Lentiviral gene transfer of the chemokine antagonist RANTES 9-68 prolongs heart graft survival.
BACKGROUND
Allograft tolerance might be achieved by expressing immunomodulatory proteins through gene therapy. We have evaluated the possibility of promoting significantly allograft survival in a vascularized cardiac allograft model by performing ex vivo gene transfer. We used a lentiviral vector encoding the chemokine antagonist RANTES 9-68 that is capable of competing with native RANTES.


METHODS
The Fisher donor/Lewis recipient rat strain combinations were used and all animals received for the first 5 days posttransplantation a subtherapeutic dose of cyclosporine A (1.5 mg/kg). Ex vivo gene transfer into heart allograft was performed by multiple injections of the SIN.cPPT lentiviral vector, which corresponds to the multiply attenuated, self-inactivating lentivector derived from the human immunodeficiency virus (HIV)-1.


RESULTS
About 6% of the cardiac tissue had integrated lentiviral vector, which closely matches the mean in vivo RANTES antagonist expression of 5% obtained by immunohistochemistry. In vivo RANTES 9-68 expression has significantly prolonged graft survival (median [25%-75%]: 20 [17-26] days), compared to the control 15 ([14-15] days; P=0.0007). Furthermore, hearts transduced with RANTES 9-68 showed a significant (P<0.05) reduction in cell infiltration and intragraft expression of TNF-alpha, IFN-gamma, endogenous RANTES, and TGF-beta.


CONCLUSIONS
Lentiviral gene transfer of RANTES 9-68 antagonist attenuates significantly the inflammatory response and delays allograft rejection, despite low levels of transduction. Future improvement of heart transduction by lentiviral vectors, as it has been achieved with other vectors, might become an attractive alternative therapy for treating allografts that require sustained gene expression for better organ preservation.
Vassalli
Giuseppe
G
Cardiology Department, CHUV-BH10, Lausanne, Switzerland.
Simeoni
Eleonora
E
Li
Jian Ping
JP
Fleury
Sylvain
S
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D018946:Chemokine CCL5 / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000627:therapeutic use*; D018076:DNA, Complementary / Q000235:genetics; D018014:Gene Transfer Techniques; D015316:Genetic Therapy; D006085:Graft Survival / Q000276:immunology; D049452:Green Fluorescent Proteins / Q000235:genetics; D016027:Heart Transplantation / Q000276:immunology; D006801:Humans; D016086:Lentivirus / Q000235:genetics; D008297:Male; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D011916:Rats, Inbred F344; D011917:Rats, Inbred Lew; D011994:Recombinant Proteins / Q000235:genetics / Q000627:therapeutic use; D014184:Transplantation, Homologous
D018946:Chemokine CCL5; D018076:DNA, Complementary; C101594:RANTES (9-68); D012333:RNA, Messenger; D011994:Recombinant Proteins; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins