Intracoronary adenovirus-mediated transfer of immunosuppressive cytokine genes prolongs allograft survival.
BACKGROUND
Intracoronary transfer and expression of recombinant genes in the intact heart is now feasible. In the transplant setting, local modulation of host immune responses by a genetically modified allograft may offer an attractive alternative to systemic immunosuppression.


METHODS
We tested the efficacy and in vivo effect of intracoronary transfer of two immunosuppressive cytokine genes. First-generation E1-deleted adenoviral vectors expressing the Epstein-Barr virus interleukin-10 (AdSvIL10) or human transforming growth factor--beta 1 (AdCMVTGF-beta) were used. Rabbit cardiac allografts were transduced during cold preservation by slow (1 ml/min) intracoronary infusion of 10(10) pfu/gm diluted viral vectors and then implanted heterotopically. Controls included E1-deleted adenovirus (Ad5dI434) and AdCMVLacZ. Beating allografts were collected on day 4 for analysis of gene transfer efficacy and distribution. Additional grafts were used for evaluation of alloreactivity (n = 34).


RESULTS
Mean allograft viral uptake was 81% (up to 91%). Polymerase chain reactions and reverse transcription-polymerase chain reactions confirmed the presence and expression of both genes in the grafts. beta-Galactosidase staining in AdCMVLacZ-infected grafts demonstrated efficient gene expression, which was highest (100%) in subepicardial regions. More homogeneous transmyocardial distribution of the transgene (in 25% to 40% of cells) could be achieved by pulsatile slow delivery. Allograft survival was 6.9 +/- 0.9 days in controls (n = 12), 11.1 +/- 1.7 days in AdCMVTGF-beta-infected grafts (n = 11, p < 10(-4)), and 11.2 +/- 3 days in AdSvIL10-infected grafts (n = 11, p < 10(-4)). Histologic scores (blinded) showed significantly (p < 0.005) higher regression coefficients for rejection in controls compared with both cytokine-transduced groups. Perioperative administration of cyclosporine A (INN: ciclosporin) to recipients had no effect on survival of AdCMVTGF-beta-infected grafts but reduced survival of AdSvIL10-infected grafts.


CONCLUSIONS
Intracoronary gene transfer of immunosuppressive cytokines to cardiac allografts is efficient and effectively prolongs graft survival. Vectors that would induce long-term expression of such genes may make this approach clinically applicable.
Brauner
R
R
Division of Cardiothoracic Surgery, UCLA Medical Center 90095, USA.
Nonoyama
M
M
Laks
H
H
Drinkwater
D C
DC
McCaffery
S
S
Drake
T
T
Berk
A J
AJ
Sen
L
L
Wu
L
L
D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D015870:Gene Expression; D018014:Gene Transfer Techniques; D015316:Genetic Therapy; D005822:Genetic Vectors; D006084:Graft Rejection / Q000517:prevention & control*; D006085:Graft Survival / Q000276:immunology*; D016027:Heart Transplantation / Q000276:immunology*; D006801:Humans; D007165:Immunosuppression Therapy / Q000379:methods*; D007261:Infusions, Intra-Arterial; D016753:Interleukin-10 / Q000008:administration & dosage / Q000235:genetics*; D016133:Polymerase Chain Reaction; D011817:Rabbits; D016212:Transforming Growth Factor beta / Q000008:administration & dosage / Q000235:genetics*; D016042:Transplantation, Heterotopic; D014184:Transplantation, Homologous; D001616:beta-Galactosidase / Q000235:genetics
D016212:Transforming Growth Factor beta; D016753:Interleukin-10; D001616:beta-Galactosidase