Author:

Keywords:

hepatocyte-directed gene transfer, adenoviral vectors, fenestrae, human liver, apo a-i, dependent adenoviral vectors, hepatic perfusion index, innate immune-responses, colorectal-cancer, recombinant adenovirus, transgene expression, sustained expression, kupffer cells, vivo, Science & Technology, Life Sciences & Biomedicine, Biochemistry & Molecular Biology, Biotechnology & Applied Microbiology, Genetics & Heredity, Medicine, Research & Experimental, Research & Experimental Medicine, APO A-I, DEPENDENT ADENOVIRAL VECTORS, HEPATIC PERFUSION INDEX, INNATE IMMUNE-RESPONSES, COLORECTAL-CANCER, RECOMBINANT ADENOVIRUS, TRANSGENE EXPRESSION, SUSTAINED EXPRESSION, KUPFFER CELLS, VIVO, Adenoviridae, Animals, Endothelial Cells, Filtration, Gene Expression, Genetic Therapy, Genetic Vectors, Humans, Liver, Liver Diseases, Mice, Mice, Inbred C57BL, Microscopy, Electron, Scanning, Rabbits, Rats, Rats, Sprague-Dawley, Species Specificity, Transduction, Genetic, Transgenes, Virus Integration, 06 Biological Sciences, 11 Medical and Health Sciences, Biotechnology, 31 Biological sciences, 32 Biomedical and clinical sciences, 42 Health sciences

Abstract:

Fenestrae allow the passage of gene transfer vectors from the sinusoidal lumen to the surface of hepatocytes. We have previously shown that the diameter of fenestrae correlates with species and strain differences of transgene expression following intravenous adenoviral transfer. In the current study, we demonstrate that the diameter of fenestrae in humans without liver pathology is 107+/-1.5 nm. This is similar to the previously reported diameter in New Zealand White (NZW) rabbits (103+/-1.3 nm) and is significantly smaller than in C57BL/6 mice (141+/-5.4 nm) and Sprague-Dawley rats (161+/-2.7 nm). We show that the diameter of fenestrae in one male NZW rabbit and its offspring characterized by a more than 50-fold increase of transgene expression after adenoviral gene transfer is significantly (113+/-1.5 nm; P< /0.001) larger than in control NZW rabbits. In vitro filtration experiments using polycarbonate filters with increasing pore sizes demonstrate that a relatively small increment of the diameter of pores potently enhances passage of adenoviral vectors, consistent with in vivo data. In conclusion, the small diameter of fenestrae in humans is likely to be a major obstacle for hepatocyte transduction by adenoviral vectors.