Engineered Cell Therapy for Sustained Local Myocardial Delivery of Nonsecreted Proteins
Novel strategies for the treatment of congestive heart failure have taken the form of gene and cell therapy to induce angiogenesis, optimize calcium handling by cardiac myocytes, or regenerate damaged myocardial tissue. Arguably both gene- and cell-based therapies would be benefited by having the ability to locally deliver specific transcription factors and other usually nonsecreted proteins to cells in the surrounding myocardial tissue. The herpes simplex virus type 1 (HSV-1) tegument protein VP22 has been shown to mediate protein intercellular trafficking to mammalian cells and finally localize into the nucleus, which makes it a useful cargo-carrying functional protein in cell-based gene therapy. While VP22 has been studied as a means to modulate tumor growth, little is known about the distribution and transport kinetics of VP22 in the heart and its potential application in combination with autologous cell transplantation for the delivery of proteins to myocardial tissue. The aim of this study was to evaluate the efficacy of VP22 fusion protein intercellular trafficking combined with autologous cell transplantation in the heart. In an in vitro study untransfected rat heart cells were cocultured with stably transfected rat cardiac fibroblasts (RCF) with fusion constructs of VP22. The control experiment was untransfected rat heart cells co-plated with RCF stably transfected with enhanced green fluorescence protein (eGFP). The Lewis rat model was selected for in vivo study. In the in vitro studies there was a 14-fold increase in the number of GFP-positive cells 48 h after initiating coculture with VP22-eGFP RCF compared to eGFP RCF. In the rat model, transplantation of VP22-eGFP expressing RCF led to VP22-eGFP fusion protein delivery to an area of myocardial tissue that was 20-fold greater than that observed when eGFP RCF were transplanted. This area appeared to reach a steady state between 7 and 10 days after transplantation. The VP22-eGFP area consisted of eGFP-positive endothelium, smooth muscle cells, and cardiac myocytes with delivery to an area of approximately 1 mm2 of myocardial tissue. Our data suggest a viable strategy for the delivery of proteins that are not naturally secreted or internalized, and provide the first insight into the feasibility and effectiveness of cell-penetrating proteins combined with cell transplantation in the heart.
Document Type: Research Article
Department of Chemical and Biomedical Engineering, Cleveland State University,Cleveland, OH 44115-2425, USA, Department of Cell Biology, Cleveland Clinic Foundation, Cleveland, OH 44195, USA
Department of Cell Biology, Cleveland Clinic Foundation, Cleveland, OH 44195, USA
Department of Cardiovascular Medicine, Cleveland Clinic Foundation, Cleveland, OH 44195, USA
Publication date: January 1, 2006
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Cell Transplantation publishes original, peer-reviewed research and review articles on the subject of cell transplantation and its application to human diseases. To ensure high-quality contributions from all areas of transplantation, separate section editors and editorial boards have been established. Articles deal with a wide range of topics including physiological, medical, preclinical, tissue engineering, and device-oriented aspects of transplantation of nervous system, endocrine, growth factor-secreting, bone marrow, epithelial, endothelial, and genetically engineered cells, among others. Basic clinical studies and immunological research papers are also featured. To provide complete coverage of this revolutionary field, Cell Transplantation will report on relevant technological advances, and ethical and regulatory considerations of cell transplants. Cell Transplantation is now an Open Access journal starting with volume 18 in 2009, and therefore there will be an inexpensive publication charge, which is dependent on the number of pages, in addition to the charge for color figures. This will allow work to be disseminated to a wider audience and also entitle the corresponding author to a free PDF, as well as prepublication of an unedited version of the manuscript.
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