Article

Engagement of the B-cell antigen receptor (BCR) allows efficient transduction of ZAP-70-positive primary B-CLL cells by recombinant adeno-associated virus (rAAV) vectors.

KKG Gene Therapy, GSF-National Research Center for Environment and Health, Munich, Germany.
Gene Therapy (Impact Factor: 4.2). 10/2004; 11(18):1416-24. DOI: 10.1038/sj.gt.3302279
Source: PubMed

ABSTRACT Engagement of the B-cell antigen receptor (BCR) by crosslinking of the surface immunoglobulin (sIg) homodimer was studied for recombinant adeno-associated virus (rAAV)-mediated gene transfer into B-cell chronic lymphocytic leukaemia (B-CLL) cells. Leukemic cells obtained from 20 patients were stimulated with anti-sIg-directed antibodies and transduced with rAAV vectors coding for enhanced green fluorescent protein (EGFP) (AAV/EGFP) or CD40L (AAV/CD40L). Transduction of B-CLL cells was enhanced after BCR engagement compared to unstimulated controls (P=0.0356). BCR crosslinking induced a significant, dose- and time-dependent upregulation of heparan sulfate proteoglycan (HSPG), the primary receptor for AAV, on B-CLL cells (mean: 38.2 versus 1.7%; P=0.0006). A correlation of HSPG expression after BCR crosslinking with transduction efficiency by AAV/EGFP (P=0.0153) and AAV/CD40L (P=0.0347) was observed. High expression of zeta-associated protein 70 (ZAP-70) in B-CLL cells correlated with a better transduction efficiency by AAV/EGFP (P<0.0001) and AAV/CD40L (P=0.002), respectively: 48 h after transduction of ZAP-70-positive samples, transgene expression was seen in a mean of 33.8% (s.e.m. 3.7%) and 28.9% (s.e.m. 6.7%) of cells, respectively, and could be specifically blocked by heparin, a soluble competitor of HSPG (P<0.0001). In summary, engagement of the BCR on ZAP-70 positive B-CLL cells allows efficient rAAV-mediated gene delivery.

Download full-text

Full-text

Available from: Clemens-Martin Wendtner, Mar 10, 2014
0 Followers
 · 
86 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The efficient gene transfer of immunostimulatory cytokines into autologous tumor cells or the transfer of tumor-associated antigens into professional antigen-presenting cells is a prerequisite for many immunotherapeutic approaches. In particular with B cells, the efficiency of gene uptake is one of the limiting factors in cell-based vaccine strategies, since normal and malignant human B cells are commonly refractory to transducing gene vectors. Due to its natural tropism for human B cells, Epstein-Barr virus (EBV), a human herpes virus, might be an option, which we wanted to explore. EBV efficiently infects human B cells and establishes a latent infection, while the viral genome is maintained extrachromosomally. Although these characteristics are attractive, EBV is an oncogenic virus. Here, we present a novel EBV-derived vector, which lacks three EBV genes including two viral oncogenes and an essential lytic gene, and encodes granulocyte-macrophage colony-stimulating factor (GM-CSF) as a cytokine of therapeutic interest. We could show that EBV vectors efficiently transduce different B-cell lines, primary resting B cells, and tumor cells of B-cell lineage. Vector-derived GM-CSF was expressed in sufficient amounts to support the maturation of dendritic cells and their presentation of model antigens to cognate T-cell clones in autologous settings and an allogeneic, HLA-matched assay. We conclude that the EBV vector system might offer an option for ex vivo manipulation of B cells and gene therapy of B-cell lymphomas.
    Gene Therapy 02/2006; 13(2):150-62. DOI:10.1038/sj.gt.3302602 · 4.20 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Conventional treatment of hematologic malignancies mainly consists of chemotherapeutic agents or a combination of both, chemotherapy and monoclonal antibodies. Despite recent advances, chemotherapeutic treatments often remain unsatisfying due to severe side effects and incomplete long-term remission. Therefore the evaluation of novel therapeutic options is of great interest. B cell malignancies, in particularly follicular lymphomas, chronic lymphocytic leukemia and multiple myeloma, represent the most immune-responsive types of all human cancer. Several immunotherapeutic strategies are presently employed to combat these B-cell malignancies. Active immunotherapies include vaccination strategies with dendritic cells (DCs) and genetically-modified tumor cell preparations as well as DNA and protein vaccination. Most of these vaccines target the tumor-specific immunoglobulin idiotype and have already demonstrated some anti-lymphoma activity in early phase clinical trials while their definitive impact is evaluated in ongoing phase III randomized trials. In contrast to these active immunizations, T cells transduced with chimeric antigen receptors and donor leukocyte infusions (DLI) represent adoptive (passive) immunotherapies. Recent advances of gene transduction technologies enabled improvement of immunotherapeutic strategies based on genetic modification of malignant cells or adoptive T cells. Current early phase clinical trials are investigating the potential of these innovative approaches. At the moment it remains unclear if the novel immunotherapeutic strategies will be able to play a similar role in the treatment of B cell malignancies than the already established antibody-based immunotherapy.
    Current drug targets 11/2006; 7(10):1371-4. DOI:10.2174/138945006778559120 · 3.60 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Gene therapy for patients with hematologic malignancies, particularly chronic lymphocytic leukemia (CLL), have focused on transducing primary leukemia cells with a virus vector to express immune-stimulating genes which can induce and propagate a productive and clinically significant immune response against the malignant cells. A variety of replication-defective vectors has been studied to transduce genes for cytokines and function-associated surface molecules. Active vaccines have been developed in vitro, and their activity has been confirmed in clinical trials. Ongoing work aims to optimize this strategy and to identify the appropriate and optimal patient groups in which to apply vaccine therapy. Clinical trials also have provided insight into unexpected alternative mechanisms through which these strategies might provide a clinical benefit.
    Bailli&egrave re s Best Practice and Research in Clinical Haematology 10/2007; 20(3):557-68. DOI:10.1016/j.beha.2007.03.006 · 2.55 Impact Factor