Cancer Immunotherapy with Cytokine-Induced Killer Cells

Current Insights into CAR T-Cell-Based Therapies for Myelodysplastic Syndrome

Myelodysplastic syndromes (MDS) are due to defective hematopoiesis in bone marrow characterized by cytopenia and dysplasia of blood cells, with a varying degree of risk of acute myeloid leukemia (AML). Currently, the only potentially curative strategy is hematopoietic stem cell transplantation (HSCT). Many patients are ineligible for HSCT, due to late diagnosis, presence of co-morbidities, old age and complications likely due to graft-versus-host disease (GvHD). As a consequence, patients with MDS are often treated conservatively with blood transfusions, chemotherapy, immunotherapy etc. based on the grade and manifestations of MDS. The development of chimeric antigen receptor (CAR)-T cell therapy has revolutionized immunotherapy for hematological malignancies, as evidenced by a large body of literature. However, resistance and toxicity associated with it are also a challenge. Hence, there is an urgent need to develop new strategies for immunological and hematopoetic management of MDS. Herein, we discuss current limitations of CAR T-cell therapy and summarize novel approaches to mitigate this. Further, we discuss the in vivo activation of tumor-specific T cells, immune check inhibitors (ICI) and other approaches to normalize the bone marrow milieu for the management of MDS.

Multi‑omics approach to improve patient‑tailored therapy using immune checkpoint blockade and cytokine‑induced killer cell infusion in an elderly patient with lung cancer: A case report and literature review

The 5-year survival rate of patients with advanced non-small cell lung cancer (NSCLC) remains low, despite recent advances in targeted therapy and immunotherapy. Therefore, there is a need to identify alternative strategies to improve treatment outcomes. Modern diagnostics can significantly facilitate the selection of treatment plans to improve patient outcomes. In the present study, multi-form diagnostic methodologies were adopted, including next-generation sequencing-based actionable gene sequencing, programmed death ligand 1 (PD-L1) immunohistochemistry, a circulating tumor cell (CTC) assay, flow cytometric analysis of lymphocyte subsets and computed tomography, to improve disease management in an 86-year-old female patient with relapsed metastatic NSCLC. High expression of PD-L1, elevated CTC tmutations, were observed. Based on these results, the patient was initially treated with the programmed death protein 1 blocking antibody sintilimab for two cycles, resulting in the stabilization of their condition, although the patient still exhibited severe pain and other symptoms, including fatigue, malaise, a loss of appetite and poor mental state. Informed by dynamic monitoring of the patient's response to treatment, the treatment plan was subsequently adjusted to a combination therapy with sintilimab and autologous cytokine-induced killer cell infusion, which eventually led to improved outcomes in both the management of the cancer and quality of life. In conclusion, multi-omics analysis may be used to establish patient-tailored therapies to improve clinical outcomes in hard-to-treat elderly patients with metastatic NSCLC.

Combination therapy of irreversible electroporation and cytokine-induced killer cells for treating mice bearing panc02 pancreatic-cancer xenografts

The current study aimed to investigate the antitumor effects and potent mechanism of cytokine-induced killer (CIK) cells combined with irreversible electroporation (IRE) via Panc02 cell-bearing mouse model in vivo. CIK cells were isolated from the spleens of Panc02 pancreatic-cancer (PC) subcutaneous-xenograft model and the proportion of different lymphocytes was also determined. The antitumor effect of the combination of IRE and CIK cells in a PC subcutaneous-xenograft model was also investigated. The proportion of cells that were positive for CD3+CD8+ and the proportion of CD3+CD56+ cells were both significantly increased after 21 days of in vitro culture. Combined treatment of IRE and CIK cell significantly inhibited tumor growth and increased the survival rate of Panc02 cell-bearing mice. Furthermore, infiltration of lymphocytes into tumor tissue was significantly increased by this combination therapy compared with the untreated group or monotherapy group. In addition, IRE significantly enhanced the expression of chemokine receptors elicited by CIK cells. In conclusion, IRE combined with CIK cells showed superior antitumor efficacy in a PC xenograft model, which we attributed to the promotion of lymphocytic infiltration, as well as to upregulation of chemokine receptor expression and the regulators of CIK cell proliferation.

Optimizing tumor-associated antigen-stimulated autologous dendritic cell and cytokine-induced killer cell coculture to enhance cytotoxicity for cancer immunotherapy in manufacturing

BACKGROUND

Dendritic Cell Cytokine-induced killer cell (DC-CIK) coculture treatment in cancer immunotherapy has been shown to be effective. However, the cost of DC- CIK therapy is prohibitive for many patients, and the lack of standard manufacturing processes and treatment strategies are major limitations. Our study used tumor lysate as a tumor-associated antigen source and DCs and CIK cells in coculture. We developed an efficient method to obtain autologous DCs- and CIK cells from peripheral blood. We used flow cytometry to assess DC activation and the cytometric bead array assay to quantify cytokines secreted by CIK cells.

RESULTS

We evaluated the antitumor activity of DC- CIK coculture in vitro with the K562 cell line. We demonstrated that a manufacturing process employing frozen immature DCs can yield the lowest loss with the highest economic benefits. DC-CIK coculture can effectively upgrade CIK cells' immunological specificity to tumors in the presence of tumor-associated antigens.

CONCLUSION

In vitro experiments revealed that when the DC- CIK cell ratio was 1: 20 in the coculture, CIK cells secreted the highest number of cytokines on the 14th day and the antitumor immune effect showed the highest potency. CIK cells' cytotoxicity to K562 cells was highest when the CIK: K562 cell ratio was 25: 1. We developed an efficient manufacturing process for DC- CIK coculture, while also establishing the optimal DC- CIK cell ratio for immunological activity and the best cytotoxic CIK: K562 cell ratio.

Expansion of mixed immune cells using CD3/CD161 co-stimulation for the treatment of cancer

Adoptive cell transfer (ACT) is a type of personalized immunotherapy in which expanded immune cells are administered to patients with cancer. However, single-cell populations, such as killer T cells, dendritic cells, natural killer (NK) cells, and NKT (NKT) cells, have been generally used, and their effectiveness remains limited. Here, we established a novel culture method via CD3/CD161 co-stimulation and successfully expanded CD3⁺/CD4⁺ helper T cells, CD3⁺/CD8⁺ cytotoxic T cells (CTLs), CD3^-/CD56⁺ NK cells, CD3⁺/CD1d⁺ NKT cells, CD3⁺/CD56⁺ NKT cells, CD3⁺/TCRγδ⁺ T cells, and CD3^-/CD11c⁺/HLA-DR⁺ dendritic cells in peripheral blood mononuclear cells from healthy donors; their respective numbers were 155.5, 1132.5, 5.7, 117.0, 659.2, 325.6, and 6.8 times higher than those before expansion. These mixed immune cells showed strong cytotoxicity against cancer cell lines Capan-1 and SW480. Moreover, both CD3⁺/CD8⁺ CTLs and CD3⁺/CD56⁺ NKT cells killed tumor cells in cell contact-dependent and -independent manners via granzyme B and interferon-γ/TNF-α, respectively. Furthermore, the cytotoxicity of the mixed cells was significantly superior to that of CTLs or NKTs alone. A bet-hedging CTL-NKT circuitry is one potential mechanism underlying this cooperative cytotoxicity. Collectively, CD3/CD161 co-stimulation may be a promising culture method to expand multiple, distinct immune cell populations for the treatment of cancer.

Immunotherapeutic approaches in Hepatocellular carcinoma: Building blocks of hope in near future

Hepatocellular carcinoma (HCC) is the most common type of primary hepatic cancer and is among the major causes of mortality due to cancer. Due to the lack of efficient conventional therapeutic options for this cancer, particularly in advanced cases, novel treatments including immunotherapy have been considered. However, despite the encouraging clinical outcomes after implementing these innovative approaches, such as oncolytic viruses (OVs), adoptive cell therapies (ACT), immune checkpoint blockades (ICBs), and cancer vaccines, several factors have restricted their therapeutic effect. The main concern is the existence of an immunosuppressive tumor microenvironment (TME). Combination of different ICBs or ICBs plus tyrosine kinase inhibitors have shown promising results in overcoming these limiting factors to some extent. Combination of programmed cell death ligand-1 (PD-L1) antibody Atezolizumab and vascular endothelial growth factor (VEGF) antibody Bevacizumab has become the standard of care in the first-line therapy for untestable HCC, approved by regulatory agencies. This paper highlighted a wide overview of the direct and indirect immunotherapeutic strategies proposed for the treatment of HCC patients and the common challenges that have hindered their further clinical applications.

MMP9-Associated Tumor Stem Cells, CCL1-Silenced Dendritic Cells, and Cytokine-Induced Killer Cells Have a Remarkable Therapeutic Efficacy for Acute Myeloid Leukemia by Activating T Cells

Purpose

Dendritic cells (DC) are specialized antigen-presenting cells, and cytokine-induced killer (CIK) cells have a specific killing activity to a variety of tumors. However, the underlining mechanism and function of DC-CIK cells in acute myeloid leukemia (AML) remain largely elusive.

Methods

Gene expression profiles of leukemia patients were obtained from TCGA, DC cell components were evaluated using the quanTIseq method, and cancer stem cell scores were estimated using machine learning methods. The transcriptomes were obtained in DC-CIK cells from normal and AML patients by high-throughput sequencing. Large differentially expressed mRNAs were verified by RT-qPCR assay, and MMP9 and CCL1 were selected for subsequent studies in vivo and in vitro experiments.

Results

Significant positive correlations were found with DC versus cancer stem cells (p = 0.008) and the expression of MMP9 versus cancer stem cells (p = 0.018). MMP9 and CCL1 were found to be highly expressed in DC-CIK cells from AML patients. DC-CIK cells with MMP9 and CCL1 knockout alone had little effect on leukemia cells, while knockdown of MMP9 and CCL1 in DC-CIK cells increased cytotoxicity, suppressed proliferation, and induced apoptosis of leukemia cells. In addition, we proved that MMP9- and CCL1-silenced DC-CIK cells significantly elevated the CD³⁺CD⁴⁺ and CD³⁺CD⁸⁺ cells and lowered the CD4⁺PD-1⁺ and CD8⁺PD-1⁺ T cells. Meanwhile, blockage of MMP9 and CCL1 in DC-CIK cells dramatically increased IL-2 and IFN-γ, increased CD107aþ (LAMP-1) and granzyme B (GZMB), and downregulated PD-1, CTLA4, TIM3, and LAG3 T cells from AML patients and AML model mice. Furthermore, activated T cells in DC-CIK cells knocking down MMP9 and CCL1 also prevented proliferation and accelerated apoptosis of AML cells.

Conclusion

Our findings demonstrated that blockage of MMP9 and CCL1 in DC-CIK cells could markedly enhance the therapeutic efficiency in AML via activating T cells.

Analysis of interactions of immune checkpoint inhibitors with antibiotics in cancer therapy

The discovery of immune checkpoint inhibitors, such as PD-1/PD-L1 and CTLA-4, has played an important role in the development of cancer immunotherapy. However, immune-related adverse events often occur because of the enhanced immune response enabled by these agents. Antibiotics are widely applied in clinical treatment, and they are inevitably used in combination with immune checkpoint inhibitors. Clinical practice has revealed that antibiotics can weaken the therapeutic response to immune checkpoint inhibitors. Studies have shown that the gut microbiota is essential for the interaction between immune checkpoint inhibitors and antibiotics, although the exact mechanisms remain unclear. This review focuses on the interactions between immune checkpoint inhibitors and antibiotics, with an in-depth discussion about the mechanisms and therapeutic potential of modulating gut microbiota, as well as other new combination strategies.

Novel IL-15 dendritic cells have a potent immunomodulatory effect in immunotherapy of multiple myeloma

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Culture DCs with GM-CSF + IL-4 + IL-15 (IL-15 DCs) can be shortened for 6 days.

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IL-15 DCs showed high expression levels of costimulatory receptors, IFN-γ and IL-12p70.

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IL-15 DCs showed strong stimulation toward T, CIK and NK cells.

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The activated lymphocytes showed high cytotoxicity against myeloma cells.

Dendritic cells (DCs) are the most potent antigen-presenting cells, and have thus been used in clinical cancer vaccines. However, the effects of DC vaccines are still limited, leading researchers to explore novel ways to make them effective. In this study, we investigated whether human monocyte-derived DCs generated via the addition of interleukin 15 (IL-15) had a higher capacity to induce antigen-specific T cells compared to conventional DCs. We isolated CD14⁺ monocytes from peripheral blood from multiple myeloma (MM) patients, and induced immature DCs with granulocyte-macrophage colony-stimulating factor (GM-CSF) and IL-4 in the presence or absence of IL-15 for 4–6 days. Then we generated mature DCs (mDCs) with lipopolysaccharide for another 2 days [IL-15 mDCs (6 days), IL-15 mDCs (8 days), and conventional mDCs (8 days)]. IL-15 mDCs (6 days) showed higher expression of MHC I and II, CD40, CD86, and CCR7, and the secretion of IFN-γ was significantly higher compared to conventional mDCs. IL-15 mDCs (6 days) showed superior polarization of naïve T cells toward Th1 cells and a higher proportion of activated T cells, cytokine-induced killer (CIK) cells, and natural killer (NK) cells for inducing strong cytotoxicity against myeloma cells, and lower proportion of regulatory T cells compared to conventional mDCs. These data imply that novel multipotent mDCs generated by the addition of IL-15, which can be cultivated in 6 days, resulted in outstanding activation of T cells, CIK cells and NK cells, and may facilitate cellular immunotherapy for cancer patients.

Retrospective analysis of the efficacy of adjuvant cytokine‐induced killer cell immunotherapy combined with chemotherapy in colorectal cancer patients after surgery

Objectives

Even though postoperative chemotherapy can eliminate residual tumor cells in patients with colorectal cancer (CRC), severe adversity, weakened immunity and drug resistance are still problems. Adjuvant cytokine‐induced killer (CIK) cell therapy is an alternative to CRC patients after surgery. The present study investigated the efficacy of adjuvant CIK cell therapy combined with chemotherapy in postoperative CRC patients.

Methods

This retrospective analysis included 137 postoperative CRC patients, including 71 who received adjuvant chemotherapy alone (control group) and 66 who received adjuvant immunotherapy based on CIK cells combined with chemotherapy (CIT group).

Results

Long‐term follow‐up study indicated that overall survival (OS) and progression‐free survival (PFS) were significantly longer in the CIT group than in the control group. Subgroup analyses showed that CIT treatment significantly improved OS and PFS of CRC patients classified as stage II and N0 stage and in patients with primary tumors in the rectum. Increasing the number of CIK infusions resulted in better prognosis. CRC patients aged < 65 years were found to benefit more from CIT‐based therapy than patients aged ≥ 65 years. A retrospective case–control study indicated that the primary tumor expression of signalling lymphocytes activating molecule family 7 (SLAMF7) was associated with increased efficacy of CIT treatment.

Conclusions

Adjuvant CIT therapy was an effective therapeutic strategy for postoperative CRC patients prolonging OS and PFS. Patient age, tumor stage and expression of SLAMF7 may be potential indicators of the efficacy of CIT therapy.

Cancer-associated fibroblasts-derived exosomes promote lung cancer progression by OIP5-AS1/ miR-142-5p/ PD-L1 axis

Cancer-associated fibroblasts (CAFs) are the most important stromal cells in the tumor microenvironment (TEM) and have been reported to regulate various cancer development. Exosomes are considered important elements involved in intercellular communication and TME regulation, while the potential function of CAFs in lung cancer immunosuppressive microenvironments remains unknown. CAFs-derived exosomes (CAFs-exo) and normal fibroblasts (NFs)-derived exosomes (NFs-exo) were isolated by ultra-centrifugation and characterized by transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA) and western blot analysis. A549 cells were co-cultured with peripheral blood mononuclear cells (PBMCs). Flow cytometry assay was performed to detect the killing role of PBMCs on A549 cells. Bioinformatics and luciferase reporter assays were used to analyze the relationship among microRNA (miRNA), long non-coding RNA (lncRNA) and target gene. BALB/c mice were used to construct the lung cancer model by subcutaneous injection. Programmed death ligand 1 (PD-L1) was up-regulated in lung cancer tissues and cells. PD-L1 also up-regulated in CAFs cell medium-mediated A549 cells. CAFs decreased PBMCs induced-cell apoptosis through increasing PD-L1 in A549 cells. Moreover, CAFs transferred exosomes to lung cancer cells to suppress the killing effect of PBMCs through up-regulating PD-L1. Using microarray assays, opa-interacting protein 5 antisense RNA 1 (OIP5-AS1) level was highly expressed in CAFs-exos. After treatment by CAFs-exos, miR-142-5p level was significantly down-regulated in A549 cells. OIP5-AS1 served as a sponge to target miR-142-5p and negatively regulated miR-142-5p expression in lung cancer cells. In addition, PD-L1 was a direct target of miR-142-5p. CAFs derived exosomal OIP5-AS1 reduced PBMCs induced-cell apoptosis and promoted tumor growth through decreasing miR-142-5p and up-regulating PD-L1. CAFs-derived exosomes suppressed the role of PBMCs induced-killing of lung cancer cells and promoted lung cancer progression by OIP5-AS1/ miR-142-5p/ PD-L1 axis, which provided a potential opportunity for diagnosis and treatment of lung cancer.

The efficacy and safety of the combination of axitinib and pembrolizumab-activated autologous DC-CIK cell immunotherapy for patients with advanced renal cell carcinoma: a phase 2 study

Objectives

Although axitinib has achieved a preferable response rate for advanced renal cell carcinoma (RCC), patient survival remains unsatisfactory. In this study, we evaluated the efficacy and safety of a combination treatment of axitinib and a low dose of pembrolizumab‐activated autologous dendritic cells–co‐cultured cytokine‐induced killer cells in patients with advanced RCC.

Methods

All adult patients, including treatment‐naive or pretreated with VEGF‐targeted agents, were enrolled from May 2016 to March 2019. Patients received axitinib 5 mg twice daily and pembrolizumab‐activated dendritic cells–co‐cultured cytokine‐induced killer cells intravenously weekly for the first four cycles, every 2 weeks for the next four cycles, and every month thereafter.

Results

The 43 patients (22 untreated and 21 previously treated) showed a median progression‐free survival (mPFS) of 14.7 months (95% CI, 11.16–18.30). mPFS in treatment‐naive patients was 18.2 months, as compared with 14.4 months in pretreated patients (log‐rank P‐value = 0.07). Overall response rates were 25.6% (95% CI, 13.5–41.2%). Grade 3 or higher adverse events occurred in 5% of patients included hypertension (11.6%) and palmar‐plantar erythrodysesthesia (7.0%). Peripheral blood lymphocyte immunophenotype and serum cytokine profile analyses demonstrated increased antitumor immunity after combination treatment particularly in patients with a long‐term survival benefit, while those with a minimal survival benefit demonstrated an elevated proportion of peripheral CD8⁺TIM3⁺ T cells and lower serum‐level immunostimulatory cytokine profile.

Conclusions

The combination therapy was active and well tolerated for treatment of advanced RCC, either as first‐ or second‐line treatment following other targeted agents. Changes in immunophenotype and serum cytokine profile may be used as prognostic biomarkers.

Overview of New Treatments with Immunotherapy for Breast Cancer and a Proposal of a Combination Therapy

According to data from the U.S. National Cancer Institute, cancer is one of the leading causes of death worldwide with approximately 14 million new cases and 8.2 million cancer-related deaths in 2018. More than 60% of the new annual cases in the world occur in Africa, Asia, Central America, and South America, with 70% of cancer deaths in these regions. Breast cancer is the most common cancer in women, with 266,120 new cases in American women and an estimated 40,920 deaths for 2018. Approximately one in six women diagnosed with breast cancer will die in the coming years. Recently, novel therapeutic strategies have been implemented in the fight against breast cancer, including molecules able to block signaling pathways, an inhibitor of poly [ADP-ribose] polymerase (PARP), growth receptor blocker antibodies, or those that reactivate the immune system by inhibiting the activities of inhibitory receptors like cytotoxic T-lymphocyte antigen 4 (CTLA-4) and programmed death protein 1 (PD-1). However, novel targets include reactivating the Th1 immune response, changing tumor microenvironment, and co-activation of other components of the immune response such as natural killer cells and CD8+ T cells among others. In this article, we review advances in the treatment of breast cancer focused essentially on immunomodulatory drugs in targeted cancer therapy. Based on this knowledge, we formulate a proposal for the implementation of combined therapy using an extracorporeal immune response reactivation model and cytokines plus modulating antibodies for co-activation of the Th1- and natural killer cell (NK)-dependent immune response, either in situ or through autologous cell therapy. The implementation of "combination immunotherapy" is new hope in breast cancer treatment. Therefore, we consider the coordinated activation of each cell of the immune response that would probably produce better outcomes. Although more research is required, the results recently achieved by combination therapy suggest that for most, if not all, cancer patients, this tailored therapy may become a realistic approach in the near future.

Increase of Antitumoral Effects of Cytokine-Induced Killer Cells by Antibody-Mediated Inhibition of MICA Shedding

Natural killer group 2D (NKG2D) receptor plays a pivotal role in cytokine-induced killer (CIK) cell-mediated cytotoxicity against malignancies, and the expression of NKG2D ligands might allow targets to be more susceptible to the CIK cell-mediated destruction. In this study, we investigated the synergistic effects of CIK cells antitumor activity and antibody-mediated inhibition of MICA/B shedding. This monoclonal antibody (7C6) has been previously shown to be able to specifically target MICA/B a3 domain on tumor cells, resulting in the increase in cell surface MICA/B expression by inhibition of their shedding. In the current study, we show that 7C6 antibody could substantially inhibit MICA shedding and stabilize the expression of MICA/B on Hela cells and MDA-MB-231 cells. In combination with 7C6, CIK cells showed higher degranulation rate, more IFN-γ production and elevated cytotoxic capacity against tumor cells. Furthermore, we demonstrate that NKG2D-MICA/B ligation could lead to activation of both CD3+ CD56− T cells and CD3+CD56+ NKT subset cells of CIK culture and NKT subset was more sensitive to NKG2D signaling than the counterpart T cells. 7C6-mediated inhibition of MICA shedding could strengthen this signal and eventually enhance the antitumor activity of CIK cells. With multiple advantages of easy ex vivo expansion, minor GVHD, natural tumor trafficking and non-MHC restricted, CIK cell-based therapy may serve as a potent combination partner with MICA antibody-mediated immunotherapy.

Autologous Cytokine-Induced Killer Cell Immunotherapy for Patients with High-Risk Diffuse Large B Cell Lymphoma After the First Complete Remission

Purpose

To evaluate whether autologous cytokine-induced killer (CIK) cell immunotherapy improves the prognosis of patients with high-risk diffuse large B cell lymphoma (DLBCL) after the first complete remission (CR).

Patients and Methods

Peripheral blood mononuclear cells (PBMCs) were extracted from 20 patients with high-risk DLBCL (IPI≥3) after the first CR. Twenty CR patients who were age- and sex-matched during the same period were selected as controls. PBMCs were cultured with IFN-γ, IL-2 and anti-CD3 mAb to generate CIK cells. These obtained cells were then transfused back into the patients; the transfusion was repeated every 3 months up to a total of four courses. Changes in peripheral blood lymphocyte subgroups and survival were assessed.

Results

Compared with the baseline proportions, the proportion of CD3⁺ T cells, CD3⁺CD8⁺ T cells, and NK cells in the peripheral blood were significantly higher after transfusions (p<0.05). The 5-year DFS was improved from 45.0 ± 11.1% to 79.3 ± 9.2% in the CIK group (HR favoring CIK, 0.29; 95% CI, 0.09 to 0.92; p = 0.035), and the 5-year OS was estimated at 90 ± 6.7% for CIK versus 55 ± 11.1% for control (HR favoring CIK, 0.20; 95% CI, 0.04 to 0.93; p = 0.040). No severe side effects were observed related to CIK treatment.

Conclusion

Autologous CIK cell immunotherapy has emerged as a safe and efficacious option to improve the prognosis of patients with high-risk DLBCL after the first CR.

Efficacy of adjuvant cytokine-induced killer cell immunotherapy in patients with colorectal cancer after radical resection

Adjuvant chemotherapy after surgery is the standard treatment modality for stage III and part of stage II or stage IV colorectal cancer (CRC) patients. However, the 5-year overall survival (OS) rate remains unsatisfactory. Thus, developing combination therapies is essential to improve the prognosis of patients with CRC. The present study aimed to determine the effect of a sequential combination of cytokine-induced killer cell (CIK) infusion and chemotherapy for patients with CRC. 122 patients with CRC treated with postoperative adjuvant chemotherapy were retrospectively included in this study. Among them, 62 patients received adjuvant chemotherapy only (control group), while the other 60 patients, with similar demographic and clinical characteristics, received adjuvant chemotherapy and sequential CIK cell immunotherapy (CIK group). Survival analysis showed significantly improved disease free survival (DFS) and OS rates in the CIK group compared with the control group (log-rank test, P = .0024; P = .008, respectively). Univariate and multivariate analyses indicated that sequential CIK cell treatment was an independent prognostic factor for patients’ DFS and OS. Subgroup analyses showed that sequential CIK cell treatment significantly improved the DFS and OS of patients with high-risk T4 stage and insufficient chemotherapy duration. In conclusion, these data indicate that sequential adjuvant CIK cell treatment combined with chemotherapy is an effective therapeutic strategy to prevent disease recurrence and prolong survival of patients with CRC, particularly for patients with high-risk T4 stage and insufficient chemotherapy duration.

Retrospective analysis of the efficacy of cytokine-induced killer cell immunotherapy combined with first-line chemotherapy in patients with metastatic colorectal cancer

Objectives

Fluoropyrimidine‐based chemotherapy regimens are the current first‐line treatment for metastatic colorectal cancer (mCRC); however, the outcome is often unsatisfactory. The present study aimed to determine the effect of combined cytokine‐induced killer (CIK) cell immunotherapy and first‐line chemotherapy in patients with mCRC.

Methods

This retrospective study included 252 patients with mCRC treated with first‐line chemotherapy. Among them, 126 patients received first‐line chemotherapy only (control group), while the other 126 patients, with similar demographic and clinical characteristics, received CIK cell immunotherapy combined with first‐line chemotherapy (CIK group). Overall survival (OS) and progression‐free survival (PFS) were compared between the two groups using the Kaplan–Meier method.

Results

The median OS for the CIK group was 54.7 versus 24.1 months for the controls, and the median PFS for the CIK group was 25.7 versus 14.6 months for the controls. Univariate and multivariate analyses indicated that CIK cell treatment was an independent prognostic factor for patients' OS and PFS. Subgroup analyses showed that CIK cell treatment significantly improved the OS and PFS of patients with metastatic colon cancer, but not those with metastatic rectal cancer. Additionally, the change in CD3⁺CD56⁺ subsets after the fourth treatment cycle might be an indicator of successful CIK cell treatment: Patients with increased CD3⁺CD56⁺ subsets had better survival than those with decreased CD3⁺CD56⁺ subsets.

Conclusion

Cytokine‐induced killer cell immunotherapy combined with first‐line chemotherapy could significantly improve the OS and PFS of patients with mCRC, particularly for patients with metastatic colon cancer.

CIK cell cytotoxicity is a predictive biomarker for CIK cell immunotherapy in postoperative patients with hepatocellular carcinoma

Adjuvant cytokine-induced killer (CIK) cell immunotherapy has shown potential in improving the prognosis of hepatocellular carcinoma (HCC) patients after curative resection. However, whether an individual could obtain survival benefit from CIK cell treatment remains unknown. In the present study, we focused on the characteristics of CIK cells and aimed to identify the best predictive biomarker for adjuvant CIK cell treatment in patients with HCC after surgery. This study included 48 patients with HCC treated with postoperative adjuvant CIK cell immunotherapy. The phenotype activity and cytotoxic activity of CIK cells were determined by flow cytometry and xCELLigence™ Real-Time Cell Analysis (RTCA) system, respectively. Correlation analysis revealed that the cytotoxic activity of CIK cells was significantly negative correlated with the percentage of CD3+ CD4+ cell subsets, but significantly positive correlated with CD3-CD56+ and CD3+ CD56+ cell subsets. Survival analysis showed that there were no significant associations between patients' prognosis and the phenotype of CIK cells. By contrast, there was statistically significant improvement in recurrence-free survival (RFS) and overall survival (OS) for patients with high cytotoxic activity of CIK cells as compared with those with low cytotoxic activity of CIK cells. Univariate and multivariate analyses indicated that CIK cell cytotoxicity was an independent prognostic factor for RFS and OS. In conclusion, a high cytotoxic activity of CIK cells can serve as a valuable biomarker for adjuvant CIK cell immunotherapy of HCC patients after surgery.

The Synergistic Use of IL-15 and IL-21 for the Generation of NK Cells From CD3/CD19-Depleted Grafts Improves Their ex vivo Expansion and Cytotoxic Potential Against Neuroblastoma: Perspective for Optimized Immunotherapy Post Haploidentical Stem Cell Transplantation

Neuroblastoma (NB) is the most common solid extracranial tumor in childhood. Despite therapeutic progress, prognosis in high-risk NB is poor and innovative therapies are urgently needed. Therefore, we addressed the potential cytotoxic capacity of interleukin (IL)-activated natural killer (NK) cells compared to cytokine-induced killer (CIK) cells for the treatment of NB. NK cells were isolated from peripheral blood mononuclear cells (PBMCs) by indirect CD56-enrichment or CD3/CD19-depletion and expanded with different cytokine combinations, such as IL-2, IL-15, and/or IL-21 under feeder-cell free conditions. CIK cells were generated from PBMCs by ex vivo stimulation with interferon-γ, IL-2, OKT-3, and IL-15. Comparative analysis of expansion rate, purity, phenotype and cytotoxicity was performed. CD56-enriched NK cells showed a median expansion rate of 4.3-fold with up to 99% NK cell content. The cell product after CD3/CD19-depletion consisted of a median 43.5% NK cells that expanded significantly faster reaching also 99% of NK cell purity. After 10–12 days of expansion, both NK cell preparations showed a significantly higher median cytotoxic capacity against NB cells relative to CIK cells. Remarkably, these NK cells were also capable of efficiently killing NB spheroidal 3D culture in long-term cytotoxicity assays. Further optimization using a novel NK cell culture medium and a prolonged culturing procedure after CD3/CD19-depletion for up to 15 days enhanced the expansion rate up to 24.4-fold by maintaining the cytotoxic potential. Addition of an IL-21 boost prior to harvesting significantly increased the cytotoxicity. The final cell product consisted for the major part of CD16⁻, NCR-expressing, poly-functional NK cells with regard to cytokine production, CD107a degranulation and antitumor capacity. In summary, our study revealed that NK cells have a significantly higher cytotoxic potential to combat NB than CIK cell products, especially following the synergistic use of IL-15 and IL-21 for NK cell activation. Therefore, the use of IL-15+IL-21 expanded NK cells generated from CD3/CD19-depleted apheresis products seems to be highly promising as an immunotherapy in combination with haploidentical stem cell transplantation (SCT) for high-risk NB patients.

Enhanced metabolic activities for ATP production and elevated metabolic flux via pentose phosphate pathway contribute for better CIK cells expansion

Objective

Ex vivo expansion is an effective way to produce cytokine‐induced killer (CIK) cells needed for clinical trials. Here, ex vivo expansion and metabolism characters of CIK cells in static and dynamic cultures and the relationship between cell expansion and metabolism were investigated.

Materials and methods

Oxygen transfer efficiency was assessed by computational fluid dynamics technique. Cell phenotype, apoptosis and of transporter expression were determined by flow cytometry and Western blotting. Metabolites and enzyme activities were assessed by biochemical methods.

Results

Dynamic cultures favoured better CIK cell expansion without impairing their phenotype and cytotoxicity, enhanced oxygen transfer efficiency. The glucose metabolism flux of cells in dynamic cultures was enhanced by upregulating surface glucose transporter 1 expression and phosphofructokinase activity. Moreover, pentose phosphate pathway (PPP) metabolic flux was enhanced through upregulating glucose‐6‐phosphate dehydrogenase activity. Glutaminolysis was also accelerated via boosting glutamine transporters expression, glutaminase (GLS) and glutamate dehydrogenase activities. Together with higher oxygen consumption rate and extracellular acidification rate, it was suggested that cells in dynamic cultures were in a more vigorous metabolic state for ATP production.

Conclusion

Dynamic cultures accelerated glucose and glutamine metabolic flux to promote ATP production, elevated glucose metabolic flux through PPP to promote biosynthesis for better cell expansion. These findings may provide the basis for ex vivo CIK cell expansion process optimization.

High-affinity T cell receptors redirect cytokine-activated T cells (CAT) to kill cancer cells

Cytokine-activated T cells (CATs) can be easily expanded and are widely applied to cancer immunotherapy. However, the good efficacy of CATs is rarely reported in clinical applications because CATs have no or very low antigen specificity. The low-efficacy problem can be resolved using T cell antigen receptor-engineered CAT (TCR-CAT). Herein, we demonstrate that NY-ESO-1_157-165 HLA-A*02:01-specific high-affinity TCR (HAT)-transduced CATs can specifically kill cancer cells with good efficacy. With low micromolar range dissociation equilibrium constants, HAT-transduced CATs showed good specificity with no off-target killing. Furthermore, the high-affinity TCR-CATs delivered significantly better activation and cytotoxicity than the equivalent TCR-engineered T cells (TCR-Ts) in terms of interferon-γ and granzyme B production and in vitro cancer cell killing ability. TCR-CAT may be a very good alternative to the expensive TCR-T, which is considered an effective personalized cyto-immunotherapy.

Recombinant Adenovirus KGHV500 and CIK Cells Codeliver Anti-p21-Ras scFv for the Treatment of Gastric Cancer with Wild-Type Ras Overexpression

The development of gastric cancer is frequently related to the overexpression of wild-type p21 proteins, but it is rarely related to mutated Ras proteins. We previously constructed a broad-spectrum anti-p21-Ras single-chain variable fragment antibody (scFv), which was carried by the oncolytic adenovirus KGHV500. Here we explored the antitumor effects of this recombinant oncolytic adenovirus carried by cytokine-induced killer (CIK) cells on human gastric SGC7901 cells that overexpress wild-type Ras. The MTT assay, scratch test, Transwell assay, and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay were performed in vitro to investigate the proliferation, migration, invasiveness, and cell apoptosis rate, respectively, of the human gastric cell line SGC7901 treated with KGHV500 adenovirus. Then, the tumor-targeting ability and systemic safety of KGHV500 adenovirus delivered by CIK cells were explored in vivo. We found that KGHV500 adenovirus could significantly inhibit proliferation, migration, and invasiveness and promote cell apoptosis in SGC7901 cells in vitro. In vivo studies showed that CIK cells could successfully deliver KGHV500 adenovirus to the tumor site; the two vectors synergistically killed tumor cells, and the treatment was relatively safe for normal tissues. In conclusion, this therapeutic strategy of recombinant adenovirus KGHV500 delivered by CIK cells offers a positive prospect for the targeted therapy of Ras-related cancers.

Dynamic suspension culture improves ex vivo expansion of cytokine-induced killer cells by upregulating cell activation and glucose consumption rate

Ex vivo expansion is an effective strategy to acquire cytokine-induced killer (CIK) cells needed for clinical trials. In this work, the effects of dynamic suspension culture, which was carried out by shake flasks on a shaker, on CIK cells were investigated by the analysis of expansion characteristics and physiological functions, with the objective to optimize the culture conditions for ex vivo expansion of CIK cells. The results showed that the expansion folds of total cells in dynamic cultures reached 69.36 ± 30.36 folds on day 14, which were significantly higher than those in static cultures (9.24 ± 1.12 folds, P < 0.05), however, the proportions of CD3⁺ cells and CD3⁺CD56⁺ cells in both cultures were similar, leading to much higher expansion of CD3⁺ cells and CD3⁺CD56⁺ cells in dynamic cultures. Additionally, expanded CIK cells in two cultures possessed comparable physiological functions. Notably, significantly higher percentages of CD25⁺ cells and CD69⁺ cells were found in dynamic cultures (P <  0.05). Besides, much higher glucose consumption rate of cells (P <  0.05) but similar Y_Lac/gluc were observed in dynamic cultures. Further, cells in dynamic cultures had better glucose utilization efficiency. Together, these results suggested that dynamic cultures improved cell activation, then accelerated glucose consumption rate, which enhanced cell expansion and promoted glucose utilization efficiency of cells.

Efficiency of Cytokine-Induced Killer Cells in Combination with Chemotherapy for Triple-Negative Breast Cancer

Purpose

The treatment of triple-negative breast cancer (TNBC) remains challenging, due to the absence of estrogen, progesterone, and human epidermal growth factor receptors. This study was designed to evaluate the efficiency and safety of cytokine-induced killer (CIK) cell immunotherapy, following regular chemotherapy, for patients with TNBC.

Methods

A total of 340 patients with postmastectomy TNBC, from January 1, 2010 to June 30, 2014, were included in this retrospective study. Seventy-seven patients received CIK cell immunotherapy, following regular chemotherapy (arm 1), and 263 patients received regular chemotherapy alone (arm 2). The primary aim was overall survival (OS) and disease-free survival (DFS), and the treatment responses and adverse events were also evaluated.

Results

The 5-year DFS and OS rates in arm 1 were 77.9% and 94.3%, compared with 69.8% and 85.6% in arm 2, respectively (p=0.159 and p=0.035, respectively). This clearly shows that there was no statistical difference in the 5-year DFS between the two groups. Multivariate analyses of arm 1 indicated that a Karnofsky performance score (KPS) ≥90 and stage I/IIA disease were significantly associated with a prolonged DFS period (hazard ratio [HR], 0.25; 95% confidence interval [CI], 0.09–0.74; p=0.012; and HR 0.21; 95% CI, 0.06–0.82; p=0.024, respectively), but a KPS ≥90 and stage I/IIA disease were not independent prognostic factors for OS. Toxicity was mild in patients who received the CIK therapy.

Conclusion

The data suggested that CIK cell immunotherapy improved the efficiency of regular chemotherapy in patients with TNBC, and the side effects of CIK cell immunotherapy were mild.

Autologous cytokine-induced killer cell immunotherapy may improve overall survival in advanced malignant melanoma patients

AIMS

Our study was conducted to explore the efficacy of autologous cytokine-induced killer (CIK) cells in patients with advanced malignant melanoma. Materials & Methods: Here we reviewed 113 stage IV malignant melanoma patients among which 68 patients received CIK cell immunotherapy alone, while 45 patients accepted CIK cell therapy combined with chemotherapy. Results: We found that the median survival time in CIK cell group was longer than the combined therapy group (21 vs 15 months, p = 0.07). In addition, serum hemoglobin level as well as monocyte proportion and lymphocyte count were associated with patients' survival time.

CONCLUSIONS

These indicated that CIK cell immunotherapy might extend survival time in advanced malignant melanoma patients. Furthermore, serum hemoglobin level, monocyte proportion and lymphocyte count could be prognostic indicators for melanoma.

Immunotherapy for Hepatocellular Carcinoma: Current Advances and Future Expectations

Primary liver cancer is a common kind of digestive cancers with high malignancy, causing 745,500 deaths each year. Hepatocellular carcinoma is the major pathological type of primary liver cancer. Traditional treatment methods for patients with hepatocellular carcinoma have shown poor efficacy in killing residual cancer cells for a long time. In recent years, tumor immunotherapy has emerged as a promising method owing to its safety and efficacy with respect to delaying the progression of advanced tumors and protecting postoperative patients against tumor relapse and metastasis. Immune tolerance and suppression in tumor microenvironments are the theoretical basis of immunotherapy. Adoptive cell therapy functions by stimulating and cultivating autologous lymphocytes ex vivo and then reinfusing them into the patient to kill cancer cells. Cancer vaccination is performed using antigenic substances to activate tumor-specific immune responses. Immune checkpoint inhibitors can reactivate tumor-specific T cells and develop an antitumor effect by suppressing checkpoint-mediated signaling. Oncolytic viruses may selectively replicate in tumor cells and cause lysis without harming normal tissues. Here, we briefly introduce the mechanism of immunosuppression in hepatocellular carcinoma and summarize the rationale of the four major immunotherapeutic approaches with their current advances.