Anti-cancer Effect of Hematopoietic Stem Cell-derived Allogeneic-DC Vaccine in Melanoma Metastasis Model

BACKGROUND: Dendritic cell (DC)-based cancer immunotherapy is studied for several years. However, it is mainly derived from autologous PBMC or leukapheresis from patient, which has limitations about yield and ability of DC production according to individual status. In order to solve these problems, inquiries about allogeneic DCs are performed but there are no preclinical trial answers for effect or toxicity of allogeneic DC to use for clinical trial. In this study, we compared the anti-tumor effect of allogeneic and autologous DCs from mouse bone marrow stem cells in mouse metastatic melanoma model. METHODS: B16F10 melanoma cells (5 x 10(4)/mouse) were injected intravenously into the C57BL/6 mouse. Therapeutic DCs were differentiated from autologous (C57BL/6: CDC) or allogeneic (B6C3F1: BDC) bone marrow stem cells with GM-CSF, SCF and IL-4 for 13days and pulsed with B16F10 tumor cell lysate (Blys) for 18hrs. DC intra-peritoneal injections began on the 8th day after the tumor cell injection by twice with one week interval. RESULTS: Anti-tumor response was observed by DC treatment without any toxicity especially in allogeneic DC treated mice (tumor burden score: 2.667+/-0.184, 2.500+/-0.463, 2.000+/-0.286, 1.500+/-0.286, 1.667+/-0.297 for saline, CDC/unpulsed-DC: U-DC, CDC/Blys-DC, BDC/U-DC and BDC/Blys-DC, respectively). IFN-gamma secretion was significantly increased in allogeneic DC group stimulated with B16F10 cell lysate (2,643.3+/-5,89.7, 8,561.5+/-2,204.9. 6,901.2+/-141.1 pg/1 x 10(6) cells for saline, BDC/U-DC and BDC/Blys-DC, respectively) with increased NK cell activity. CONCLUSION: Conclusively, promising data was obtained that allogeneic DC can be used for DC-based cancer immunotherapy.

Effect of Dendritic Cell Based Cancer Vaccine Using Allogeneic Tumor Cell Lysate in Melanoma Pulmonary Metastasis Model

BACKGROUND: To perform the successful dendritic cell-based cancer immunotherapy one of the main issues to be solved is the source of antigen for DC pulsing. Limitations occur by using auto-tumor lysate due to the difficulties obtaining enough tumor tissue(s) quantitatively as well as qualitatively. In this study the possibility of allogeneic tumor cell lysate as a DC pulsing antigen has been tested in mouse melanoma pulmonary metastasis model. METHODS: B16F10 melanoma cells (1x10(5)/mouse) were inoculated intravenously into the C57BL/6 mouse. Therapeutic DCs were cultured from the bone marrow myeloid lineage cells with GM-CSF and IL-4 (1,000 U/ml each) for 7 days and pulsed with lysate of either autologous B16F10 (B-DC), allogeneic K1735 (C3H/He origin; K-DC) or CloneM3 (DBA2 origin; C-DC) melanoma cells for 18 hrs. Pulsed-DCs (1x10(6)/mouse)[CGP1] were injected i.p. twice with one week interval starting from the day 1 after tumor cell inoculation. RESULTS: Without observable toxicity, allogeneic tumor cell lysate pulsed-DC induced the significantly better anti-tumor response (tumor scale: 2.7+/-0.3, 0.7+/-0.3 and 0.3+/-0.2 for saline, B-DC and C-DC treated group, respectively). Along with increased tumor specific lymphocyte proliferations, induction of IFN-gamma secretion against both auto- and allo-tumor cell lysates was observed from the DC treated mice. (w/B16F10-lysate: 44.97+/-10.31, 1787.94+/-131.18, 1257.15+/-48.27, w/CloneM3 lysate: 0, 1591.13+/-1.83, 1460.47+/-86.05 pg/ml for saline, B-DC and C-DC treated group, respectively) Natural killer cell activity was also increased in the mice treated with tumor cell lysate pulsed-DC (8.9+/-[CGP2]0.1, 11.6+/-0.8 and 12.6+/-0.7% specific NK activity for saline, B-DC and C-DC treated group, respectively). CONCLUSION: Conclusively, promising data were obtained that allogeneic-tumor cell lysate can be used as a tumor antigen for DC-based cancer immunotherapy.

Immunocell Therapy for Lung Cancer: Dendritic Cell Based Adjuvant Therapy in Mouse Lung Cancer Model

BACKGROUND: The anti-tumor therapeutic effect of autologous tumor cell lysate pulsed-dendritic cells (DCs) was studied for non-immunogenic and immune suppressive lung cancer model. To test the possibility as an adjuvant therapy, minimal residual disease model was considered in mouse in vivo experiments. METHODS: Syngeneic 3LL lung cancer cells were inoculated intravenously into the C57BL/6 mouse. Autologous tumor cell (3LL) or allogeneic leukemia cell (WEHI-3) lysate pulsed-DCs were injected twice in two weeks. Intraperitoneal DC injection was started one day (MRD model) after tumor cell inoculation. Two weeks after the final DC injection, tumor formation in the lung and the tumor-specific systemic immunity were observed. Tumor-specific lymphocyte proliferation and the IFN-r secretion were analyzed for the immune monitoring. Therapeutic DCs were cultured from the bone marrow myeloid lineage cells with GM-CSF and IL-4 for 7 days and pulsed with tumor cell lysate for 18 hrs. RESULTS: Compared to the saline treated group, tumor formation was suppressed in 3LL tumor cell lysate pulsed-DC treated group, while 3LL-specific immune stimulation was minimum. WEHI-3-specific immune stimulation occurred in WEHI-3 lysate-pulsed DC treated group, which had no correlation with tumor regression. CONCLUSION: The data suggest the possible anti-tumor effect of cultured DCs as an adjuvant therapy for minimal residual disease state of lung cancer. The significance of immune modulation in DC therapy including the possible involvement of NK cell as well as antigen-specific cytotoxic T cell activity induction was discussed.

Dendritic Cell Based Cancer Immunotherapy: in vivo Study with Mouse Renal Cell Carcinoma Model

BACKGROUND: As a potent antigen presenting cell and a powerful inducer of antigen specific immunity, dendritic cells (DCs) are being considered as a promising anti-tumor therapeutic module. The expected therapeutic effect of DCs in renal cell carcinoma was tested in the mouse model. Established late-stage tumor therapeutic (E-T) and minimal residual disease (MRD) model was considered in the in vivo experiments. METHODS: Syngeneic renal cell carcinoma cells (RENCA) were inoculated either subcutaneously (E-T) or intravenously (MRD) into the Balb/c mouse. Tumor cell lysate pulsed-DCs were injected twice in two weeks. Intraperitoneal DC injection was started 3 week (E-T model) or one day (MRD model) after tumor cell inoculation. Two weeks after the final DC injection, the tumor growth and the systemic immunity were observed. Therapeutic DCs were cultured from the bone marrow myeloid lineage cells with GM-CSF and IL-4 for 7 days and pulsed with RENCA cell lysate for 18 hrs. RESULTS: Compared to the saline treated group, tumor growth (E-T model) or formation (MRD model) was suppressed in pulsed-DC treated group. RENCA specific lymphocyte proliferation was observed in the RENCA tumor-bearing mice treated with pulsed-DCs. Primary cytotoxic T cell activity against RENCA cells was increased in pulsed-DC treated group. CONCLUSION: The data suggest the possible anti-tumor effect of cultured DCs in established or minimal residual disease/metastasis state of renal cell carcinoma. Systemic tumor specific immunity including cytotoxic T cell activity was modulated also in pulsed-DC treated group.

Toll-Like Receptor-Targeting Immunotherapy for Oral Cancer / Oral Science International

It is important to augment the anti-cancer host response in cancer treatment. Recent studies have suggested that the signaling that occurs via the Toll-like receptors (TLRs), which are newly identified receptor molecules recognizing many pathogens, are involved in the induction of anti-cancer immunity. OK-432, a penicillin-killed and lyophilized preparation of <i>Streptococcus pyogenes</i>, is being successfully used as an immunotherapeutic agent in many types of malignancies. However, the molecular mechanisms of OK-432, a whole bacterial preparation, and the active components which make it effective against cancer, remain uncertain. We have succeeded in isolating the active component of OK-432 (lipoteichoic acid-related molecule, OK-PSA) by affinity chromatography of a butanol extract of OK-432 on the CNBr-activated sepharose 4B bound TS-2 monoclonal antibody that neutralizes the interferon (IFN)-γ-inducing activity of OK-432. OK-PSA induced Th1-type cytokines both in human and in mice, and elicited an anti-cancer effect in tumor-bearing mice via TLR4. Furthermore, our clinical study revealed that TLR4 signaling is intimately involved in the anti-cancer effect achieved by OK-432 in patients with oral cancer. We elucidated that OK-432 is first captured and digested by phagocytes, such as dendritic cells and macrophages, and then its active component, OK-PSA, which is released from the phagocytes, stimulates TLR4 signaling. It is strongly suggested that OK-PSA is the molecule most responsible for the anti-cancer effect of OK-432, and that TLR4 may be a definite molecular target for cancer immunotherapy with OK-432/OK-PSA.