Personalized Dendritic-cell-based Vaccines Targeting Cancer Neoantigens.

Cancer immunotherapy activates the host immune system against tumor cells and has the potential to lead to the development of innovative strategies for cancer treatment. Neoantigens are non-self-antigens produced by genetic mutations in tumor cells that induce a strong immune response against tumor cells without central immune tolerance. Along with advances in neoantigen analysis technology, the development of vaccines focusing on neoantigens is being accelerated. Whereas there are various platforms for neoantigen vaccines, combined immuno-therapies are being developed simultaneously with the clinical application of synthetic long peptides and mRNA and dendritic-cell (DC)-based vaccines. Personalized DC-based vaccines not only can load various antigens including neoantigens, but also have the potential to elicit a strong immune response in T cells as antigen-presenting cells. In this review, we describe the properties of neoantigens and the basic characteristics of DCs. We also discuss the clinical applications of neoantigen vaccines, focusing on personalized DC-based vaccines, as well as future research and development directions and challenges.

A pilot study on the safety and efficacy of neoadjuvant chemo­adoptive immunotherapy for locally advanced rectal cancer.

The safety and efficacy of combination therapy of immune cell therapy and chemotherapy [chemo-adoptive immunotherapy (CAIT)] for patients with stage IV or recurrent colorectal cancer have been reported. In the present study, the safety and efficacy of neoadjuvant CAIT were investigated for preoperative therapy of locally advanced rectal cancer. The study included patients with cT3/T4 or cN (+) rectal adenocarcinoma scheduled for curative surgery. Six patients who consented to participate in the current study were selected as subjects. Neoadjuvant CAIT involves administration of activated autologous lymphocytes, αß T cells, and mFOLFOX6 every 2 weeks for six courses, followed by surgery 4-6 weeks thereafter. Common Terminology Criteria for Adverse Events grade 3 neutropenia was observed in one patient. Neoadjuvant CAIT and curative surgery were performed on all the patients. The confirmed response rate was 67%. Downstaging was confirmed in five patients (83%). Regarding histological effects, two patients were grade 1a and four were grade 2. Regarding immunological reactions, both CD4+ and CD8+ T cell infiltration rates increased after treatment in three patients on tumor-infiltrating lymphocyte (TIL) analysis. In peripheral blood analysis, the total lymphocyte count was maintained in all patients, and the CD8+ T cell count increased by ≥3 times on the pretreatment count in two patients but may not be associated with changes in TILs. During the median postoperative follow-up duration of 24 months, liver and lung metastases occurred in one patient, but all patients survived. In conclusion, neoadjuvant CAIT (αß T cells + mFOLFOX6) can be safely administered for the treatment of advanced rectal cancer. Verification of the efficacy of comprehensive immune cell therapy, especially the induction of antitumor immunity for the prevention of recurrence, will be maintained. The current study is registered with the Japan Registry of Clinical Trials (jRCT; ID, jRCTc030190248; January 21, 2019).

Effects of adoptive T-cell immunotherapy on immune cell profiles and prognosis of patients with unresectable or recurrent cholangiocarcinoma.

The identification of immune cell profiles (ICP) involved in anti-tumor immunity is crucial for immunotherapy. Therefore, we herein investigated cholangiocarcinoma patients (CCA) who received adoptive T-cell immunotherapy (ATI). Eighteen unresectable or recurrent CCA received ATI of αß T cells alone or combined with chemotherapy. ICP were evaluated by flow cytometry. There were 14 patients with intrahepatic cholangiocarcinoma (iCCA) and four with distal cholangiocarcinoma (dCCA). After one course of treatment, nine iCCA and four dCCA had progressive disease (PD), while five iCCA had stable disease (SD). Median overall survival (OS) was prolonged to 21.9 months. No significant differences were observed in OS between the PD and SD groups of iCCA. The frequency of helper T cells (HT) in iCCA decreased from 70.3% to 65.5% (P = .008), while that of killer T cells (KT) increased from 27.0% to 30.6% (P = .005). dCCA showed no significant changes of immune cells. OS was prolonged in iCCA with increased frequencies of CD3+ T cells (CD3) (P = .039) and αß T cells (αß) (P = .039). dCCA showed no immune cells associated with OS. The frequencies of CD3+ T cells and αß T cells in the PD group for iCCA decreased from 63.5% to 53% (P = .038) and from 61.6% to 52.2% (P = .028), respectively. In the SD group, the frequency of HT decreased from 65.8% to 56.9% (P = .043), whereas that of KT increased from 30.1% to 38.3% (P = .043). In conclusions, ATI affected ICP and prolonged OS. Immune cells involved in treatment effects differed according to the site of cholangiocarcinoma.

Safety evaluation of immune-cell therapy for malignant tumor in the Cancer Immune-cell Therapy Evaluation Group (CITEG).

BACKGROUND AIMS: With the aim of strengthening the scientific evidence of immune-cell therapy for cancer and further examining its safety, in October 2015, our hospital jointly established the Cancer Immune-Cell Therapy Evaluation Group (CITEG) with 39 medical facilities nationwide. METHODS: Medical information, such as patients' background characteristics, clinical efficacy and therapeutic cell types obtained from each facility, has been accumulated, analyzed and evaluated by CITEG. In this prospective study, we analyzed the adverse events associated with immune-cell therapy until the end of September 2022, and we presented our interim safety evaluation. RESULTS: A total of 3839 patients with malignant tumor were treated with immune-cell therapy, with a median age of 64 years (range, 13-97 years) and a male-to-female ratio of 1:1.08 (1846:1993). Most patients' performance status was 0 or 1 (86.8%) at the first visit, and 3234 cases (84.2%) were advanced or recurrent cases, which accounted for the majority. The total number of administrations reported in CITEG was 31890, of which 960 (3.0%) showed adverse events. The numbers of adverse events caused by treatment were 363 (1.8%) of 19661 administrations of αßT cell therapy, 9 of 845 administrations of γδT-cell therapy (1.1%) and 10 of 626 administrations of natural killer cell therapy (1.6%). The number of adverse events caused by dendritic cell (DC) vaccine therapy was 578 of 10748 administrations (5.4%), which was significantly larger than those for other treatments. Multivariate analysis revealed that αßT cell therapy had a significantly greater risk of adverse events at performance status 1 or higher, and patients younger than 64 years, women or adjuvant immune-cell therapy had a greater risk of adverse events in DC vaccine therapy. Injection-site reactions were the most frequently reported adverse events, with 449 events, the majority of which were associated with DC vaccine therapy. Among all other adverse events, fever (228 events), fatigue (141 events) and itching (131 events) were frequently reported. In contrast, three patients had adverse events (fever, abdominal pain and interstitial pneumonia) that required hospitalization, although they were weakly related to this therapy; rather, it was considered to be the effect of treatment for the primary disease. CONCLUSIONS: Immune-cell therapy for cancer was considered to be a safe treatment without serious adverse events.

Efficacy of Adjuvant Immune-cell Therapy Combined With Systemic Therapy for Solid Tumors.

BACKGROUND/AIM: The efficacy of adjuvant systemic therapy after surgical resection remains unsatisfactory; therefore, a new treatment strategy is required. We aimed to examine the efficacy of adjuvant immune-cell therapy using activated T lymphocytes with or without dendritic cell vaccination in combination with standard adjuvant systemic therapies in terms of the survival of patients with solid tumors, such as lung, gastric, pancreatic, colorectal, and breast cancers. PATIENTS AND METHODS: A total of 141 patients with solid tumors were enrolled in this study. The correlation of overall survival and disease-free survival with various clinical factors such as age, sex, performance status score, clinical stage, treatment strategies, and vital status was investigated by univariate and multivariate analyses. RESULTS: Multivariate analysis revealed that a performance status score of 0 was a favorable prognostic factor in the full analysis set of solid tumors (HR=0.209, 95%CI=0.065-0.676, p=0.0089) and might be the indication for immune-cell therapy in the adjuvant setting. CONCLUSION: Adjuvant immune-cell therapy combined with other systemic therapies would potentially provide a survival benefit in patients with solid tumors.

Prognostic Factors for Advanced/Recurrent Breast Cancer Treated With Immune-cell Therapy.

BACKGROUND/AIM: Advanced/recurrent breast cancer (ARBC) still has a poor prognosis; therefore, new treatment strategies are required. In this retrospective study, we aimed to investigate the efficacy of immune-cell therapy using T lymphocytes activated in vitro with or without dendritic cell vaccination in combination with standard therapies in terms of the survival of patients with ARBC. PATIENTS AND METHODS: A total of 127 patients with ARBC were enrolled in this study. The correlation between overall survival and various clinical factors of each ARBC subset was examined by univariate and multivariate analyses. RESULTS: Multivariate analysis demonstrated that performance status (PS) 0, the absence of prior chemotherapy, liver/pleural metastasis, and the presence of combined surgery in ARBC and PS 0 or the absence of liver metastasis in the HR+/HER- subset are indications for immune-cell therapy. CONCLUSION: A survival benefit could be potentially obtained by a combination of immune-cell therapy with other therapies in ARBC patients.

Esophageal cancer responsive to the combination of immune cell therapy and low-dose nivolumab: two case reports.

BACKGROUND: Blocking the programmed death 1 pathway by immune checkpoint inhibitors induces dramatic antitumor activity in patients with malignant tumors. However, the clinical response to immune checkpoint inhibitors remains limited owing to the patients' immunological status, such as the number of lymphocytes, programmed death ligand 1 expression, and tumor mutation burden. In this study, we successfully treated two patients with advanced esophageal cancer who responded to the combination of adoptive immune cell therapy and a low-dose immune checkpoint inhibitor, nivolumab. CASE PRESENTATION: Two Asian (Japanese) patients with advanced esophageal cancer who were resistant to conventional chemoradiation therapy were referred to our hospital for immune therapy. Case 1 was a 66-year-old woman who was diagnosed as having esophageal cancer. She received concurrent chemoradiation therapy and then underwent subtotal esophagectomy, after which she became cancer free. However, she relapsed, and cancer cells were found in the lung and lymph nodes 6 months later. She enrolled in a clinical trial at our institution (clinical trial number UMIN000028756). She received adoptive immune cell therapy twice at a 2-week interval followed by low-dose nivolumab with adoptive immune cell therapy four times at 2-week intervals. A follow-up computed tomography scan showed partial response, with mass reduction of the metastatic lung and mediastinal lesions. Case 2 was a 77-year-old man. He received concurrent chemoradiation therapy with fluoropyrimidine/platinum, and gastroscopy revealed complete remission of esophageal cancer. He was disease free for 5 months, but routine computed tomography revealed multiple metastases in his lungs and lymph nodes. He visited our clinic to receive adoptive immune cell therapy and immune checkpoint inhibitor combination therapy. Radiographic evidence showed continuous improvement of lesions. There was no evidence of severe adverse events during the combination therapy. CONCLUSION: The combination of adoptive immune cell therapy and an immune checkpoint inhibitor might be a possible treatment strategy for advanced esophageal cancer. Trial registration UMIN000028756. Registered 14 September 2017.

Effect of adoptive T-cell immunotherapy on immunological parameters and prognosis in patients with advanced pancreatic cancer.

BACKGROUND AIMS: Immunotherapy is effective for many types of cancer, but its benefits in advanced pancreatic cancer, which has a poor prognosis, are not well established. In this study, the authors examined the effects of adoptive T-cell immunotherapy (ATI) on immune cell profiles and prognosis in patients with unresectable advanced pancreatic cancer. METHODS: Seventy-seven patients with unresectable advanced pancreatic cancer were treated with six cycles of αß T cells alone or in combination with chemotherapy or chemoradiation. Immune cell profiles in peripheral blood samples obtained before and after treatment were comprehensively evaluated by flow cytometry. Furthermore, associations between changes in immune cell frequencies and prognosis were determined. RESULTS: ATI prolonged survival to 18.7 months compared with previous estimates of 6.2-11.1 months for patients treated with chemotherapy alone. ATI decreased CD3+CD4+CD8- T cell frequency in peripheral blood and increased CD3+CD4-CD8+ T cell frequency. An increase in CD3+ T cells and CD3+TCRγδ- T cells in peripheral blood after treatment was associated with a good prognosis. CONCLUSIONS: ATI altered the immune profile in peripheral blood, including CD3+CD4-CD8+ T cells, and improved prognosis in pancreatic cancer.

Prognostic Factors for Endometrial and Cervical Cancers of Uterus Treated With Immune-cell Therapy: A Retrospective Study.

BACKGROUND/AIM: In this retrospective study, we aimed to investigate the efficacy of immune-cell therapy using T lymphocytes activated in vitro with or without dendritic cell vaccination in combination with standard therapies in terms of the survival of patients with advanced or recurrent endometrial and cervical cancers of the uterus. PATIENTS AND METHODS: A total of 187 patients with advanced or recurrent uterine cancer were enrolled in this study. The correlation between overall survival and various clinical factors was examined by univariate and multivariate analyses. RESULTS: Univariate analysis revealed that the prognosis was improved in uterine cancer patients who received immune-cell therapy without prior chemotherapy or without distant metastasis. Multivariate analysis demonstrated that the absence of prior chemotherapy for endometrial cancer and liver/lung metastasis of cervical cancer are indications for immune-cell therapy. CONCLUSION: Survival benefit in uterine cancer patients could be potentially obtained by a combination of immune-cell therapy with other therapies.

Adoptive Immune-Cell Therapy for the Treatment of Neuroendocrine Carcinoma of the Uterine Cervix.

BACKGROUND/AIM: We aimed to investigate the efficacy of immune-cell therapy in terms of the survival of patients with neuroendocrine carcinoma of the uterine cervix (NECC), which lacks standardized therapeutic approaches. PATIENTS AND METHODS: We identified 17 patients who were diagnosed as having NECC and treated with immune-cell therapy. The clinical characteristics of these patients were extracted from their records and their overall survival was measured. RESULTS: Of the 17 patients, two patients with early-stage NECC without recurrence and three patients with less than four treatments were excluded. The median survival times from the time of diagnosis and from the initial administration of immune-cell therapy were 49.7 and 24.4 months, respectively. The overall survival rates at 1, 2, and 5 years were 63.6%, 38.2%, and 25.5%, respectively. Long-term survival was observed in the patients with distant metastases. CONCLUSION: The preliminary results of this retrospective study suggested the potential efficacy of immune-cell therapy for NECC.

Changes in Immunological Status in Patients With Metastatic Colorectal Cancer Treated With First-line Chemoimmunotherapy.

BACKGROUND/AIM: Chemoimmunotherapy is a promising treatment for various malignant diseases. In this study, we examined whether first-line chemoimmunotherapy using adoptive immune-cell therapy was effective for metastatic colorectal cancer (mCRC). PATIENTS AND METHODS: The therapeutic efficacy and safety of the standard first-line chemoimmunotherapy with adoptive αß T cell therapy and bevacizumab were assessed using thirty-two patients with mCRC in our hospital. Immunological status after this chemoimmunotherapy was also evaluated. RESULTS: The response and disease control rates were 68.8% and 87.5%, respectively. Further, median progression-free and overall survival were 14.2 and 35.3 months. Immunotherapy-associated toxicity was minimal. Significant decrease in the change of monocyte number (p=0.006) and increase in the change of rate of lymphocyte-to-monocyte ratio (p=0.039) were seen in the complete response group. CONCLUSION: First-line chemoimmunotherapy with adoptive αß T cell therapy may be useful for mCRC.

Effects of adaptive immune cell therapy on the immune cell profile in patients with advanced gastric cancer.

BACKGROUND: Immunotherapy for cancer patients has been the subject of attention in recent years. In this study, we investigated whether αßT-cell therapy causes changes in the host's immune cell profile, and if so, the effect of these changes on prognosis. METHODS: Peripheral blood mononuclear cells (PBMCs) from 30 gastric cancer patients who had completed one course of αßT-cell therapy were analyzed. The peripheral blood immune cell profile was established using PBMCs by counting the frequency of CD4+ helper T cells, CD8+ killer T cells, regulatory T cells (Tregs), and myeloid-derived suppressor cells and measuring the expression of their surface markers. The changes after treatment and their association with response to treatment were investigated. RESULTS: Immune cell profiles changed greatly after treatment. The frequency of CD4+ helper T cells decreased, but that of CD8+ killer T cells increased. The frequency of programmed cell death 1 (PD-1)+ effector Tregs increased significantly, but only in the non-progressive disease (non-PD) group, in which it was significantly higher compared with the PD group. Patients in whom the frequency of PD-1+ effector Tregs increased had a significantly better prognosis than those in whom it decreased. CONCLUSION: Our results suggested that αßT-cell therapy changes the host's immune cell profile, and an increase in PD-1+ effector Tregs may help improve prognosis.

Identification of prognostic factors for γδT cell immunotherapy in patients with solid tumor.

BACKGROUND AIMS: Activated γδT cells have been shown to exhibit cytotoxicity against tumor cells. However, the efficacy of γδT cell immunotherapy for a large number of patients with solid tumors remains unclear. In this study, we examined the efficacy of γδT cell immunotherapy using in vitro-activated γδT lymphocytes in combination with standard therapies in terms of the survival of patients with solid tumors, and determined prognostic factor for γδT cell immunotherapy. METHODS: 131 patients enrolled in this study received γδT cell immunotherapy with or without standard therapies. Their overall survival was analyzed by the Kaplan-Meier with log-rank test and Cox regression methods. Immunological analysis was performed by flow cytometry (FCM) before and after six cycles of γδT cell immunotherapy. RESULTS: Multivariable analysis revealed that patients who showed stable disease (SD) and partial response (PR) to γδT cell immunotherapy showed better prognosis than those with a progressive disease (PD) (P = 0.0269, hazard ratio [HR], 0.410, 95% confidence interval [CI], 0.190-0.901). Furthermore, when immunological parameters were examined by FCM, the high Vγ9/γδT ratio (i.e., the high purity of the Vγ9 cells within the adoptively transferred γδT cells) before treatment was found to be a good prognostic factor for γδT cell immunotherapy (P = 0.0142, HR, 0.328, 95% CI, 0.125-0.801). No serious adverse events were reported during γδT cell immunotherapy. CONCLUSION: Thus, γδT cell immunotherapy might extend the survival of patients with solid tumors.

Prognostic Factors for Colorectal Cancer Patients Treated With Combination of Immune-cell Therapy and First-line Chemotherapy: A Retrospective Study.

BACKGROUND/AIM: In this retrospective study, we aimed to investigate the efficacy of immune-cell therapy using T lymphocytes activated in vitro with or without dendritic cells vaccination (DCs), in combination with 1st-line chemotherapies in terms of the survival of patients with advanced colorectal cancer (CRC). PATIENTS AND METHODS: A total of 198 patients who were diagnosed with advanced CRC and administered 1st-line chemotherapies were enrolled in this study. The correlation between overall survival (OS) and various clinical factors was examined by univariate and multivariate analyses. RESULTS: Univariate analyses revealed that the prognosis was improved in CRC patients who received immune-cell therapy with PS 0, bevacizumab (BV), and capecitabine-including regimens (Cap). Finally, multivariate analysis demonstrated that PS=0, and the combination of immune-cell therapy and Cap provided a survival benefit in patients with advanced CRC. CONCLUSION: The survival benefit could be potentially obtained with better PS by the combination of immune-cell therapy and Cap as a 1st-line setting in patients with CRC.

Significant clinical response of advanced colorectal cancer to combination therapy involving capecitabine and adoptive cell transfer therapy: a case report.

Significant clinical response was obtained in a patient with stage IV colorectal cancer (CRC) following combination therapy involving capecitabine and adoptive cell transfer therapy. She had laparoscopic lower anterior resection and left liver metastatic carcinoma resecting in 20th, February, 2017. Capecitabine was used to further treatment for an unresectable hepatic metastasis. The serum level of carcinoembryonic antigen (CEA) was increased significantly after dropped temporarily. Since then, the patient took the adoptive cell transfer therapy at the same time. αßT cells and NK cells were injected intravenously into the patient. After the first transfusion with αßT cells, the tumor biomarker, CEA, dropped obviously from 14.7 to 6.1 ng/mL. And it came to 1.9 ng/mL after four times treatment, which was back into normal range (<5 ng/mL). Flow cytometry (FCM) was used to reveal the detailed immunological status of this patient before and after adoptive cell transfer therapy. With 19-month follow-up, neither recurrence or complication was founded. Combination therapy involving adoptive immunotherapy and capecitabine may be the potential method for advanced CRC with less complication.

Prognostic Factors for Pancreatic Cancer Patients Treated with Immune-cell Therapy.

BACKGROUND/AIM: The past 17 years, immune-cell therapy has been administered to 990 patients with advanced or recurrent pancreatic adenocarcinoma and 50 patients with curatively resected pancreatic adenocarcinoma. MATERIALS AND METHODS: The correlation between overall survival (OS) and various factors including sex, age, performance status (PS), distant metastasis, chemotherapy, radiotherapy, and type of immune-cell therapy were evaluated by univariate and multivariate analyses. RESULTS: The median OS of advanced or recurrent pancreatic cancer was 5.8 months, and the prognosis was improved in pancreatic cancer patients who received immune-cell therapy with PS scores of 0-1 [hazard risk (HR)=0.56; 95% confidence interval (CI)=0.46-0.68; p<0.0001], chemotherapy (HR=0.68; 95%CI=0.54-0.87; p=0.002), or radiotherapy (HR=0.76; 95%CI=0.63-0.93; p=0.006). Multivariate analysis demonstrated that distant metastasis indicated a poor prognosis for pancreatic cancer patients that were administered immune-cell therapy (HR=1.62; 95%CI=1.37-1.93; p<0.0001). Additionally, the combined immune-cell therapy with αß T cell and dendritic cell (DC) vaccine provided a survival benefit in advanced or recurrent pancreatic cancer patients (HR=0.69; 95%CI=0.57-0.83; p<0.0001). CONCLUSION: A survival benefit could be potentially obtained with better PS by the combination of αß T cell therapy, DC vaccine therapy, and chemotherapy at an early stage in pancreatic cancer.

Comprehensive immunotherapy combined with intratumoral injection of zoledronate-pulsed dendritic cells, intravenous adoptive activated T lymphocyte and gemcitabine in unresectable locally advanced pancreatic carcinoma: a phase I/II trial.

Dendritic cell (DC)-based vaccines prepared using various antigen loading methods have been studied for cancer immunotherapy. The in vivo provocation of immunity by the direct injection of DCs without using tumor-specific antigens into tumors after apoptosis-inducing chemotherapy is more applicable. We previously reported that zoledronate-pulsed DCs (Zol-DCs) may induce tumor-antigen-specific CD8+ T cells by activating Vγ9γδT cells. In this report, we studied the feasibility, safety, and efficacy of a comprehensive immunotherapy involving the combined intratumoral injection of Zol-DC, gemcitabine (GEM) and αßT cells in locally advanced pancreatic carcinoma. Seven of 15 patients showed a stable disease (SD) and most of the patients showed long-term clinical responses. The FACT-BRM score was significantly higher in the patients with SD. Additionally the CD8+/Treg ratio significantly increased in SD patients after treatment. The median over-all survival and progression-free-survival of 15 patients were 12.0 months and 5.5 months, respectively. Patients with a pretreatment neutrophil/lymphocyte ratio (NLR) lower than 5.0 showed significantly longer survival. Even in an analysis limited to the patients with an NLR lower than 5.0, the patients whose CD8+/Treg ratio increased more than twofold tended to survive longer. In conclusion, the comprehensive immunotherapy using Zol-DCs, systemic αßT cells, and GEM may synergistically show a therapeutic effect on locally advanced pancreatic carcinoma. By using appropriate and precise biomarkers, such as NLR and CD8+/Treg ratio, the present comprehensive immunotherapy could be more beneficial for patients with pancreatic carcinoma.

Low-dose valproic acid with low-dose gemcitabine augments MHC class I-related chain A/B expression without inducing the release of soluble MHC class I-related chain A/B.

To improve natural killer group 2 member D (NKG2D)-dependent cytotoxicity, the inhibition of cleavage and release of major histocompatibility complex class 1-related chain (MIC) molecules from the tumor surface are required. Valproic acid (VPA), a histone deacetylase (HDAC) inhibitor, is able to induce cell-surface MICA/B on tumor cells. In the present study, the ability of VPA and gemcitabine (GEM) to upregulate MICA/B in pancreatic cancer cells was investigated, resulting in the inhibition of cleavage and release of MIC molecules from the tumor surface. Flow cytometry was used to quantify MICA/B expression in six human pancreatic cancer lines. Functional cytotoxic activity of γδT cells against pancreatic cancer cells treated with VPA and GEM was determined using cytotoxicity assays. At low doses of VPA (0.7 mM) and GEM (0.001 µM), which did not induce tumor growth alterations, the agents individually increased cell-surface MICA/B expression in MICA/B-positive cell lines, but not in the MICA/B-negative cell line. Furthermore, the combination of VPA and GEM synergistically induced cell-surface MICA/B expression. In MICA/B-positive cell lines, the increase in MICA/B expression was dependent on VPA concentration. The combination of low-dose VPA and GEM enhanced the susceptibility of the PANC-1 cell line to γδT cell-mediated tumor cell lysis. It was observed that soluble MIC was released from PANC-1 in the culture supernatant following treatment with GEM. However, the combination of low-dose VPA with low-dose GEM increased MICA/B expression without inducing soluble MIC, resulting in enhanced tumor cell lysis. The results of the present study suggest that the combined administration of low-dose VPA with low-dose GEM has the potential to enhance the therapeutic effects of immunotherapy in pancreatic cancer. Furthermore, it is proposed that the combination acts, in part, by upregulating MICA/B and prevents soluble MIC from being released.

Systemic Intravenous Adoptive Transfer of Autologous Lymphokine-activated αß T-Cells Improves Temozolomide-induced Lymphopenia in Patients with Glioma.

In this clinical study, we investigated the safety and clinical usefulness of systemic adoptive immunotherapy using autologous lymphokine-activated αß T-cells (αß T-cells), combined with standard therapies, in patients with malignant brain tumors. Twenty-three patients with different malignant brain tumors, consisting of 14 treated with temozolomide (TMZ group) and 9 treated without temozolomide (non-TMZ group), received systemic intravenous injections of αß T-cells (mean=10.4 injections/patient for the TMZ group, and 4.78 for the non-TMZ group). No significant adverse effects associated with the αß T-cell injection were observed, and the total lymphocyte count (TLC) improved significantly in the TMZ group after five injections. Furthermore, CD8-positive or T-cell receptor V gamma -positive cells were increased with TLC in three patients with glioblastoma multiforme. These findings suggest that systemic αß T-cell immunotherapy is well tolerated, and may help restore an impaired and imbalanced T-cell immune status, and temozolomide- and/or radiotherapy-induced lymphopenia. Future prospective study is needed to clarify the clinical merits of this immunotherapy.

Hepatectomy for Liver Metastases of Colorectal Cancer After Adoptive Chemoimmunotherapy Using Activated αß T-cells.

BACKGROUND/AIM: Various types of chemoimmunotherapies for malignant tumors have been reported. However, there are few reports on hepatectomy after chemoimmunotherapy. We evaluated the safety and efficacy of hepatectomy for patients with stage IV colorectal liver metastases (CLM) after chemoimmunotherapy using activated αß T-cells. PATIENTS AND METHODS: From June 2012 to December 2016, five patients who underwent hepatectomy after receiving capecitabine and oxaliplatin (XELOX) plus bevacizumab and ex vivo-expanded αß T-lymphocytes as first-line chemoimmunotherapy were included. RESULTS: The median age of the five patients (two men, three women) was 61.4 (range=56-75) years. The surgical procedure was partial hepatectomy in two, laparoscopic partial hepatectomy in two, and one case of partial hepatectomy with subsegmentectomy. There was no postoperative complication of Clavien-Dindo grade 3A or higher. One patient had multiple lung metastases. CONCLUSION: Hepatectomy after chemoimmunotherapy using activated αß T-cells for CLM can be performed safely.