Retrovirus-mediated gene transfer into rhesus monkey hematopoietic stem cells: the effect of viral titers on transduction efficiency.
We have generated a cell line, designated POAM-P1, shedding amphotropic recombinant retroviruses carrying the human adenosine deaminase (hADA) gene. It exhibits a 1 log increased retrovirus titer on NIH-3T3 cells and a five-fold more efficient transduction of human ADA-deficient T lymphocytes, as compared to the previously generated cell line POC-1 which produces the same recombinant hADA retrovirus. To study whether the titer of retrovirus-producing cell lines influences the transduction efficiency of hematopoietic stem cells in a co-culture setting, we compared the POAM-P1 and POC-1 cell lines with respect to their gene transfer efficiency on rhesus monkey bone marrow. Following co-cultivation of rhesus monkey bone marrow with POAM-P1 cells, successful transduction could be demonstrated in approximately 10% of myeloid progenitor colonies (CFU-C) and 0.1% of peripheral blood mononuclear cells (PBMC) and granulocytes in vivo until > 1 year after autologous transplantation. In addition, the presence of functional hADA enzyme was detected in red blood cells, PBMC, and granulocytes. Monkeys receiving POC-1 co-cultured bone marrow carried transduced blood cells for > 2 years after transplantation. Despite the higher retrovirus titer of POAM-P1 cells as compared to POC-1 cells, no difference was observed in gene transfer efficiency into CFU-C and long-term repopulating stem cells. This shows that in our co-cultivation procedure the retrovirus titer was not limiting the transduction efficiency of primate hematopoietic stem cells.
Van Beusechem
V W
VW
Department of Gene Therapy, TNO Institute of Applied Radiobiology and Immunology, Rijswijk, The Netherlands.
Bakx
T A
TA
Kaptein
L C
LC
Bart-Baumeister
J A
JA
Kukler
A
A
Braakman
E
E
Valerio
D
D
D016475:3T3 Cells; D000243:Adenosine Deaminase / Q000235:genetics*; D000818:Animals; D016026:Bone Marrow Transplantation; D002478:Cells, Cultured; D005822:Genetic Vectors; D006412:Hematopoietic Stem Cells / Q000382:microbiology; D008253:Macaca mulatta; D051379:Mice; D012190:Retroviridae / Q000235:genetics*; D014161:Transduction, Genetic; D014162:Transfection; D014182:Transplantation, Autologous
D000243:Adenosine Deaminase