Background And Objectives: Primary graft failure is a serious complication following hematopoietic cell transplants, particularly when using unrelated donors. We analyzed factors affecting primary graft failure in recipients of hematopoietic cell transplants from unrelated donors, which were performed using reduced intensity conditioning.
Design And Methods: This was a retrospective analysis of 144 patients whose transplants took place between March 1998 and October 2004.
Nonviral producer cell proteins incorporated into retroviral vector surfaces profoundly influence infectivity and in vivo half-life. We report the purification and concentration of lentiviral vectors using these surface proteins as an efficient gene transduction strategy. Biotinylation of these proteins and streptavidin paramagnetic particle concentration enhances titer 400- to 2,500-fold (to 10(9) CFU/ml for vesicular stomatitis virus G protein and 5 x 10(8) for amphotropic murine leukemia virus envelope).
View Article and Find Full Text PDFBiochem Biophys Res Commun
October 2005
The serological analysis of recombinant cDNA expression libraries (SEREX) technique was used to immunoscreen a testes cDNA expression library with sera from newly diagnosed acute myeloid leukaemia (AML) patients. We used a testis cDNA library to aid our identification of cancer-testis (CT) antigens. We identified 44 antigens which we further immunoscreened with sera from AML, chronic myeloid leukaemia (CML), and normal donors.
View Article and Find Full Text PDFRev Clin Exp Hematol
December 2004
Background: Existing methods of selecting patients with hepatocellular carcinoma (HCC) for liver transplantation rely on computed tomography and magnetic resonance imaging, which fail to detect vascular invasion or micrometastases. Vascular invasion cannot be assessed pretransplant because of the risks of tumor biopsy. Pretransplant detection of micrometastases in bone marrow is an alternative method that may identify patients at risk of recurrence and permit better organ allocation.
View Article and Find Full Text PDFEnd-stage liver disease due to chronic hepatitis C virus (HCV) infection is now the most frequent indication for liver transplantation. HCV infection is associated with extrahepatic disease including cryoglobulinemia and lymphoma. The number of patients requiring liver transplantation (LT) for cirrhosis secondary to HCV infection has increased over the past 10 years; consequently, associated extrahepatic manifestations (in particular hematological malignancies) will be more commonly observed in this patient group.
View Article and Find Full Text PDFBiochem Biophys Res Commun
August 2005
Acute myeloid leukaemia (AML) is a difficult to treat disease, especially for those patients who have no eligible haematopoietic stem cell (HSC) donor. One of the most promising treatment options for these patients is immunotherapy. To investigate the expression of known tumour antigens in AML, we analysed microarray data from 124 presentation AML patient samples and investigated the present/absent calls of 82 tumour-specific or -associated antigens.
View Article and Find Full Text PDFCancer Immunol Immunother
January 2006
We describe the modification of tumour cells to enhance their capacity to act as antigen presenting cells with particular focus on the use of costimulatory molecules to do so. We have been involved in the genetic modification of tumour cells to prepare a whole cell vaccine for nearly a decade and we have a particular interest in acute myeloid leukaemia (AML). AML is an aggressive and difficult to treat disease, especially, for patients for whom haematopoietic stem cell (HSC) transplant is not an option.
View Article and Find Full Text PDFIn this study, we have used the human BV173 and the mouse BaF3/Bcr-Abl-expressing cell lines as model systems to investigate the molecular mechanisms whereby STI571 and FoxO3a regulate Bim expression and apoptosis. FoxO3a lies downstream of Bcr-Abl signalling and is constitutively phosphorylated in the Bcr-Abl-positive BV173 and BaF3/Bcr-Abl cells. Inhibition of Bcr-Abl kinase by STI571 results in FoxO3a activation, induction of Bim expression and apoptosis.
View Article and Find Full Text PDFCombined expression of costimulatory factors and proinflammatory cytokines stimulate effective immune-mediated tumor rejection in a variety of murine tumor models. Specifically, syngeneic tumor cells genetically modified to express B7.1 (CD80) have been shown to induce rejection of previously established murine solid tumors, and transduction with IL-2 can further increase survival.
View Article and Find Full Text PDFWe showed previously that tumor-derived supernatant (TSN) from acute myeloid leukemia (AML) myeloblasts inhibits peripheral blood T cell activation and proliferation, rendering the T cells functionally incompetent. We show here that the AML TSN also significantly delays apoptosis of both resting and stimulated T cells, as judged by reduction in annexin V/propidium iodide staining. In addition, we show that this is not unique to T cells and that AML TSN inhibits apoptosis of peripheral B cells, neutrophils, and monocytes.
View Article and Find Full Text PDFBest Pract Res Clin Haematol
December 2004
Recent advances in molecular genetics have advanced the knowledge regarding the mechanisms leading to myelodysplastic syndrome (MDS), secondary acute myeloid leukemia, and therapy-induced MDS. Unfavorable cytogenetics associated with this group of disorders includes monosomy or deletion of the long arm of chromosomes 5 or 7, inversions of chromosome 3, translocations, deletions, and trisomies involving several other chromosomes. These unbalanced chromosomal aberrations result in hemizygosity and unmasking of oncogenes, changes in levels of expressed genes, or inactivation of tumor suppressor genes.
View Article and Find Full Text PDFReduced-intensity conditioned (RIC) hematopoietic stem cell transplantation (HSCT) has improved the accessibility of transplantation in patients previously ineligible. We report the results of allografting following conditioning with fludarabine, busulphan, and alemtuzumab in 62 patients with myelodysplastic syndromes (MDSs) (matched sibling donors [24] or volunteer unrelated donors [VUDs, 38]). The median age for sibling recipients was 56 years (range, 41-70 years) and for VUD recipients, 52 years (range, 22-65 years), with a median follow-up (survivors) of 524 days (range, 93-1392 days) and 420 days (range, 53-1495 days), respectively.
View Article and Find Full Text PDFTargeted therapies for hematological malignancies have come of age since the advent of all trans retinoic acid (ATRA) for treating APL and STI571/Imatinib Mesylate/Gleevec for CML. There are good molecular targets for other malignancies and several new drugs are in clinical trials. In this review, we will concentrate on individual abnormalities that exist in the myelodysplastic syndromes (MDS) and myeloid leukemias that are targets for small molecule therapies (summarised in Fig.
View Article and Find Full Text PDFThe activation of T cells plays a central role in antitumor immunity. In order to activate naïve T cells, two key signals are required. Signal one is provided through the T-cell receptor (TCR) while signal two is that of costimulation.
View Article and Find Full Text PDFBloom's syndrome (BS) is an autosomal recessive disorder associated with an elevated incidence of cancers. The gene mutated in BS, BLM, encodes a RecQ helicase family member. BS cells exhibit genomic instability, including excessive homologous recombination and chromosomal aberrations.
View Article and Find Full Text PDFApoptosis is upregulated in early myelodysplastic syndromes (MDS) and may contribute to the peripheral cytopenias commonly observed. Conversely, leukemic progression is associated with abrogation of programmed cell death (PCD). The stage of hematopoietic cell maturation at which defects in PCD arise and the underlying causes of apoptosis dysregulation remain unknown.
View Article and Find Full Text PDFThe last decade has witnessed a multistep evolution in the understanding of the natural history, clinical manifestations, and some of the molecular mechanisms that underlie the ineffective hematopoiesis and leukemic transformation in the myelodysplastic syndrome (MDS). The international prognostic scoring system, FAB, and WHO classifications have helped define specific subgroups with their characteristic cytogenetic, molecular and immunological abnormalities. Until recently the mainstay of the treatment has been entirely supportive with blood and platelet transfusions.
View Article and Find Full Text PDFCyclin D2 affects B cell proliferation and differentiation in vivo. It is rate-limiting for B cell receptor (BCR)-dependent proliferation of B cells, and cyclin D2-/- mice lack CD5+(B1) B lymphocytes. We show here that the bone marrow (BM) of cyclin D2-/- mice contains half the numbers of Sca1+B220+ B cell progenitors but normal levels of Sca1+ progenitor cells of other lineages.
View Article and Find Full Text PDFWe report the outcomes of reduced-intensity allogeneic stem cell transplantation using BEAM-alemtuzumab conditioning (carmustine, etoposide, cytosine arabinoside, melphalan, and alemtuzumab 10 mg/d on days -5 to -1) in 6 United Kingdom transplant centers. Sixty-five patients with lymphoproliferative diseases underwent sibling (n = 57) or matched unrelated donor (n = 8) transplantation. Sustained donor engraftment occurred in 60 (97%) of 62 patients.
View Article and Find Full Text PDFMyelodysplastic syndromes (MDS) are neoplastic dyscrasias characterized by peripheral cytopenia, despite a normocellular or hypercellular bone marrow. In the past decade, it has become apparent that this ineffective hemopoiesis is largely caused by excessive apoptosis of myeloid precursors. There is no evidence for gain-of-function mutations within the apoptotic machinery in MDS.
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