European Journal of Cardio-Thoracic Surgery, Vol 12, 792-797, Copyright © 1997 by European Association for Cardio-thoracic Surgery
In vivo liposome-mediated transfection of HLA-DR alpha-chain gene into pig hearts
I Aleksic, M Ren, A Popov, D Freimark, C Blanche, L Czer, A Trento and P Barath
Department of Thoracic and Cardiovascular Surgery, Georg August University, Gottingen, Germany.
Scarcity of suitable donor organs remains a major problem for organ
transplantation. Transfer of recipient HLA-genes into animal donor- organs
during harvest could induce graft-tolerance without suppressing the
recipient immune system. OBJECTIVE: This pilot study aimed to test the
feasibility of an in vivo gene transfer into pig hearts by intracoronary
infusion of DNA:liposome-complexes and to detect the gene product by
immunohistochemistry. METHODS: The pcDV1-pL2-vector, containing the
basesequence for HLA-DR alpha-chain in plasmids (1.3 kb) was selected. The
plasmids were isolated with ethidiumbromide and incubated with lipofectin
in a 1:3-ratio for 10 min. The DNA:lipofectin- complex was diluted to 10 cc
with physiologic saline and delivered into the left anterior descending
artery of 6 farm pigs over 10 min. As a control within the same animal, the
same amount of lipofectin alone was infused into the first diagonal branch.
Three pigs were sacrificed after 24 h, the other 3 after 48 h. Delivery of
DNA:liposome-complexes was detected by oil red 0 staining, expression of
HLA-DR alpha-chain- antigen with a monoclonal anti-HLA-DR alpha-antibody.
RESULTS: Transfection of the HLA-class-II DR-alpha-chain occurred in
endothelial cells. Infiltrating cells around capillaries stained positively
for HLA- DR-alpha. These infiltrating cells were negative for the pan B-
and the pan T-cell-marker L26 and UCHL-1. There was no transfection and
hypercellularity in the myocardium around the first diagonal branch.
CONCLUSIONS: In vivo intracoronary infusion of the HLA-DR alpha-chain-
DNA:lipofectin-complex leads to expression of the corresponding antigen on
pig endothelium for 48 h. The infiltrating cells require further
characterization.
