Engraftment of DLA-haploidentical marrow with ex vivo expanded, retrovirally transduced cytotoxic T lymphocytes.
Genetically modified donor T cells with an inducible "suicide" gene have the potential to improve the safety and availability of allogeneic hematopoietic stem cell transplantation by enhancing engraftment and permitting control of graft-versus-host disease (GVHD). However, several clinical studies of gene-modified T cells have shown limited to no in vivo function of the ex vivo expanded T cells. Using the well-established dog model of allogeneic marrow transplantation, the question was asked if retrovirally transduced, donor derived, ex vivo expanded cytotoxic T lymphocytes (CTLs) that are recipient specific could enhance engraftment of dog leukocyte antigen (DLA)-haploidentical marrow following a single dose of 9.2 Gy total body irradiation and no postgrafting immunosuppression. In this setting, only 4 of 11 control recipients of DLA-haploidentical marrow without added CTLs engrafted. CTLs did not enhance engraftment of CD34(+) selected peripheral blood stem cells. However, recipient-specific CTLs enhanced engraftment of DLA-haploidentical marrow in 9 of 11 evaluable recipients (P =.049). All dogs that engrafted developed multiorgan GVHD. To facilitate in vivo tracking, 8 dogs received CTLs transduced with a retroviral vector encoding green fluorescent protein (GFP) and neomycin phosphotransferase (neo). Recipients that engrafted had sharp increases in the numbers of circulating GFP(+) CTLs on days +5 to +6 after transplantation. GFP(+) CTLs isolated from blood were capable of recipient-specific lysis. At necropsy, up to 7.1% of CD3(+) cells in tissues were GFP(+) and polymerase chain reaction in situ hybridization for neo showed infiltration of transduced CTLs in GVHD-affected organs. These results show that ex vivo expanded, transduced T cells maintained in vivo function and enhanced marrow engraftment.
Georges
G E
GE
Clinical Research Division, Fred Hutchinson Cancer Research Center, University of Washington, Seattle 98109, USA. ggeorges@fhcrc.org
Storb
R
R
Bruno
B
B
Brodie
S J
SJ
Thompson
J D
JD
Taranova
A G
AG
Zaucha
J M
JM
Little
M T
MT
Zellmer
E
E
Moore
P F
PF
Gooley
T
T
Sale
G
G
Kiem
H P
HP
Sandmaier
B M
BM
Lyons
R M
RM
Nash
R A
RA
D000818:Animals; D018952:Antigens, CD34 / Q000032:analysis; D016026:Bone Marrow Transplantation; D002469:Cell Separation; D004285:Dogs; D015870:Gene Expression; D005822:Genetic Vectors; D006084:Graft Rejection; D006085:Graft Survival; D006086:Graft vs Host Disease / Q000276:immunology; D049452:Green Fluorescent Proteins; D006680:HLA Antigens / Q000032:analysis; D006239:Haplotypes; D006648:Histocompatibility; D017403:In Situ Hybridization; D019868:Kanamycin Kinase / Q000235:genetics; D008164:Luminescent Proteins / Q000235:genetics; D016133:Polymerase Chain Reaction; D012190:Retroviridae / Q000235:genetics; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology / Q000378:metabolism / Q000637:transplantation*; D014162:Transfection; D014184:Transplantation, Homologous; D014916:Whole-Body Irradiation
D018952:Antigens, CD34; D006680:HLA Antigens; D008164:Luminescent Proteins; D049452:Green Fluorescent Proteins; D019868:Kanamycin Kinase