Lipid Emulsions Potently Increase Transgene Expression in Hepatocytes after Adenoviral Transfer

Abstract

Elimination of Kupffer cells by cytotoxic clodronate liposomes increases transgene expression in the liver after adenoviral transfer. Here, we demonstrate that empty l-alpha-phosphatidylcholine liposomes block uptake of vectors in the reticuloendothelial cells of the liver and increase human apolipoprotein (apo) A-I (approved gene symbol apo A-I) expression in C57BL/6 (1.3-fold) and Balb/c mice (3.1-fold) to the same extent as clodronate liposomes (1.5- and 3.4-fold, respectively). A similar elevation of human apo A-I levels was induced by the lipid emulsion Intralipid (1.5- and 2.8-fold in C57BL/6 and Balb/c mice, respectively). Not only Kupffer cells but also hepatic sinusoidal endothelial cells (HSEC) constitute the reticuloendothelial cells of the liver. The uptake of adenoviral vectors 1 h after transfer in C57BL/6 mice was 2.9-fold lower in Kupffer cells than in HSEC. In contrast, Kupffer cell uptake in Balb/c mice was 2.6-fold higher than in HSEC. Vector uptake in reticuloendothelial cells of the liver was reduced and transgene expression was increased in splenectomized and Rag2-deficient Balb/c mice but not in splenectomized and Rag1-deficient C57BL/6 mice. In conclusion, lipid emulsions for parenteral clinical use block uptake of adenoviral vectors by the reticuloendothelial cells of the liver and potently increase transgene expression.

The Role of Liver Sinusoidal Cells in Hepatocyte-Directed Gene Transfer

“…[31][32][33][34] Kupffer cells may bind adenoviral vectors via multiple mechanisms including scavenger receptor-A, complement, and natural antibodies. [35][36][37] In contrast to hepatocytes, uptake of adenoviral vectors by Kupffer cells is independent of factor X.…”

“…34 Indeed, uptake of vectors by nonparenchymal liver cells (ie, mainly liver sinusoidal endothelial cells and Kupffer cells) inversely correlates with transduction of parenchymal liver cells. 34 The transgene DNA copy number in the nonparenchymal liver cells at 1 hour after transfer in BALB/c mice was nearly sixfold higher than in C57BL/6 mice.…”

“…34 Indeed, uptake of vectors by nonparenchymal liver cells (ie, mainly liver sinusoidal endothelial cells and Kupffer cells) inversely correlates with transduction of parenchymal liver cells. 34 The transgene DNA copy number in the nonparenchymal liver cells at 1 hour after transfer in BALB/c mice was nearly sixfold higher than in C57BL/6 mice. 34 This difference in scavenging of vectors between these strains is a major determinant of the approximately threefold higher transgene DNA levels in hepatocytes and higher transgene expression levels in C57BL/6 mice compared with BALB/c mice.…”

Direct comparison of hepatocyte-specific expression cassettes following adenoviral and nonviral hydrodynamic gene transfer

“…57 Quantification of liver inflammation following adenoviral and hydrodynamic transfer After euthanasia, livers were fixed overnight in 1% paraformaldehyde and embedded in paraffin. Seven mm thick sections were stained with rabbit anti-human CD3 antibody (DakoCytomation, Glostrup, Denmark) or rat anti-mouse neutrophil antibody clone 7/4 (AbD Serotec, Oxford, UK) 58 followed by incubation with an anti-rabbit Envision secondary antibody or a peroxidase-labeled donkey anti-rat secondary antibody (AbD Serotec), respectively.…”

Species differences in transgene DNA uptake in hepatocytes after adenoviral transfer correlate with the size of endothelial fenestrae

“…PC and NPC were isolated as described previously by Seglen et al, 24 Nagelkerke et al 25 and Snoeys et al 7 For cell isolations in rabbits, the procedure was adapted as described before. 5 Quantification of adenoviral particles in plasma All plasma samples used for quantification of adenoviral particles in plasma were obtained after centrifugation at 3400 r.p.m.…”