Copyright © 2006, European Society of Cardiology
Reduction of hyperacute rejection and protection of metabolism and function in hearts of human decay accelerating factor (hDAF)-expressing pigs
aHeart Science Centre, Imperial College at Harefield Hospital, Harefield, Middlesex, UB9 6JH, U.K.
bDIMORFIPA, University of Bologna, 40064 Bologna, Italy
cIst.Chir.Tor. Card. University of Siena, Italy
dDepartment of Biochemistry, Medical University of Gdansk, 80-211 Gdansk, Debinki 1, Poland
eDepartment of Surgical Sciences, University of Milano-Bicocca, 20052 Milano, Italy
fBlood Transfusion Service, Rizzoli Orthopaedic Institute, Bologna, Italy
gUniversity "La Sapienza", 00161 Roma, Italy
* Corresponding author. Dept. of Surgical Sciences, Università di Milano-Bicocca, Via Cadore, 48, 20052 Monza, Milano, Italy. Tel.: +39 02 6448 8336; fax: +39 02 6448 8341. Email address: marialuisa.lavitrano{at}unimib.it
Objective: The use of pig hearts can solve the problem of shortage of donor hearts for transplantation. However, targeting rejection by single genetic modification was proven to be ineffective, highlighting the requirement for complex genetic modifications and more effective methods for transgenic animal production. We evaluated here whether hearts of hDAF transgenic pigs generated using our technique sperm-mediated gene transfer (SMGT) will be protected from structural damage, metabolic changes, and mechanical dysfunction during perfusion with human blood.
Methods: Hearts from control (C, n=6) or transgenic (T, n=5) pigs were perfused ex vivo for 4 h with fresh human blood using the ex vivo working mode system allowing monitoring of the function, metabolism, and structure.
Results: Cardiac output (mean±SEM) was maintained in T constant throughout the experiment, at 3.58±0.36 and 3.83±0.14 l/min after 30 min and 4 h, respectively, while cardiac output decreased to 1.95±0.35 l/min in C after 30 min of perfusion (p<0.01 vs. T). The maximum increase in coronary perfusion pressure was reduced in T to 154±16% as compared to C (237±10%, p<0.001). Myocardial ATP after 4 h was 21.1±1.1 nmol/mg dry wt (similar to initial) in T, while it decreased in C to 17.2±1.4 (p<0.05). Deposition of complement factors C3 and C5b9 was present in C but not in T after perfusion.
Conclusion: We have shown that hearts from hDAF transgenic pigs produced by SMGT are protected during perfusion with human blood and are metabolically stable and maintain mechanical function above the threshold level for life support.
KEYWORDS Xenotransplantation; Transgenic pigs; Hyperacute rejection; SMGT; Cardiac function
Abbreviations: BSA, bovine serum albumine • hDAF, human decay accelerating factor • LDTI, low-density triton-insoluble • MoAb, monoclonal antibody • NK cells, natural killer cells • SFM, swine fertilization medium • SMGT, sperm mediated gene transfer.
1 Present address: Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, 99 Brookline Ave., RN #361, Boston, MA 02215, USA.
This study was supported by the Magdi Yacoub Institute, Grants MiPAF D.M. 427/7303/2002, DM581/7240/96, 564/7240/97, and 404/7240/99, Ministero per la Ricerca Scientifica Grant DD 21.09.99, n462 ric., F.A.R. 2003 Grant University of Milano-Bicocca (to M.L.).