Sensitivity of multidrug-resistant tumor cell lines to immunologic effector cells

Efficacy and Safety of Cellular Immunotherapy by Local Infusion for Liver Tumor: A Systematic Review and Meta-Analysis

Background

Cellular immunotherapy has become a new and promising treatment for patients with liver tumor. However, as most immune cells are delivered by intravenous injection, the effect is limited and is likely to produce systemic toxicity. Here, the objective was to investigate the efficacy and safety of cellular immunotherapy by local infusion, which seems to be a promising approach and has not been well-studied.

Methods

The PubMed, Web of Science, Embase, and Cochrane Library databases were searched to obtain literature. The overall response rate (ORR), overall survival (OS) rates, and adverse events were investigated to evaluate the effectiveness and safety of locoregional therapy. The methodological quality of the articles was assessed using the methodological index for non-randomized studies (MINORS) score. The meta-analysis was performed using Stata 15.0.

Results

The eligible 17 studies involved a total of 318 patients. The random-effects model demonstrated that the ORR of local cell infusion therapy was 48% (95% confidence interval [CI]: 26%–70%). The pooled OS rate was 94% (95% CI: 83%–100%) at 6 months, 87% (95% CI: 74%–96%) at 12 months, and 42% (95% CI: 16%–70%) at 24 months. Subgroup analyses suggested that minimally invasive treatment and absence of metastasis were significantly associated with better ORR. Fourteen studies reported a variety of adverse events related to cell therapy by local perfusion. The most common complications after regional infusion of immune cells were myelosuppression (66%), fever (50%), gastrointestinal toxicity (22%), hepatic dysfunction (15%), and pleural effusion and/or ascites (14%).

Conclusions

Immune cell therapy through local perfusion is effective for patients with liver cancer, with manageable toxicity. It demonstrates better prognosis when combined with minimally invasive therapy. Considering the potential limitations, more randomized controlled trials are needed to provide solid evidence for our findings.

The Characteristics of Tumor Microenvironment in Triple Negative Breast Cancer

Triple-negative breast cancer (TNBC) is a special subtype of breast cancer, accounting for 10-20% of breast cancers with high intrinsic heterogeneity. Its unique immune microenvironment, including high expression of vascular endothelial growth factors, tumor infiltrating lymphocytes (TILs), tumor-associated macrophages (TAMs), and other molecules that promote the growth and migration of tumor cells, has been shown to play a dual role in the occurrence, growth, and metastasis of TNBC. Understanding the TNBC microenvironment is of great significance for the prognosis and treatment of TNBC. In this article, we describe the composition and function of immune cells in the TNBC microenvironment and summarize the major cytokine growth factors and chemokines in the TNBC microenvironment. Finally, we discuss the progress of TNBC, cytokine-induced killer cell therapy, and immune checkpoint therapy.

Cellular immunotherapy plus chemotherapy ameliorates survival in gastric cancer patients: a meta-analysis

The efficacy of cellular immunotherapy plus chemotherapy in treatment of gastric cancer (GC) remains inconsistent even controversial. Hence, we performed a meta-analysis to better comprehend the clinical value of cellular immunotherapy plus chemotherapy for GC patients. We searched PubMed, Embase and EBSCO databases to identify the studies evaluating the association of cellular immunotherapy plus chemotherapy and overall survival (OS) and/or disease-free survival (DFS) in patients with GC, and then combined relevant data into hazard ratios (HRs) for OS, DFS and clinicopathological features such as TNM stage, etc. with STATA 12.0. Eleven studies with 1244 patients were included in this meta-analysis. We found that cellular immunotherapy plus chemotherapy remarkably improved overall survival (OS) and diseases-free survival (DFS) as compared to the chemotherapy for GC patients. In subgroup analyses, pooled data showed that the combined therapy was significantly associated with better 3-year and 5-year survival rate, but not with 1-year survival rate of patients; the application of cellular immunotherapy based on either CIK or DC-CIK cells could enhance survival as well as NK, γδT and CIK cells-based immunotherapy. More importantly, the addition of cellular immunotherapy considerably improved OS and DFS only in patients with stage III rather than stage II. In addition, we also discovered that the combined therapy did not cause intolerable side effects to patients. Cellular immunotherapy plus chemotherapy ameliorates survival in GC, especially in patients with stage III, implicating that it is a valuable therapeutic strategy for these patients.

Cytokine-induced killer cell/dendritic cell combined with cytokine-induced killer cell immunotherapy for treating advanced gastrointestinal cancer

Background

This study aimed to investigate the efficacy and safety of cytokine-induced killer (CIK)/dendritic cell combined with CIK (DC–CIK) cell therapy in advanced gastrointestinal cancer (GIC).

Methods

The PubMed, Cochrane library, and Embase were searched to conduct a meta-analysis of clinical controlled trials to evaluate the efficacy and safety of CIK/DC–CIK cell therapy in advanced GIC. The pooled risk ratios (RRs) or weighted mean difference (WMD) with 95% confidence intervals (95% CIs) were calculated.

Results

A total of nine studies with 1113 patients were identified. The overall survival (RR = 1.84, 95% CI = 1.41–2.40, P_{heterogeneity} = 0.654, I² = 0%), progression-free survival (RR = 1.99, 95% CI = 1.52–2.60, P_{heterogeneity} = 0.727, I² = 0%), and quality of life (WMD = 16.09, 95% CI = 1.66–30.52, P_{heterogeneity} < 0.001, I² = 98.8%) were significantly improved in patients who received chemotherapy combined with CIK/DC–CIK cells, and no severe adverse events were reported.

Conclusion

This meta-analysis suggested that the combination of CIK/DC–CIK immunotherapy and chemotherapy was safe and applicable for patients with advanced GIC. It is a feasible choice to prolong survival and improve quality of life.

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.

Research progress and clinical prospect of immunocytotherapy for the treatment of hepatocellular carcinoma

As a common malignant tumor, hepatocellular carcinoma (HCC) has high fatality rate due to its strong metastasis and high degree of malignancy. Current treatment strategies adopted in clinical practice were still conventional surgery, assisted with interventional therapy, radiotherapy and chemotherapy. However these treatments have limited effects with high recurrence rate. Current research progress of immunocytotherapy has shown that tumor cells can be directly identified and killed by stimulating the immune function and enhancing the anti-tumor immunity in tumor microenvironment. Targeted immunotherapeutics have therefore become the hope of conquering cancer in the future. It can kill tumor cells without damaging the body's immune system and function, restore and strengthen the body's natural anti-tumor immune system. It can reduce the toxic side effects of radiotherapy and chemotherapy, reduce the recurrence rate and prolong the survival period of patients with HCC. Currently, the immune cells widely studied are mainly as follows: Dendritic cells (DC), Cytokine-induced killer (CIK), DC-CIK, Chimeric antigen receptor T cells (CAR-T), Tumor infiltrating lymphocyte (TIL) and Natural killer cell (NK). Immunocytotherapy is a long-term treatment method, some studies have combined traditional therapy with immunocytotherapy and achieved significant effects, providing experimental basis for the application of immunocytotherapy. However, there are still some difficulties in the clinical application of immune cells. In this article, we discuss the application of immunocytotherapy in the clinical treatment of HCC, their effectiveness either alone or in combination with conventional therapies, and how future immunocytotherapeutics can be further improved from investigations in tumour immunology.

Improving Clinical Manufacturing of IL-15 Activated Cytokine-Induced Killer (CIK) Cells

Cytokine-induced killer (CIK) cells are an immunotherapeutic approach to combat relapse following allogeneic hematopoietic stem cell transplantation (HSCT) in acute leukemia or myelodysplastic syndrome (MDS) patients. Prompt and sequential administration of escalating cell doses improves the efficacy of CIK cell therapy without exacerbating graft vs. host disease (GVHD). This study addresses manufacturing-related issues and aimed to develop a time-, personal- and cost-saving good manufacturing process (GMP)-compliant protocol for the generation of ready-for-use therapeutic CIK cell doses starting from one unstimulated donor-derived peripheral blood (PB) or leukocytapheresis (LP) products. Culture medium with or without the addition of either AB serum, fresh frozen plasma (FFP) or platelet lysate (PL) was used for culture. Fresh and cryopreserved CIK cells were compared regarding expansion rate, viability, phenotype, and ability to inhibit leukemia growth. Cell numbers increased by a median factor of 10-fold in the presence of FFP, PL, or AB serum, whereas cultivation in FFP/PL-free or AB serum-free medium failed to promote adequate CIK cell proliferation (p < 0.01) needed to provide clinical doses of 1 × 10⁶ T cells/kG, 5 × 10⁶ T cells/kG, 1 × 10⁷ T cells/kG, and 1 × 10⁸ T cells/kG recipient body weight. CIK cells consisting of T cells, T- natural killer (T-NK) cells and a minor fraction of NK cells were not significantly modified by different medium supplements. Moreover, neither cytotoxic potential against leukemic THP-1 cells nor cell activation shown by CD25 expression were significantly influenced. Moreover, overnight and long-term cryopreservation had no significant effect on the composition of CIK cells, their phenotype or cytotoxic potential. A viability of almost 93% (range: 89–96) and 89.3% (range: 84–94) was obtained after freeze-thawing procedure and long-term storage, respectively, whereas viability was 96% (range: 90-97) in fresh CIK cells. Altogether, GMP-complaint CIK cell generation from an unstimulated donor-derived PB or LP products was feasible. Introducing FFP, which is easily accessible, into CIK cell cultures was time- and cost-saving without loss of viability and potency in a 10-12 day batch culture. The feasibility of cryopreservation enabled storage and delivery of sequential highly effective ready-for-use CIK cell doses and therefore reduced the number of manufacturing cycles.

Clearance of Hematologic Malignancies by Allogeneic Cytokine-Induced Killer Cell or Donor Lymphocyte Infusions

Well-established donor lymphocyte infusion (DLI) and novel cytokine-induced killer (CIK) cell therapy for the treatment of relapsing hematologic malignancies after allogeneic hematopoietic stem cell transplantation (HSCT) were compared with respect to feasibility, safety, and efficacy. Altogether, a total of 221 infusions were given to 91 patients (DLI, n = 55; CIK, n = 36). T cell recovery was significantly improved after CIK cell therapy (P < .0001). Although patients with CIK cell treatment showed a significantly worse prognosis at the time of HSCT (risk score, 1.7 versus 2.1; P < .0001), DLI and CIK cell therapy induced complete remission (CR) in 29% and 53% patients, respectively, whereas relapse occurred in 71% and 47%. In both groups, all patients with overt hematologic relapse at the time of immunotherapy (DLI, n = 11; CIK, n = 8) succumbed to their disease, while 36% and 68% patients with DLI or CIK cell therapy applied due to molecular relapse or active disease at the time of transplantation achieved CR. The 6-month overall survival rate in the latter patients was 57% and 77%, respectively, with a median follow-up of 27.9 months (range, .9 to 149.2 months). The 6-month cumulative incidence of relapse was 55% and 22% in patients who received DLI and CIK cell therapy, respectively (P = .012). Acute graft-versus-host disease developed in 35% of the patients who received DLI and in 25% of those who received CIK. No transfusion-related deaths occurred. These data, while underscoring the therapeutic value of conventional DLI, suggest the improved safety and to a certain extent efficacy of CIK cell therapy for patients at high risk for post-transplantation relapse of various hematologic malignancies.

Promising immunotherapy: Highlighting cytokine-induced killer cells

For many years, cancer therapy has appeared to be a challenging issue for researchers and physicians. By the introduction of novel methods in immunotherapy, the prospect of cancer therapy even more explained than before. Cytokine-induced killer (CIK) cell-based immunotherapy demonstrated to have potentiality in improving clinical outcomes and relieving major side effects of standard treatment options. In addition, given the distinctive features such as high safety, low toxicity effects on healthy cells, numerous clinical trials conducted on CIK cells. Due to the shortcomings that observed in CIK cell immunotherapy alone, arising a tendency to make modifications (combined modality therapy or combination therapy) including the addition of various types of cytokines, genetic engineering, combination with immune checkpoints, and so on. In this review, we have tried to bring forth the latest immunotherapy methods and their overview. We have discussed the combination therapies with CIK cells and the conducted clinical trials. This helps the future studies to use integrated therapies with CIK cells as a promising treatment of many types of cancers.

Adoptive Cell Transfer: Is it a Promising Immunotherapy for Colorectal Cancer?

The last decade has witnessed significant advances in the adoptive cell transfer (ACT) technique, which has been appreciated as one of the most promising treatments for patients with cancer. Utilization of ACT can enhance the function of the immune system or improve the specificity and persistence of transferred cells. Various immune cells including T lymphocytes, natural killer cells, dendritic cells, and even stem cells can be used in the ACT despite their different functional mechanisms. Colorectal cancer (CRC) is among the most common malignancies and causes millions of deaths worldwide every year. In this review, we discuss the status and perspective of the ACT in the treatment of CRC.

Clinical Effect of Adjuvant Cytokine-Induced Killer Cells Immunotherapy in Patients with Stage II-IVB Nasopharyngeal Carcinoma after Chemoradiotherapy: A propensity score analysis

As an adjuvant immunotherapy, cytokine-induced killer cells (CIKs) infusion has been demonstrated to exert potent effectiveness in several types of cancer patients who received curative treatment. However, controversy exists regarding whether nasopharyngeal carcinoma (NPC) patients can benefit from additional treatment after radical radiotherapy or chemoradiotherapy to improve their distant control and survival. In this retrospective study, we aimed to evaluate the efficacy of adjuvant CIK cells therapy in NPC patients with stage II-IVB after curative treatment. From January 1, 2005 to December 31, 2012, 85 pairs of NPC patients matching by propensity score matching (PSM) method to balance prognostic factors were included in this study: 85 cases underwent radical treatment, 85 cases received radical treatment and sequential CIKs infusion. We found that disease-free survival (DFS) and overall survival (OS) were significantly better in the CIK group than that in the control group (P = 0.009, P < 0.001, respectively). Adjuvant CIK cells immunotherapy was showed to be an independent prognostic factor for survival of the patients in further multivariate analysis. In subgroup analyses, the DFS and OS of patients with T3/4, III and IV A-B TNM (tumor-node-metastasis) stages were significantly enhanced in CIK group compared to control group. Nevertheless, both NPC patients with high and low EBV DNA benefited from adjuvant CIK cells immunotherapy. In conclusion, CIKs infusion is an effective adjuvant immunotherapy for enhancing the prognosis of NPC patients who have received the standard treatment, particularly for those with more aggressive tumor (T3/4) or advanced TNM stage.

Cancer Immunotherapy with Cytokine-Induced Killer Cells

Cytokine-induced killer (CIK) cells form under certain stimulation conditions in cultures of peripheral blood mononuclear cells (PBMCs). They are a heterogeneous immune cell population and contain a high percentage of cells with a mixed T-NK phenotype (CD3+CD56+). The ready availability of a lymphocyte source, together with the high proliferative rate and potent anti-tumor activity of CIK cells, has allowed their use as immunotherapy in a wide variety of neoplasms. Cytotoxicity mediated by CD3+CD56+ T cells depends on the major histocompatibility antigen (MHC)-independent recognition of tumor cells and the activation of signaling pathways through the natural killer group 2 member D (NKG2D) cell-surface receptor. Clinical trials have demonstrated the feasibility and efficacy of CIK cell immunotherapy even in advanced stage cancer patients or those that have not responded to first-line treatment. This review summarizes biological and technical aspects of CIK cells, as well as past and current clinical trials and future trends in this form of immunotherapy.

Innovative Clinical Perspectives for CIK Cells in Cancer Patients

Cytokine-induced killer (CIK) cells are T lymphocytes that have acquired, in vitro, following extensive manipulation by Interferon gamma (IFN-γ), OKT3 and Interleukin 2 (IL-2) addition, the expression of several Natural Killer (NK) cell-surface markers. CIK cells have a dual "nature", due to the presence of functional TCR as well as NK molecules, even if the antitumoral activity can be traced back only to the NK-like structures (DNAM-1, NKG2D, NKp30 and CD56). In addition to antineoplastic activity in vitro and in several in-vivo models, CIK cells show very limited, if any, GvHD toxicity as well as a strong intratumoral homing. For all such reasons, CIK cells have been proposed and tested in many clinical trials in cancer patients both in autologous and allogeneic combinations, up to haploidentical mismatching. Indeed, genetic modification of CIK cells as well as the possibility of combining them with specific monoclonal antibodies will further expand the possibility of their clinical utilization.

Correlations of ICAM-1 gene polymorphisms with susceptibility and multidrug resistance in colorectal cancer in a Chinese population

BACKGROUND

Colorectal cancer (CRC) is a malignant gastrointestinal tumor with a high mortality rate, including both colon and rectal cancer. In order to provide clinical guidance for the treatment of CRC, this study is conducted to investigate the correlations of intercellular adhesion molecule 1 (ICAM-1) gene polymorphisms with susceptibility and multidrug resistance (MDR) of colorectal cancer (CRC).

METHODS

A total of 195 patients with CRC were selected as the observation group and 188 healthy people enrolled as the control group. Polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) was used to test ICAM-1 A13848G and K469E polymorphisms. The expressions of MDR-associated protein topoisomerase II (Topo II) and P-glycoprotein (P-gp) in CRC tissues were detected by immunohistochemistry. The analysis on association of clinical indexes of CRC patients with ICAM-1 gene polymorphisms was performed.

RESULTS

The frequencies of KK genotype and K allele of K469E in the observation group were significantly higher than that in the control group. KE + EE genotype and E allele might be protective factors for CRC. The distribution of genotypes, K469E KK and KE+EE, was highly correlated with histologic grade of tumor differentiation. Compared with adjacent normal tissues, positive rates of Topo II and P-gp expression were significantly increased in CRC tissues. Topo II expression in CRC patients was positively associated with lymph node metastasis and depth of tumor invasion, whereas P-gp expression was only associated with depth of tumor invasion. Higher positive rates of Topo II and P-gp expression were observed in ICAM-1 K469E KK genotype carriers, indicating that ICAM-1 K469E KK genotype might be related to MDR in CRC.

CONCLUSION

These findings in the current study suggested that ICAM-1 K469E polymorphism is highly correlated with susceptibility and MDR in CRC.

Influence of the number and interval of treatment cycles on cytokine-induced killer cells and their adjuvant therapeutic effects in advanced non-small-cell lung cancer (NSCLC)

OBJECTIVE

Cytokine-induced killer (CIK) cells have important therapeutic effects in adoptive cell transfer (ACT) for the treatment of various malignancies. In this study, we focused on in vitro expansion of CIK cells and their clinical efficacy in combination with chemotherapy in patients with advanced non-small-cell lung cancer (NSCLC).

METHODS

A total of 64 patients with NSCLC (enrolled from 2011 to 2012), including 32 patients who received chemotherapy alone or with sequential radiotherapy (conventional treatment, control group) and 32 patients who received conventional treatment and sequential CIK infusion (study group), were retrospectively analyzed. The time to progression (TTP), overall survival (OS) and adverse effects were analyzed and the phenotype of lymphocytes in CIK population was also determined by flow cytometry.

RESULTS

After in vitro expansion, the average percentage of CIK cells was 26.35%. During the 54-month follow up, the median OS and TTP were significantly longer in the study group than in the control group (P=0.0189 and P=0.0129, respectively). The median OS of the ACT≥4cycles subgroup was significantly longer than that of the ACT<4cycles subgroup (P=0.0316). The percentage of CIK cells in patients who received ≥4cycles of ACT was higher than that in patients treated with <4cycles of ACT (P=0.0376). Notably, CIK cells were difficult to expand in vitro in some patients after the first ACT cycle but became much easier as the treatment cycles increased monthly. Longer treatment interval negatively impacted the expansion of CIK cells.

CONCLUSIONS

Systematic immune levels can be increasingly boosted by reinfusion of ACT. Conventional treatment plus CIK cells is an effective therapeutic strategy to prevent progression and prolong survival of patients with advanced NSCLC.

Chemotherapy in combination with cytokine-induced killer cell transfusion: An effective therapeutic option for patients with extensive stage small cell lung cancer

BACKGROUND AND AIMS

In the past decade of clinical studies, the combination of chemotherapy with cytokine induced killer (CIK) cell transfusion has confirmed a promised efficacy in several types of cancer. CIK cells are a mixture of T lymphocytes, generated from peripheral blood mononuclear cells induced by multiple cytokines. This study was aimed to evaluate the clinical efficacy of chemotherapy combined with CIK- cell therapy in patients with extensive stage small cell lung cancer (ES SCLC).

PATIENTS AND METHODS

Forty four patients with ES SCLC were enrolled in this study. All the patients received treatment from Oct 2010 to Sep 2013 in the First Affiliated Hospital of Zhengzhou University. Included patients were equally divided into 2 groups according to the treatment strategies. Patients in the combined treatment group received chemotherapy combined with CIK-cell transfusion and patients in the control group received chemotherapy alone. The short-term effects, overall survival (OS), progress free survival (PFS) and therapy-related adverse events were analyzed retrospectively.

RESULTS

Short-term efficacy evaluation indicated that the total response rates in the combined treatment group and control group were 40.9% (9/22) and 9.1% (2/22), respectively. There was a significant difference between the two groups (p=0.0339). Furthermore, the PFS of the combined treatment group was significantly longer than that of the control group (8 vs. 4months, P=0.005). No severe side effect was observed after transfusion of CIK cells.

CONCLUSION

These results indicated that chemotherapy combined with CIK-cell immunotherapy might provide a safe and effective treatment for patients with ES SCLC.

Cytokine-induced killer cells hunt individual cancer cells in droves in a mouse model

Cytotoxicity of cytokine-induced killer (CIK) cells depends mainly on their encounters with target cells, but how many CIK cells are required to kill an individual cancer cell is unknown. Here we used time-lapse imaging to quantify the critical effector cell number required to kill an individual target cell. CIK cells killed MHC-I-negative and MHC-I-positive cancer cells, but natural killer (NK) cells destroyed MHC-I-negative cells only. The average threshold number of CIK cells required to kill an individual cancer cell was 6.7 for MHC-I-negative cells and 6.9 for MHC-I-positive cells. That of NK cells was 2.4 for MHC-I-negative cells. Likely due to the higher threshold numbers, killing by CIK cells was delayed in comparison with NK cells: 40% of MHC-negative target cells were killed after 5 h when co-cultured with CIK cells and after 2 h with NK cells. Our data have implications for the rational design of CIK cell-based immunotherapy of cancer patients.

Autologous cytokine-induced killer (CIK) cell immunotherapy combined with cyclophosphamide in five patients with POEMS syndrome

The primary objective of this study was to evaluate the safety and clinical efficacy of autologous cytokine-induced killer (CIK) cells combined with cyclophosphamide in the treatment of polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy and skin changes (POEMS) syndrome patients. We evaluated five POEMS syndrome patients treated with autologous CIK cell immunotherapy combined with cyclophosphamide from 1 May 2012 to 30 November 2014. The Overall Neuropathy Limitation Scale (ONLS), computed tomography of the chest and abdomen, ultrasound of the abdomen, serum vascular endothelial growth factor (VEGF) level and lymphocyte count findings in the five patients were recorded. The median age of the patients was 40 years (range: 25-62), and all the patients were male. CIK cells were generated routinely from peripheral blood mononuclear cells (PBMCs) of all five patients, and the numbers of CIK cells increased by approximately 105-fold after 14 days of culture. All five patients (100%) responded to their neuropathy treatment, the ONLS scores were reduced by at least 1 and a paired-sample t-test revealed a significant difference (t = 5·715, P = 0·003 < 0·01). The extravascular volume overload responses indicated partial remission (PR = 60%) or stable disease (SD = 40%), and no cases of progressive disease (PD) or complete remission (CR) were observed. During clinical treatment, the serum VEGF of patient 5 decreased after one cycle of transfusion within 1 month. The lymphocyte counts of all the patients increased significantly after CIK transfusion, and a paired-sample t-test revealed a significant difference (t = 5·101, P = 0·004 < 0·01). Autologous CIK cell infusion combined with cyclophosphamide was found to be highly safe and elicited no adverse reactions. CIK cells can improve both the symptoms and quality of life, decrease serum VEGF levels and increase lymphocyte counts in patients with POEMS syndrome.

Cytokine-induced killer cells as immunotherapy for solid tumors: current evidence and perspectives

Cytokine-induced killer (CIK) cells are ex vivo expanded T lymphocytes endowed with potent MHC-independent antitumor activity. CIK cells are emerging as promising therapeutic approach in the field of cancer adoptive immunotherapy, with biologic features favoring their transferability into clinical applications. Aim of this review is to present the biologic characteristic of CIK cells, discussing the main preclinical findings and initial clinical applications in the field of solid tumors.

Sequential Cytokine-Induced Killer Cell Immunotherapy Enhances the Efficacy of the Gemcitabine Plus Cisplatin Chemotherapy Regimen for Metastatic Nasopharyngeal Carcinoma

In this study, we investigated the efficacy of sequential cytokine-induced killer cell (CIK) immunotherapy with gemcitabine plus cisplatin (GC) regimen chemotherapy in metastatic nasopharyngeal carcinoma (NPC) patients. Between September 2006 and April 2010, 222 NPC patients with distant metastasis after radiotherapy completion were retrospectively analyzed: 112 patients received 4–6 cycles of GC chemotherapy at 4-week intervals, followed by at least 4 cycles of CIK immunotherapy at 2-week intervals (GC+CIK group); the remaining 110 patients received 4–6 cycles of GC chemotherapy alone (GC group). The evaluation of long-term efficacy showed that the progression-free survival (PFS) rate was significantly higher in the GC+CIK group (log-rank test; p = 0.009), as was the overall survival (OS) rate (p = 0.006). In conclusion, sequential CIK treatment may be effective in enhancing the therapeutic efficacy of GC chemotherapy for metastatic NPC patients. This study provides a basis for alternative therapeutic strategies for metastatic NPC.

Adjuvant cellular immunotherapy in patients with resected primary non-small cell lung cancer

Postoperative non-small cell lung cancer (NSCLC) patients require adjuvant therapy to improve their prognosis. In this study, we investigated the efficacy of a sequential combination of autologous cellular immunotherapy (CIT) and chemotherapy for postoperative NSCLC. This retrospective study included 120 postoperative NSCLC patients: 60 cases received only chemotherapy; 33 cases received chemotherapy and sequential CIT with cytokine-induced killer (CIK) cells; and 27 cases received chemotherapy and sequential CIT with alternate CIK and natural killer (NK) cells. Survival analysis showed significantly higher overall survival rates in the CIT group compared with the control group. Overall survival was higher in patients who received CIT with alternate CIK and NK cells than those who received treatment with only CIK cells. Multivariate analysis showed that adjuvant CIT was an independent prognostic factor for overall survival of patients with NSCLC. In subgroup analyses, adjuvant CIT significantly improved the overall survival of patients with less than 60 y old and positive lymph node. In conclusions, these data indicate that adjuvant CIT, especially with alternate application of CIK and NK cells, is an effective therapeutic approach to prolong survival of patients with NSCLC, particularly for patients ≤60 y old with positive lymph nodes.

Adoptive Cell Therapy of Melanoma with Cytokine-induced Killer Cells

Melanoma is the most aggressive skin cancer and its incidence is gradually increasing worldwide. Patients with metastatic melanoma have a very poor prognosis (estimated 5-year survival rate of <16%). In the last few years, several drugs have been approved for malignant melanoma, such as tyrosine kinase inhibitors and immune checkpoint blockades. Although new therapeutic agents have improved progression-free and overall survival, their use is limited by drug resistance and drug-related toxicity. At the same time, adoptive cell therapy of metastatic melanoma with tumor-infiltrating lymphocytes has shown promising results in preclinical and clinical studies. In this review, we summarize the currently available drugs for treatment of malignant melanoma. In addition, we suggest cytokine-induced killer (CIK) cells as another candidate approach for adoptive cell therapy of melanoma. Our preclinical study and several previous studies have shown that CIK cells have potent anti-tumor activity against melanomas in vitro and in an in vivo human tumor xenograft model without any toxicity.

Adoptive immunotherapy strategies with cytokine-induced killer (CIK) cells in the treatment of hematological malignancies

Cytokine-induced killer (CIK) cells are a heterogeneous population of immune effector cells that feature a mixed T- and Natural killer (NK) cell-like phenotype in their terminally-differentiated CD3+CD56+ subset. The easy availability, high proliferation rate and widely major histocompatibility complex (MHC)-unrestricted antitumor activity of CIK cells contribute to their particularly advantageous profile, making them an attractive approach for adoptive immunotherapy. CIK cells have shown considerable cytotoxicity against both solid tumors and hematological malignancies in vitro and in animal studies. Recently, initial clinical experiences demonstrated the feasibility and efficacy of CIK cell immunotherapy in cancer patients, even at advanced disease stages. Likewise, the clinical application of CIK cells in combination with standard therapeutic procedures revealed synergistic antitumor effects. In this report, we will focus our consideration on CIK cells in the treatment of hematological malignancies. We will give insight into the latest advances and future perspectives and outline the most prominent results obtained in 17 clinical studies. Overall, CIK cells demonstrated a crucial impact on the treatment of patients with hematological malignancies, as evidenced by complete remissions, prolonged survival durations and improved quality of life. However, up to now, the optimal application schedule eventually favoring their integration into clinical practice has still to be developed.

Evaluation of tumor response to cytokine-induced killer cells therapy in malignant solid tumors

CIK cells therapy has been evaluated as an adoptive cell immunotherapy for cancer patients, but there still have not been any standardized systems for evaluating the antitumor efficacy yet. The WHO and RECIST criteria have already been established for a few years but not sufficient to fully characterize the activity of immunotherapy. Based on these two criteria, the irRC was proposed for evaluating the efficacy of immunotherapy. A variety of bioassays for immune monitoring including the specific and non-specific methods, have been established. We recommend detect levels of various immunocytes, immune molecules and soluble molecules to find the correlations among them and clinicopathological characteristics to establish criteria for immunological classification. We also recommend a paradigm shift for the oncologists in the evaluation of immune therapies to ensure assessment of activity based on clinically relevant criteria and time points.

Cytokine-induced killer cells in the treatment of patients with renal cell carcinoma: a pooled meta-analysis

Cytokine-induced killer cells (CIKs) have been applied in multifarious cancer. Here, we address the connection between immune therapy and clinical responses by a systematic meta-analysis. A total of 385 patients (including 183 controls) were identified for renal cell cancer (RCC) in the seven selected trials. The estimated pooled complete response and partial response showed a significant improvement for patients receiving CIK immunotherapy compared with non-CIK therapy (p < 0.0001), which was up to 62% of clinical response. The overall analysis showed a significant survival benefit (1-year overall survival [OS]: p = 0.0002; 3-year OS: p < 0.0001) in favor of CIK-based therapy in RCC, thus a statistically significant effect of OS and clinical response was demonstrated in RCC patients.

Clinical activity of adjuvant cytokine-induced killer cell immunotherapy in patients with post-mastectomy triple-negative breast cancer

PURPOSE

Triple-negative breast cancer (TNBC) is a high risk form of this disease, even after surgery, due to the absence of targets for hormone treatment and anti-Her-2 therapy. Chemotherapy is the main therapeutic strategy for such patients with breast cancer, although the outcome is often unsatisfactory. Thus, the development of combination adjuvant therapies is essential for improved prognosis in patients with TNBC. In this study, we investigated the efficacy of a sequential combination of cytokine-induced killer cell (CIK) infusion and chemotherapy for patients with post-mastectomy TNBC.

EXPERIMENTAL DESIGN

From 2008 to 2012, 90 patients with post-mastectomy TNBC were included in this retrospective study: 45 cases received chemotherapy alone or with sequential radiotherapy; a further 45 cases received chemotherapy with/without radiotherapy and sequential CIK infusion.

RESULTS

Survival analysis showed significantly higher disease-free survival (DFS) and overall survival (OS) rates in the CIK treatment group compared with the control group (P = 0.0382, P = 0.0046, respectively; log-rank test). Multivariate survival analysis showed that CIK adjuvant treatment was an independent prognostic factor for OS of patients with TNBC. In subgroup analyses, CIK adjuvant treatment significantly increased the DFS rate of patients with pathologic grade 3, and significantly increased the OS rate of patients in N1, N2, N3, IIB, III TNM (tumor-node-metastasis) stages, and with pathologic grade 3.

CONCLUSIONS

These data indicate that adjuvant CIK treatment combined with chemotherapy is an effective therapeutic strategy to prevent disease recurrence and prolong survival of patients with TNBC, particularly those with lymph node metastasis, advanced TNM stage, and poor pathologic grade. Clin Cancer Res; 20(11); 3003-11. ©2014 AACR.

Clinical studies applying cytokine-induced killer cells for the treatment of gastrointestinal tumors

Tumors of the gastrointestinal system represent a significant share of solid tumors worldwide. Despite the advances in diagnosis and treatment, the prognosis of gastrointestinal tumors is still very poor and improved therapies are indispensable. Cytokine-induced killer (CIK) cells are feasible for an immunotherapeutic approach as they are easily available and have an advantageous biologic profile; they are rapidly proliferating and their high cytotoxicity is non-MHC-restricted. We summarize and discuss twenty recent clinical studies applying CIK cells for the treatment of gastric, pancreatic, hepatocellular, and colorectal cancer. Autologous CIK cells were transfused intravenously, intraperitoneally, or via the common hepatic artery. In all studies side effects and toxicity of CIK cell therapy were mild and easily controllable. The combination of CIK cell therapy with conventional adjuvant or palliative therapies was superior to the standard therapy alone, indicating the benefit of CIK cell therapy for cancer patients. Thus, CIK cells represent a promising immunotherapy for the treatment of gastrointestinal tumors. The optimal treatment schedule and ideal combination with conventional therapies should be evaluated in further clinical studies.

The phenotype of ex vivo generated cytokine-induced killer cells is associated with overall survival in patients with cancer

Cytokine-induced killer (CIK) cells are ex vivo generated heterogeneous NK-like T lymphocytes. It is not very clear whether the phenotype of CIK cells is associated with their therapeutic efficacy to cancer patients. Thus, in this study, the association of phenotype of CIK cells and the overall survival of 121 patients with hepatocellular carcinoma (HCC), 74 patients with lung cancer and 42 patients with colorectal cancer, all of whom underwent surgical resection and received autogenous CIK cell therapy, was analyzed. We found that high ratio of the CD3+CD4+ subset was associated with poorer overall survival in colorectal cancer, but not HCC or lung cancer. A high ratio of the CD3+CD8+ subset was associated with improved overall survival in all three types of cancer. A high ratio of the CD3+CD56+ NK-like subset was associated with improved overall survival in lung and colorectal cancer, but not HCC. A high ratio of the CD3-CD56+ NK subset was associated with poorer overall survival in lung and colorectal cancer, but not HCC. In conclusion, the CD3+CD8+ and CD3+CD56+ subsets, especially the CD3+CD8+ subset, may be the major phenotypes responsible for anti-tumor immunity in vivo after autogenous CIK cell therapy.

Effect of anti-asthma Chinese medicine Chuankezhi on the anti-tumor activity of cytokine-induced killer cells

Chuankezhi (CKZ), a new Chinese medicine, plays an important role in immunoregulation. Cytokine-induced killer (CIK) cells have been commonly used for immunotherapy in recent years. In this study, we aimed to investigate the immunoregulatory effect of CKZ on CIK cells. Peripheral blood monocytes were isolated from healthy donors, and CIK cells were generated by culturing monocytes with interferon-gamma (IFN-γ) and interleukin 2. Different concentrations of CKZ were added on day 2. After incubation for 14 days in culture, the antitumor effects of CIK cells were measured by cytotoxicity assay. Flow cytometry was used to explore the effect of CKZ on CIK cell immunophenotype, intracellular cytokine production, and apoptosis. The effect of CKZ on the antitumor activity of CIK cells in nude mice was also investigated. CKZ increased the percentage of CD3⁺CD56⁺ CIK cells but did not significantly change the percentage of CD4⁺, CD8⁺, or CD4⁺CD25⁺ CIK cells. CKZ-conditioned CIK cells showed a greater ability to kill tumor cells, as well as a higher frequency of IFN-γ and TNF-α production, compared with the CIK cells in the control group. CKZ also suppressed the apoptosis of CIK cells in vitro. Furthermore, CKZ combined with CIK cells had a stronger suppressive effect on tumor growth in vivo than the CIK, CKZ, or normal saline control groups. Our results indicate that CKZ enhances the antitumor activity of CIK cells and is a potential medicine for tumor immunotherapy.

Clinical studies applying cytokine-induced killer cells for the treatment of renal cell carcinoma

Metastatic renal cell carcinoma (RCC) seems to be resistant to conventional chemo- and radiotherapy and the general treatment regimen of cytokine therapy produces only modest responses while inducing severe side effects. Nowadays standard of care is the treatment with VEGF-inhibiting agents or mTOR inhibition; nevertheless, immunotherapy can induce complete remissions and long-term survival in selected patients. Among different adoptive lymphocyte therapies, cytokine-induced killer (CIK) cells have a particularly advantageous profile as these cells are easily available, have a high proliferative rate, and exhibit a high antitumor activity. Here, we reviewed clinical studies applying CIK cells, either alone or with standard therapies, for the treatment of RCC. The adverse events in all studies were mild, transient, and easily controllable. In vitro studies revealed an increased antitumor activity of peripheral lymphocytes of participants after CIK cell treatment and CIK cell therapy was able to induce complete clinical responses in RCC patients. The combination of CIK cell therapy and standard therapy was superior to standard therapy alone. These studies suggest that CIK cell immunotherapy is a safe and competent treatment strategy for RCC patients and further studies should investigate different treatment combinations and schedules for optimal application of CIK cells.

CIK cells from recurrent or refractory AML patients can be efficiently expanded in vitro and used for reduction of leukemic blasts in vivo

Autologous cytokine-induced killer (CIK) cell transfusion may prevent tumor relapse in acute myeloid leukemia (AML). This study investigated whether CIK cells from recurrent or refractory AML patients with high peripheral leukemia cell burdens could be expanded to a clinically usable number, and it further evaluated the antitumor potentials in vitro and in vivo. The numbers and phenotypes of CIK cells expanded from nine AML patients and 10 healthy donors were compared. Cytotoxicity (against K562 and U937 cell lines) and cytokine secretion (interleukin-2, interferon-γ, tumor necrosis factor-α and vascular endothelial growth factor) were tested for AML-derived and healthy donor-derived CIK cells and fresh peripheral blood mononuclear cells from healthy donors. Importantly, we assessed the therapeutic effects of autologous CIK cell infusions in two patients with AML. The proportions of CD3(+)and CD3(+)CD56(+) CIK cells from patients with AML were similar to those from healthy donors, and the number of CD3(+)CD56(+) cells in AML-derived CIK cells was expanded approximately 1,020-fold. Phenotype analyses with flow cytometry showed that the leukemic cells were gradually eliminated during the process of CIK cell preparation to an almost undetectable level. Although the cytotoxic effect of AML-derived CIK cells was equivalent to that of healthy donors, AML-derived CIK cells had a significantly higher cytokine-secreting capacity. In clinical treatment, the leukemia burden in the peripheral blood of one patient was dramatically decreased after four transfusions within 4 months. CIK cells can be efficiently expanded in vitro from patients with recurrent or refractory AML and may be used for reduction of leukemic blasts in vivo.

Review of Chinese clinical trials on CIK cell treatment for malignancies

China is the country where the most clinical trials on CIK cells have been performed. We aimed to provide definite evidence for using CIK cell treatment and extrapolate a common applicative standard for malignancies. We chose the VIP database of Chinese scientific and technological journals to search the literature. We entered the keywords "CIK" or "xi bao yin zi you dao de sha shang xi bao" (the equivalent Chinese phrase for CIK cells, by Chinese characters) and searched for in vivo human trials. In 24 collected trials, 936 patients were treated with CIK cells, 525 men and 246 women. The cultivation time of CIK cells ranged from 7 to 28 days. In five studies, CIK cells were co-cultured with dendritic cells. The total number of CIK cells used ranged from 6×10(6) to 1.5×10(10). The total number of DC-CIK cells used ranged from 1×10(9) to 1.3×10(10). In all studies, those immune parameters and tumour markers examined increased, but not all increased significantly. Of the reported 563 patients, 40 had a complete response, 126 had a partial response, 125 had a minimal response, 135 had stable disease and 58 had progressive disease. The remaining 76 patients did not reach an objective response. The total response rate was 51.7% (291/563). The toxicities were slight. CIK cell treatment is a promising and safe modality for treating malignancies. We proposed a standard for cultivating CIK cells.

Efficacy of adjuvant immunotherapy with cytokine-induced killer cells in patients with locally advanced gastric cancer

Purpose

To determine the long-term efficacy of adjuvant immunotherapy with autologous cytokine-induced killer (CIK) cells for locally advanced gastric cancer patients.

Experimental design

One hundred and fifty-one patients with stage III/IV gastric cancer who had undergone gastrectomy were enrolled, assigned to two groups (immunotherapy group versus no immunotherapy group/or control group), and followed.

Results

The 5-year overall survival (OS) and 5-year disease-free survival (DFS) rates for immunotherapy versus control group were 32.4 versus 23.4 % (P = 0.071) and 28.3 versus 10.4 % (P = 0.044), respectively. For patients with intestinal-type tumors, the 5-year OS and DFS rates were significantly higher for immunotherapy (OS, 46.8 vs. 31.4 % and P = 0.045; DFS, 42.4 vs. 15.7 % and P = 0.023). In the immunotherapy group, the mean CD3⁺ level, CD4⁺ level, and CD4⁺/CD8⁺ ratio increased from 50.8, 26.5, and 0.9 %, respectively, at baseline to 62.6, 35.0, and 1.4 %, respectively, 1 week after the first CIK-cell treatment, returned to baseline after 2 months, and maintained a higher level (60.7 ± 8.2 %, 34.2 ± 7.1 %, and 1.3 ± 0.3 %, respectively) 2 months after 3 cycles of immunotherapy.

Conclusions

Adjuvant immunotherapy with CIK cells prolongs DFS in patients with locally advanced gastric cancer and significantly improves OS in patients with intestinal-type tumors. Intestinal-type tumors could be selected as an important indication for CIK-cell therapy. This treatment may help improve T-lymphocyte subset distribution and improve the host’s immune functions, but multiple cycles are necessary for long-term therapeutic efficacy.

Cytokine-induced killer (CIK) cells as feasible and effective adoptive immunotherapy for the treatment of solid tumors

INTRODUCTION

Cytokine-induced killer (CIK) cells are heterogeneous ex vivo-expanded T lymphocytes with mixed T-NK phenotype and endowed with a wide MHC-unrestricted antitumor activity. CIK cells can be expanded from peripheral blood mononuclear cells (PBMC) cultured with the timed addition of IFN-γ, Ab anti-CD3 and IL2. A consistent subset of mature CIK cells presents a CD3(+)CD56(+) phenotype. The CD3(+)CD56(+) cellular subset is the main responsible for the tumor-killing activity, mostly mediated by the interaction of NKG2D receptor with MHC-unrestricted ligands (MIC A/B; ULBPs) on tumor cells.

AREAS COVERED

In the present work, we described the biologic characteristics of CIK cells, focusing on those aspects that may favor their clinical translation. We reviewed preclinical data and analyzed reports from clinical trials. A specific paragraph is dedicated to future research perspectives in the field.

EXPERT OPINION

CIK cells represent a realistic new option in the field of cancer immunotherapy. Crucial issues, favoring their clinical translation, are the easy availability of large amounts of expanded CIK cells and their MHC-unrestricted tumor killing, potentially effective against many tumor types. Intriguing future perspectives and open challenges are the investigation of synergisms with other immunotherapy approaches, targeted therapies or even conventional chemotherapy.

Emergence of peripheral CD3+CD56+ cytokine-induced killer cell in HIV-1-infected Chinese children

Cytokine-induced killer (CIK) cells are immune effector cells characterized by co-expression of CD3 and CD56 molecules. We examined the quantities of CIK cells and the changes of these cell expressing NK cell receptors in HIV-1-positive children infected via mother-to-child transmission. The percentage of CIK cells was quantified and the changes in the surface cell receptor profiles in 18 HIV-1-infected children were examined. We found that CIK cell percentages were dramatically increased in HIV-1-infected children. Furthermore, the expressions of CD16, NKp30, NKp44, NKp46, NKp80 and CD244 on CIK cells were decreased, while the expressions of KIR3DL1 and NKG2D on CIK cells were increased in HIV-1-infected children. However, the expressions of KIR2D and NTB-A on CIK cells did not change in the HIV-1-infected children. CIK cells possessed the characteristics of promoting the maturation of dendritic cells and killing functions in HIV-1-infected children. Moreover, serum concentrations of IL-4 and IFN-γ were significantly increased in HIV-1-infected children compared with the HIV-negative controls. These changes likely occurred as a protective mechanism against transmission of maternal HIV-1 virus and thereby helped to limit viral spread, eliminate infected cells and help HIV-1-infected patients to slow the progression to AIDS.

The anti-tumour activity of allogeneic cytokine-induced killer cells in patients who relapse after allogeneic transplant for haematological malignancies

We performed a Phase I/II clinical trial to study the feasibility, toxicity and efficacy of allogeneic cytokine-induced killer (CIK) cell expansion, and treatment for patients with haematological malignancies who relapsed after allogeneic haemopoietic SCT (allo-HSCT). Allogeneic CIK cells were successfully generated for a total of 24 patients, including those from patients' own leukapheresis products in 5 patients who had no access to further donor cells. The median CD3(+) T-cell expansion was 9.33 (1.3-38.97) fold, and CD3(+)CD56(+) natural killer (NK)-like T-cell expansion was 27.77 (2.59-438.93) fold. A total of 55 infusions were done for 16 patients who had either failed or progressed after initial response to various individualized chemotherapy regimens and donor lymphocyte infusion (DLI), at doses ranging from 10 to 200 million CD3(+) cells/kg. Response attributable to CIK cell infusion was observed in five patients. These included two with ALL, two with Hodgkin's disease (HD) and one with AML, and two of whom had a response sustained for more than 2 years. Acute GVHD occurred in three and was easily treatable. This study provides some evidence suggestive of the efficacy of allogeneic CIK cells even after failure of DLI in some cases.

Dual-functional capability of CD3+CD56+ CIK cells, a T-cell subset that acquires NK function and retains TCR-mediated specific cytotoxicity

CD3(+)CD56(+) cytokine-induced killer (CIK) cells display a potent cytolytic activity. The adhesion molecule lymphocyte function-associated antigen-1 plays a crucial role in binding as well as in cytolytic activity of CIK cells against tumor target cells expressing the corresponding ligands. CIK cells express activating natural killer (NK) receptors, including NKG2D, DNAX accessory molecule-1 (DNAM-1), and low levels of NKp30. Cell signaling not only through TCR/CD3 but also through NKG2D, DNAM-1, and NKp30 leads to CIK cell activation resulting in granule exocytosis, cytokine secretion, and cytotoxicity. Antibody blocking experiments showed that DNAM-1, NKG2D, and NKp30 are involved in the TCR-independent tumor cell recognition and killing. Anti-CMV-specific CIK cells could be expanded in standard CIK cultures and mediate both specific, MHC-restricted recognition and TCR-independent NK-like cytolytic activity against leukemic cell lines or fresh leukemic blasts. Antibody blocking of lymphocyte function-associated antigen-1 and DNAM-1 led to significant reduction of both CTL and NK-cell functions, whereas blocking of NKG2D and NKp30 only inhibited NK-like cytotoxicity. Their dual-effector function suggests that CIK cells, when used in a clinical setting, may control both neoplastic relapses and viral infections, 2 frequently associated complications in patients who received a transplant.

Cytokine induced killer cells as promising immunotherapy for solid tumors

Cytokine-induced killer (CIK) cells are a heterogeneous subset of ex-vivo expanded T lymphocytes which present a mixed T-NK phenotype and are endowed with a MHC-unrestricted antitumor activity. The main functional properties of CIK cells may address some of the main limitations that are currently preventing the successful clinical translation of adoptive immunotherapy strategies. Clinically adequate quantities of immune effectors, sufficient for multiple adoptive infusions, may be obtained based on their relatively easy and inexpensive ex-vivo expansion starting from peripheral blood mononuclear cells. The MHC-unrestricted tumor-killing is mainly based on the interaction between NKG2D molecules on CIK cells and MIC A/B or ULBPs molecules on tumor cells; it has been proved effective against several solid and hematological malignancies and does not require any HLA-restriction increasing the number of patients that might potentially benefit from such approach. Finally, CIK cells present a reduced alloreactivity across HLA-barriers with important clinical implications for their potential use as alternative to conventional Donor Lymphocyte Infusions after allogeneic hemopoietic cell transplant with a reduced risk of GVHD. In the present report we review the main functional characteristics of CIK cells discussing recent findings and future perspectives to improve their antitumor activity and potential clinical applications.

Adoptive immunotherapy with cytokine-induced killer cells for patients with relapsed hematologic malignancies after allogeneic hematopoietic cell transplantation

Donor leukocyte infusions induce remissions in some patients with hematologic malignancies who relapse after allogeneic hematopoietic cell transplantation (HCT); however, graft-versus-host disease (GVHD) remains the major complication of this strategy. Cytokine-induced killer (CIK) cells are a unique population of cytotoxic T lymphocytes that express the CD3(+)CD56(+) phenotype and show marked up-regulation of the natural killer cell receptor NKG2D (CD314). CIK cells are non-major histocompatibility complex-restricted and NKG2D-dependent in target recognition and cytotoxicity. We explored the feasibility of ex vivo expansion of allogeneic CIK cells in patients with relapsed hematologic malignancies after allogeneic HCT. Eighteen patients (median age, 53 years; range, 20-69 years) received CIK cell infusions at escalating doses of 1 × 10(7) CD3(+) cells/kg (n = 4), 5 × 10(7) CD3(+) cells/kg (n = 6), and 1 × 10(8) CD3(+) cells/kg (n = 8). The median expansion of CD3(+) cells was 12-fold (range, 4- to 91-fold). CD3(+)CD56(+) cells represented a median of 11% (range, 4%-44%) of the harvested cells, with a median 31-fold (range, 7- to 515-fold) expansion. Median CD3(+)CD314(+) cell expression was 53% (range, 32%-78%) of harvested cells. Significant cytotoxicity was demonstrated in vitro against a panel of human tumor cell lines. Acute GVHD grade I-II was seen in 2 patients, and 1 patient had limited chronic GVHD. After a median follow-up of 20 months (range, 1-69 months) from CIK infusion, the median overall survival was 28 months, and the median event-free survival was 4 months. All deaths were due to relapsed disease; however, 5 patients had longer remissions after infusion of CIK cells than from allogeneic HCT to relapse. Our findings indicate that this form of adoptive immunotherapy is well tolerated and induces a low incidence of GVHD, supporting further investigation as an upfront modality to enhance graft-versus-tumor responses in high-risk patient populations.

Increasing the frequency of CIK cells adoptive immunotherapy may decrease risk of death in gastric cancer patients

AIM: To analyze the correlation between cytokine-induced killer (CIK) cells adoptive immunotherapy and cancer-related death in gastric cancer patients.

METHODS: One hundred and fifty-six gastric cancer patients after operation at the Third Affiliated Hospital of Soochow University were enrolled in this study. Their clinical data including demographic characteristics, operation time, tumor size, pathological type and staging, tumor metastasis, outcome of chemotherapy or CIK cells adoptive immunotherapy, survival time or time of death were collected with a standard structured questionnaire. Kaplan-Meier method was used to estimate the median survival time, and the 2- and 5- year survival rates. Hazard risk (HR) and 95% confidence interval (95% CI) of CIK cells adoptive immunotherapy for gastric cancer were calculated using the two-stage time-dependent covariates Cox model.

RESULTS: The survival time of gastric cancer patients was longer after CIK cells adoptive immunotherapy than after chemotherapy (χ² = 10.907, P = 0.001). The median survival time of gastric cancer patients was also longer after CIK cells adoptive immunotherapy than after chemotherapy (49 mo vs 27 mo, P < 0.05). The 2- and 5-year survival rates of gastric cancer patients were significantly higher after CIK cells adoptive immunotherapy than after chemotherapy (73.5% vs 52.6%, 40.4% vs 23.9%, P < 0.05). A significant difference was observed in the survival curve for patients who received CIK cells adoptive immunotherapy (0, 1-10, 11-25, and over 25 frequencies) (χ² = 14.534, P = 0.002). The frequencies of CIK cells adoptive immunotherapy were significantly related with the decreasing risk of death in gastric cancer patients after adjustment for sex and age of the patients, tumor stage and relapse (HR = 0.54, 95% CI: 0.36-0.80) when the first stage Cox model was used to define the subjects who remained alive beyond 36 mo as survivors. However, no correlation was observed between the frequencies of death in CIK cells adoptive immunotherapy and the risk of gastric cancer patients (HR = 1.09, 95% CI: 0.63-0.89) when the second stage Cox model was used to define the subjects who survived for more than 36 mo as survivors.

CONCLUSION: The survival time of the gastric cancer patients treated with chemotherapy combined with CIK cells adoptive immunotherapy is significantly longer than that of the patients treated with chemotherapy alone and increasing the frequency of CIK cells adoptive immunotherapy seems to benefit patients more.

Growth of human colorectal cancer SW1116 cells is inhibited by cytokine-induced killer cells

Previous reports have suggested that treatment with cytokine-induced killer (CIK) cells may benefit patients with various types of tumor. The aim of this study was to evaluate the antitumor effects of CIK cells against the colorectal cancer line SW1116 in vitro and in vivo. CIK cells were generated routinely from peripheral blood mononuclear cells of healthy human donors, and the number of CD3(+)CD56(+) cells was expanded more than 1300-fold after 14-day culture. At an effector : target cell ratio of 50 : 1, the percentage lysis of SW1116 cells reached 68% in the presence of CIK cells, Experimental mice injected with SW1116 cells subcutaneously were divided randomly into four groups: untreated, 5-fluorouracil (5-FU)-treated, CIK-consecutive treated (injected once/day) and CIK-interval treated (injected once every 5 days). CIK cells were injected abdominally five times in total. Compared with the untreated group, xenograft growth was inhibited greatly by CIK treatment, to nearly the same extent as with 5-FU treatment. We demonstrated that the necrotic area in the tumor xenograft was markedly larger in the CIK-treated groups than in the other groups. These findings suggest that CIK-based immunotherapy may represent an effective choice for patients with colorectal cancer.

Anti-tumor effects of CIK combined with oxaliplatin in human oxaliplatin-resistant gastric cancer cells in vivo and in vitro

BACKGROUND

Drug resistance remains a great challenge in the treatment of gastric cancer. The goal of this study was to explore the anti-tumor effects and mechanism of cytokine-induced killer (CIK) cell combined with oxaliplatin (L-OHP) in human oxaliplatin-resistant gastric cancer cells.

METHODS

After producing oxaliplatin-resistant gastric cancer cells, cell morphology, growth and doubling time were observed, followed by detection of cell cycle distribution and apoptosis, drug sensitivity (e.g., L-OHP) and expression of P-gp and livin. MTT assay, in vivo pharmacodynamics and pathomorphology experiments were used to detect killing activities of CIK combined with L-OHP.

RESULTS

Compared with parental gastric cancer cells, oxaliplatin-resistant gastric cancer cells in S phase were reduced and cell apoptosis rate was increased (P < 0.05), the inhibition rate of 10 chemotherapeutics on oxaliplatin-resistant gastric cancer cells was significantly lower and the expression of P-gp was significantly higher (P < 0.05). However, there was no significant difference in livin expression between parental gastric cancer cells and oxaliplatin-resistant gastric cancer cells (P > 0.05). The in vitro killing activity of CIK combined with L-OHP on parental cells and oxaliplatin-resistant cells were significantly enhanced compared with L-OHP or CIK alone. And it showed greater synergetic effects against oxaliplatin-resistant cells compared with parental cells (P < 0.05). In addition, survival rate, abdominal circumference and pathomorphology results revealed stronger in vivo anti-tumor effects when the two therapies were combined.

CONCLUSIONS

The mechanism of oxaliplatin-resistant cell secondary multidrug resistance was correlated with the variation of cell cycle distribution, extension of doubling time and upregulation of P-gp expression. The synergistic effect of CIK in combination with L-OHP on killing activity against oxaliplatin-resistant cells was shown in vivo and in vitro.

Cytokine-induced NK-like T cells: from bench to bedside

Cytokine-induced killer (CIK) cells are polyclonal T effector cells generated when cultured under cytokine stimulation. CIK cells exhibit potent, non-MHC-restricted cytolytic activities against susceptible tumor cells of both autologous and allogeneic origins. Over the past 20 years, CIK cells have evolved from experimental observations into early clinical studies with encouraging preliminary efficacy towards susceptible autologous and allogeneic tumor cells in both therapeutic and adjuvant settings. This paper is our attempt to summarize the available published literature related to CIK cells. Looking into the future, we anticipate that the continuous therapeutic application of CIK cells will likely be developed along two major directions: overcoming the challenge to organize large prospective randomized clinical trials to define the roles of CIK cells in cancer immunotherapy and expanding its spectrum of cytotoxicity towards resistant tumor cells through experimental manipulations.

Autologous cytokine-induced killer cells in the treatment of multiple myeloma concomitant with lung cancer and paraneoplastic dermatoses

Cytokine-induced killer (CIK) cells have been shown to be effective in the treatment of advanced cancer and minimal residual diseases. We report a multiple myeloma (MM) patient with concomitant lung cancer and paraneoplastic dermatoses, who received cellular immunotherapy with CIK cells which were derived from peripheral blood mononuclear cells (PBMCs) after being primed with anti-cluster of differentiation 3 (CD3) monoclonal antibody, interleukin-2 (IL-2), interferon-γ (IFN-γ) and IL-1. After treatment MM and lung cancer remained stable and no progression or recurrence was observed. Paraneoplastic dermatoses were obviously improved after treatment, which was first reported. No evident side effects were observed. These findings suggested that cellular immunotherapy with CIK cells was safe and effective in this patient with MM and lung cancer, and it might be a potent therapeutic option for paraneoplastic dermatoses.

Characterization of the recognition and functional heterogeneity exhibited by cytokine-induced killer cell subsets against acute myeloid leukaemia target cell

The polyclonal cytokine-induced killer (CIK) cells exhibit potent cytotoxicity against a variety of tumour cells including autologous and allogeneic acute myeloid leukaemic (AML) targets. At maturity, three lymphocyte subsets: CD3(-) CD56(+), CD3(+) CD56(-) and CD3(+) CD56(+), constitute the bulk of the CIK cell culture. The CD3(-) CD56(+) subset behaves like classical natural killer (NK) cells where cytotoxicity is potentiated by blocking the human leucocyte antigen Class I molecules in the AML targets. Both the CD3(+) CD56(+) and CD3(+) CD56(-) subsets, though known to kill autologous and allogeneic targets to a comparable degree and therefore non-major histocompatibility complex (MHC)-restricted, nevertheless require the presence of the MHC molecule on the target, which interacts with their CD3-T-cell receptor complex. Although CIK cells are often termed 'NK-like' T cells, we have demonstrated that the well-characterized NK receptors KIR, NKG2C/E, NKG2D and DNAM-1 are not involved in the process of AML recognition for the CD3(+) CD56(-) and CD3(+) CD56(+) subsets. The CD3(+) CD56(+) and CD3(+) CD56(-) subsets express a polyclonal and comparable TCRVbeta repertoire in a Gaussian distribution. The CD3(+) CD56(+) subset kills AML targets more efficiently than its CD3(+) CD56(-) counterpart because of the presence of a higher proportion of CD8(+) cells. The CD3(+) CD56(+) subset comprise more terminally differentiated late effector T cells that bear the CD27(+) CD28(-) or CD27(-) CD28(-) phenotype, with a higher granzyme A content. In comparison, the phenotype of the CD3(+) CD56(-) subset is consistent with early effector T cells that are CD27(+) CD28(+) and CD62L(+), known to be less cytotoxic but possess greater proliferative potential.