Canine T cells transduced with a herpes simplex virus thymidine kinase gene: a model to study effects on engraftment and control of graft-versus-host disease.
BACKGROUND
Alloreactive donor T cells in marrow grafts mediate graft-versus-host disease (GVHD), but T-cell depletion has resulted in increased graft failure. Add-back of gene-modified alloreactive donor T cells could prevent graft rejection. After engraftment, in vivo depletion of those modified T cells with ganciclovir may control GVHD.


METHODS
Canine recipient-specific donor cytotoxic T lymphocytes (CTL) were retrovirally transduced with the herpes simplex virus thymidine kinase gene.


RESULTS
Gibbon ape leukemia virus-pseudotyped vector yielded primary CTL transduction efficiency of 22.9+/-9.9%. After selection and expansion, 96.7+/-0.8% of CTL expressed retrovirally transferred genes. Recipient-specific cytotoxic activity was maintained with 84.3% specific lysis. After ganciclovir treatment, herpes simplex virus thymidine kinase-transduced CTL proliferation was reduced 98.7+/-0.2% compared with controls.


CONCLUSIONS
We have demonstrated efficient ex vivo transduction, expansion, maintenance of alloreactivity, and ganciclovir-mediated ablation of canine CTL, which will permit in vivo studies in the dog, a well-established model for GVHD and engraftment.
Georges
G E
GE
Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA.
Storb
R
R
Brunvand
M W
MW
Kiem
H P
HP
Moore
P F
PF
Malik
P
P
Ennist
D
D
Nash
R A
RA
D000818:Animals; D004285:Dogs; D018139:Simplexvirus / Q000235:genetics*; D013602:T-Lymphocytes, Cytotoxic / Q000502:physiology*; D013937:Thymidine Kinase / Q000235:genetics*; D014161:Transduction, Genetic
D013937:Thymidine Kinase