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.
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.
Authors: Melinda Mata; Juan F Vera; Claudia Gerken; Cliona M Rooney; Tasha Miller; Catherine Pfent; Lisa L Wang; Heather M Wilson-Robles; Stephen Gottschalk Journal: J Immunother Date: 2014-10 Impact factor: 4.456