Innovative Clinical Perspectives for CIK Cells in Cancer Patients

Patterns and prognostic values of programmed cell death-ligand 1 expression and CD8 + T-cell infiltration in small cell carcinoma of the esophagus: a retrospective analysis of 34 years of National Cancer Center data in China

BACKGROUND

Small cell carcinoma of the esophagus (SCCE) is an extremely rare and highly aggressive neuroendocrine malignancy with a strikingly poor prognosis. Given the great clinical successes of checkpoint immunotherapies, we explored the expression profile and clinical significance of programmed cell death-ligand 1 (PD-L1) and CD8 + T cell in SCCE for the first time.

MATERIALS AND METHODS

Tumor-infiltrating immune cells (TIICs) and tumor cells in postoperative, whole tumor sections from 147 SCCE patients were stained for PD-LI expression. We also evaluated each patient's Combined Positive Score (CPS). Multiplex immunofluorescence staining (CD3, CD20, CD68, and PD-L1) was introduced to clarify the location of PD-L1. CD8 density was analyzed by digital imaging and analysis of entire slides. Clinical outcomes were tested for correlations with both PD-L1 expression and CD8 density.

RESULTS

No patients had PD-L1 expressed in their tumor cells. PD-L1 + expression in TIICs was detected in 65 patients (44.2%) and 42 (28.6%) exhibited CPS positivity. Multiplex immunofluorescence staining demonstrated that most of the PD-L1 was expressed on the CD68 + monocytes/macrophages. PD-L1 expression in the TIICs and CPS was found to be correlated with paraffin block age, tumor length, macroscopic type, T stage, and increased overall survival (OS). Expression of PD-L1 in TIICs showed significantly prolonged relapse-free survival (RFS). Increasing CD8 densities were associated with increased PD-L1 expression ( Ptrend <0.0001). Multivariate regression confirmed that PD-L1 in TIICs and CD8 states were independent predictors of OS, and CD8 status were found to be independently predictive of RFS. A stratification based on PD-L1 and CD8 status was also significantly associated with both OS and RFS.

CONCLUSION

Expression of PD-L1 was only detected in TIICs from approximately half of the patients with SCCEs. In SCCEs, PD-L1 and CD8 status are novel prognostic biomarkers and may inform the implementation of risk-related therapeutic strategies. SCCEs with higher CD8 infiltration also had higher expression of PD-L1, suggesting the development of resistance against adaptive immunity. These findings support the assertion that PD-L1/programmed cell death 1 inhibitors should be investigated in this rare malignancy.

The Therapeutic Potential of Cytokine-Induced Killer in Patients with Cancer

Despite the promising results of immunotherapy, further experiments need to be considered because of several factors ranging from physical barriers to off-tumor adverse effects. It is surprising that adoptive cellular immunotherapy, particularly dendritic cell and cytokine-induced killer (DC-CIK) therapy, is far less emphasized in the treatment of cancer diseases. DC-CIK therapy in cancer patients presents auspicious results with low or no side effects, which should not be overlooked. More interestingly, almost all DC-CIK clinical trials are ongoing in China that highlight the limitations of therapeutic strategies and require large-scale research. To date, it is advisable to consider combination therapy with chemotherapy since it has shown promising outcomes with higher efficacy. In this article, the efficacy of DC-CIK therapy in patients with cancer is summarized by underscoring the lack of experiments on soft cancers on an unprecedented scale. In brief, DC-CIK therapy is a safe and effective therapeutic agent for malignant and nonmalignant diseases that enhances short-term and long-term effects.

The Progress and Prospects of Immune Cell Therapy for the Treatment of Cancer

Immune cell therapy as a revolutionary treatment modality, significantly transformed cancer care. It is a specialized form of immunotherapy that utilizes living immune cells as therapeutic reagents for the treatment of cancer. Unlike traditional drugs, cell therapies are considered "living drugs," and these products are currently customized and require advanced manufacturing techniques. Although chimeric antigen receptor (CAR)-T cell therapies have received tremendous attention in the industry regarding the treatment of hematologic malignancies, their effectiveness in treating solid tumors is often restricted, leading to the emergence of alternative immune cell therapies. Tumor-infiltrating lymphocytes (TIL) cell therapy, cytokine-induced killer (CIK) cell therapy, dendritic cell (DC) vaccines, and DC/CIK cell therapy are designed to use the body's natural defense mechanisms to target and eliminate cancer cells, and usually have fewer side effects or risks. On the other hand, cell therapies, such as chimeric antigen receptor-T (CAR-T) cell, T cell receptor (TCR)-T, chimeric antigen receptor-natural killer (CAR-NK), or CAR-macrophages (CAR-M) typically utilize either autologous stem cells, allogeneic or xenogeneic cells, or genetically modified cells, which require higher levels of manipulation and are considered high risk. These high-risk cell therapies typically hold special characteristics in tumor targeting and signal transduction, triggering new anti-tumor immune responses. Recently, significant advances have been achieved in both basic and clinical researches on anti-tumor mechanisms, cell therapy product designs, and technological innovations. With swift technological integration and a high innovation landscape, key future development directions have emerged. To meet the demands of cell therapy technological advancements in treating cancer, we comprehensively and systematically investigate the technological innovation and clinical progress of immune cell therapies in this study. Based on the therapeutic mechanisms and methodological features of immune cell therapies, we analyzed the main technical advantages and clinical transformation risks associated with these therapies. We also analyzed and forecasted the application prospects, providing references for relevant enterprises with the necessary information to make informed decisions regarding their R&D direction selection.

Advances of cell therapy in lung cancer: a narrative review

Background and Objective

Lung cancer is the second most prevalent malignancy and has the highest death rate. The main approaches for lung cancer treatment include surgery, chemotherapy, radiotherapy, targeted therapy, and immunotherapy. However, the treatments of the disease need to be further improved. An increasing number of scientific investigations indicated cell therapy to be a successful new treatment for lung cancer. Cell therapy can improve the host's immunity to disease and can compensate for the shortcomings in the therapeutic effects of traditional treatments, particularly in the case of cancer treatment. However, due to its recent development, its clinical efficacy still needs to be further examined. In order to provide an updated source on cell therapy for lung cancer, this paper summarizes the clinical use of chimeric antigen receptor T cells (CAR-Ts), stem cells, cytokine-induced killer cells (CIKs), and tumor-infiltrating lymphocytes (TILs) and discusses recent clinical advancements.

Methods

We performed a search of the PubMed database on March 28, 2023, and again on June 10, 2023. A review of retrieved literature related to cell therapy and treatments for lung cancer was completed.

Key Content and Findings

Cell therapy has been applied in clinical studies on the treatment of disorders of the hematologic system, digestive system, respiratory system, and other systems. CAR-T therapy has been successfully used in the treatment of B-cell malignancies, which suggests that cell therapy has broad prospects in the treatment of malignant tumors. CAR-T, stem cells, CIKs, and TILs exert antitumor activity and can recognize and could be used to treat lung cancer.

Conclusions

Cell therapy represents a novel solution in the treatment of lung cancer. Cell therapy, when combined with traditional therapies, can compensate for the shortcomings of these methods. Further research is needed to reduce the occurrence of adverse reactions and provide a more effective approach in treating lung cancer.

Adoptive cell therapy in paediatric extracranial solid tumours: current approaches and future challenges

Immunotherapy has ignited hope to cure paediatric solid tumours that resist traditional therapies. Among the most promising methods is adoptive cell therapy (ACT). Particularly, ACT using T cells equipped with chimeric antigen receptors (CARs) has moved into the spotlight in clinical studies. However, the efficacy of ACT is challenged by ACT-intrinsic factors, like lack of activation or T cell exhaustion, as well as immune evasion strategies of paediatric solid tumours, such as their highly immunosuppressive microenvironment. Novel strategies, including ACT using innate-like lymphocytes, innovative cell engineering techniques, and ACT combination therapies, are being developed and will be crucial to overcome these challenges. Here, we discuss the main classes of ACT for the treatment of paediatric extracranial solid tumours, reflect on the available preclinical and clinical evidence supporting promising strategies, and address the challenges that ACT is still facing. Ultimately, we highlight state-of-the-art developments and opportunities for new therapeutic options, which hold great potential for improving outcomes in this challenging patient population.

The effect of serum origin on cytokines induced killer cell expansion and function

BACKGROUND

Cytokine-induced killer (CIK) cells have shown promising results in adoptive immunotherapy. However, serum may play a determining role in the large-scale expansion of these cells for clinical applications. According to Good Manufacturing Practice (GMP) guidelines to reduce the use of animal products in cell-based therapies; therefore, this study sought to investigate the impact of serum origin and the reduced serum concentration on the pattern of cell expansion and function.

METHODS

Peripheral blood mononuclear cells (PBMCs) isolated from a healthy donor were expanded based on the CIK cell expansion protocol. The cell culture medium was supplemented with three types of sera comprising fetal bovine serum (FBS), human serum (HS), or human-derived platelet lysate (hPL) at different concentrations (10%, 5%, and 2.5%). The proliferation kinetics for each group were investigated for 30 days of cell culture.

RESULTS

Cell proliferation in 10% concentration of all sera (hPL, FBS, HS) was higher than their lower concentrations. Moreover, hPL was significantly associated with higher expansion rates than FBS and HS in all three concentrations. Furthermore, cells cultured in hPL showed higher viability, cytotoxicity effect, and CIK CD markers expression.

CONCLUSION

hPL at a concentration of 10% showed the best effect on CIK cell proliferation and function.

How can Cytokine-induced killer cells overcome CAR-T cell limits

The successful treatment of patients affected by B-cell malignancies with Chimeric Antigen Receptor (CAR)-T cells represented a breakthrough in the field of adoptive cell therapy (ACT). However, CAR-T therapy is not an option for every patient, and several needs remain unmet. In particular, the production of CAR-T cells is expensive, labor-intensive and logistically challenging; additionally, the toxicities deriving from CAR-T cells infusion, such as cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS), have been documented extensively. Alternative cellular therapy products such as Cytokine-induced killer (CIK) cells have the potential to overcome some of these obstacles. CIK cells are a heterogeneous population of polyclonal CD3+CD56+ T cells with phenotypic and functional properties of NK cells. CIK cell cytotoxicity is exerted in a major histocompatibility complex (MHC)-unrestricted manner through the engagement of natural killer group 2 member D (NKG2D) molecules, against a wide range of hematological and solid tumors without the need for prior antigen exposure or priming. The foremost potential of CIK cells lies in the very limited ability to induce graft-versus-host disease (GvHD) reactions in the allogeneic setting. CIK cells are produced with a simple and extremely efficient expansion protocol, which leads to a massive expansion of effector cells and requires a lower financial commitment compared to CAR-T cells. Indeed, CAR-T manufacturing involves the engineering with expensive GMP-grade viral vectors in centralized manufacturing facilities, whereas CIK cell production is successfully performed in local academic GMP facilities, and CIK cell treatment is now licensed in many countries. Moreover, the toxicities observed for CAR-T cells are not present in CIK cell-treated patients, thus further reducing the costs associated with hospitalization and post-infusion monitoring of patients, and ultimately encouraging the delivery of cell therapies in the outpatient setting. This review aims to give an overview of the limitations of CAR-T cell therapy and outline how the use of CIK cells could overcome such drawbacks thanks to their unique features. We highlight the undeniable advantages of using CIK cells as a therapeutic product, underlying the opportunity for further research on the topic.

Murine models to study human NK cells in human solid tumors

Since the first studies, the mouse models have provided crucial support for the most important discoveries on NK cells, on their development, function, and circulation within normal and tumor tissues. Murine tumor models were initially set to study murine NK cells, then, ever more sophisticated human-in-mice models have been developed to investigate the behavior of human NK cells and minimize the interferences from the murine environment. This review presents an overview of the models that have been used along time to study NK cells, focusing on the most popular NOG and NSG models, which work as recipients for the preparation of human-in-mice tumor models, the study of transferred human NK cells, and the evaluation of various enhancers of human NK cell function, including cytokines and chimeric molecules. Finally, an overview of the next generation humanized mice is also provided along with a discussion on how traditional and innovative in-vivo and in-vitro approaches could be integrated to optimize effective pre-clinical studies.

Natural Killer T-like Cells: Immunobiology and Role in Disease

CD56+ T cells are generally recognized as a distinct population of T cells and are categorized as NKT-like cells. Although our understanding of NKT-like cells is far from satisfactory, it has been shown that aging and a number of disease situations have impacted these cells. To construct an overview of what is currently known, we reviewed the literature on human NKT-like cells. NKT-like cells are highly differentiated T cells with "CD1d-independent" antigen recognition and MHC-unrestricted cell killing. The genesis of NKT-like cells is unclear; however, it is proposed that the acquisition of innate characteristics by T cells could represent a remodeling process leading to successful aging. Additionally, it has been shown that NKT-like cells may play a significant role in several pathological conditions, making it necessary to comprehend whether these cells might function as prognostic markers. The quantification and characterization of these cells might serve as a cutting-edge indicator of individual immune health. Additionally, exploring the mechanisms that can control their killing activity in different contexts may therefore result in innovative therapeutic alternatives in a wide range of disease settings.

Efficacy of adoptively transferred allogeneic CIK cells on colorectal cancer: Augmentative antitumoral effects of GvHD

OBJECTIVE

A preclinical study was designed to evaluate the effects of adoptively transferred cytokine-induced killer (CIK) cells on colorectal adenocarcinoma.

METHODS

Forty NOG mice bearing HT-29 xenograft tumors were developed and equally divided into 2 groups of treatment and control. The mice in the treatment group received cumulatively 40-60 × 10⁶ CIK cells in four divided doses.

RESULTS

Median tumor doubling times for HT-29 xenograft tumors in the treatment and control groups were found to be 8.98 and 4.32 days; respectively. The treatment resulted in tumor growth delay (TGD) of 52.5 %. CIK cell-induced log cell kill (LCK) was found to be 0.67, which implies reduction of 78.6 % of neoplastic colorectal cells. Median length of survival in the treated mice was significantly longer than controls (57 (41-63) vs 41 (31-57) days, P < 0.001). Mice in the treatment group experienced graft-versus-host disease (GvHD) from median of day 13th after the cell therapy. LCK and TGD significantly increased after emergence of GvHD. After necropsy, tumors of the treatment group contained high levels of human-originated CD3⁺, CD4⁺ and CD8⁺ cells and showed significantly lower mitotic counts (P < 0.001) and residual tumor scores (P = 0.005) than the controls (entirely negative for the mentioned CD markers). Ninety percent of the treated mice were found to be responding.

CONCLUSIONS

Adoptive transfer of allogeneic CIK cells may be an efficient antitumoral therapy for colorectal cancer. Allogeneic CIK cell-mediated GvHD may contribute to amplification of graft-versus-tumor effects of the cellular therapy.

Therapeutic strategies for gastric cancer targeting immune cells: Future directions

Gastric cancer (GC) is a malignancy with a high incidence and mortality, and the emergence of immunotherapy has brought survival benefits to GC patients. Compared with traditional therapy, immunotherapy has the advantages of durable response, long-term survival benefits, and lower toxicity. Therefore, targeted immune cells are the most promising therapeutic strategy in the field of oncology. In this review, we introduce the role and significance of each immune cell in the tumor microenvironment of GC and summarize the current landscape of immunotherapy in GC, which includes immune checkpoint inhibitors, adoptive cell therapy (ACT), dendritic cell (DC) vaccines, reduction of M2 tumor-associated macrophages (M2 TAMs), N2 tumor-associated neutrophils (N2 TANs), myeloid-derived suppressor cells (MDSCs), effector regulatory T cells (eT_regs), and regulatory B cells (B_regs) in the tumor microenvironment and reprogram TAMs and TANs into tumor killer cells. The most widely used immunotherapy strategies are the immune checkpoint inhibitor programmed cell death 1/programmed death-ligand 1 (PD-1/PD-L1) antibody, cytotoxic T lymphocyte–associated protein 4 (CTLA-4) antibody, and chimeric antigen receptor T (CAR-T) in ACT, and these therapeutic strategies have significant anti-tumor efficacy in solid tumors and hematological tumors. Targeting other immune cells provides a new direction for the immunotherapy of GC despite the relatively weak clinical data, which have been confirmed to restore or enhance anti-tumor immune function in preclinical studies and some treatment strategies have entered the clinical trial stage, and it is expected that more and more effective immune cell–based therapeutic methods will be developed and applied.

Immunotherapy for advanced hepatocellular carcinoma: From clinical trials to real-world data and future advances

Hepatocellular carcinoma (HCC) is a leading cause of cancer-associated mortality worldwide. HCC is an inflammation-associated immunogenic cancer that frequently arises in chronically inflamed livers. Advanced HCC is managed with systemic therapies; the tyrosine kinase inhibitor (TKI) sorafenib has been used in 1^st-line setting since 2007. Immunotherapies have emerged as promising treatments across solid tumors including HCC for which immune checkpoint inhibitors (ICIs) are licensed in 1^st- and 2^nd-line treatment setting. The treatment field of advanced HCC is continuously evolving. Several clinical trials are investigating novel ICI candidates as well as new ICI regimens in combination with other therapeutic modalities including systemic agents, such as other ICIs, TKIs, and anti-angiogenics. Novel immunotherapies including adoptive cell transfer, vaccine-based approaches, and virotherapy are also being brought to the fore. Yet, despite advances, several challenges persist. Lack of real-world data on the use of immunotherapy for advanced HCC in patients outside of clinical trials constitutes a main limitation hindering the breadth of application and generalizability of data to this larger and more diverse patient cohort. Consequently, issues encountered in real-world practice include patient ineligibly for immunotherapy because of contraindications, comorbidities, or poor performance status; lack of response, efficacy, and safety data; and cost-effectiveness. Further real-world data from high-quality large prospective cohort studies of immunotherapy in patients with advanced HCC is mandated to aid evidence-based clinical decision-making. This review provides a critical and comprehensive overview of clinical trials and real-world data of immunotherapy for HCC, with a focus on ICIs, as well as novel immunotherapy strategies underway.

NK and cells with NK-like activities in cancer immunotherapy-clinical perspectives

Natural killer (NK) cells are lymphoid cells of innate immunity that take important roles in immune surveillance. NK cells are considered as a bridge between innate and adaptive immunity, and their infiltration into tumor area is related positively with prolonged patient survival. They are defined as CD16⁺ CD56⁺ CD3^- cells in clinic. NK cells promote cytolytic effects on target cells and induce their apoptosis. Loss of NK cell cytotoxic activity and reduction in the number of activating receptors are the current issues for application of such cells in cellular immunotherapy, which resulted in the diminished long-term effects. The focus of this review is to discuss about the activity of NK cells and cells with NK-like activity including natural killer T (NKT), cytokine-induced killer (CIK) and lymphokine-activated killer (LAK) cells in immunotherapy of human solid cancers.

Cytokine-induced killer cells mediated pathways in the treatment of colorectal cancer

Cytokine-induced killer (CIK) cell therapy is a type of adoptive immunotherapy that due to its high proliferation rate and anti-tumor characteristics, is being investigated to treat various solid tumors. Since advanced colorectal cancer (CRC) has high mortality and poor survival rates, and the efficacy of chemotherapy and radiotherapy is limited in treatment, the application of CIK cell therapy in CRC has been evaluated in numerous studies. This review aims to summarize the clinical studies that investigated the safety and clinical efficacy of CIK cell therapy in CRC. Therefore, 1,969 enrolled CRC patients in the clinical trials, of which 842 patients received CIK cells in combination with chemotherapy with or without dendritic cell (DC) infusions, were included in the present review. Furthermore, the signaling pathways involved in CIK cell therapy and novel methods for improving migration abilities are discussed.

Cellular immunotherapy in gastric cancer: adoptive cell therapy and dendritic cell-based vaccination

Gastric cancer (GC) is one of the most frequently diagnosed malignancies. Recent studies have highlighted cellular immunotherapy (CI) as a promising approach for treating this disease. Among the CI-based approaches, adoptive cell therapy and dendritic cell-based vaccination are commonly studied in preclinical and clinical trials. Here we review the current evidence on the potentiality of CI in treating GC, the targets for adoptive cell therapy, ongoing clinical trials, constraints and the future outlook. The results suggest that there is a need to identify novel biomarkers that predict which GC patients will most likely respond to these approaches. Also, CI plus chemotherapy or immune checkpoint inhibitors can improve the survival of patients with late-stage GC. Therefore, this approach can be promising for treating these patients.

Interferon Gamma Secretion of Adaptive and Innate Immune Cells as a Parameter to Describe Leukaemia-Derived Dendritic-Cell-Mediated Immune Responses in Acute Myeloid Leukaemia in vitro

INTRODUCTION

Myeloid leukaemic blasts can be converted into leukaemia-derived dendritic cells (DCleu), characterised by the simultaneous expression of dendritic- and leukaemia-associated antigens, which have the competence to prime and enhance (leukaemia-specific) immune responses with the whole leukaemic antigen repertoire. To display and further specify dendritic cell (DC)- and DCleu-mediated immune responses, we analysed the interferon gamma (IFNy) secretion of innate and adaptive immune cells.

METHODS

DC/DCleu were generated from leukaemic whole blood (WB) with (blast)modulatory Kit-I (granulocyte-macrophage colony-stimulating factor [GM-CSF] + Picibanil [OK-432]) and Kit-M (GM-CSF + prostaglandin E1) and were used to stimulate T cell-enriched immunoreactive cells. Initiated anti-leukaemic cytotoxicity was investigated with a cytotoxicity fluorolysis assay. Initiated IFNy secretion of T, NK, CIK, and iNKT cells was investigated with a cytokine secretion assay (CSA). IFNy positivity was additionally evaluated with an intracellular cytokine assay (ICA). Recent activation of leukaemia-specific cells was verified through addition of leukaemia-associated antigens (LAA; WT-1 and Prame).

RESULTS

We found Kit-I and Kit-M competent to generate mature DC and DCleu from leukaemic WB without induction of blast proliferation. Stimulation of immunoreactive cells with DC/DCleu regularly resulted in an increased anti-leukaemic cytotoxicity and increased IFNy secretion of T, NK, and CIK cells, pointing to the significant role of DC/DCleu in leukaemia-specific alongside anti-leukaemic reactions. Interestingly, an addition of LAA did not further increase IFNy secretion, suggesting an efficient activation of leukaemia-specific cells. Here, both the CSA and ICA yielded comparable frequencies of IFNy-positive cells. Remarkably, the anti-leukaemic cytotoxicity positively correlated with the IFNy secretion in TCD3+, TCD4+, TCD8+, and NKCD56+ cells.

CONCLUSION

Ultimately, the IFNy secretion of innate and adaptive immune cells appeared to be a suitable parameter to assess and monitor the efficacy of in vitro and potentially in vivo acute myeloid leukaemia immunotherapy. The CSA in this regard proved to be a convenient and reproducible technique to detect and phenotypically characterise IFNy-secreting cells. In respect to our studies on DC-based immunomodulation, we were able to display the potential of DC/DCleu to induce or improve leukaemia-specific and anti-leukaemic activity.

Somatic copy number alteration predicts clinical benefit of lung adenocarcinoma patients treated with cytokine-induced killer plus chemotherapy

Somatic copy number alterations (SCNA), which are widespread in cancer, can predict the efficacy of immune checkpoint inhibitors in non-small-cell lung cancer (NSCLC). However, the usefulness of SCNA for predicting the survival of patients treated with cytokine-induced killer (CIK) cells or chemotherapy (CT) is unknown. This study aimed to explore the correlation between SCNA and clinical outcome in NSCLC patients treated with CIK + CT or CT alone. We performed whole-exome sequencing on 45 NSCLC patients treated with CIK + CT, as well as 305 NSCLC patients treated with CT alone, from The Cancer Genome Atlas, which showed SCNA had a superiority in predicting the progression-free survival (PFS) over tumor mutation burden (TMB) and SCNA + TMB in NSCLC patients treated with CIK + CT, especially in lung adenocarcinoma, while SCNA could not predict the efficacy of CT alone. Additionally, we investigated the association between SCNA and immune cell infiltration by RNA sequencing and immunohistochemistry. The results revealed that SCNA was negatively associated with the expression of dendritic cells. Collectively, this study revealed a negative correlation between SCNA and response to CIK + CT and showed that SCNA is a predictive indicator in LUAD patients treated with CIK + CT.

30 years of CIK cell therapy: recapitulating the key breakthroughs and future perspective

Emerging evidence from the numerous clinical trials involving cytokine-induced killer (CIK) cell therapy suggests that its optimization in combination with other contemporary cancer therapies in a complementary manner (rather than as competition) will be a key to combat cancer.

The Dual Role of Innate Lymphoid and Natural Killer Cells in Cancer. from Phenotype to Single-Cell Transcriptomics, Functions and Clinical Uses

Simple Summary

Innate lymphoid cells (ILCs), a family of innate immune cells including natural killers (NKs), play a multitude of roles in first-line cancer control, in escape from immunity and in cancer progression. In this review, we summarize preclinical and clinical data on ILCs and NK cells concerning their phenotype, function and clinical applications in cellular therapy trials. We also describe how single-cell transcriptome sequencing has been used and forecast how it will be used to better understand ILC and NK involvement in cancer control and progression as well as their therapeutic potential.

Abstract

The role of innate lymphoid cells (ILCs), including natural killer (NK) cells, is pivotal in inflammatory modulation and cancer. Natural killer cell activity and count have been demonstrated to be regulated by the expression of activating and inhibitory receptors together with and as a consequence of different stimuli. The great majority of NK cell populations have an anti-tumor activity due to their cytotoxicity, and for this reason have been used for cellular therapies in cancer patients. On the other hand, the recently classified helper ILCs are fundamentally involved in inflammation and they can be either helpful or harmful in cancer development and progression. Tissue niche seems to play an important role in modulating ILC function and conversion, as observed at the transcriptional level. In the past, these cell populations have been classified by the presence of specific cellular receptor markers; more recently, due to the advent of single-cell RNA sequencing (scRNA-seq), it has been possible to also explore them at the transcriptomic level. In this article we review studies on ILC (and NK cell) classification, function and their involvement in cancer. We also summarize the potential application of NK cells in cancer therapy and give an overview of the most recent studies involving ILCs and NKs at scRNA-seq, focusing on cancer. Finally, we provide a resource for those who wish to start single-cell transcriptomic analysis on the context of these innate lymphoid cell populations.

The Immune Privilege of Cancer Stem Cells: A Key to Understanding Tumor Immune Escape and Therapy Failure

Cancer stem cells (CSCs) are broadly considered immature, multipotent, tumorigenic cells within the tumor mass, endowed with the ability to self-renew and escape immune control. All these features contribute to place CSCs at the pinnacle of tumor aggressiveness and (immune) therapy resistance. The immune privileged status of CSCs is induced and preserved by various mechanisms that directly affect them (e.g., the downregulation of the major histocompatibility complex class I) and indirectly are induced in the host immune cells (e.g., activation of immune suppressive cells). Therefore, deeper insights into the immuno-biology of CSCs are essential in our pursuit to find new therapeutic opportunities that eradicate cancer (stem) cells. Here, we review and discuss the ability of CSCs to evade the innate and adaptive immune system, as we offer a view of the immunotherapeutic strategies adopted to potentiate and address specific subsets of (engineered) immune cells against CSCs.

Recruitment, Infiltration, and Cytotoxicity of HLA-Independent Killer Lymphocytes in Three-Dimensional Melanoma Models

Simple Summary

Limited therapeutic results of immune checkpoint inhibitors in definite tumor settings, such as melanoma, call for alternative or complementary approaches. Among these, adoptive cell therapy (ACT) by means of HLA-independent tumor killer lymphocytes is a promising approach. We aimed at developing a pre-clinical 3D model to investigate and visualize the interaction between tumor and immune effectors in melanoma. To this aim, we employed Cytokine-Induced Killer cells (CIK) and NK-92 on patient-derived melanoma samples. By means of imaging-based methods, we measured the effector recruitment on the 3D targets, their infiltration, and cytotoxic activity. Our results and methodologies can be easily generalized to other effectors and other classes of tumors and help elucidate fundamental questions on the basic biology and kinetics of immune effector recruitment in a realistic 3D setting mimicking a solid tumor.

Abstract

Cancer adoptive cell therapy (ACT) with HLA-independent tumor killer lymphocytes is a promising approach, with intrinsic features potentially addressing crucial tumor-escape mechanisms of checkpoint inhibitors. Cytokine-induced Killer (CIK) and Natural Killer (NK) lymphocytes share similar tumor-killing mechanisms, with preclinical evidence of intense activity against multiple solid tumors and currently testing in clinical studies. To improve the effective clinical translation of such ACT approaches, several fundamental questions still need to be addressed within appropriate preclinical contexts, capable of overcoming limitations imposed by most traditional two-dimensional assays. Here, we developed a novel experimental approach to explore, dissect, and visualize the interactions of CIK and NK lymphocytes with melanoma tumors in vitro in 3D. Primary melanoma cells were assembled into small tumors that were dispersed in a 3D matrix and challenged with patient-derived CIK or the NK-92 cell line. By means of imaging-based methods, we reported, visualized, and quantitatively measured the recruitment of CIK and NK on the 3D targets, their infiltration, and cytotoxic activity. Our results support the effective tumor recruitment and tumor infiltration by CIK and NK. Such features appeared dependent on the specific geometric aspects of the environment but can be explained in terms of directional migration toward the tumor, without invoking major feedback components. Overall, our 3D platform allows us to monitor the processes of tumor recruitment, infiltration, and killing by means of live measurements, revealing important kinetic aspects of ACT with CIK and NK against melanoma.

Isolation, purification, structural characteristics, pharmacological activities, and combined action of Hedyotis diffusa polysaccharides: A review

Hedyotis diffusa polysaccharides, as the main component and an important bioactive substance of Hedyotis diffusa, are effective immunomodulators with various pharmacological activities, including antitumour, anti-inflammatory, antioxidant, anti-fatigue and immunity-enhancing activities. The total polysaccharides extracted from Hedyotis diffusa and Scutellaria barbata have great effects in treating liver cancer, gastric cancer, rectal cancer, glioma and nasopharyngeal carcinoma. Moreover, different materials and extraction methods result in differences in the structure and bioactivity of Hedyotis diffusa polysaccharides. Therefore, this paper summarizes the isolation, purification, structural characteristics, pharmacological activities, and combined action of Hedyotis diffusa polysaccharides to provide a reference for further study.

Arming Immune Cells for Battle: A Brief Journey through the Advancements of T and NK Cell Immunotherapy

Simple Summary

This review is intended to provide an overview on the history and recent advances of T cell and natural killer (NK) cell-based immunotherapy. While the thymus was discovered as the origin of T cells in the 1960s, and NK cells were first described in 1975, the clinical application of adoptive cell therapies (ACT) only began in the early 1980s with the first lymphokine activated killer (LAK) cell product for the treatment of cancer patients. Over the past decades, further immunotherapies have been developed, including ACT using cytokine-induced killer (CIK) cells, products based on the NK cell line NK-92 as well as specific T and NK cell preparations. Recent advances have successfully improved the effectiveness of T, NK, CIK or NK-92 cells towards tumor-targeting antigens generated by genetic engineering of the immune cells. Herein, we summarize the promising development of ACT over the past decades in the fight against cancer.

Abstract

The promising development of adoptive immunotherapy over the last four decades has revealed numerous therapeutic approaches in which dedicated immune cells are modified and administered to eliminate malignant cells. Starting in the early 1980s, lymphokine activated killer (LAK) cells were the first ex vivo generated NK cell-enriched products utilized for adoptive immunotherapy. Over the past decades, various immunotherapies have been developed, including cytokine-induced killer (CIK) cells, as a peripheral blood mononuclear cells (PBMCs)-based therapeutic product, the adoptive transfer of specific T and NK cell products, and the NK cell line NK-92. In addition to allogeneic NK cells, NK-92 cell products represent a possible “off-the-shelf” therapeutic concept. Recent approaches have successfully enhanced the specificity and cytotoxicity of T, NK, CIK or NK-92 cells towards tumor-specific or associated target antigens generated by genetic engineering of the immune cells, e.g., to express a chimeric antigen receptor (CAR). Here, we will look into the history and recent developments of T and NK cell-based immunotherapy.

Cellular Immunotherapy Targeting Cancer Stem Cells: Preclinical Evidence and Clinical Perspective

The term “cancer stem cells” (CSCs) commonly refers to a subset of tumor cells endowed with stemness features, potentially involved in chemo-resistance and disease relapses. CSCs may present peculiar immunogenic features influencing their homeostasis within the tumor microenvironment. The susceptibility of CSCs to recognition and targeting by the immune system is a relevant issue and matter of investigation, especially considering the multiple emerging immunotherapy strategies. Adoptive cellular immunotherapies, especially those strategies encompassing the genetic redirection with chimeric antigen receptors (CAR), hold relevant promise in several tumor settings and might in theory provide opportunities for selective elimination of CSC subsets. Initial dedicated preclinical studies are supporting the potential targeting of CSCs by cellular immunotherapies, indirect evidence from clinical studies may be derived and new studies are ongoing. Here we review the main issues related to the putative immunogenicity of CSCs, focusing on and highlighting the existing evidence and opportunities for cellular immunotherapy approaches with T and non-T antitumor lymphocytes.

Expanded activated autologous lymphocyte infusions improve outcomes of low- and intermediate-risk childhood acute myeloid leukemia with low level of minimal residual disease

The presence of minimal residual disease (MRD) is a risk factor for relapse among children with acute myeloid leukemia (AML), and eliminating MRD can usually improve survival rates. To investigate the effect of expanded activated autologous lymphocytes (EAALs) combined with chemotherapy on eliminating MRD and improving survival rates of children with AML, we retrospectively analyzed the results of 115 children with low- or intermediate-risk AML with MRD treated at the Pediatric Hematological Center, Peking University People's Hospital, between January 2010 and January 2016. The patients were assigned to the chemotherapy plus EAAL (combined therapy) group (n = 61) and chemotherapy group (n = 54). The MRD-negativity rates were 95.1% (58/61) in the combined therapy group and 63.0% (34/54) in the chemotherapy group (P < 0.0001) during consolidation treatment. The 5-year event-free survival rate was higher in the combined therapy group than in the chemotherapy group (86.3 ± 4.6% vs. 72.1 ± 6.1%, P = 0.025). No severe adverse event was observed after EAAL infusion. The present study showed that EAAL combined with chemotherapy could improve the MRD-negativity rate and event-free survival rate among children with AML with low level MRD-positive status.

ERBB2-CAR-Engineered Cytokine-Induced Killer Cells Exhibit Both CAR-Mediated and Innate Immunity Against High-Risk Rhabdomyosarcoma

High-risk rhabdomyosarcoma (RMS) occurring in childhood to young adulthood is associated with a poor prognosis; especially children above the age of 10 with advanced stage alveolar RMS still succumb to the disease within a median of 2 years. The advent of chimeric antigen receptor (CAR)-engineered T cells marked significant progress in the treatment of refractory B cell malignancies, but experience for solid tumors has proven challenging. We speculate that this is at least in part due to the poor quality of the patient's own T cells and therefore propose using CAR-modified cytokine-induced killer (CIK) cells as effector cells. CIK cells are a heterogeneous population of polyclonal T cells that acquire phenotypic and cytotoxic properties of natural killer (NK) cells through the cultivation process, becoming so-called T-NK cells. CIK cells can be genetically modified to express CARs. They are minimally alloreactive and can therefore be acquired from haploidentical first-degree relatives. Here, we explored the potential of ERBB2-CAR-modified random-donor CIK cells as a treatment for RMS in xenotolerant mice bearing disseminated high-risk RMS tumors. In otherwise untreated mice, RMS tumors engrafted 13-35 days after intravenous tumor cell injection, as shown by in vivo bioluminescence imaging, immunohistochemistry, and polymerase chain reaction for human gDNA, and mice died shortly thereafter (median/range: 62/56-66 days, n = 5). Wild-type (WT) CIK cells given at an early stage delayed and eliminated RMS engraftment in 4 of 6 (67%) mice, while ERBB2-CAR CIK cells inhibited initial tumor load in 8 of 8 (100%) mice. WT CIK cells were detectable but not as active as CAR CIK cells at distant tumor sites. CIK cell therapies during advanced RMS delayed but did not inhibit tumor progression compared to untreated controls. ERBB2-CAR CIK cell therapy also supported innate immunity as evidenced by selective accumulation of NK and T-NK cell subpopulations in disseminated RMS tumors, which was not observed for WT CIK cells. Our data underscore the power of heterogenous immune cell populations (T, NK, and T-NK cells) to control solid tumors, which can be further enhanced with CARs, suggesting ERBB2-CAR CIK cells as a potential treatment for high-risk RMS.

Cytokine-Induced Killer (CIK) Cells, In Vitro Expanded under Good Manufacturing Process (GMP) Conditions, Remain Stable over Time after Cryopreservation

Cytokine-induced killer (CIK) cells are advanced therapy medicinal products, so their production and freezing process has to be validated before their clinical use, to verify their stability as a drug formulation according to the good manufacturing practice (GMP) guidelines. We designed a stability program for our GMP-manufactured CIK cells, evaluating the viability, identity and potency of cryopreserved CIK cells at varying time periods from freezing, and compared them with fresh CIK cells. We evaluated the effects of the cryopreservation method, transportation, and the length of time of different process phases (pre-freezing, freezing and post-thawing) on the stability of CIK cells. This included a worst case for each stage. The expanded CIK cells were viable for up to 30 min from the addition of the freezing solution, when transported on dry ice within 48 h once frozen, within 60 min from thawing and from 12 months of freezing while preserving their cytotoxic effects. The reference samples, cryopreserved simultaneously in tubes and following the same method, were considered representative of the batch and useful in the case of further analysis. Data obtained from this drug stability program can inform the accurate use of CIK cells in clinical settings.

Preclinical immunotherapy with Cytokine-Induced Killer lymphocytes against epithelial ovarian cancer

Despite improvements in surgery and medical treatments, epithelial ovarian cancer (EOC) remains the most lethal gynaecological malignancy. Aim of this study is to investigate the preclinical immunotherapy activity of cytokine-induced killer lymphocytes (CIK) against epithelial ovarian cancers, focusing on platinum-resistant settings. We generated CIK ex vivo starting from human peripheral blood samples (PBMCs) collected from EOC patients. Their antitumor activity was tested in vitro and in vivo against platinum-resistant patient-derived ovarian cancer cells (pdOVCs) and a Patient Derived Xenograft (PDX), respectively. CIK were efficiently generated (48 fold median ex vivo expansion) from EOC patients; pdOVCs lines (n = 9) were successfully generated from metastatic ascites; the expression of CIK target molecules by pdOVC confirmed pre and post treatment in vitro with carboplatin. The results indicate that patient-derived CIK effectively killed autologous pdOVCs in vitro. Such intense activity was maintained against a subset of pdOVC that survived in vitro treatment with carboplatin. Moreover, CIK antitumor activity and tumor homing was confirmed in vivo within an EOC PDX model. Our preliminary data suggest that CIK are active in platinum resistant ovarian cancer models and should be therefore further investigated as a new therapeutic option in this extremely challenging setting.

Tumor Immunology and Tumor Evolution: Intertwined Histories

Cancer is a complex disease whose outcome depends largely on the cross-talk between the tumor and its microenvironment. Here, we review the evolution of the field of tumor immunology and the advances, in lockstep, of our understanding of cancer as a disease. We discuss the involvement of different immune cells at distinct stages of tumor progression and how immune contexture determinants shaping tumor development are being exploited therapeutically. Current clinical stratification schemes focus on the tumor histopathology and the molecular characteristics of the tumor cell. We argue for the importance of revising these stratification systems to include immune parameters so as to address the immediate need for improved prognostic and/or predictive information to guide clinical decisions.

Dendritic Cells Therapy with Cytokine-Induced Killer Cells and Activated Cytotoxic T Cells Attenuated Th2 Bias Immune Response

THE AIM OF THIS STUDY

The purpose of this study is to investigate whether the DC cells combined with CIK cells (DC/CIK) and DC activated cytotoxic T cells (DC-ACT) treatment can promote antitumor response and change the immune indicators by targeting the heterogeneous tumor cell populations at a system level.

METHODS

In this study, 112 patients with cancer were assigned to the DC/CIK treatment and 116 patients received the DC-ACT therapy. We detected the lymphocyte subsets and other immune indicators pre- and post-treatment to evaluate the changes of patient's immunity and compare the differences in immune status between two adoptive cellular immunotherapies.

RESULTS

DC/CIK therapy elevated the percentage of CD3+ HLA-DR+ T cells, NK cells and several serological cytokines such as IL-2, IL-6 after cell infusion (p < .05). DC-ACT therapy could increase the total CD3 + T cells, CD8 + T cells, CD3+ HLA-DR+ cells and IL-12 cytokines after cell infusion (p < .05). The levels of IL-4/IFN-γ, IL-4/IL-12 and IL-6/IL-12 were reduced significantly in the DC-ACT group compared with DC/CIK group. These observations suggested that DC-ACT therapy has more dominance to induce Th1 cytokine response instead of skewing toward the Th2 cytokine profile based on the immunomodulatory properties.

CONCLUSIONS

These results indicated that DC, CIK, and DC-ACT cells exert anti-tumor activity through the different pathways. Thus, this work may provide valuable insights into the clinical curative effect evaluation of immunocyte therapy and the design of combined immunotherapeutic strategies for malignant tumors.

Radiotherapy combined with cytokine-induced killer cell therapy for liver metastasis from rectal cancer: A case report

RATIONALE

Colorectal cancer is the most common type of cancer leading to death; approximately 10% to 25% of rectal cancer patients present with synchronous colorectal liver metastases. However, the management of synchronous colorectal liver metastases is difficult, especially for patients unable to tolerate chemotherapy or surgery. To date, the optimum treatment of colorectal liver metastasis patients remains controversial, and the curative effect is unsatisfactory. Therefore, we established a novel therapeutic approach to treat colorectal liver metastases employing radiotherapy plus immunotherapy.

PATIENT CONCERNS

A 56-year-old man presented with mucous bloody defecation occurring >20 times a day and accompanied by fatigue and poor appetite. After 4 months, he was admitted to the hospital due to increased fecal blood volume.

DIAGNOSIS

Highly differentiated adenocarcinoma was diagnosed based on rectal biopsy, and abdominal computed tomography (CT) showed multiple metastatic tumors in the liver.

INTERVENTIONS

The patient underwent 1 cycle of chemotherapy, which was terminated owing to severe gastrointestinal reactions. Several days later, he was administered cytokine-induced killer (CIK) cell therapy plus adjuvant radiotherapy.

OUTCOMES

Dynamic changes in the patient's tumor markers returned to normal levels, and abdominal CT and abdominal magnetic resonance imaging (MRI) revealed no metastatic liver tumors.

LESSONS

Sequent therapy provided a curative effect for liver metastasis in a rectal cancer patient. Radiation may have activated the body to produce distant effects, eliminating the live metastasis. CIK cell-immunotherapy and radiotherapy may have synergistic therapeutic effects and could be combined for successful treatment of liver metastasis from rectal cancer.

The biological macromolecule Nocardia rubra cell-wall skeleton as an avenue for cell-based immunotherapy

Promoting the antitumor effects of cell-based immunotherapy for clinical application remains a difficult challenge. Nocardia rubra cell-wall skeleton (N-CWS) is an immunotherapeutic agent for cancers that have been proven to possess the ability to activate immune response without showing toxicity. However, its effects on immune cells that are derived from tumor patients and cultured in vitro remain unclear. As expected, N-CWS can enhance the proliferation and viability of cytokine-induced killer (CIK) cells, dendritic cells (DCs), and natural killer (NK) cells. The maturation of DCs and specific cytotoxicity against NK cells and CIK cells were consistently promoted. The TUNEL-staining and the Annexin V/propidium iodide assay revealed that after treatment with N-CWS, the stimulated CIK/NK cells could induce DNA breaks in tumor cells. Furthermore, quantitative real-time polymerase chain reaction and western blot analysis showed upregulation of proapoptotic biomarkers (caspase-3 and caspase-9) and a downregulation of the antiapoptotic biomarker Bcl-2 in the tumor cells of the N-CWS-treated group, indicating that N-CWS could induce hepatocellular carcinoma cell apoptosis via CIK/NK cells. Finally, CIK/NK cells could notably suppress the invasion and migration of tumor cells in the presence of N-CWS. Our study provides evidence that N-CWS could significantly increase the growth of CIK cells, DCs, and NK cells, particularly due to its robust antitumor activities by inducing apoptosis, and attenuate the invasion and migration of tumor cells.

Generation of donor-derived Wilms tumor antigen 1-specific cytotoxic T lymphocytes with potent anti-leukemia activity for somatic cell therapy in children given haploidentical stem cell transplantation: a feasibility pre-clinical study

BACKGROUND

The Wilms tumor antigen 1 (WT1) is over-expressed in a vast majority of adult and childhood acute leukemia and myelodysplastic syndromes, being lowly or transiently expressed in normal tissues and hematopoietic stem cells (HSCs). A number of HLA-restricted WT1 epitopes are immunogenic, allowing the in vitro induction of WT1-specific cytotoxic T lymphocytes (CTLs) from patients and healthy donors.

AIM

The aim of the study was to investigate the feasibility of producing WT1-specific CTLs suitable for somatic cell therapy to prevent or treat relapse in children with acute myeloid or lymphoblastic leukemia given haploidentical HSC transplantation (haplo-HSCT).

METHODS

For WT1-specific CTL production, donor-derived either peripheral blood mononuclear cells (PBMCs) or CD8+ lymphocytes were stimulated with WT1 peptide-loaded donor dendritic cells in the presence of interleukin (IL)-7 and IL-12. Effector cells were re-stimulated once with irradiated donor PBMCs pulsed with WT1-peptides, and then expanded in an antigen-independent way.

RESULTS

WT1-specific CTLs, displaying high-level cytotoxicity against patients' leukemia blasts and negligible activity against patients' non-malignant cells, were obtained from both PBMCs and CD8+ lymphocytes. WT1-specific CTLs obtained from PBMCs showed a better expansion capacity and better anti-leukemia activity than those obtained from CD8+ lymphocytes, even though the difference was not statistically significant. In CTLs derived from PBMCs, both CD8+ and CD4+ subpopulations displayed strong anti-leukemia cytotoxic activity.

DISCUSSION

Results of this pre-clinical study pave the way to a somatic cell therapy approach aimed at preventing or treating relapse in children given haplo-HSCT for WT1-positive leukemia.

Donor-Derived Cytokine-Induced Killer Cell Infusion as Consolidation after Nonmyeloablative Allogeneic Transplantation for Myeloid Neoplasms

Non-myeloablative conditioning, such as with total lymphoid irradiation and antithymocyte globulin (TLI-ATG), has allowed allogeneic hematopoietic cell transplantation (allo-HCT) with curative potential for older patients and those with comorbid medical conditions with myeloid neoplasms. However, early achievement of full donor chimerism (FDC) and relapse remain challenging. Cytokine-induced killer (CIK) cells have been shown to have antitumor cytotoxicity. Infusion of donor-derived CIK cells has been studied for hematologic malignancies relapsed after allo-HCT but has not been evaluated as post-transplant consolidation. In this phase II study, we prospectively studied whether a one-time infusion of 1 × 10⁸/kg CD3⁺ donor-derived CIK cells administered between day +21 and day +35 after TLI-ATG conditioning could improve achievement of FDC by day +90 and 2-year clinical outcomes in patients with myeloid neoplasms. CIK cells, containing predominantly CD3⁺CD8⁺NKG2D⁺ cells along with significantly expanded CD3⁺CD56⁺ cells, were infused in 31 of 44 patients. Study outcomes were compared to outcomes of a retrospective historical cohort of 100 patients. We found that this one-time CIK infusion did not increase the rate of FDC by day +90. On an intention-to-treat analysis, 2-year non-relapse mortality (6.8%; 95% confidence interval [CI], 0-14.5%), event-free survival (27.3%; 95% CI, 16.8-44.2%), and overall survival (50.6%; 95% CI, 37.5-68.2%) were similar to the values seen in the historical cohort. The cumulative incidence of grade II-IV acute graft-versus-host disease at 1-year was 25.1% (95% CI, 12-38.2%). On univariate analysis, the presence of monosomal or complex karyotype was adversely associated with relapse-free survival and overall survival. Given the favorable safety profile of CIK cell infusion, strategies such as repeat dosing or genetic modification merit exploration. This trial was registered at ClinicalTrials.gov (NCT01392989).

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.

Cytokine-induced killer cells co-cultured with non-cell derived targeting peptide-loaded dendritic cells induce a specific antitumor response

Cancer is a severe lethal disease. Currently, immunotherapy has become an effective alternative therapeutic approach for cancers. Cytokine-induced killer (CIK) cells have a higher proliferation rate, increased efficacy with few side-effects, and non-MHC-restricted killing after co-culturing with dendritic cells (DCs). Therefore, it has been widely studied and applied in the treatment of cancers. In our study, we explored the antitumor effects of CIK cells co-culturing with DCs pulsed with non-cell derived targeting peptides, which could specifically bind to certain tumor cells. Our results indicated that targeting peptide-loaded DCs could enhance the differentiation and cytotoxicity of CIK cells. Moreover, CIK cells, which were treated with specific targeting peptide-loaded DCs, could effectively and specifically kill tumor cells in vitro and in vivo, as long as tumor cells were pre-coated with the specific binding peptides. In conclusion, targeting peptides could guide DC-CIK to effectively and specifically kill tumor cells which were pre-coated with these targeting peptides and non-cell derived targeting peptide-loaded-DC-CIK may work as a novel means for cancer therapy.

Clinical value of neutrophil-to-lymphocyte ratio as a predictor of prognosis of RetroNectin®-activated cytokine-induced killer cell therapy in advanced non-small-cell lung cancer

AIM

To assess the impact of neutrophil-to-lymphocyte ratio (NLR) on time to progression (TTP) and overall survival (OS) and explore the value of NLR as an indicator in patients with non-small-cell lung cancer (NSCLC) treated with RetroNectin^®-activated cytokine-induced killer (R-CIK) cells.

PATIENTS & METHODS

Using data gathered from a single center between January 2010 and June 2015, 201 patients with stage IIIB or IV NSCLC receiving at least four cycles of R-CIK cell therapy were included. Univariate and multivariate Cox regression analyses were performed to evaluate the associations of NLR with TTP and OS.

RESULTS

The pretreatment NLR was correlated with TTP and OS. Multivariate analysis showed that NLR was an independent factor for survival.

CONCLUSION

NLR was an independent indicator to predict benefit from R-CIK-based combination therapy.

Programmed cell death protein-1/programmed death-ligand 1 blockade enhances the antitumor efficacy of adoptive cell therapy against non-small cell lung cancer

Background

Cytokine-induced killer (CIK) cells and natural killer (NK) cells are employed by two different approaches to adoptive cell immunotherapy for cancer. It has been reported that adoptive cell immunotherapy could prolong the overall survival (OS) of advanced cancer patients. The introduction of agents that induce immune checkpoint blockades has improved the efficacy of immune-mediated therapy for metastatic cancers. However, the effects of combining a checkpoint inhibitor with CIK cells or NK cells to target non-small cell lung cancer (NSCLC)remain unknown.

Methods

The present study investigated the effects of combining CIK cells with a programmed cell death protein-1 (PD-1) inhibitor (an anti-PD-1 monoclonal antibody). During the expansion cultivation, the addition of the PD-1 antibody promoted CIK-mediated cytotoxicity in H1975 lung adenocarcinoma cells. Co-cultivation of CIK cells with the PD-1 antibody for 6 days induced CD3⁺CD56⁺ T cell expansion, with increases in the levels of CD107a and interferon γ (IFN-γ).

Results

When NK cells were co-cultured with 5 µg/mL of an anti-programmed death-ligand 1 (PD-L1) mAb for 24 hours at an effector cell: target ratio of 10:1, it led to more potent cytotoxicity compared to other time points and concentrations. However, combining NK cells with the anti-PD-L1 mAb showed no significant advantages over treatment with NK cells alone.

Conclusions

Our results suggest that combining CIK cells with PD-1 blockade before transfusion might improve the efficiency of CIK therapy for NSCLC patients. This effect does not seem to occur for NK cell therapy.

Immunotherapy for Gastric Cancer: Time for a Personalized Approach?

Over the last decade, our understanding of the mechanisms underlying immune modulation has greatly improved, allowing for the development of multiple therapeutic approaches that are revolutionizing the treatment of cancer. Immunotherapy for gastric cancer (GC) is still in the early phases but is rapidly evolving. Recently, multi-platform molecular analyses of GC have proposed a new classification of this heterogeneous group of tumors, highlighting subset-specific features that may more reliably inform therapeutic choices, including the use of new immunotherapeutic drugs. The clinical benefit and improved survival observed in GC patients treated with immunotherapeutic strategies and their combination with conventional therapies highlighted the importance of the immune environment surrounding the tumor. A thorough investigation of the tumor microenvironment and the complex and dynamic interaction between immune cells and tumor cells is a fundamental requirement for the rational design of novel and more effective immunotherapeutic approaches. This review summarizes the pre-clinical and clinical results obtained so far with immunomodulatory and immunotherapeutic treatments for GC and discusses the novel combination strategies that are being investigated to improve the personalization and efficacy of GC immunotherapy.

Emergence of immunotherapy as a novel way to treat hepatocellular carcinoma

Tumor immunity proceeds through multiple processes, which consist of antigen presentation by antigen presenting cells (APCs) to educate effector cells and destruction by the effector cytotoxic cells. However, tumor immunity is frequently repressed at tumor sites. Malignantly transformed cells rarely survive the attack by the immune system, but cells that do survive change their phenotypes to reduce their immunogenicity. The resultant cells evade the attack by the immune system and form clinically discernible tumors. Tumor microenvironments simultaneously contain a wide variety of immune suppressive molecules and cells to dampen tumor immunity. Moreover, the liver microenvironment exhibits immune tolerance to reduce aberrant immune responses to massively-exposed antigens via the portal vein, and immune dysfunction is frequently associated with liver cirrhosis, which is widespread in hepatocellular carcinoma (HCC) patients. Immune therapy aims to reduce tumor burden, but it is also expected to prevent non-cancerous liver lesions from progressing to HCC, because HCC develops or recurs from non-cancerous liver lesions with chronic inflammatory states and/or cirrhosis and these lesions cannot be cured and/or eradicated by local and/or systemic therapies. Nevertheless, cancer immune therapy should augment specific tumor immunity by using two distinct measures: enhancing the effector cell functions such as antigen presentation capacity of APCs and tumor cell killing capacity of cytotoxic cells, and reactivating the immune system in immune-suppressive tumor microenvironments. Here, we will summarize the current status and discuss the future perspective on immune therapy for HCC.