Successful immunogene therapy using colon cancer cells (colon 26) transfected with plasmid vector containing mature interleukin-18 cDNA and the Igkappa leader sequence.
IL-18 is a novel cytokine that induces interferon (IFN)-gamma secretion and plays an important role in antitumor immunity. In the present study, we constructed plasmid vectors encoding the murine mature IL-18 cDNA linked with the Igkappa leader sequence and the pro-IL-18 cDNA to estimate the efficacy of the mature IL- 18 vector and to evaluate IL-18--producing tumor cells as a tumor vaccine. Colon 26 cells were transfected with the abovementioned vectors or with vector alone (mock). Reverse transcription-polymerase chain reaction analysis showed increased expression of murine IL-18 cDNA in both mature IL-18 and pro-IL-18 transfectants in comparison to that in mock transfected cells. The ability of the culture supernatants of mature IL-18 transfectants to induce IFN-gamma secretion was extremely high (40-140 pg/10(6) cells) in comparison to that of pro-IL-18 transfectants (4-18 pg/10(6) cells). When injected into syngeneic BALB/c mice, the growth of mature IL-18 transfectants, but not pro-IL-18 transfectants, was significantly less than that in mock transfected cells ( P< .01, by ANOVA and analysis of covariance). In addition, injection of colon 26 or Meth-A cells into mice immunized with a mature IL-18 transfectant revealed acquired immunity. Depletion of natural killer cells did not affect the growth of transfectants. However, the growth inhibitory effects were partially abrogated following treatment with anti-CD4+ and anti-CD8+ antibodies. These data suggest that the rejection of mature IL-18/colon 26 cells was mediated through T-cell activation. Gene therapy using mature IL-18 transfectants containing a plasmid vector and the Igkappa leader sequence may be a useful tumor vaccine.
Yoshimura
K
K
Department of Surgery II, Yamaguchi University School of Medicine, Ube, Japan.
Hazama
S
S
Iizuka
N
N
Yoshino
S
S
Yamamoto
K
K
Muraguchi
M
M
Ohmoto
Y
Y
Noma
T
T
Oka
M
M
D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D015703:Antigens, CD / Q000378:metabolism; D018122:B7-1 Antigen / Q000378:metabolism; D051940:B7-2 Antigen; D015704:CD4 Antigens / Q000378:metabolism; D016827:CD8 Antigens / Q000378:metabolism; D003110:Colonic Neoplasms / Q000628:therapy*; D017931:DNA Primers / Q000737:chemistry; D005354:Fibrosarcoma / Q000139:chemically induced / Q000628:therapy*; D015870:Gene Expression; D005805:Genes, MHC Class I / Q000502:physiology; D005802:Genes, MHC Class II / Q000502:physiology; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors / Q000008:administration & dosage / Q000235:genetics; D007124:Immunoenzyme Techniques; D007074:Immunoglobulin G / Q000276:immunology; D007136:Immunoglobulins / Q000235:genetics* / Q000378:metabolism; D007371:Interferon-gamma / Q000378:metabolism; D020382:Interleukin-18 / Q000235:genetics* / Q000378:metabolism; D007694:Killer Cells, Natural / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D011993:Recombinant Fusion Proteins / Q000008:administration & dosage / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection / Q000379:methods; D014407:Tumor Cells, Cultured
D015703:Antigens, CD; D018122:B7-1 Antigen; D051940:B7-2 Antigen; D015704:CD4 Antigens; D016827:CD8 Antigens; C497965:Cd86 protein, mouse; D017931:DNA Primers; C014609:IgK; D007074:Immunoglobulin G; D007136:Immunoglobulins; D020382:Interleukin-18; D008562:Membrane Glycoproteins; D011993:Recombinant Fusion Proteins; D007371:Interferon-gamma