0000000000201199
AUTHOR
C Huber
Inhibitors of apoptosis confer resistance to tumour suppression by adoptively transplanted cytotoxic T-lymphocytes in vitro and in vivo
Deregulation of apoptosis signalling is commonly found in cancer and results in resistance to cytotoxic therapies. Immunotherapy is a promising strategy to eliminate resistant cancer cells. The transfer of T-lymphocytes during allogeneic stem cell transplantation is clinically explored to induce a 'graft-versus-tumor' effect (GvT). Cytotoxic T-lymphocytes (CTL), which are major effectors of GvT, eliminate cancer cells by inducing apoptosis via multiple parallel pathways. Here, we study in vitro and in vivo the susceptibility of murine cancer cells engineered to express single antiapoptotic genes to CTL-mediated cytotoxicity. Interestingly, we find that single inhibitors of caspase activatio…
Coordinate downregulation of multiple MHC class I antigen processing genes in chemical-induced murine tumor cell lines of distinct origin
In murine tumor cell lines, downregulation of MHC class I surface expression has been frequently detected, but the underlying molecular mechanisms of such deficiencies have not been defined. In this study, murine tumor cell lines of different histology derived from spontaneous or from chemical-induced tumors were analyzed for the expression of multiple components of the major histocompatibility complex (MHC) class I antigen-processing machinery (APM), including the peptide transporter TAP, the interferon (IFN)-gamma inducible proteasome subunits and several chaperones. The tumor cell lines analyzed demonstrated a heterogeneous expression pattern of various APM components. In comparison to c…
Safety and feasibility of CHOP/rituximab induction treatment followed by high-dose chemo/radiotherapy and autologous PBSC-transplantation in patients with previously untreated mantle cell or indolent B-cell-non-Hodgkin's lymphoma
Patients with no prior chemotherapy and with advanced and progressive follicular lymphoma (FCL) or mantle cell lymphoma (MCL) were enrolled into a treatment protocol combining CHOP/rituximab-CHOP therapy with subsequent consolidation high-dose therapy (HDT) to evaluate the safety and feasibility of this treatment. Overall, 15 patients were enrolled and 13 patients completed the entire treatment protocol without major toxicities or increased infectious complications. One patient withdrew consent after achieving complete remission (CR) prior to HDT. One patient was taken off study with signs of disease progression after induction treatment. All patients showed stable engraftment after HDT. Re…
Multiple levels of MHC class I down-regulation by ras oncogenes.
A number of tumours and oncogene transformed cells displayed reduced MHC class I surface expression which seemed to enable their escape from immune surveillance. To test whether oncogenic activation is directly involved in suppressing MHC class I expression, a model of inducible oncogene expression was chosen. Mouse fibroblasts transfected with different oncogenes expressed under the control of the dexamethasone-inducible MMTV promoter were analysed in the presence and absence of hormone for the mRNA and protein expression of MHC class I molecules as well as the respective oncogenes. Immunofluorescence analyses demonstrated an inverse association of MHC class I and oncogene expression after…
Rapid identification of minor histocompatibility antigen HA-1 subtypes H and R using fluorescence-labeled oligonucleotides
Acknowledgments: We thank Brigitte Schuch and Karola Schmidt for excellent technical assistance. This work was supported by a grant of the Deutsche Krebshilfe (Nr. 70-2427 and Nr. 70-2428). Abstract: Donor-recipient disparitiy of the minor histocompatibility antigen HA-1 is relevant for the development of graft-versus-host disease after HLA-matched sibling allogeneic bone marrow transplantation in HLA-A*0201-positive individuals. Two different alleles of HA-1 with a single amino acid polymorphism have been identified. Here we describe a time- and cost-efficient method for HA-1 typing of genomic DNA, using site-specific hybridization probes with the LightCycler. This method was compared with…
Functional deficiencies of components of the MHC class I antigen pathway in human tumors of epithelial origin
An association between oncogenic transformation and repression of different components of the MHC class I antigen processing machinery (APM) have been described in murine model systems. In order to discover whether a similar correlation exists, human tumor cell lines of distinct histology with altered ras protein were analyzed for the expression of APM components utilizing RT-PCR and Western blot analyses. A heterogeneous expression pattern of MHC class I antigens, TAP peptide transporter, proteasome subunits, proteasome activator PA28 and the chaperones calnexin, calreticulin as well as tapasin was displayed by these tumor cell lines. Single or combined deficiencies in the expression and/o…
Downregulation of the constitutive tapasin expression in human tumor cells of distinct origin and its transcriptional upregulation by cytokines
Human tumor cells frequently exhibit abnormalities in the major histocompatibility complex (MHC) class I surface expression which can be due to structural alterations and/or dysregulation of various components of the MHC class I antigen processing machinery, such as HLA class I heavy and light chains, the peptide transporter and the proteasome subunits. Although several cofactors critical for proper MHC class I assembly have been identified, their contribution to the immune escape phenotype of tumor cells has not been analyzed. In order to determine whether tapasin deficits are an integral part of immune escape mechanisms of human tumors, we studied the constitutive and cytokine-regulated e…
Analysis of the MHC Class I Antigen Presentation Machinery in Human Embryonal Carcinomas: Evidence for Deficiencies in TAP, LMP and MHC Class I Expression and their Upregulation by IFN‐γ
The expression of the major histocompatibility complex (MHC) class I antigens is suppressed in early post-implantation embryonic cells as well as in embryonal carcinoma (EC) cells, but could be upregulated by treatment with interferon (IFN)-gamma or retinoic acid. In a number of human and murine tumours, defects in the expression of the different components of the MHC class I antigen processing machinery, such as the proteasomal subunits LMP-2 and LMP-7 and the peptide transporters TAP-1 and TAP-2, account for impaired MHC class I surface expression. Here, we analysed the constitutive and IFN-gamma regulated mRNA and protein expression of the LMP, TAP and MHC class I molecules in the human …
Rituximab in vivo purging is safe and effective in combination with CD34-positive selected autologous stem cell transplantation for salvage therapy in B-NHL.
The purpose of this study was to evaluate feasibility and efficacy of Rituximab included into a sequential salvage protocol for CD20(+) B-NHL in relapse or induction failure. Twenty-seven patients with CD20(+) B-NHL in relapse or induction failure received Rituximab combined with DexaBEAM (R-DexaBEAM) for stem cell mobilization. Additional ex vivo selection of CD34-positive cells was performed using the CliniMacs device. Two doses of Rituximab were included in the high-dose therapy regimen (HDT). R-DexaBEAM was well tolerated and 26 of 27 patients mobilized sufficient numbers of CD34(+) blood stem cells. Application of R-DexaBEAM resulted in significant depletion of peripheral B cells. No t…
Advanced Bladder Cancer (Stages pT3b, pT4a, pN1 and pN2): Improved Survival after Radical Cystectomy and 3 Adjuvant Cycles of Chemotherapy. Results of a Controlled Prospective Study
A total of 49 bladder cancer patients with tumor stages pT3b, pT4a and/or pelvic lymph node involvement without microscopic or macroscopic evidence of residual tumor was randomized into 2 comparative groups: the chemotherapy group was to receive 3 adjuvant cycles of methotrexate, vinblastine and cisplatin plus doxorubicin (M-VAC) or epirubicin (M-VEC) after radical cystectomy. The control group received no additional treatment. The protocol was activated in May 1987. Patient recruitment was concluded in December 1990 because an interim analysis of the 49 randomized patients revealed a significant prognostic advantage in favor of 26 patients randomized to the chemotherapy group compared to 2…
Gene transfer of the Co-stimulatory molecules B7-1 and B7-2 enhances the immunogenicity of human renal cell carcinoma to a different extent.
Stimulation of a specific antitumour immune response with recruitment and induction of T-cell effector functions represents an attractive concept in human cancer therapy. Different cytokines and the B7 co-stimulatory molecules are both able to provide proliferation and activation signals for T cells. In the present study, we first demonstrated the absence of both B7-1 and B7-2 expression in human renal cell carcinoma (RCC) cell lines. The lack of B7 expression was associated with a low or absent proliferative response of allogeneic and autologous T cells upon stimulation with tumour cells. In order to investigate the role of B7-1 and B7-2, the human RCC cell line, MZ1257RC, which expresses …
Efficacy of Rituximab Combined in Salvage- and High Dose-Therapy (HDT) for Patients with Relapsed NHL; Interim Analysis of a Multicenter Phase II Study.
Abstract The introduction of Rituximab (R) in the treatment of B-NHL resulted in improvement in first line therapies for indolent (ind.) and aggressive (agg.) B-NHL. However, the value of R in intensive chemotherapy relapse strategies has not definitely been demonstrated. In a phase I/II clinical trial we have demonstrated safety of R as an in vivo purging agens in salvage and high dose therapy for relapsed/refractory B-NHL. This led, with promising response rates, to the initiation of a multicenter phase II trial to further prove therapeutic efficacy. Inclusion criteria were: Pt < 65 years, ECOG < 3, relapse or progression for patients with ind. NHL and induction failure or relapse f…
Deficient expression of components of the MHC class I antigen processing machinery in human cervical carcinoma.
In cervical carcinomas abnormalities in the MHC class I surface expression are a frequent event, which are often associated with the deficient expression of the peptide transporter subunit TAP1 thereby resulting in impaired T cell response. In order to understand the role of other components of the MHC class I antigen processing machinery (APM) in the immune escape, 16 surgically removed primary cervical carcinoma lesions were analyzed for their mRNA expression of the heterodimeric peptide transporter TAP, the constitutive and interferon (IFN)-gamma inducible proteasome subunits and their activators PA28alpha/beta, various chaperones as well as MHC class I antigens. High expression levels o…
Failure of sustained engraftment after non-myeloablative conditioning with low-dose TBI and T cell-reduced allogeneic peripheral stem cell transplantation
We investigated whether a T cell-reduced allogeneic stem cell transplant (SCT) with minimal conditioning and subsequent donor lymphocyte infusions (DLI) could reduce the incidence and severity of GVHD while retaining stable engraftment. Five patients with hematological malignancies (three MM, one CLL, one Chediak-Higashi syndrome) were conditioned with TBI (200 cGy). One patient additionally received fludarabine (120 mg/m(2)). CsA and mofetyl-mycophenolate (MMF) were administered to prevent GVHD. All patients were grafted with >3 x 10(6)/kg highly purified CD34(+) cells together with 2 x 10(6)/kg CD3(+) cells (three patients) or 1 x 10(5)/kg CD3(+) cells (two patients). Quick hematopoietic …
Durable Molecular Remissions in Patients with Relapsed CML Post Allogeneic Stem Cell Transplantation upon Treatment with Imatinib-Mesylate (Glivec®, STI-571). Follow-Up Results of a Phase II Open-Label Study.
Abstract Purpose: In a phase II clinical trial we have previously reported on the safety and efficacy of imatinib mesylate (IM) to induce hematologic, cytogenetic and molecular remissions in case of relapse post allogeneic stem cell transplantation (SCT) in patients with chronic myelogenous leukaemia (CML). Here we report on an extended follow-up phase, which was performed to monitor stability of responses and further disease course in patients enrolled. Patients and Methods: Within the trial, patients, transplanted in chronic phase (CP) CML with molecular or cytogenetic relapse (n=37), received IM at a starting dose of 400mg. Close monitoring was performed, which, besides evaluation of sid…