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C Arndt,
M von Bonin,
M Cartellieri,
A Feldmann,
S Koristka,
I Michalk,
S Stamova,
M Bornhäuser, M Schmitz,
G Ehninger,
M Bachmann
Leukemia: official journal of the Leukemia Society of America, Leukemia Research Fund, U.K 01/2013; · 8.30 Impact Factor
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S Stamova,
M Cartellieri,
A Feldmann,
C C Bippes,
H Bartsch,
R Wehner, M Schmitz,
M von Bonin,
M Bornhäuser,
G Ehninger,
E P Rieber,
M Bachmann
Leukemia: official journal of the Leukemia Society of America, Leukemia Research Fund, U.K 03/2011; 25(6):1053-6. · 8.30 Impact Factor
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ABSTRACT: Immunomodulatory properties of IDO1 relate to tryptophan catabolism. The degradation of tryptophan by IDO1 leads to suppression of T cell responses. Recently, another enzyme with IDO-like activity, indoleamine 2,3-dioxygenase-like-protein 1 (INDOL1, IDO2), has been described in both mice and humans. In order to study the gene expression of IDO1 and IDO2, we have developed a quantitative PCR (qPCR) assay. In an exploratory application to the study of the differential expression of IDO1 and IDO2 by professional antigen-presenting cells and MSCs (mesenchymal stromal cells) under the influence of interferon-γ (IFN-γ) and T-lymphocyte conditioned media (TCM), substantial differences were observed. IDO expression measured by qPCR was valid and reliable in the cell types investigated. Further studies are needed to delineate factors driving IDO expression in MSCs.
Tissue Antigens 02/2011; 77(2):136-42. · 2.59 Impact Factor
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Leukemia: official journal of the Leukemia Society of America, Leukemia Research Fund, U.K 11/2010; 24(11):1965-7. · 8.30 Impact Factor
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U Canzler,
H Bartsch,
S Ulitzsch,
B T Kurien,
Y Dorri,
R H Scofield,
K Grossmann,
W Lehmann,
C Pilarsky,
A Denz,
R Grützmann,
K Conrad, M Schmitz,
E P Rieber,
W Distler,
M P Bachmann
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ABSTRACT: It is well known that sera of patients with systemic autoimmunity contain autoantibodies to nuclear antigens. It is also known that patients with systemic autoimmunity have an increased risk for the development of tumours. Interestingly, tumour patients frequently develop autoantibodies and there is a growing list of potential tumour-associated antigens. It is, however, not known whether or not patients with systemic autoimmunity also develop antibodies to tumour-associated antigens. Here we describe the development of a novel multiprotein array allowing us to screen for autoantibodies to 30 different tumour-associated antigens in parallel. Using this novel assay, we found that the frequency of autoantibodies to the selected tumour-associated antigens is increased between 2- and 14-fold in patients with systemic autoimmunity compared with an age-matched control group.
Scandinavian Journal of Immunology 07/2009; 69(6):563-9. · 2.23 Impact Factor
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M von Bonin,
F Stölzel,
A Goedecke,
K Richter,
N Wuschek,
K Hölig,
U Platzbecker,
T Illmer,
M Schaich,
J Schetelig,
A Kiani,
R Ordemann,
G Ehninger, M Schmitz,
M Bornhäuser
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ABSTRACT: Mesenchymal stem cells have been shown to mediate immunomodulatory effects. They have been used in patients with steroid-refractory acute GVHD (aGVHD), but their relevance as a therapeutic agent targeting aGVHD has still to be defined. In this case series, we report 13 patients with steroid-refractory aGVHD who received BM-derived MSC expanded in platelet lysate-containing medium from unrelated HLA disparate donors. MSC were characterized by their morphological, phenotypical and functional properties. All tested preparations suppressed the proliferation of in vitro activated CD4+ T cells. MSC were transfused at a median dosage of 0.9 x 10(6)/kg (range 0.6-1.1). The median number of MSC applications was 2 (range 1-5). Only two patients (15%) responded and did not require any further escalation of immunosuppressive therapy. Eleven patients received additional salvage immunosuppressive therapy concomitant to further MSC transfusions, and after 28 days, five of them (45%) showed a response. Four patients (31%) are alive after a median follow-up of 257 days, including one patient who initially responded to MSC treatment. In our patient cohort, response to MSC transfusion was lower than in the series reported earlier. However, our experience supports the potential efficacy of MSC in the treatment of steroid-refractory aGVHD.
Bone marrow transplantation 10/2008; 43(3):245-51. · 3.00 Impact Factor
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ABSTRACT: Bortezomib is a potent drug for the treatment of multiple myeloma. Its anti-tumor activity is mediated by proteasome inhibition leading to decreased cell proliferation and induction of apoptosis. However, an unimpaired proteasomal function plays a crucial role for the induction of anti-tumor immunity by dendritic cells (DCs), which are currently used for therapeutic vaccination against various tumors including myeloma. In the present study, we investigated the impact of bortezomib on the immunostimulatory capacity of 6-sulfo LacNAc (slan) DCs, which represent a major subset of human blood DCs. We demonstrated that this proteasome inhibitor efficiently impairs the spontaneous in vitro maturation of slanDCs and the release of tumor necrosis factor (TNF)-alpha as well as interleukin (IL)-12 upon lipopolysaccharide (LPS) stimulation. Functional data revealed that bortezomib profoundly inhibits slanDC-induced proliferation and differentiation of CD4(+) T cells. In addition, the capacity of slanDCs to promote interferon-gamma secretion and tumor-directed cytotoxicity of natural killer (NK) cells is markedly impaired by bortezomib. These results provide evidence that bortezomib significantly reduces the ability of native human blood DCs to regulate innate and adaptive anti-tumor immunity and may have implications for the design of therapeutic strategies combining DC vaccination and bortezomib treatment.
Leukemia 08/2007; 21(7):1464-71. · 9.56 Impact Factor
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M Schmitz,
A Temme,
V Senner,
R Ebner,
S Schwind,
S Stevanovic,
R Wehner,
G Schackert,
H K Schackert,
M Fussel,
M Bachmann,
E P Rieber,
B Weigle
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ABSTRACT: Prognosis for patients suffering from malignant glioma has not substantially improved. Specific immunotherapy as a novel treatment concept critically depends on target antigens, which are highly overexpressed in the majority of gliomas, but the number of such antigens is still very limited. SOX2 was identified by screening an expression database for transcripts that are overexpressed in malignant glioma, but display minimal expression in normal tissues. Expression of SOX2 mRNA was further investigated in tumour and normal tissues by real-time PCR. Compared to cDNA from pooled normal brain, SOX2 was overexpressed in almost all (9 out of 10) malignant glioma samples, whereas expression in other, non-malignant tissues was almost negligible. SOX2 protein expression in glioma cell lines and tumour tissues was verified by Western blot and immunofluorescence. Immunohistochemistry demonstrated SOX2 protein expression in all malignant glioma tissues investigated ranging from 6 to 66% stained tumour cells. Human leucocyte antigen-A(*)0201-restricted SOX2-derived peptides were tested for the activation of glioma-reactive CD8+ cytotoxic T lymphocytes (CTLs). Specific CTLs were raised against the peptide TLMKKDKYTL and were capable of lysing glioma cells. The abundant and glioma-restricted overexpression of SOX2 and the generation of SOX2-specific and tumour-reactive CTLs may recommend this antigen as target for T-cell-based immunotherapy of glioma.
British Journal of Cancer 05/2007; 96(8):1293-301. · 5.04 Impact Factor
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M Bornhauser,
C Thiede,
J Babatz,
J Schetelig,
T Illmer,
A Kiani,
U Platzbecker,
W Herr,
E-P Rieber,
G Ehninger, M Schmitz
Leukemia 12/2006; 20(11):2055-7. · 9.56 Impact Factor
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Leukemia 10/2006; 20(9):1629-32. · 9.56 Impact Factor
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ABSTRACT: Glioblastoma multiforme (GBM) is a highly malignant brain tumor that is resistant to conventional radiotherapy and chemotherapy. The median survival time of patients with GBM has remained less than 2 years despite concerted efforts to improve therapy. As a new approach to treat GBM we generated retroviral particles encoding mutant survivin for transduction of glioma cells. We demonstrate here that retroviral overexpression of a nonphosphorylatable Thr-34 --> Ala mutant of survivin (survivinT34A), in the glioma cell lines U373 and H4 resulted in a marked increase in the percentage of cells bearing multiple nuclei, which was accompanied by significantly decreased cell proliferation, and in greater numbers of cells with hypodiploid DNA content. Administration of the broad caspase inhibitor z-Val-Ala-Asp(OMe)-fluoromethyl-ketone did not reduce the cell death rate. Yet increased nuclear translocation of apoptosis-inducing factor (AIF) was observed in cells transduced with survivinT34A, indicating caspase-independent cell death. Transduction of retroviral vectors encoding wild-type survivin also led to the appearance of multinuclear cells. In contrast to mutant survivin, overexpressed wild-type survivin did not increase the cell death rate and no enhanced nuclear AIF translocation was observed. We suggest that retroviral vectors delivering mutant survivinT34A might be employed for the treatment of glioblastoma.
Human Gene Therapy 02/2005; 16(2):209-22. · 4.22 Impact Factor
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ABSTRACT: The development of T-cell-based immunotherapies of cancer largely depends on the availability of tumour-associated antigens capable of eliciting tumour-directed cytotoxic T-cell responses. In prostate cancer, the number of antigens defined as suitable targets of cytotoxic T lymphocytes (CTLs) is still limited. Recently, prostein was identified as a transmembrane protein that is highly restricted to prostate tissues. In our study, prostein transcripts were found to be abundant in both malignant and nonmalignant prostate tissue samples. To identify immunogenic CD8+ T-cell epitopes, human leucocyte antigen-A(*)0201-binding peptides were selected from the amino-acid sequence of prostein and were used for the in vitro stimulation of CD8+ T lymphocytes. Specific CTLs were raised against the prostein-derived peptide CLAAGITYV that were capable of lysing prostate cancer cells, indicating that this peptide is naturally generated by tumour cells. Our data suggest that prostein is a suitable candidate to be included in a T-cell-based immunotherapy of prostate cancer.
British Journal of Cancer 04/2004; 90(5):1034-40. · 5.04 Impact Factor
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ABSTRACT: Dendritic cells (DC) are professional antigen-presenting cells that are widely used in the experimental immunotherapy of cancer. For clinical use GMP-like protocols for the preparation of functionally active dendritic cells (DC) in large numbers and at high purity are needed. However, the currently available protocols have certain disadvantages. In this study we tested the generation and clinical applicability of DC from monocyte preparations produced by immunomagnetic CD14(+) selection using a semiautomated clinical scale immunomagnetic column. Peripheral blood mononuclear cells (PBMC) of 10 patients with metastatic solid tumors were used. With the immunomagnetic separation, we obtained a cell suspension of high CD14(+) purity (median 97.4%, range 94.9-99.0) with a high monocyte yield (median 82.3%, range 63.9-100.0). Differentiation of CD14(+) cells into mature monocyte-derived DC was induced by incubation with IL-4, GM-CSF, TNF-alpha, PGE(2), IL-1 beta, and IL-6. Mature DC showed a high expression of CD83, HLA-DR, and the co-stimulatory molecules CD80 and CD86. Overall CD83(+) yield was 12.1% (range 4.0-29.4). Allogeneic T stimulatory capacity could be demonstrated for all DC preparations in proliferation assays. No significant differences in marker expression or T cell stimulation was detected between fresh DC and those derived from cryopreserved immature DC. Clinical administration of autologous DC by three different parenteral routes was tolerated by all 10 patients without systemic signs of toxicity. Our results indicate that immunomagnetic isolation of CD14(+) monocytes using the CliniMACS device is a suitable method for clinical-scale generation of functional DC under GMP-grade conditions. The selection can be performed in a closed system. Therefore, immunomagnetic CD14(+) selection can be seen as an alternative way to generate DC for clinical tumor vaccination protocols.
Journal of Hematotherapy & Stem Cell Research 11/2003; 12(5):515-23.
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ABSTRACT: Differentiation of genetically modified CD34(+) hematopoietic stem cells into dendritic cells (DCs) will contribute to the development of immunotherapeutic anticancer protocols. Retroviral vectors that have been used for the transduction of CD34(+) cells face the problem of gene silencing when integrated into the genome of repopulating stem cells. We reasoned that a high copy number of retroviral DNA sequences might overcome silencing of transgene expression during expansion and differentiation of progenitor cells into functional DCs. To prove this, we utilized a retroviral vector with bicistronic expression of the melanoma-associated antigen tyrosinase and the enhanced green fluorescent protein (EGFP). Human cord blood CD34(+) cells were transduced with vesicular stomatitis virus G-protein (VSV-G) pseudotyped Moloney murine leukemia virus (MoMuLV) particles using 100-150 multiplicity of infection. During expansion of transduced cells with immature phenotype, transgene expression was strongly silenced, but upon differentiation into mature DCs, residual transgene expression was retained. Intracellular processing of the provirally expressed tyrosinase was tested in a chromium release assay utilizing a cytotoxic T cell clone specific for a HLA-A*0201-restricted tyrosinase peptide. We suggest that retroviral transduction of tumor-associated antigens in hematopoietic progenitor cells and subsequent differentiation into DCs is a suitable basis for the development of potent anti-tumor vaccines.
Gene Therapy 12/2002; 9(22):1551-60. · 3.71 Impact Factor
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ABSTRACT: The enzyme-linked immunospot (ELISPOT) assay has become a widely employed method for quantification of antigen-reactive T lymphocytes. In recent years, various types of antigen-presenting cells (APCs) have been tested as stimulator cells in ELISPOT protocols to achieve a highly sensitive and rapid assay which is not impaired by a marked nonspecific cytokine release. However, the currently available APCs still have disadvantages, such as significant background reactivities, limited sensitivity, and time-consuming preparation procedures. Recently, we succeeded in defining a novel subpopulation of circulating dendritic cells (DCs) that can easily be prepared from human blood. These M-DC8+ DCs proved to be very effective in the induction of antigen-specific T cell responses. In the present study we provide evidence that M-DC8+ DCs are particularly well suited as APCs for the detection of antigen-specific CD8+ T cells after challenge with viral or tumor peptides in ELISPOT assays. In addition, protein-loaded M-DC8+ DCs proved to be quite efficient in the presentation of MHC class II-bound peptides, thus allowing the determination of frequencies of antigen-reactive CD4+ T cells. The use of M-DC8+ DCs as stimulator cells can improve the ELISPOT assay by combining high sensitivity, rapidity, and low background reactivity.
Journal of Clinical Laboratory Analysis 02/2002; 16(1):30-6. · 1.38 Impact Factor
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M Kappler,
T Köhler,
C Kampf,
P Diestelkötter,
P Würl, M Schmitz,
F Bartel,
C Lautenschläger,
E P Rieber,
H Schmidt,
M Bache,
H Taubert,
A Meye
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ABSTRACT: Survivin, a recently identified inhibitor of apoptosis protein (IAP), is expressed in diverse embryonic tissues and in various human cancers. We have investigated the quantitative expression of survivin mRNA by a sensitive TaqMan-based RT-PCR assay in tissue samples from 94 patients with soft tissue sarcomas (STS). Survivin transcript levels were measured and normalized to GAPDH transcripts. By using a multivariate Cox regression analysis, we found an inverse correlation between the level of survivin mRNA (ratio >2 zmol survivin/amol GAPDH) and the rate of overall survival (p = 0.009, RR = 2.7). Survivin transcript variants as detected by qualitative RT-PCR analysis were revealed in 36 of 56 STS patients (64%). Only survivin DeltaEx3 and/or full-length survivin variants but not survivin 2B were identified. Our results suggest that a higher level of survivin mRNA is an independent predictor of survival for STS patients.
International Journal of Cancer 12/2001; 95(6):360-3. · 5.44 Impact Factor
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Cancer Research 05/2001; 61(8):3524-8. · 7.86 Impact Factor
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ABSTRACT: The identification of tumor-associated antigens recognized by CD8+ cytotoxic T cells paved the way to new concepts in adjuvant anticancer therapy. However, the number of tumor-associated proteins found to be expressed in the majority of human cancers is still rather limited. Recently, the newly identified apoptosis inhibitor protein survivin has been recognized as a widely occurring tumor-associated protein. In the present study, we demonstrate that survivin is capable of inducing specific CD8+ effector T cells in vitro. T cells from healthy donors were subjected to several cycles of stimulation by autologous dendritic cells (DCs) pulsed with soluble recombinant survivin protein. Activation of CD8+ cytotoxic T cells by survivin-derived peptides cross-presented by DCs was demonstrated by lysis of autologous survivin-expressing B cell transfectants. Using a peptide-motif scoring system, two survivin peptides (ELTLGE-FLKL and TLPPAWQPFL) were predicted and proved to bind to the HLA-A*0201 molecule. Both peptides were shown to induce CD8+ effector T cells when presented on DCs; one peptide could be verified to result from natural intracellular processing of survivin. These findings recommend survivin as a new and widely applicable target for protein- and peptide-based immunotherapy of tumors.
Cancer Research 10/2000; 60(17):4845-9. · 7.86 Impact Factor
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ABSTRACT: Antibody reactivity against survivin, a recently identified tumor-associated protein, was determined in sera from patients with lung (n = 51) or colorectal cancer (n = 49). The same collection of sera was tested for the presence of antibodies against p53. Eleven sera from lung cancer patients and four sera from colorectal cancer patients reacted with purified recombinant survivin in an ELISA (21.6% and 8.2%, respectively), whereas four sera from lung cancer patients and nine sera from colorectal cancer patients contained anti-p53 antibodies (7.8% and 18.4%, respectively). The increase in prevalence when anti-survivin and anti-p53 antibodies were determined in parallel was statistically significant (29.4% versus 7.8%, P = 0.005 in lung cancer population; 26.6% versus 8.2%, P = 0.015 in colorectal cancer population). The high prevalence of anti-survivin antibodies makes these antibodies an attractive novel marker for the diagnosis of lung and colorectal cancer, particularly in patients lacking anti-p53 antibodies.
Cancer Research 05/2000; 60(7):1815-7. · 7.86 Impact Factor
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ABSTRACT: We investigated the ability of both acute myelogenous leukemia (AML) and acute lymphoblastic leukemia (ALL) blasts to differentiate into dendritic cells (DC) in vitro. Cytokine-supplemented suspension cultures of leukemic blasts in 98 patients with AML and five patients with ALL (normal karyotype, n = 2; BCR/ABL, n = 3) were performed. Mononuclear cells out of peripheral blood or bone marrow containing between 60% and 90% leukemic blasts were cultured for eight days using different growth factor combinations. The highest yield of CD1a(+)/CD14(-) cells could be obtained with stem cell factor, transforming growth factor-beta, tumor necrosis factor-alpha, GM-CSF, and FLT-3-ligand. In the AML samples the median content of CD1a(+)/CD14(-) cells after eight days of culture was 3.5% (r = 0%-82%). In five informed patients CD1a(+)/CD14(-) cells were sorted by fluorescence-activated cell sorting or immunomagnetic separation. Cytogenetic and polymerase chain reaction analyses showed known primary chromosomal aberrations (monosomy 7 and inversion 16) in the sorted fractions, respectively. Dendritic cells (DC) could be generated out of leukemic blasts in 68% of AML patients. Leukemic DC showed no phagocytosis of latex beads, but stimulated allogeneic naive cord blood-derived T cells more efficiently than did uncultured blasts. In ALL patients the median percentage of CD1a(+)/CD14(-) cells was 1.2% (r = 0.7%-3.8%) after culture. The sorted CD1(+)/CD14(-) fractions were BCR/ABL-negative when analyzed with fluorescence in situ hybridization, indicating their nonleukemic origin. Leukemic DC can be generated out of leukemic progenitors in patients with AML. These cells might become relevant for autologous and allogeneic immunotherapy in selected patients. BCR/ABL-positive lymphoblasts could not be transformed into cells with an early dendritic phenotype with the cytokines used in our experiments.
Stem Cells 02/2000; 18(2):139-47. · 7.78 Impact Factor