Comparison of five retrovirus vectors containing the human IL-2 receptor gamma chain gene for their ability to restore T and B lymphocytes in the X-linked severe combined immunodeficiency mouse model.
X-linked severe combined immunodeficiency (XSCID) is caused by mutations in the IL-2 receptor gamma chain (IL2RG) gene, resulting in absent T lymphocytes and nonfunctional B lymphocytes. Recently T lymphocyte production and B lymphocyte function were restored in XSCID patients infused with autologous stem cells transduced with a retrovirus containing the human IL2RG cDNA. To optimize the expression of human IL2RG for future clinical trials, we compared five retroviral vectors expressing human IL2RG from different LTR enhancer-promoter elements in a mouse model. Northern and Southern blot analysis of hematopoietic tissues from repopulated mice revealed that the retroviral vector with the highest expression per copy number was MFG-S-hIL2RG, followed by MND-hIL2RG. All five vectors were capable of restoring lymphopoiesis in irradiated XSCID mice transplanted with transduced IL2RG-deficient hematopoietic stem cells. Transduction of IL2RG-deficient hematopoietic stem cells with all five vectors restored T lymphopoiesis in transplanted stem cell-deficient W/W(v) mouse recipients. However, only XSCID stem cells transduced with the MFG-S-hIL2RG vector generated B lymphocytes in W/W(v) mice. We conclude that the MFG-S-hIL2RG vector provides the best opportunity for in vivo selection and development of B and T lymphocytes for human XSCID gene therapy.
Avilés Mendoza
G J
GJ
Hematopoiesis Section, National Institutes of Health, Bethesda, Maryland 20892, USA.
Seidel
N E
NE
Otsu
M
M
Anderson
S M
SM
Simon-Stoos
K
K
Herrera
A
A
Hoogstraten-Miller
S
S
Malech
H L
HL
Candotti
F
F
Puck
J M
JM
Bodine
D M
DM
D016475:3T3 Cells; D000818:Animals; D001402:B-Lymphocytes / Q000378:metabolism*; D015152:Blotting, Northern; D015139:Blotting, Southern; D018076:DNA, Complementary / Q000378:metabolism; D004195:Disease Models, Animal; D005260:Female; D005434:Flow Cytometry; D008040:Genetic Linkage; D015316:Genetic Therapy / Q000379:methods; D005822:Genetic Vectors; D006412:Hematopoietic Stem Cells / Q000378:metabolism; D006801:Humans; D008214:Lymphocytes / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D016513:Mice, SCID; D008957:Models, Genetic; D009154:Mutation; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000378:metabolism; D015375:Receptors, Interleukin-2 / Q000235:genetics*; D012190:Retroviridae / Q000235:genetics* / Q000378:metabolism; D016511:Severe Combined Immunodeficiency / Q000628:therapy*; D013601:T-Lymphocytes / Q000378:metabolism*; D013997:Time Factors; D014161:Transduction, Genetic; D014960:X Chromosome / Q000235:genetics*
D018076:DNA, Complementary; D012333:RNA, Messenger; D015375:Receptors, Interleukin-2