Development of cancer immunogene therapy with gene-modified adenoviral vector re-targeted by tumor-specific peptides

点击翻译按钮获取中文摘要

CD4O ligand (CD40L) is a good candidate molecule for the immunotherapy of B cell malignancies including B-chronic lymphocytic leukemia (B-CLL), because it may increase the capacity of the malignant cells to present tumor antigens. However, efforts to manipulate expression of the human CD40L (hCD40L) molecule have foundered on problems associated with lack of consistent gene transfer into the malignant target cells. We have developed a new, highly reproducible method for inducing hCD40L surface expression on malignant B cells. Ten B-CLL samples were cocultured with MRC-5 fibroblasts previously transduced with an adenoviral vector encoding the hCD40Lgene. The malignant cells expressed high levels of surface hCD40L, B7-1, B7-2, and ICAM-1 after coculture. hCD40L transfer was not mediated, by membrane fusion. The transferred hCD40L was functionally intact and B-CLL cells expressing this molecule induced increased interferon-g production from autologous peripheral blood T lymphocytes. This … More approach does not use any direct gene transfer to primary leukemia cells and can readily be scaled up for prod uction of clinical B-CLL vaccines.On the other hand, to provide cell-binding ligands for ex vivo gene therapy and B-CLL-targeting ligands for in vivo drug and gene therapy, we have selected 44 20-mer peptides from peptide-presenting phage libraries by panning against patient primary B-CLL cells. 29 of the selected peptides were assayed for cell binding. Fourteen of the selected peptides bound B-CLL, B, T, and monocyte cells, six bound only B-CLL and B cells, and one peptide bound only B cells. However, eight of the selected peptides were B-CLL specific. When peptides were tested out of the context of phage, synthetic peptide 1-5 was able to functionally re-target adenoviral vectors for increased ex vivo gene delivery to primary B-CLL cells. This work also emphasizes the importance of patient to patient tumor heterogeneity for the identification of targeting peptides and their functional application for gene therapy vector targeting. We are now planning the clinical application with these methods. Less