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164. Intratumoral Interferon-alpha Gene Transfer Enhances Tumor Immunity after Allogeneic Hematopoietic Stem Cell Transplantation
Cancer - Immunotherapy: Cytokine Gene Therapy, Dendritic Cells, and Modified Effector Cells shedding issues in cancer clinical trials and the measles eradication campaign.
Cancer – Immunotherapy: Cytokine Gene Therapy, Dendritic Cells, and Modified Effector Cells 164. Intratumoral Interferon-alpha Gene Transfer Enhances Tumor Immunity after Allogeneic Hematopoietic Stem Cell Transplantation Kazunori Aoki,1 Hidehiko Hara,1 Akihiko Kobayashi,1 Kimiko Yoshida,1 Kenta Narumi,1 Teruhiko Yoshida.2 1 Section for Studies on Host-Immune Response, National Cancer Center Research Institute, Tokyo, Japan; 2Genetics Division, National Cancer Center Research Institute, Tokyo, Japan.
Allogeneic hematopoietic stem cell transplantation (alloHSCT) often leads to a significant graft-versus-tumor (GVT) effect not only for hematological malignancies but also for solid cancers such as renal cancer. Although the precise immunologic mechanisms of the GVT effect have not been fully elucidated, two categories of antigens are target candidates for the GVT effect in MHC-matched alloHSCTs: polymorphic minor histocompatibility antigens (mHAs) and tumorassociated antigens (TAAs). On the other hand, the benefit of the GVT effect is often offset by the development of graft-versus-host disease (GVHD), a potentially fatal adverse effect primarily mediated by donor T cells. It is commonly believed that the target antigens for GVHD are mHAs. Therefore, in theory, efforts to selectively enhance a donor T cell response to TAAs could likely augment antitumor activity without a concomitant increase in toxicity. Interferon (IFN) is a cytokine with pleiotropic biological functions including a direct cytotoxicity to cancer cells, anti-angiogenesis activity and induction of antitumor immunity. Although the general toxicities following a systemic administration of the recombinant IFN protein often impede the use of a dosage sufficient to induce effective antitumor responses in the clinical setting, gene transfer of IFN-α allows an increased and sustained local concentration of IFN-α in the target tumor sites with minimal leakage into the systemic blood circulation, which ought to enhance the therapeutic effect and safety of IFN-α. In this study, we examined whether intratumoral IFN-α gene transfer can enhance the recognition of TAAs by donor T cells and augment the antitumor activity of alloHSCT. First, when a mouse IFN-α adenovirus (Ad-mIFN) was injected into subcutaneous xenografts of syngeneic Renca renal and CT26 colon cancer cells in BALB/c mice, tumor growth was significantly suppressed due to cell death in a dose-dependent manner of the vector. The significant tumor cell death and the infiltration of immune cells were recognized in the AdmIFN-injected tumors, and the dendrtic cells isolated from the tumors showed a strong Th1-oriented response. Then, the antitumor effect of Ad-mIFN was then examined in a mHA-mismatched alloHSCT murine model (DBA/2→BALB/c: H-2d). The intratumoral IFN-α gene transfer caused significant tumor suppression in the alloHSCT recipients, and this suppression was evident not only in the genetransduced tumors but also in simultaneously inoculated distant tumors which did not receive the vector injection. Depletion of CD4+ T cells still resulted in significant inhibition of tumor growth, whereas the antitumor activities were inhibited in animals depleted of either CD8+ T cells or NK cells, suggesting that CD8 + T cells and NK cells play a major role in in vivo antitumor immunity. GVHD was not exacerbated serologically or clinically in the treated mice. This combination strategy has important implications for the development of therapies for human solid cancers.
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165. Blocking LTB4 Signaling Maintains the Antitumor Effect of GM-CSF in the Tumor Challenge Model Using BLT-1-/-Mice
Haruka Nabeta,1 Hiroyuki Inoue,1,2 Mutsunori Iga,1 Meng Xin,1 Ryo Kurita,1 Fumiyuki Sasaki,3 Koichi Takayama,2 Yoichi Nakanishi,2 Takehiko Yokomizo,3 Kenzaburo Tani.1 1 Department of Molecular Genetics, Medical Institute of Bioregulation, Kyushu University, Fukuka, Japan; 2Research Institute of Diseases of the Chest, Kyushu University, Fukuoka, Japan; 3Department of Medical Biochemistry, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan. Leukotriene B4 (LTB4) is an extremely potent lipid inflammatory mediator derived from membrane phospholipids by the sequential actions of cytosolic phospholipase A2, 5-lipoxygenase (5-LO) and LTA4 hydrolase. The major activities of LTB4 include the recruitment and activation of leukocytes. Though structurally completely different, the lipid LTB4 and the peptide chemokines mediate their functions through the same class of receptors, the G protein-coupled seven transmembrane domain receptor (GPCR) superfamily. Two distinct receptors for LTB4, BLT1 and BLT2 participate both in the recruitment and activation of leukocytes as part of host immune responses to invading pathogens, as well as in the pathogenesis of inflammatory diseases. However, the role of LTB4 in tumor immunology is not well known. Previously we demonstrated the gene transduction of granulocyte-colony stimulating-factor (GM-CSF) gene into murine monocytic leukemia cell line of WEHI3B (W/GM) eliminated the tumorigenicity in wild type (wt) BALB/c mice. The rejection process of subcutaneous tumor was as follows; transient tumor growth peaked around 10 days after tumor injection, then the tumors were rejected within 2 weeks. The same tumor rejection was also reproducible in BLT1-/- mice (n=12). 50 days after the challenge, all BLT1-/- mice rejected the rechallenge of WEHI3B cells and survived, but none of wt mice rejected and survived. To explore the mechanism underlying the different outcome from rechallenge test, we next compared several immune cell (memory CD4+/CD8+ T cells subsets, dendritic cells (DCs) subsets, and myeloid suppressor cells (MSCs)) distribution in the draining lymph nodes (DLNs) and spleen at day 0 and 50 between wt and BLT1-/- mice. The results showed that, at 50 days after tumor challenge, in spleen, the proportions of both CD4+ and CD8 + central memory T cells (CD44+CD62L+) of BLT1-/- mice increased, but both CD4+ and CD8 + effector memory T cells (CD44+CD62L-) decreased compared with those of wt mice. In DLNs, the results of CD8+ memory T cells propotion were similar to those observed in spleen, but those of memory CD4+ T cells were opposite to those observed in spleen. These results suggested the blocking LTB4 signaling may be useful to maintain the antitumor effects of GM-CSF transduced tumor vaccines.
166. Prospects of Combination of Gene Directed Enzyme Prodrug Therapy with Other Systemic Therapies in Treatment of Prostate Cancer
Aparajita Khatri,1 Preetinder Pal Singh,1 Yasmin Husaini,2 Kim Ow,1 Jane Chapman,1 Pamela J. Russell.1 1 Oncology Research Centre, Prince of Wales Hospital, University of New South Wales, Sydney, New South Wales, Australia; 2Centre for Immunology, St Vincent’s Hospital, Sydney, NSW, Australia.
No single treatment can adequately cure late stage prostate cancer (PC). We are exploring combinations of gene directed enzyme prodrug mediated molecular therapy (GDEPT) with systemic immunotherapy or traditional chemotherapy to enhance efficacy and quality of life. Two studies are described. Combination of cytosine deaminase (CD) & uracil phosphoribosyl transferase (UPRT) (CDUPRT) with immunostimulatory murine cytokines IL12 and IL18: We have shown that local & distant bystander effects of CDUPRT-GDEPT Molecular Therapy Volume 16, Supplement 1, May 2008 Copyright © The American Society of Gene Therapy
Cancer – Immunotherapy: Cytokine Gene Therapy, Dendritic Cells, and Modified Effector Cells 164. Intratumoral Interferon-alpha Gene Transfer Enhances Tumor Immunity after Allogeneic Hematopoietic Stem Cell Transplantation Kazunori Aoki,1 Hidehiko Hara,1 Akihiko Kobayashi,1 Kimiko Yoshida,1 Kenta Narumi,1 Teruhiko Yoshida.2 1 Section for Studies on Host-Immune Response, National Cancer Center Research Institute, Tokyo, Japan; 2Genetics Division, National Cancer Center Research Institute, Tokyo, Japan.
Allogeneic hematopoietic stem cell transplantation (alloHSCT) often leads to a significant graft-versus-tumor (GVT) effect not only for hematological malignancies but also for solid cancers such as renal cancer. Although the precise immunologic mechanisms of the GVT effect have not been fully elucidated, two categories of antigens are target candidates for the GVT effect in MHC-matched alloHSCTs: polymorphic minor histocompatibility antigens (mHAs) and tumorassociated antigens (TAAs). On the other hand, the benefit of the GVT effect is often offset by the development of graft-versus-host disease (GVHD), a potentially fatal adverse effect primarily mediated by donor T cells. It is commonly believed that the target antigens for GVHD are mHAs. Therefore, in theory, efforts to selectively enhance a donor T cell response to TAAs could likely augment antitumor activity without a concomitant increase in toxicity. Interferon (IFN) is a cytokine with pleiotropic biological functions including a direct cytotoxicity to cancer cells, anti-angiogenesis activity and induction of antitumor immunity. Although the general toxicities following a systemic administration of the recombinant IFN protein often impede the use of a dosage sufficient to induce effective antitumor responses in the clinical setting, gene transfer of IFN-α allows an increased and sustained local concentration of IFN-α in the target tumor sites with minimal leakage into the systemic blood circulation, which ought to enhance the therapeutic effect and safety of IFN-α. In this study, we examined whether intratumoral IFN-α gene transfer can enhance the recognition of TAAs by donor T cells and augment the antitumor activity of alloHSCT. First, when a mouse IFN-α adenovirus (Ad-mIFN) was injected into subcutaneous xenografts of syngeneic Renca renal and CT26 colon cancer cells in BALB/c mice, tumor growth was significantly suppressed due to cell death in a dose-dependent manner of the vector. The significant tumor cell death and the infiltration of immune cells were recognized in the AdmIFN-injected tumors, and the dendrtic cells isolated from the tumors showed a strong Th1-oriented response. Then, the antitumor effect of Ad-mIFN was then examined in a mHA-mismatched alloHSCT murine model (DBA/2→BALB/c: H-2d). The intratumoral IFN-α gene transfer caused significant tumor suppression in the alloHSCT recipients, and this suppression was evident not only in the genetransduced tumors but also in simultaneously inoculated distant tumors which did not receive the vector injection. Depletion of CD4+ T cells still resulted in significant inhibition of tumor growth, whereas the antitumor activities were inhibited in animals depleted of either CD8+ T cells or NK cells, suggesting that CD8 + T cells and NK cells play a major role in in vivo antitumor immunity. GVHD was not exacerbated serologically or clinically in the treated mice. This combination strategy has important implications for the development of therapies for human solid cancers.
S62
165. Blocking LTB4 Signaling Maintains the Antitumor Effect of GM-CSF in the Tumor Challenge Model Using BLT-1-/-Mice
Haruka Nabeta,1 Hiroyuki Inoue,1,2 Mutsunori Iga,1 Meng Xin,1 Ryo Kurita,1 Fumiyuki Sasaki,3 Koichi Takayama,2 Yoichi Nakanishi,2 Takehiko Yokomizo,3 Kenzaburo Tani.1 1 Department of Molecular Genetics, Medical Institute of Bioregulation, Kyushu University, Fukuka, Japan; 2Research Institute of Diseases of the Chest, Kyushu University, Fukuoka, Japan; 3Department of Medical Biochemistry, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan. Leukotriene B4 (LTB4) is an extremely potent lipid inflammatory mediator derived from membrane phospholipids by the sequential actions of cytosolic phospholipase A2, 5-lipoxygenase (5-LO) and LTA4 hydrolase. The major activities of LTB4 include the recruitment and activation of leukocytes. Though structurally completely different, the lipid LTB4 and the peptide chemokines mediate their functions through the same class of receptors, the G protein-coupled seven transmembrane domain receptor (GPCR) superfamily. Two distinct receptors for LTB4, BLT1 and BLT2 participate both in the recruitment and activation of leukocytes as part of host immune responses to invading pathogens, as well as in the pathogenesis of inflammatory diseases. However, the role of LTB4 in tumor immunology is not well known. Previously we demonstrated the gene transduction of granulocyte-colony stimulating-factor (GM-CSF) gene into murine monocytic leukemia cell line of WEHI3B (W/GM) eliminated the tumorigenicity in wild type (wt) BALB/c mice. The rejection process of subcutaneous tumor was as follows; transient tumor growth peaked around 10 days after tumor injection, then the tumors were rejected within 2 weeks. The same tumor rejection was also reproducible in BLT1-/- mice (n=12). 50 days after the challenge, all BLT1-/- mice rejected the rechallenge of WEHI3B cells and survived, but none of wt mice rejected and survived. To explore the mechanism underlying the different outcome from rechallenge test, we next compared several immune cell (memory CD4+/CD8+ T cells subsets, dendritic cells (DCs) subsets, and myeloid suppressor cells (MSCs)) distribution in the draining lymph nodes (DLNs) and spleen at day 0 and 50 between wt and BLT1-/- mice. The results showed that, at 50 days after tumor challenge, in spleen, the proportions of both CD4+ and CD8 + central memory T cells (CD44+CD62L+) of BLT1-/- mice increased, but both CD4+ and CD8 + effector memory T cells (CD44+CD62L-) decreased compared with those of wt mice. In DLNs, the results of CD8+ memory T cells propotion were similar to those observed in spleen, but those of memory CD4+ T cells were opposite to those observed in spleen. These results suggested the blocking LTB4 signaling may be useful to maintain the antitumor effects of GM-CSF transduced tumor vaccines.
166. Prospects of Combination of Gene Directed Enzyme Prodrug Therapy with Other Systemic Therapies in Treatment of Prostate Cancer
Aparajita Khatri,1 Preetinder Pal Singh,1 Yasmin Husaini,2 Kim Ow,1 Jane Chapman,1 Pamela J. Russell.1 1 Oncology Research Centre, Prince of Wales Hospital, University of New South Wales, Sydney, New South Wales, Australia; 2Centre for Immunology, St Vincent’s Hospital, Sydney, NSW, Australia.
No single treatment can adequately cure late stage prostate cancer (PC). We are exploring combinations of gene directed enzyme prodrug mediated molecular therapy (GDEPT) with systemic immunotherapy or traditional chemotherapy to enhance efficacy and quality of life. Two studies are described. Combination of cytosine deaminase (CD) & uracil phosphoribosyl transferase (UPRT) (CDUPRT) with immunostimulatory murine cytokines IL12 and IL18: We have shown that local & distant bystander effects of CDUPRT-GDEPT Molecular Therapy Volume 16, Supplement 1, May 2008 Copyright © The American Society of Gene Therapy