Prolongation of allograft survival with viral IL-10 transfection in a highly histoincompatible model of rat heart allograft rejection.
BACKGROUND
The ability to express genes with potential immunoregulatory capacity could reduce the immunogenicity of allografts and result in long-term graft survival. In this study, we examine the feasibility of transferring viral interleukin-10 (vIL-10) gene into rat hearts using adenovirus by intracoronary administration. The subsequent effects of delivered vIL-10 alone or with subtherapeutic doses of cyclosporine A (CsA) on parameters of allograft rejection (AR) were also examined.


METHODS
Recombinant adenovirus vectors containing vIL-10 (Ad-vIL-10) or beta-galactosidase (Ad-beta-gal) were derived from adenovirus type 5. vIL-10 expression in supernatants of transfected COS7 cell cultures and in transfected heart allografts were examined by enzyme immunoassay (EIA) and reverse transcriptase-polymerase chain reaction (RT-PCR), respectively. Rat heart transplants (LEWS->ACI) were performed in five groups [group 1: no treatment, group 2: Ad-beta-gal, group 3: AdvIL-10, group 4: CsA (10 mg/kg), and group 5: Ad-vIL10+CsA (10 mg/kg)]. Allograft survival was determined by palpating heartbeats. Allograft tissues were also submitted for histological study.


RESULTS
vIL-10 expression was shown in both transfected COS7 cells and heart isografts. Animals transfected with vIL-10 showed prolongation of graft survival (19.6 vs. 12 days, P<0.001) when compared to beta-gal transfected controls. Animals treated with a single low dose injection of CsA showed no significant prolongation of graft survival compared to controls (11.7 vs. 10.5 days). Animals treated with both vIL-10 and CsA demonstrated a synergistic prolongation of allograft survival compared with controls and with animals treated with CsA or vIL-10 treatment alone (36.7 days vs. 11.7, P<0.001 or 36.7 vs.19.6, P<0.001, respectively). Histological study showed that allografts from untreated controls exhibited extensive AR with loss of graft architecture by day 7 posttransplant while those from the vIL-10 group showed less AR. The best pathological scores were seen in vIL-10 + CsA-treated animals.


CONCLUSIONS
1) Delivering Ad-vIL-10 into donor hearts by intracoronary perfusion results in overexpression of vIL-10 and significantly prolongs cardiac allograft survival in a highly histoincompatible rat model. 2) Subtherapeutic doses of CsA do not prolong allograft survival, but act synergistically with vIL-10 to significantly prolong graft survival beyond that achieved with either agent alone.
Zuo
Z
Z
Department of Pediatrics, Cedars-Sinai Medical Center/UCLA School of Medicine, Los Angeles, CA 90048, USA.
Wang
C
C
Carpenter
D
D
Okada
Y
Y
Nicolaidou
E
E
Toyoda
M
M
Trento
A
A
Jordan
S C
SC
D000256:Adenoviridae / Q000378:metabolism*; D000818:Animals; D019556:COS Cells; D016572:Cyclosporine / Q000494:pharmacology; D006084:Graft Rejection / Q000503:physiopathology*; D006085:Graft Survival / Q000187:drug effects*; D016027:Heart Transplantation; D006648:Histocompatibility; D007166:Immunosuppressive Agents / Q000494:pharmacology; D016753:Interleukin-10 / Q000494:pharmacology*; D008297:Male; D051381:Rats; D011912:Rats, Inbred ACI; D011917:Rats, Inbred Lew; D013997:Time Factors; D014162:Transfection; D014184:Transplantation, Homologous
D007166:Immunosuppressive Agents; D016753:Interleukin-10; D016572:Cyclosporine