Soyoung Baek

Combination therapy of renal cell carcinoma or breast cancer patients with dendritic cell vaccine and IL-2: results from a phase I/II trial

BackgroundTen cancer patients (Six renal cell carcinoma and four breast cancer patients) were treated in a phase I/II study with a vaccine composed of autologous dendritic cells (DCs) and IL-2 to evaluate the DC vaccine-related toxicity and antigen-specific immune alteration.MethodsCancer patients were treated twice with autologous CD34+ hematopoietic stem cell-derived, GM-CSF/IFN-γ-differentiated DCs pulsed with autologous tumor lysate and KLH, by 4-week interval. Following each subcutaneous injection of therapeutic DCs, low-dose (200 MIU) IL-2 was introduced for 14 consecutive days as an immune adjuvant. To determine the DC vaccine-induced immunological alterations, the KLH-specific lymphocyte proliferation, number of IFN-γ secreting T cells (ELISPOT assay), NK activity and the cytokine modulation were measured.ResultsCultured-DCs expressing HLA-DR, CD11c, CD83, and B7.1/B7.2 produced IL-12p70. After vaccination, the patients tolerated it. Clinical response was observed in one RCC patient as stable disease. However DC-vaccine related antigen-specific immune responses including peripheral blood lymphocyte proliferation and the number of IFN-r secreting cells were induced in six patients without clear correlation with clinical responses. Also NK activity was induced significantly in six patients after vaccination. DC vaccine-related decrease of TGF-β level or increase of IL-12p70 level and decline of CD4+CD25+ T cells were observed in three patients. However only in the RCC patient whose disease stabilized, combination of stimulatory as well as inhibitory immune alterations including induction of IFN-γ secreting T cell with reduction of CD4+ CD25+ T cell were correlated with clinical responses.ConclusionData indicated that DC vaccine combined with IL-2 is well tolerated without major side effects. DC vaccine induced the specific immunity against introduced antigen. Combinatorial alterations of immunological parameters indicating antigen-specific immune induction along with reduction of inhibitory immunity were correlated with clinical responses in DC vaccine treated patients.

Therapeutic DC vaccination with IL-2 as a consolidation therapy for ovarian cancer patients: a phase I/II trial

While ovarian cancer (OvCa) responds well to surgery and conventional chemotherapy, a high recurrence rate of advanced OvCa is observed. In this phase I/II study, 10 OvCa patients with minimal residual disease were treated with autologous dendritic cells (DCs) and IL-2 to evaluate the safety and feasibility of this therapeutic strategy and to characterize the antigen-specific immune alterations induced through this treatment. Approximately 4 months after initial debulking and chemotherapy, patients received two subcutaneous doses of autologous monocyte-derived DCs pulsed with autologous tumor lysate and keyhole limpet hemocyanin (KLH) at 4-week intervals. After each DC inoculation, low-dose (200 mIU) IL-2 was introduced for 14 consecutive days as an immune adjuvant. The vaccination was well tolerated. In three out of 10 patients, the inclusion status after the initial therapy showed the maintenance of complete remission (CR) after DC vaccination for 83, 80.9 and 38.2 months without disease relapse. One patient with stable disease (SD) experienced the complete disappearance of tumor after DC vaccination, and this status was maintained for 50.8 months until tumor recurrence. In two patients with partial response (PR) was not responding to DC vaccination and their disease recurred. In the three patients with disease free long-term survival, significant immune alterations were observed, including increased natural killer (NK) activity, IFN-γ-secreting T cells, immune-stimulatory cytokine secretion and reduced immune-suppressive factor secretion after DC vaccination. Thus, in patients with NED status and increased overall survival, DC vaccination induced tumor-related immunity, potentially associated with long-term clinical responses against OvCa.

Cellular Mechanism of Newly Synthesized Indoledione Derivative-induced Immunological Death of Tumor Cell

Background EY-6 is one of the newly synthesized indoledione derivatives to induce tumor cell-specific cell death. In this study, we investigated the mechanism of immunological death induced by EY-6 at mouse colon cancer cell as well as at the normal immune cell represented by dendritic cell. Methods C57BL/6 mouse syngeneic colon cancer cell MC38 was treated with EY-6, and analyzed by MTT for viability test, flow cytometry for confirming surface expressing molecules and ELISA for detection of cytokine secretion. Normal myeloid-dendritic cell (DC) was ex vivo cultured from bone marrow hematopoietic stem cells of C57BL/6 mice with GM-CSF and IL-4 to analyze the DC uptake of dead tumor cells and to observe the effect of EY-6 on the normal DC. Results EY-6 killed the MC38 tumor cells in a dose dependent manner (25, 50 and 100 µM) with carleticulin induction. And EY-6 induced the secretion of IFN-γ but not of TNF-α from the MC38 tumor cells. EY-6 did not kill the ex-vivo cultured DCs at the dose killing tumor cells and did slightly but not significantly induced the DC maturation. The OVA-specific cross-presentation ability of DC was not induced by chemical treatment (both MHC II and MHC I-restricted antigen presentation). Conclusion Data indicate that the EY-6 induced tumor cell specific and immunological cell death by modulation of tumor cell phenotype and cytokine secretion favoring induction of specific immunity eliminating tumor cells.

Dendritic Cell (DC) Vaccine in Mouse Lung Cancer Minimal Residual Model; Comparison of Monocyte-derived DC vs. Hematopoietic Stem Cell Derived-DC

The anti-tumor effect of monocyte-derived DC (MoDC) vaccine was studied in lung cancer model with feasible but weak Ag-specific immune response and incomplete blocking of tumor growth. To overcome this limitation, the hematopoietic stem cell-derived DC (SDC) was cultured and the anti-tumor effect of MoDC & SDC was compared in mouse lung cancer minimal residual model (MRD). Therapeutic DCs were cultured from either CD34+ hematopoietic stem cells with GM-CSF, SCF and IL-4 for 14 days (SDC) or monocytes with GM-CSF and IL-4 for 7 days (MoDC). DCs were injected twice by one week interval into the peritoneum of mice that are inoculated with Lewis Lung Carcinoma cells (LLC) one day before the DC injection. Anti-tumor responses and the immune modulation were observed 3 weeks after the final DC injection. CD11c expression, IL-12 and TGF-β secretion were higher in SDC but CCR7 expression, IFN-γ and IL-10 secretion were higher in MoDC. The proportion of CD11c+CD8a+ cells was similar in both DC cultures. Although both DC reduced the tumor burden, histological anti-tumor effect and the frequencies of IFN-γ secreting CD8+ T cells were higher in SDC treated group than in MoDC. Conclusively, although both MoDC and SDC can induce the anti-tumor immunity, SDC may be better module as anti-tumor vaccine than MoDC in mouse lung cancer.

Chemotherapeutic Candidate Inducing Immunological Death of Human Tumor Cell Lines

The immunological death induction by EY-6 on the human tumor cell lines was screened. Human colon carcinoma (HCT15, HCT116), gastric carcinoma (MKN74, SNU668), and myeloma (KMS20, KMS26, KMS34) cells were died by EY-6 treatment with dose-dependent manner. CRT expression, a typical marker for the immunological death, was increased on the EY-6-treated colorectal and gastric cancer cells. Interestingly, the effects on the myeloma cell lines were complicated showing cell line dependent differential modulation. Cytokine secretion from the EY-6 treated tumor cells were dose and cell-dependent. IFN-γ and IL-12 secretion was increased in the treated cells (200% to over 1000% of non-treated control), except HCT116, SNU668 and KMS26 cells which their secretion was declined by EY-6. Data suggest the potential of EY-6 as a new type of immuno-chemotherapeutics inducing tumor-specific cell death. Further studies are planned to confirm the efficacy of EY-6 including in vivo study.

Systemic immune modulation induced by alcoholic beverage intake in obese-diabetes (db/db) mice.

Alcohol over-consumption is generally immunosuppressive. In this study, the effects of single or repetitive alcohol administration on the systemic immunity of db/db mice were observed to clarify the possible mechanisms for the increased susceptibility of obese individuals to alcohol-related immunological health problems. Alcohol (as a form of commercially available 20% distilled-alcoholic beverage) was orally administered one-time or seven times over 2 weeks to db/db mice and normal C57BL/6J mice. Immunologic alterations were analyzed by observation of body weight and animal activity, along with proportional changes of splenocytes for natural killer cells, macrophages, and T and B lymphocytes. Modulation of plasma cytokine level and immune-related genes were also ascertained by micro-bead assay and a microarray method, respectively. The immune micro-environment of db/db mice was an inflammatory state and adaptive cellular immunity was significantly suppressed. Low-dose alcohol administration reversed the immune response, decreasing inflammatory responses and the increment of adaptive immunity mainly related to CD4(+) T cells, but not CD8(+) T cells, to normal background levels. Systemic immune modulation due to alcohol administration in the obese-diabetic mouse model may be useful in the understanding of the induction mechanism, which will aid the development of therapeutics for related secondary diseases.

P3-021: Dendritic cell vaccine in murine lung cancer model: comparison of monocyte-derived DC and stem cell derived-DC

Dendritic cell vaccine in murine lung cancer model: comparison of monocyte-derived DC and stem cell derived-DC Lee, Seog Jae1 Kim, Myoung Joo2 Baek, Soyoung2 Kim, Hyun Soo3 Lee, Hyunah4 1 Eulji University, School of Medicine, Seoul, Korea 2 Samsung Medical Center, Seoul, Korea 3 Stem cell Institute, FCB-Pharmicell Co Ltd, Seoul, Korea 4 Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea Background: Although anti-tumor effect of monocyte-derived DC (M-DC) vaccine was studied in several tumor models with feasible responses, the major huddle is yield of therapeutic cells in culture. Hematopoietic stem cell-derived DC (S-DC) was introduced as alternatives. In this study the in vivo anti-tumor effect of M-DC & S-DC was compared as well as the DC characters. Methods: Syngeneic Lewis lung carcinoma cells (LLC) were inoculated intravenously into C57BL/6 mice to simulate the minimal residual disease (MRD). M-DCs were cultured from myeloid lineage cells negatively selected from bone marrow cells by antibody panning. Selected cells were cultured with GM-CSF and IL-4 for 6 days. Mouse bone marrow stem cells were isolated by MACS lineage cell depletion kit and cultured with GM-CSF, SCF and IL-4 for 13days. Tumor antigen pulsing was performed with autologous tumor cell lysate. Antigen pulsed therapeutic-DCs were injected twice by one week interval into the peritoneum of mice that are inoculated with LLC one day before the DC injection. Cultured therapeutic-DCs were characterized by phenotype and cytokine production nature. Anti-tumor responses and the immune modulation were observed 2 weeks after the final DC injection. Pulmonary tumor burden as well as tumor antigen specific lymphocyte proliferation (CFSE assay) and IFN-r secreting CD8+ T cell proportion (ELISPOT) were detected from the splenocytes of mice in each group. Results: Both M-DC and S-DC vaccine treatment inhibit the tumor growth in the lung. Especially anti-tumor response of tumor lysate pulsed DCs (LDCs) were significant compared to saline treated mice. Over 90% M-DC & S-DC were expressed MHC I/II molecules. Interestingly, less than 10 % of M-DCs express CD11c but about 45 % of M-DCs express CD11b. S-DC expresses CD11c in about 80% of the cells especially CD11c+CD8a+ proportions were about 35% in S-DC but less than 2% in M-DC. IL-12 secretion was higher in S-DC (424.82+87.26 pg/106 cells) than in M-DC (73.51+6.15 pg/106 cells), but the secretion of IL-10 was higher in M-DC (65.99+4.30 vs. 180.70+18.99 pg/106 cells for S-DC vs. M-DC respectively). Induction of tumor antigen-specific lymphocyte proliferation was only observed in M-DC/LDC treated group (2.6% vs. 60.5% proliferating cells by media vs. tumor lysate stimulation in vitro). However the frequency of IFN-r secreting CD8+ T cells were in S-DC treated group was significantly higher than that in M-DC treated group (58.7+8.3 vs. 11.7+1.8 spots for S-DC/LDC vs. M-DC/LDC treated group, respectively). Conclusion: Although the characters of M-DC and S-DC were different, anti-tumor effect of DC vaccines was similar in LLC MRD model. Tumor antigen specific lymphocyte proliferation was significant in M-DC treated group, however as a effector cells the frequency of IFN-r secreting CD8+ T cells were higher in S-DC treated group than in M-DC group. Conclusively, data suggested that S-DC might be better module as anti-tumor vaccine than M-DC in both yield and function. P3-022 NT: Immunotherapy/Vaccines Posters, Wed, Sept 5 – Thur, Sept 6