0000000000347381
AUTHOR
M. Lejarreta
Humanα1-Antitrypsin Gene Transfer toIn VivoMouse Hepatocytes
ABSTRACT The in vivo gene transfer to mouse hepatocytes of pTG 7101, a plasmid containing the full-length gene encoding human α1-antitrypsin (α1-AT) DNA, has been studied by iv administration of recombinant DNA (100 ng/mouse) encapsulated in large and small liposomes. Our results from immunohistochemical liver sections and cytophotometric analysis of hepatocyte chromophore absorbance indicate that human α1-AT was expressed in liver parenchymal cells from mice treated (48 hr before) with DNA encapsulated in small liposomes, and this effect remained for at least 2 weeks. In contrast, the efficiency was greatly limited when large liposomes were used as a vehicle for gene transfer. Additional e…
In vivo delivery of human alpha 1-antitrypsin gene to mouse hepatocytes by liposomes.
The pTG7101 plasmid containing the full length human alpha 1-Antitrypsin was encapsulated in large (142 +/- 15 nm of diameter) and small (54 +/- 11 nm of diameter) liposomes and administered i.v. to mice (80 ng/mouse). Control animals were treated with empty (small and large) liposomes plus free DNA and with the liposome solvent buffer. The immunohistochemical results on liver cryosections and cytophotometric analysis of hepatocyte chromophore absorbance, after peroxidase reaction, indicated that significant presence of immunoreactive human alpha 1-antitrypsin was present 7 days after mice treatment with encapsulated DNA in small liposomes but not when large liposomes were used. This effect…
Antimetastatic Effect of Immunization with Liposome-Encapsulated Tumor Cell-Membrane Proteins Obtained from Experimental Tumors
Immunization of C57BL/6 mice with tumor-derived membrane-proteins encapsulated in sized liposomes (0.2 microgram/mouse) and composed by phosphatidylcholine or sphingomyelin, significantly reduced the mean values of spontaneous lung metastasis from both B16 (0.7 +/- 0.5 and 1.2 +/- 0.6, respectively) and 3LL (4.8 +/- 2.5 and 7.2 +/- 4.1, respectively) tumors, with respect to control (HEPES) groups (4.8 +/- 1.1 and 19.0 +/- 4.4, respectively). However, no significant antimetastatic effect was observed using free tumor-derived proteins (2 micrograms/mouse) or liposome vehicle alone. Specific humoral immune response after the vaccination was studied by flow cytometry of tumor cells incubated wi…
Recombinant cDNA encapsulation in small liposomes with hepatocyte access ability.
Liposomal encapsulation efficiency of a recombinant cDNA was studied by several procedures. We observed that supernatant fraction of ultracentrifuged liposomes prepared by extrusion through polycarbonate filters of 400 nm pore size yielded a very homogeneous suspension of small (50 nm diameter) unilamellar liposomes with highest DNA/lipid ratio and great ability to access to hepatocytes.