Interleukin-12 (IL-12) gene therapy of leukemia: immune and anti-leukemic effects of IL-12-transduced hematopoietic progenitor cells.
Recombinant interleukin-12 (rlL-12) is a potent immunomodulatory cytokine that has been shown to exert strong antitumoral and antimetastatic activity against several mouse tumors grown as solid lesions. The therapeutic efficacy of rIL-12 against hematological tumors and the transfer of IL-12 genes into hematopoietic progenitor cells to deliver IL-12 to the bone marrow (BM) to treat residual leukemia has not been studied adequately. We have investigated the retroviral-mediated transduction of hematopoietic progenitor cells with IL-12 genes and the in vivo anti-leukemic activity of transduced cells against the murine myeloid leukemia cell line 32Dp210. We were able to efficiently transduce the IL-3-dependent 32Dc13 myeloid progenitor cell line and primary hematopoietic progenitor cells using an MFG-based polycistronic retroviral vector containing the cDNAs of p35 and p40 murine IL-12 genes. 32Dc13 myeloid progenitor cells expressing IL-12 genes (32DIL-12 cells) have stably secreted biologically active murine IL-12 for >9 months. Mice transplanted with 32DIL-12 cells transiently express the transgene in the BM and spleen, which is associated with a rapid elevation of interferon-gamma (IFN-gamma) in the circulation and with secretion of IFN-gamma by spleen cells in vitro. In addition, spleen and BM cells of mice injected with 32DIL-12 cells readily acquire the capacity to lyse natural killer cell-sensitive YAC-1 target cells and 32Dp210 myeloid leukemia cells. Furthermore, whereas mice challenged with leukemia cells suffered 100% mortality within 14 days, approximately 40% of mice coinjected with 32Dp210 leukemia cells and 32DIL-12 progenitor cells exhibited long-term, leukemia-free survival (>60 days). This study demonstrates that IL-12 can be stably expressed in hematopoietic cells; in addition, when transplanted, transduced cells induce IFN-gamma production and activation of natural killer cells, both of which may be involved in inhibiting the progression of leukemia in vivo.
Gautam
S C
SC
Division of Hematology/Medical Oncology, Henry Ford Hospital, Detroit, Michigan 48202, USA.
Xu
Y X
YX
Dumaguin
M
M
Janakiraman
N
N
Chapman
R A
RA
D000818:Animals; D003602:Cytotoxicity, Immunologic; D004797:Enzyme-Linked Immunosorbent Assay; D015870:Gene Expression; D015316:Genetic Therapy; D005822:Genetic Vectors; D006412:Hematopoietic Stem Cells / Q000276:immunology*; D007371:Interferon-gamma / Q000096:biosynthesis; D018664:Interleukin-12 / Q000235:genetics*; D007694:Killer Cells, Natural / Q000276:immunology; D007942:Leukemia, Experimental / Q000276:immunology / Q000473:pathology / Q000628:therapy*; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D016133:Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000235:genetics; D012190:Retroviridae / Q000235:genetics; D013154:Spleen / Q000166:cytology / Q000276:immunology; D014162:Transfection
D011994:Recombinant Proteins; D018664:Interleukin-12; D007371:Interferon-gamma