Nov 12.
Article in English | MEDLINE | ID: mdl-24149176

ABSTRACT

BACKGROUND: Allogeneic haematopoietic stem cell transplantation (allo-SCT) may provide donor cytotoxic T cell-/NK cell-mediated disease control in patients with rhabdomyosarcoma (RMS). However, little is known about the prevalence of graft-vs-RMS effects and only a few case experiences have been reported. METHODS: We evaluated allo-SCT outcomes of 30 European Group for Blood and Marrow Transplantation (EBMT)-registered patients with advanced RMS regarding toxicity, progression-free survival (PFS) and overall survival (OS) after allo-SCT. Twenty patients were conditioned with reduced intensity and ten with high-dose chemotherapy. Twenty-three patients were transplanted with HLA-matched and seven with HLA-mismatched grafts. Three patients additionally received donor lymphocyte infusions (DLIs). Median follow-up was 9 months. RESULTS: Three-year OS was 20% (s.e.±8%) with a median survival time of 12 months. Cumulative risk of progression was 67% (s.e.±10%) and 11% (s.e.±6%) for death of complications. Thirteen patients developed acute graft-vs-host disease (GvHD) and five developed chronic GvHD. Eighteen patients died of disease and four of complications. Eight patients survived in complete remission (CR) (median: 44 months). No patients with residual disease before allo-SCT were converted to CR. CONCLUSION: The use of allo-SCT in patients with advanced RMS is currently experimental. In a subset of patients, it may constitute a valuable approach for consolidating CR, but this needs to be validated in prospective trials.


Subject(s)
Hematopoietic Stem Cell Transplantation/methods , Rhabdomyosarcoma/surgery , Adolescent , Adult , Child , Child, Preschool , Disease Progression , Female , Graft vs Host Disease/etiology , Graft vs Host Disease/mortality , Hematopoietic Stem Cell Transplantation/adverse effects , Humans , Male , Neoplasm Recurrence, Local/epidemiology , Neoplasm Recurrence, Local/mortality , Retrospective Studies , Rhabdomyosarcoma/mortality , Transplantation, Homologous , Young Adult
4.
Klin Padiatr ; 224(6): 353-8, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22821288

ABSTRACT

BACKGROUND: Risk stratification criteria for patients with Ewing's sarcoma family of tumors (ESFT) are still limited. We hypothesized divergent human leukocyte antigen (HLA) patterns in ESFT patients and compared HLA-A, -B and -DR phenotype frequencies of patients with advanced ESFT with those of healthy controls. PATIENTS: HLA types of all German Caucasian patients with advanced ESFT and available HLA-A, -B and -DR data registered in the European Group for Blood and Marrow Transplantation, Paediatric Registry for Stem Cell Transplantation and the MetaEICESS data bases (study group, n=30) were retrospectively compared with HLA types of healthy German stem cell donors (control group, n=8 862 for single HLA frequencies and n=8 839 for allele combinations). Study group patients had been immuno-typed due to eligibility for allogeneic stem cell transplantation for high risk of treatment failure, and thus constituted a selected subgroup of ESFT patients. RESULTS: After Bonferroni correction for multiple testing (PC), phenotype frequencies of HLA-A24 remained significantly higher in the study group compared to controls (PC<0.05). Furthermore, several HLA combinations were significantly more frequent in the study group compared to controls (all PC<0.05). CONCLUSION: We report an increased incidence of circumscribed HLA patterns in German Caucasians with advanced ESFT. The possible clinical significance of this observation has to be re-assessed in prospective trials comprising larger ESFT patient numbers of all risk groups.


Subject(s)
Blood Donors , Bone Marrow Transplantation , Bone Neoplasms/genetics , Bone Neoplasms/therapy , HLA-A Antigens/genetics , HLA-B Antigens/genetics , HLA-DR Antigens/genetics , Hematopoietic Stem Cell Transplantation , Sarcoma, Ewing/genetics , Sarcoma, Ewing/therapy , Tissue Donors , Adolescent , Adult , Bone Neoplasms/pathology , Child , Disease Progression , Female , Gene Frequency , Genetics, Population , Germany , Humans , Male , Neoplasm Recurrence, Local/genetics , Neoplasm Recurrence, Local/pathology , Neoplasm Recurrence, Local/therapy , Neoplasm Staging , Retrospective Studies , Sarcoma, Ewing/pathology , Young Adult
5.
Br J Cancer ; 104(6): 948-56, 2011 Mar 15.
Article in English | MEDLINE | ID: mdl-21407224

ABSTRACT

BACKGROUND: The development of a successful immunotherapy is hampered by an ineffective T-cell repertoire against tumour antigens and the inability of the patient's immune system to overcome tolerance-inducing mechanisms. Here, we test the specific recognition and lytical potential of allo-restricted CD8(+) T cells against Ewing tumour (ET) associated antigens Enhancer of Zeste, Drosophila Homolog 2 (EZH2), and Chondromodulin-I (CHM1) identified through previous microarray analysis. METHODS: Following repetitive CHM1(319) (VIMPCSWWV) and EZH2(666) (YMCSFLFNL) peptide-driven stimulations with HLA-A 0201(+) dendritic cells (DC), allo-restricted HLA-A 0201(-) CD8(+) T cells were stained with HLA-A 0201/peptide multimers, sorted and expanded by limiting dilution. RESULTS: Expanded T cells specifically recognised peptide-pulsed target cells or antigen-transfected cells in the context of HLA-A 0201 and killed HLA-A 0201(+) ET lines expressing the antigen while HLA-A 0201(-) ET lines were not affected. Furthermore, adoptively transferred T cells caused significant ET growth delay in Rag2(-/-)γ(C)(-/-) mice. Within this context, we identified the CHM1(319) peptide as a new candidate target antigen for ET immunotherapy. CONCLUSION: These results clearly identify the ET-derived antigens, EZH2(666) and CHM1(319), as suitable targets for protective allo-restricted human CD8(+) T-cell responses against non-immunogenic ET and may benefit new therapeutic strategies in ET patients treated with allogeneic stem cell transplantation.


Subject(s)
Antigens, Neoplasm/immunology , Bone Neoplasms/pathology , Isoantigens/immunology , Sarcoma, Ewing/pathology , T-Lymphocytes, Cytotoxic/immunology , Animals , Antigens, Neoplasm/metabolism , Bone Neoplasms/immunology , Cell Line, Tumor , Cell Proliferation , Cells, Cultured , Cytotoxicity, Immunologic/immunology , DNA-Binding Proteins/genetics , Down-Regulation , Humans , Immunotherapy, Adoptive , Isoantigens/metabolism , K562 Cells , Mice , Mice, Knockout , Sarcoma, Ewing/immunology , T-Cell Antigen Receptor Specificity/immunology , T-Lymphocytes, Cytotoxic/metabolism
6.
Ann Oncol ; 22(7): 1614-1621, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21245159

ABSTRACT

BACKGROUND: Outcomes of Ewing tumor (ET) patients treated with allogeneic stem cell transplantation (allo-SCT) were compared regarding the use of reduced-intensity conditioning (RIC) and high-intensity conditioning (HIC) regimens as well as human leukocyte antigen (HLA)-matched and HLA-mismatched grafts. PATIENTS AND METHODS: We retrospectively analyzed data of 87 ET patients from the European Group for Blood and Marrow Transplantation, Pediatric Registry for Stem Cell Transplantations, Asia Pacific Blood and Marrow Transplantation and MetaEICESS registries treated with allo-SCT. Fifty patients received RIC (group A) and 37 patients received HIC (group B). Twenty-four patients received HLA-mismatched grafts and 63 received HLA-matched grafts. RESULTS: Median overall survival was 7.9 months [±1.24, 95% confidence interval (CI) 5.44-10.31] for group A and 4.4 months (±1.06, 95% CI 2.29-6.43) for group B patients (P = 1.3). Death of complications (DOC) occurred in 4 of 50 (0.08) and death of disease (DOD) in 33 of 50 (0.66) group A and in 16 of 37 (0.43) and 17 of 37 (0.46) group B patients, respectively. DOC incidence was decreased (P < 0.01) and DOD/relapse increased (P < 0.01) in group A compared with group B. HLA mismatch was not generally associated with graft-versus-Ewing tumor effect (GvETE). CONCLUSIONS: There was no improvement of survival with RIC compared with HIC due to increased DOD/relapse incidence after RIC despite less DOC incidence. This implicates general absence of a clinically relevant GvETE with current protocols.


Subject(s)
Bone Neoplasms/mortality , Bone Neoplasms/therapy , Graft vs Host Disease/therapy , Sarcoma, Ewing/mortality , Sarcoma, Ewing/therapy , Stem Cell Transplantation , Adolescent , Adult , Child , Child, Preschool , Female , Follow-Up Studies , Humans , Male , Middle Aged , Retrospective Studies , Survival Rate , Transplantation Conditioning , Transplantation, Homologous , Treatment Outcome , Young Adult
7.
Bone Marrow Transplant ; 45(3): 483-9, 2010 Mar.
Article in English | MEDLINE | ID: mdl-19684633

ABSTRACT

We examined the role of total body magnetic resonance imaging (TB-MRI)-governed involved compartment irradiation (ICI) and high-dose chemotherapy (HDC), followed by stem cell rescue (SCR) in patients with high-risk Ewing tumors (ETs) with multiple primary bone metastases (high-risk ET-MBM). Eleven patients with high-risk ET-MBM receiving initial assessment of involved bones by TB-MRI were registered from 1995 to 2000 (group A). In all, 6 patients out of 11 had additional lung disease at initial diagnosis; all had multifocal bone disease with more than three bones involved. After systemic induction with etoposide, vincristine, adriamycin (doxorubicin), ifosfamide, and actinomycin D (EVAIA) or VAIA chemotherapy, ICI of all sites positive by TB-MRI was administered, followed by HDC and SCR. A second group matched for observation period and consisting of 26 patients with more than three involved bones at diagnosis was treated with the European Intergroup Cooperative Ewing Sarcoma Study-92 (EICESS-92) protocol (group B). These patients did not receive TB-MRI and consequently did not receive TB-MRI-governed ICI, or HDC and SCR. Survival in group A vs group B was 45 vs 8% at 5 years and 27 vs 8% at 10 years after diagnosis (log rank and Breslow: P<0.005). We conclude that TB-MRI-governed ICI followed by HDC and SCR in ET-MBM is feasible and warrants further evaluation in prospective studies.


Subject(s)
Bone Neoplasms/therapy , Sarcoma, Ewing/therapy , Adolescent , Adult , Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Bone Neoplasms/drug therapy , Bone Neoplasms/radiotherapy , Bone Neoplasms/secondary , Child , Clinical Protocols , Combined Modality Therapy , Female , Hematopoietic Stem Cell Transplantation , Humans , Kaplan-Meier Estimate , Magnetic Resonance Imaging , Male , Sarcoma, Ewing/drug therapy , Sarcoma, Ewing/radiotherapy , Sarcoma, Ewing/secondary , Whole-Body Irradiation/methods , Young Adult
8.
Mol Vis ; 14: 1437-45, 2008 Aug 04.
Article in English | MEDLINE | ID: mdl-18682810

ABSTRACT

PURPOSE: To analyze protein patterns in the aqueous humor of glaucoma patients in comparison to control subject using two different methods. METHODS: Aqueous humor was collected from 52 patients with primary open-angle glaucoma (POAG) and from 55 control subjects (CO). Twenty-two POAG samples and 24 CO samples were used for protein profiling through surface enhanced laser desorption/ionization-time of flight-mass spectrometry (SELDI-TOF-MS) ProteinChip arrays. The data were analyzed by multivariate statistical methods and artificial neural networks. One highly significant biomarker was identified through matrix assisted laser desorption/ionisation time of flight-mass spectrometry (MALDI-TOF). Thirty samples from patients with POAG and 31 control samples were analyzed through two-dimensional electrophoresis. Subsequently, the protein spots of all gels were detected, and the two groups were compared. One spot group exhibiting clear differential abundance was identified by mass spectrometry (electrospray ionization mass spectrometry). RESULTS: In the samples analyzed by SELDI-TOF-MS, about 250 protein peaks could be consistently clustered in both groups. The analyses revealed eight biomarkers, which discriminated glaucoma from non-glaucoma controls with a sensitivity of 90% and a specificity of 87%. These biomarkers were purified further, and one marker, which was upregulated in glaucoma patients (p=0.006), was identified as transthyretin. The upregulation of transthyretin in POAG patients was also confirmed by enzyme linked immunosorbent assay (ELISA; p=0.03). In all samples analyzed by two-dimensional electrophoresis, complex protein patterns were detected in a total of 177 spot groups. The aqueous humor of all glaucoma patients revealed some regions that were clearly different from the controls. Several spots were significantly increased in the aqueous humor of glaucoma patients. One of the proteins that is highly abundant in the aqueous of glaucoma patients was identified as transthyretin. CONCLUSIONS: The aqueous humor of glaucoma patients revealed characteristic differences in protein/peptide profiles from control patients using two different analytical methods, SELDI-TOF-MS and two-dimensional electrophoresis. Interestingly, we could detect elevated transthyretin concentrations in glaucoma samples. Transthyretin might play a role in the onset of glaucoma since it has been shown to form amyloid deposits. These particles could cause outflow obstructions thereby increasing intraocular pressure as a possible onset mechanism.


Subject(s)
Aqueous Humor/chemistry , Eye Proteins/analysis , Glaucoma, Open-Angle/metabolism , Prealbumin/analysis , Aged , Case-Control Studies , Electrophoresis, Gel, Two-Dimensional , Enzyme-Linked Immunosorbent Assay , Eye Proteins/chemistry , Humans , Prealbumin/chemistry , ROC Curve , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
9.
Urologe A ; 42(1): 104-12, 2003 Jan.
Article in German | MEDLINE | ID: mdl-12577160

ABSTRACT

Today, the classical bacteria that cause venereal diseases, e.g. gonorrhea, syphilis, chancroid and inguinal granuloma, only account for a small proportion of all known sexually transmitted diseases (STDs). Other bacteria and viruses as well as yeasts, protozoa and epizoa must also be regarded as causative organisms of STD. Taken together, all sexually transmitted infections comprise more than 30 relevant STD pathogens. However, not all pathogens that can be sexually transmitted manifest diseases in the genitals and not all infections of the genitals are exclusively sexually transmitted. Concise information and tables summarising the diagnostic and therapeutic management of STDs in the field of urology allow a synoptic overview, and are in agreement with the recent international guidelines of other specialist areas. Special considerations (i.e. HIV infection, pregnancy, infants, allergy) and recommended regimens are presented.


Subject(s)
Genital Diseases, Male/diagnosis , Sexually Transmitted Diseases/diagnosis , Disease Notification/legislation & jurisprudence , Female , Genital Diseases, Male/therapy , Germany , Humans , Infant, Newborn , Male , Pregnancy , Sexually Transmitted Diseases/therapy , Societies, Medical
11.
Free Radic Res ; 34(2): 137-51, 2001 Feb.
Article in English | MEDLINE | ID: mdl-11264891

ABSTRACT

During continuous ambulatory peritoneal dialysis (CAPD) the peritoneal immune cells, mainly macrophages, are highly compromised by multiple factors including oxidative stress, resulting in a loss of functional activity. One reason for the increase of inflammatory reactions could be an imbalance in the thiol-disulfide status. Here, the possible protective effects of the antioxidant flavonoid complex silymarin and its major component silibinin on the cellular thiol status were investigated. Peritoneal macrophages from dialysis fluid of 30 CAPD patients were treated with silymarin or silibinin up to 35 days. A time-dependent increase of intracellular thiols was observed with a nearly linear increment up to 2.5-fold after 96 hours, reaching a maximum of 3.5-fold after 20 days of culture. Surface-located thiols were also elevated. The stabilization of the cellular thiol status was followed by an improvement of phagocytosis and the degree of maturation as well as significant changes in the synthesis of IL-6 and IL-1ra. Furthermore, the treatment of peritoneal macrophages with flavonoids in combination with cysteine donors resulted in a shortened and more efficient time course of thiol normalization as well as in a further increased phagocytosis. In addition, GSH-depletion in thiol-deficient media simulating CAPD procedures led to intracellular thiol deficiency similar to the in vivo situation. It is concluded that treatment with milk thistle extracts silymarin and silibinin alone or, more effectively in combination with cysteine donors, provide a benefit for peritoneal macrophages of CAPD-patients due to a normalization and activation of the cellular thiol status followed by a restoration of specific functional capabilities.


Subject(s)
Macrophages, Peritoneal/drug effects , Peritoneal Dialysis, Continuous Ambulatory , Silymarin/pharmacology , Sulfhydryl Compounds/metabolism , Acetylcysteine/pharmacology , Adult , Aged , Antigens, CD/biosynthesis , Cells, Cultured/drug effects , Coloring Agents , Cysteine/physiology , Female , Flow Cytometry , Fluoresceins/analysis , Gene Expression Regulation/drug effects , Glutathione/physiology , Humans , Interleukin 1 Receptor Antagonist Protein , Interleukin-6/biosynthesis , Interleukin-6/genetics , Male , Middle Aged , Oxidative Stress , Peritoneal Dialysis, Continuous Ambulatory/adverse effects , Phagocytosis/drug effects , Sialoglycoproteins/biosynthesis , Sialoglycoproteins/genetics
12.
Free Radic Biol Med ; 29(11): 1160-5, 2000 Dec.
Article in English | MEDLINE | ID: mdl-11121724

ABSTRACT

In increasing numbers of pulmonary diseases an association with a loss of intracellular thiols, mainly glutathione, is postulated. Therefore, the quantitative measurement of thiols within different viable cells is a possible metabolic parameter for cellular function and defense capacity of all pulmonary immune cells including alveolar macrophages (AM), that are highly compromised by oxidative stress. In this study the cellular thiol content was determined using fluorochrom conjugated chloromethyl derivatives (5-chloromethylfluorescein diacetate, CMFDA) in flow cytometry. The procedure was evaluated in vitro using biochemical techniques for glutathione quantification. Based on this approach, AM obtained from bronchoalveolar lavage (BAL) of smokers and patients with chronic obstructive pulmonary disease (COPD) showed a significant thiol deficiency compared to a nonsmoker/non-COPD group. The cellular thiol expression of AM from smokers and COPD patients reached only 50 and 53% of the control group. Lowest thiol concentrations (47% of control) were detected within the smoker(+)/COPD(+) group. This intracellular thiol deficiency significantly correlated with reduced lung function (FEV(1), PaO(2)). With regard to the tightly regulated thiol metabolism of immune cells, these results imply the onset of functional disturbances in thiol deficient AM. The determination of the cellular thiol content of AM, obtained from BAL by flow cytometry, presents a simple and reliable tool to monitor the effect of therapeutic measures focusing on the stabilization of the cellular thiol status.


Subject(s)
Lung Diseases, Obstructive/metabolism , Macrophages, Alveolar/metabolism , Smoking , Sulfhydryl Compounds/analysis , Aged , Bronchoalveolar Lavage Fluid/cytology , Flow Cytometry , Fluoresceins , Fluorescent Dyes , Glutathione/analysis , Humans , Macrophages, Alveolar/chemistry , Middle Aged , Oxidative Stress
13.
Eur J Biochem ; 267(8): 2447-51, 2000 Apr.
Article in English | MEDLINE | ID: mdl-10759871

ABSTRACT

The intracellular amounts of diphospho-myo-inositol phosphates and InsP6 were determined in Dictyostelium discoideum AX2 throughout the life cycle, including exponential growth, starvation, differentiation, sporulation and spore germination. Similar experiments were performed with the closely related species Polysphondylium pallidum under conditions resulting in microcyst formation. A distinct accumulation of these compounds is observed during the early starvation phase of the cell population before the onset of the actual differentiation program. When exponentially growing D. discoideum cells were shifted to starvation conditions, a 25-fold accumulation of 5,6-bis-PP-InsP4 within 3 h was observed. In P. pallidum, the 5,6-bis-PP-InsP4 pool rises around 20-fold within 8 h during the formation of microcysts from vegetative cells. Finally, the diphosphoinositol phosphates are deposited in spores or microcysts and are degraded when spores or microcysts germinate at low cell density.


Subject(s)
Dictyostelium/metabolism , Eukaryota/metabolism , Inositol Phosphates/metabolism , Animals , Cell Differentiation , Cell Division , Phosphorylation , Reproduction
14.
Exp Hematol ; 25(7): 601-7, 1997 Jul.
Article in English | MEDLINE | ID: mdl-9216735

ABSTRACT

The proteindisulfide isomerase (PDI), a multifunctional cytoplasmic enzyme with additional chaperone activity, has been shown recently, using monoclonal antibodies, to be located on the membrane of mature human B lymphocytes and B cell chronic lymphocytic leukemia (B-CLL) cells. Here, evidence is presented that this antigen exhibits catalytic activity as measured by the reductive degradation of insulin (release of A chain molecules) on intact B cells in patients suffering from B-CLL, as well as on JVM 13 cells (B-CLL cell line). More than 98% of these cells exhibited PDI activity which could be inhibited by bacitracin and also by monoclonal and polyclonal antibodies to PDI. Interestingly, surface PDI expression was strongly correlated in our study with protein-bound membrane SH groups. These surface protein thiols were specifically determined by using low concentrations of the chloromethyl-derivative based fluorescent probe 5-(and6)-(((4-chloromethyl)-benzoyl)amino)-tetramethyl-rhodamine (CMTMR) at low temperature in the presence of sodium azide in flow cytometry. The highest PDI and SH expression was found on B lymphocytes, particularly B-CLL cells. The mean fluorescence intensity (MFI) of CMTMR-positive B cells in the B-CLL line was up to 10-fold higher than that of controls, indicating a strong elevation of cell membrane-located protein thiols on malignant B cells. The link between PDI and SH expression on cell surfaces points to a functional interaction between the two. Treatment with bacitracin resulted in a strong inhibition of PDI and a dramatic increase in surface protein thiol expression of B-CLL cells. Similar effects could be observed by cell treatment with anti-PDI antibodies, indicating that this enzyme system plays a crucial role in the regulation of protein-bound SH groups. Interestingly, artificially induced protein thiol expression led to significantly higher cellular resistance to the cytostatic drugs chlorambucil, vinblastin, and cisplatin in vitro as measured by cell growth. These data suggest for the first time a regulatory effect of PDI on the surface protein thiol status of B cells. The increased expression of PDI may play a crucial role in SH-mediated protection and drug resistance in malignant B lymphocytes.


Subject(s)
B-Lymphocytes/metabolism , Isomerases/metabolism , Leukemia, Lymphocytic, Chronic, B-Cell/drug therapy , Sulfhydryl Compounds/metabolism , Bacitracin/pharmacology , Chlorambucil/pharmacology , Cisplatin/pharmacology , Cytarabine/pharmacology , Drug Resistance, Neoplasm , Humans , Isomerases/antagonists & inhibitors , Leukemia, Lymphocytic, Chronic, B-Cell/enzymology , Protein Disulfide-Isomerases , Surface Properties , Tumor Cells, Cultured , Vinblastine/pharmacology
16.
Biochem J ; 315 ( Pt 3): 715-20, 1996 May 01.
Article in English | MEDLINE | ID: mdl-8645148

ABSTRACT

Diphospho-myo-inositol phosphates (PP-InsP5 and bis-PP-InsP4) were isolated from Dictyostelium in order to clarify the precise positional isomerism by two-dimensional 1H/31P-NMR analysis. The diphosphorylated inositol phosphates are 4-PP-Ins(1,2,3,5,6)P5 and 4,5-bis-PP-Ins(1,2,3,6)P4 or their corresponding enantiomers. The vicinal arrangement of the diphospho groups with its steric and electrostatic constraints possibly qualifies bis-PP-InsP4 as a metabolite with high phosphate-group-transfer potential in phosphotransferase reactions.


Subject(s)
Dictyostelium/chemistry , Inositol Phosphates/chemistry , Animals , Hydrogen/chemistry , Inositol Phosphates/isolation & purification , Magnetic Resonance Spectroscopy , Molecular Structure , Phosphorus Isotopes
17.
Cell Immunol ; 170(1): 63-70, 1996 May 25.
Article in English | MEDLINE | ID: mdl-8660800

ABSTRACT

Dipeptidyl peptidase IV (DP IV, CD26), known as an activation marker of T lymphocytes, is a proline-specific protease thought to be involved in the regulation of the immune response. The physiological role of dipeptidyl peptidase IV in the immune system and the molecular events of lymphocyte activation mediated by this enzyme are only partly established. Former results suggested the occurrence of different molecular forms of DP IV in distinct human sources. As yet it has been unknown whether DP IV from human hematopoietic cells also appears in different forms and whether similar structural modifications are involved in functional processes of the regulation of the immune response. Here we describe that lymphocytic DP IV/CD26 occurs in various molecular forms and that some of them are associated with the activation process. In cell lysates of mitogen-activated lymphocytes at least 5 enzymatically active DP IV forms and up to 11 immunoreactive molecular forms of this enzyme with isoelectric points between pH 3.5 and 5.9 were discernible. Corresponding analyses of soluble and membrane cell fractions of human lymphocytes showed significant differences in the staining pattern of molecular DP IV structures. After mitogenic stimulation a special molecular form of DP IV arises in the membrane, which was originated either from the soluble part of the cell (translocation) or represents a new synthesized form. Particularly, changes of molecular DP IV forms after mitogenic stimulation strongly suggest that special forms/epitopes of this enzyme are directly involved in the process of lymphocyte activation and growth. Importantly, different monoclonal DP IV antibodies partly define different molecular forms of DP IV. Moreover, the pattern of immunostaining and enzymatic staining (Gly-Pro-beta-methoxynaphthylamide) also reveals drastic differences. These data strongly suggest a direct relationship between the expression/recognition of special DP IV epitopes and the contradictory functional effects of monoclonal DP IV antibodies found by us and other groups.


Subject(s)
Dipeptidyl Peptidase 4/chemistry , Dipeptidyl Peptidase 4/metabolism , Lymphocyte Activation , T-Lymphocytes/chemistry , T-Lymphocytes/enzymology , Cells, Cultured , Dipeptidyl Peptidase 4/immunology , Enzyme Activation/immunology , Humans , Isoelectric Focusing , Isoenzymes/chemistry , Isoenzymes/immunology , Isoenzymes/metabolism , Structure-Activity Relationship , T-Lymphocytes/immunology
18.
J Biol Chem ; 268(6): 4009-15, 1993 Feb 25.
Article in English | MEDLINE | ID: mdl-8440693

ABSTRACT

A new class of inositol phosphates containing energy-rich pyrophosphoryl residues has been characterized. D/L-1-Diphosphoinositol pentakisphosphate(s) and D/L-bis-(1,4)-diphosphoinositol tetrakisphosphate(s) are present as soluble ionic species in the cytosol of amoebae (Dictyostelium discoideum) at concentrations in the range of 0.05-0.25 mM. These compounds are rapidly metabolized in intact cells and can be synthesized in cell lysates from myo-inositol hexakisphosphate in the presence of ATP. Their phosphomonoester groups have predicted C-O-P bond energies of between 3.3 and 4 kcal mol-1; however, the bond energies of the P-O-P links in their diphosphate moieties are 6.6 kcal mol-1 and hence similar to the equivalent bonds in ADP, indicating a potential role for these compounds as phosphate donors in phosphotransferase reactions. Compounds with similar chromatographic properties are found in a variety of mammalian cell types.


Subject(s)
Inositol Phosphates/chemistry , Animals , Cells, Cultured , Chromatography, High Pressure Liquid , Dictyostelium/chemistry , Dictyostelium/metabolism , Humans , Inositol/chemistry , Inositol Phosphates/isolation & purification , Inositol Phosphates/metabolism , Magnetic Resonance Spectroscopy , Mice , Molecular Structure , Phytic Acid/metabolism , Spectrometry, Mass, Fast Atom Bombardment , Tumor Cells, Cultured
20.
Hybridoma ; 10(6): 651-7, 1991 Dec.
Article in English | MEDLINE | ID: mdl-1816070

ABSTRACT

The Protein disulphide-isomerase (PDI, EC 5.3.4.1, Thiol-proteindisulphide oxidoreductase, EC 1.8.4.2) is thought to regulate the sulfhydryl status of cells and to catalyze thiol/disulphide exchange reactions involved in the post-translational processing of disulphide containing secretory proteins. The aim of the present investigations was to study the possible function of this enzyme in differentiation of B lymphocytes and immunoglobulin synthesis. Non-adherent human mononuclear cells or purified T cells were cultured in presence and absence of Pokeweed mitogen over 3, 5 and 7 days. Monoclonal antibodies and a rabbit polyclonal antiserum specific for human liver PDI were produced to determine the concentration of PDI by an ELISA technique and cytoplasmic immunofluorescence. After PWM stimulation, both, the cellular content of PDI as well as that of immunoglobulin, particularly IgM, have been found to be induced in a time dependent manner with a 2-3 fold increase in comparison to unstimulated cells. The specific induction of PDI in human B lymphocytes was also confirmed in Western blotting. Our findings suggest that PDI plays a critical role in the final stages of B cell differentiation and immunoglobulin synthesis by activated B cells and plasma cells, respectively.


Subject(s)
B-Lymphocytes/drug effects , Immunoglobulins/biosynthesis , Isomerases/biosynthesis , Pokeweed Mitogens , Antibodies, Monoclonal/immunology , B-Lymphocytes/metabolism , Cell Differentiation , Cells, Cultured , Enzyme Induction/drug effects , Gene Expression Regulation/drug effects , Humans , Immunoglobulin M/biosynthesis , Isomerases/immunology , Lymphocyte Activation , Protein Disulfide-Isomerases
SELECTION OF CITATIONS
SEARCH DETAIL
...