T cell-based immunotherapy of metastatic renal cell carcinoma: modest success and future perspective

Function of gamma delta (γδ) T cell in cancer with special emphasis on cervical cancer

Cervical cancer is the second-most prevalent gynecologic cancer in India. It is typically detected in women between the ages of 35 and 44. Cervical cancer is mainly associated with the human papillomavirus (HPV). The report shows that 70 % of cervical cancer is caused by HPV 16 and 18. There are few therapeutic options and vaccines available for cervical cancer treatment and γδ T cell therapy is one of them. This therapy can kill various types of cancers, including cervical cancer. The major γδ T cell subset is the Vγ9Vδ2 T cell, mainly distributed in peripheral blood which recognize non-MHC peptide antigens and can eliminate MHC-downregulated cancer. Moreover, γδ T cells can express different types of receptors that bind to the molecules of stressed cells, often produced on cancerous cells but absent from healthy tissue. γδ T cells possess both direct and indirect cytotoxic capabilities against malignancies and show potential antitumoral responses. However, γδ T cells also encourage the progression of cancer. Cancer immunotherapy using γδ T cells will be a potential cancer treatment, as well as cervical cancer. This review focused on the γδ T cell and its function in cancer, with special emphasis on cervical cancer. It also focused on the ligand recognition site of γδ T cells, galectin-mediated therapy and pamidronate-treated therapy for cervical cancer. Instead of the great potential of γδ T cell for the eradication of cervical cancer, no comprehensive in-depth review is available to date, so there is a need to jot down the various roles and modes of action and different applications of γδ T cells for cancer research, which we believe will be a handy tool for the researchers and the readers.

Overcoming current challenges to T-cell receptor therapy via metabolic targeting to increase antitumor efficacy, durability, and tolerability

The antitumor potential of personalized immunotherapy, including adoptive T-cell therapy, has been shown in both preclinical and clinical studies. Combining cell therapy with targeted metabolic interventions can further enhance therapeutic outcomes in terms of magnitude and durability. The ability of a T cell receptor to recognize peptides derived from tumor neoantigens allows for a robust yet specific response against cancer cells while sparing healthy tissue. However, there exist challenges to adoptive T cell therapy such as a suppressive tumor milieu, the fitness and survival of transferred cells, and tumor escape, all of which can be targeted to further enhance the antitumor potential of T cell receptor-engineered T cell (TCR-T) therapy. Here, we explore current strategies involving metabolic reprogramming of both the tumor microenvironment and the cell product, which can lead to increased T cell proliferation, survival, and anti-tumor cytotoxicity. In addition, we highlight potential metabolic pathways and targets which can be leveraged to improve engraftment of transferred cells and obviate the need for lymphodepletion, while minimizing off-target effects. Metabolic signaling is delicately balanced, and we demonstrate the need for thoughtful and precise interventions that are tailored for the unique characteristics of each tumor. Through improved understanding of the interplay between immunometabolism, tumor resistance, and T cell signaling, we can improve current treatment regimens and open the door to potential synergistic combinations.

Tumor-infiltrating lymphocytes for treatment of solid tumors: It takes two to tango?

Tumor-infiltrating lymphocytes (TILs), frontline soldiers of the adaptive immune system, are recruited into the tumor site to fight against tumors. However, their small number and reduced activity limit their ability to overcome the tumor. Enhancement of TILs number and activity against tumors has been of interest for a long time. A lack of knowledge about the tumor microenvironment (TME) has limited success in primary TIL therapies. Although the advent of engineered T cells has revolutionized the immunotherapy methods of hematologic cancers, the heterogeneity of solid tumors warrants the application of TILs with a wide range of specificity. Recent advances in understanding TME, immune exhaustion, and immune checkpoints have paved the way for TIL therapy regimens. Nowadays, TIL therapy has regained attention as a safe personalized immunotherapy, and currently, several clinical trials are evaluating the efficacy of TIL therapy in patients who have failed conventional immunotherapies. Gaining favorable outcomes following TIL therapy of patients with metastatic melanoma, cervical cancer, ovarian cancer, and breast cancer has raised hope in patients with refractory solid tumors, too. Nevertheless, TIL therapy procedures face several challenges, such as high cost, timely expansion, and technical challenges in selecting and activating the cells. Herein, we reviewed the recent advances in the TIL therapy of solid tumors and discussed the challenges and perspectives.

Evaluating Biomaterial- and Microfluidic-Based 3D Tumor Models

Cancer is a major cause of morbidity and mortality worldwide, with a disease burden estimated to increase over the coming decades. Disease heterogeneity and limited information on cancer biology and disease mechanisms are aspects that 2D cell cultures fail to address. Here, we review the current ‘state-of-the-art’ in 3D tissue-engineering (TE) models developed for, and used in, cancer research. We assess the potential for scaffold-based TE models and microfluidics to fill the gap between 2D models and clinical application. We also discuss recent advances in combining the principles of 3D TE models and microfluidics, with a special focus on biomaterials and the most promising chip-based 3D models.

Establishment and characterization of a highly immunogenic human renal carcinoma cell line

Renal cell carcinoma (RCC) is the most common kidney cancer, and accounts for ~3% of all adult malignancies. RCC has proven refractory to conventional treatment modalities but appears to be the only histological form that shows any consistent response to immunotherapeutic approaches. The development of a clinically effective vaccine remains a major strategic target for devising active specific immunotherapy in RCC. We aimed to identify a highly immunogenic antigenic format for immunotherapeutic approaches, so as to boost immune responses in RCC patients. We established and cloned an immunogenic cell line, RCC85#21 named Elthem, which was derived from a non-aggressive and non-metastatic clear cell carcinoma. The cell line characterization was performed by genomics (real-time PCR, genome instability), proteomics (two dimensional electrophoresis, mass spectro-metry) and immunological analysis (mixed lymphocytes tumor cell cultures). Real-time PCR confirmed the RCC85#21 cell expression of tumor antigens and cytokine genes. No difference in microsatellite instability (MSI) in RCC85#21 cell line was found as compared to control, loss of heterozygosity was observed in the RCC85#21 clone, but not in the renal cancer cell lines from which it was generated. The image analysis of RCC85#21 by two-dimensional gels showed 700±26 spots and 119 spots were identified by mass spectrometry analysis. RCC85#21 promoted a significant RCC-specific T cells activation by exhibiting a cytotoxic phenotype after mixed lymphocyte and tumor cell cultures. CD8+ T cells isolated from RCC patients displayed an elevated reactivity against RCC85#21 and efficiently lysed the RCC85#21 clone. The RCC85#21 immunogenic cell line will be suitable for immune stimulation. The identification of novel tumor associated antigens will allow the evaluation of the immune response in vitro and, subsequently, in vivo paving the way for new immunotherapeutic strategies in the RCC setting.

Efficacy of RetroNectin-activated cytokine-induced killer cell therapy in the treatment of advanced hepatocelluar carcinoma

The present study aimed to investigate the efficacy of RetroNectin-activated cytokine-induced killer cell (R-CIK) therapy in advanced hepatocellular carcinoma patients as compared with conventional chemotherapy, a comparison that has not yet been thoroughly studied. From January 2010 to October 2013, 74 patients with an initial diagnosis of advanced hepatocelluar carcinoma were enrolled in the study. Patients were assigned to one of two treatment arms: patients in arm 1 (n=37) received R-CIK treatment as the first line therapy, whereas those in arm 2 (n=37) received chemotherapy as the first line treatment. The primary end point measured in this study was median overall survival (mOS). Median progression-free survival time (mPFS) and 1- and 2-year survival rates were recorded as secondary end points. Kaplan-Meier analysis was performed on all mOS and mPFS data, and treatment hazard ratios were established using the Cox proportional hazards model. The 1-year survival rate in treatment arm 1 was 42.47% vs. 24.89% in arm 2 (95% CI, 24.91-59.01% vs. 12.10-40.02%, P=0.066); the 2-year survival rates were 21.24 and 5.53% (95% CI, 4.60-45.86 vs. 0.46-21.06%, P=0.106) in arms 1 and 2, respectively; the mPFS in arm 1 was 4.37 vs. 3.90 (x²=0.182, P=0.670) in arm 2; and the mOS in arm 1 was 14.03 months vs. 9.46 months(x²=4.406, P=0.036) in arm 2. Calculations of univariate analyses of arm 1, R-CIK cycles ≥6, KPS >70, AFP ≤400 ng/ml, and findings of no vascular invasion and no extra-hepatic metastasis were potential predictive factors (P<0.05). Calculations from multivariate analyses similarly identified these factors as potentially having predictive value (P<0.05). The main adverse effects of R-CIK therapy included fever and headache pain. R-CIK treatment may prolong mOS in advanced hepatocellular carcinoma patients compared with conventional chemotherapy. Patients who underwent ≥6 cycles of R-CIK, had KPS scores >70, AFP ≤400 ng/ml, displayed no evidence of vascular invasion, and no extra-hepatic metastasis appeared to have longer survival times compared with other cohorts in the present study.

Adoptive immunotherapy with interleukin-2 & induced killer cells in non-small cell lung cancer: A systematic review & meta-analysis

BACKGROUND & OBJECTIVES

The effectiveness of interleukin-2 (IL-2) and induced killer cells for non-small cell lung cancer (NSCLC) is controversial. This study evaluates the efficacy and safety of interleukin-2 and induced killer cells on NSCLC, so as to provide references for further clinical practice and research.

METHODS

Relevant randomized controlled trials (RCTs) were searched in Cochrane library (Issue 2, 2013), Web of Science (1980-March 2013), PubMed (1966-March 2013), China Knowledge Resource Integrated database (CNKI) (1994-March 2013), China Biology Medicine database (CBM) (1978-March 2013), VIP (1989-March 2013), and Wan Fang databases (1997-March 2013). There were no language restrictions. After independent quality assessment and data extraction by two authors, meta-analysis was conducted by RevMan 5.1 software.

RESULTS

Ten RCTs were included. Odds ratio (OR), 95% confidence intervals (CI), P value expressed as test group (interleukin-2 or induced killer cells combined chemotherapy) versus control group (chemotherapy alone), was 2.02 (1.24, 3.29; P=0.004) for disease control rate. Hazard ratios (HR) (95% CI; P value), expressed as test group (interleukin-2 or induced killer cells) versus control group, were 0.60 (0.46, 0.79; P=0.0003) for overall survival of postoperative treatment, and 0.77 (0.60, 0.99; P =0.04) for overall survival of combination with chemotherapy. Mean differences (MD) (95% CI; P value), expressed as test group (interleukin-2 or induced killer cells) versus control group (after treatment), were 11.32 (6.32, 16.33; P=0.00001) for NK cells, 11.79 (2.71, 20.86; P=0.01) for CD3+ cells, 14.63 (2.62, 26.64; P=0.02) for CD4+ cells, and -4.49 (-7.80, 1.18; P=0.008) for CD8+ cells.

INTERPRETATION & CONCLUSIONS

The meta-analysis showed that IL-2 or induced killer cells combination therapy was efficacious in treating NSCLC and improved overall survival. Further analysis of trials having adequate information and data need to be done to confirm these findings.

Tumor-infiltrating lymphocytes for the treatment of metastatic cancer

Over the past few years melanoma incidence has been rising steadily, resulting in an increase in melanoma related mortality. Until recently, therapeutic options for metastatic melanoma were scarce. Chemotherapy and, in some countries, IL-2 were the only registered treatment modalities. In the last five years, treatment with immunotherapy (anti CTLA-4, anti PD-1, or the combination of these antibodies) has shown very promising results and was able to improve survival in patients with metastatic melanoma. Adoptive cell therapy using tumor-infiltrating lymphocytes is yet another, but highly promising, immunotherapeutic strategy for patients with metastatic melanoma. This review will discuss the development of TIL as a treatment option for melanoma, its mode of action and simplification over time, and the possibilities to expand this therapy to other types of cancer. Also, the future directions of TIL based therapies will be highlighted.

Increased survival time of a patient with metastatic malignant melanoma following immunotherapy: A case report and literature review

Metastatic malignant melanoma is treated with chemotherapy and radiotherapy. A number of previous studies have indicated that cytokine-induced killer cells (CIK cells) are a heterogeneous cell population that express cluster of differentiation (CD)3 and CD56, in addition to the natural killer cell NKG2D activating receptor. CIK cells possess major histocompatibility complex-unrestricted cytotoxicity towards cancer, but not towards normal targets. The present study investigated whether the addition of CIK cells resulted in an improved therapeutic response in a patient with metastatic malignant melanoma. In the current case, a patient with metastatic malignant melanoma received CIK therapy, which resulted in a relatively long survival time of 28 months. To the best of our knowledge, there have been no previous studies reporting such positive effects in a patient who received CIK cell immunotherapy. Based on the findings of the present study, CIK cell therapy may be an option that results in a good prognosis in certain patients with metastatic malignant melanoma.

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.

A randomized phase II study of autologous cytokine-induced killer cells in treatment of hepatocellular carcinoma

PURPOSE

This prospective study aims to explore the benefit of cytokine-induced killer cell (CIK) treatment in hepatocellular carcinoma patients, which has not yet been thoroughly studied before.

METHODS

From January 2004 to May 2009, 132 patients who were initially diagnosed with hepatocellular carcinoma of Barcelona Clinic Liver Cancer (BCLC) stage A, B or C, Child-Pugh scores of A or B and without prior treatment were enrolled in the study. Patients were randomly assigned to either arm 1 (n = 66) to receive CIK treatment plus standard treatment, or arm 2 (n = 66) to receive standard treatment only. The primary end point was overall survival (OS) and the secondary endpoint was progression-free survival as evaluated by Kaplan-Meier analyses and treatment hazard ratios with the Cox proportional hazards model.

RESULTS

The 1-year (OS: 74.2% vs. 50.0%, 95% CI: 63.6-84.8% vs. 37.8-62.2, p = 0.002), 2-year (OS: 53.0% vs. 30.3%, 95% CI: 40.8-65.2% vs. 19.1-41.5%, p = 0.002), 3-year (OS: 42.4% vs. 24.2%, 95% CI: 30.4-54.4% vs. 13.8-34.6%, p = 0.005) and median overall and progression-free survivals of arm 1 patients were significantly higher than those of arm 2. Therefore, in patients who are not suitable for surgery, significant benefit is obtained from CIK treatment. The main adverse effects of CIK included fever, allergy and headache pain.

CONCLUSIONS

Hepatocellular carcinoma patients who were not suitable for surgery demonstrate prolonged overall and progression-free survival from CIK treatment.

Autologous CIK cell immunotherapy in patients with renal cell carcinoma after radical nephrectomy

Objective. To evaluate the efficacy of autologous cytokine-induced killer (CIK) cells in patients with renal cell carcinoma (RCC). Methods. 20 patients diagnosed with TNM stage I or II RCC were randomly divided into two groups, a CIK cell treatment group and a control group. The endpoint was progression-free survival (PFS) evaluated by Kaplan-Meier analyses. Results. CD3⁺, CD3⁺/CD8⁺, CD3⁺/CD4⁺, and CD3⁺/CD56⁺ levels increased after CIK cell culture (P < 0.01). The median PFS in CIK cell treatment group was significantly longer than that in control group (PFS, 32.2 months versus 21.6 months; log-rank, P = 0.032), all patients were alive during the course of followup, and there are no statistically significant differences between two groups in OS (log-rank, P = 0.214). Grade III or greater adverse events were not observed. Conclusions. CIK cells treatment could prolong survival in patients with RCC after radical nephrectomy and showed acceptable curative effect with potential enhancement of cellular immune function. This trial is registered with Clinicaltrials.gov NCT01799083.

Dendritic cell-based immunotherapy in prevention and treatment of renal cell carcinoma: efficacy, safety, and activity of Ad-GM·CAIX in immunocompetent mouse models

The dendritic cell vaccine DC-Ad-GM·CAIX is an active, specific immunotherapy with the potential of providing a safe and effective therapy against renal cell carcinoma (RCC). Using immunocompetent Balb/c mouse models we tested the efficacy and mechanism of the vaccine to prevent and treat the growth of a syngeneic RCC (RENCA) engineered to overexpress the human TAA carbonic anhydrase IX (NPR-IX). In a prevention model, NPR-IX tumor development was specifically and significantly delayed by 13 days in DC-Ad-GM·CAIX-treated mice (P < 0.001), tumor volumes were 79% smaller (day 24, P < 0.007), and body weight was maintained at study termination compared with the controls. Six of these mice remained tumor-free for > 1 year. In a treatment model, NPR-IX tumors remained smaller in DC-Ad-GM·CAIX-treated mice for 8 days (P < 0.002), achieving a 60% growth inhibition at termination. No vaccine-related organ toxicity was observed in either model. The critical mechanistic parameter separating responsive from nonresponsive tumors was hCAIX protein expression, demonstrated by aggressive growth of tumors that did not express hCAIX protein and in sham-treated mice (DC-Ad-Null). No murine serum anti-hCAIX antibodies were detected. Moreover, altered mechanisms of immunoediting as a means for immune evasion were suggested by differential gene expression (Ccl1, Hmgb1, Fgl2, Cd209a, and Klra2) and therapy evasion miRNAs (miR-1186, miR-98, miR-5097, miR-1942, and miR-708) in tumors that evaded DC-Ad-GM·CAIX immunotherapy. This is the first study in immunocompetent mice that provides a proof of concept for the specificity, efficacy, safety, and activity of the DC-Ad-GM·CAIX immunotherapy, forming the basis for a first-in-human phase I trial in RCC patients.

The immune environment of paediatric solid malignancies: evidence from an immunohistochemical study of clinical cases

Childhood malignancies are relatively poorly studied in terms of tumour/host interaction. Using tissue arrays of childhood cancers, we analysed immunohistochemical staining for CD68, CD3 and FOXP3 to evaluate infiltration of myeloid cells, lymphocytes and regulatory T cells. Staining for phosphorylated STAT3 was performed in a subset. The majority of paediatric tumours demonstrated a marked infiltration of CD68+ myeloid cells but, with the exception of neuroblastoma, most showed only sparse infiltration of CD3+/ FOXP3- cells. There was evidence for activation of STAT3 in pPNET (50%), ependymoma (45%) and undifferentiated sarcoma (38%), but it was rarely activated in other tumours.

Adoptive cellular immunotherapy in metastatic renal cell carcinoma: a systematic review and meta-analysis

Purpose

Metastatic renal cell carcinoma (mRCC), as one of the most immunogenic tumors has been the focus of adoptive cellular immunotherapy (ACI), but the effects of ACI on objective response and survival in patients with mRCC are still controversial. Therefore, a systematic review and meta-analysis was performed to address this issue.

Methods

A search was conducted in the PubMed database for randomized clinical trials (RCTs) with ACI in mRCC. All included articles in this study were assessed according to the selection criteria and were divided into two groups: ACI versus no ACI. Outcomes were toxicity, objective response, 1-, 3- and 5-year survival. Risk ratio (RR) and 95% confidence intervals (CI) were calculated using a fixed-effects meta-analysis. Heterogeneity was measured by value of I² or P.

Results

4 studies (469 patients) were included. Most of ACI-related adverse reactions were grade 1 or 2 and reversible. ACI provided significant benefit in terms of objective response (RR = 1.65; 95% CI, 1.15 to 2.38; P = 0.007, I² = 49%), 1-year survival (RR = 1.30; 95% CI, 1.12 to 1.52; P = 0.0008, I² = 0%), 3-year survival (RR = 2.76; 95% CI, 1.85 to 4.14; P<0.00001, I² = 46%) and 5-year survival (RR = 2.42; 95% CI, 1.21 to 4.83; P = 0.01, I² = 28%).

Conclusions

ACI may be a safe and effective treatment for improving objective response, 1-, 3- and 5-year survival in patients with mRCC. Besides, five obstacles for ACI, including high degree of personalization, unsuitable WHO/RECIST response criteria, inadequate identification of tumor-associated antigens (TAAs), lack of effective combination treatments and less attention paid to the quality of ACI products, should be overcome during the successful development of more potent ACI for cancer in the future.

Autologous cytokine-induced killer cell immunotherapy in lung cancer: a phase II clinical study

OBJECTIVE

Cytokine-induced killer (CIK) cells have the ability to kill tumor in vitro and in vivo. This study was designed to evaluate the clinical efficacy of CIK cell immunotherapy following regular chemotherapy in patients with non-small cell lung cancer (NSCLC) after surgery.

METHODS

A paired study, with 87 stage I-IV NSCLC patients in each group, was performed. Patients received either chemotherapy (arm 2) or chemotherapy in combination with autologous CIK cell immunotherapy (arm 1). Progression-free survival (PFS) and overall survival (OS) were evaluated.

RESULTS

Of the 87 paired patients, 50 had early-stage disease (stage I-IIIA) and 37 had advanced-stage disease (stage IIIB-IV). Among early-stage patients, the distribution of 3-year PFS rate and median PFS time showed no statistical difference between the two groups (p = 0.259 and 0.093, respectively); however, the 3-year OS rate and median OS time in arm 1 were significantly higher than those in arm 2 (82 vs. 66 %; p = 0.049 and 73 vs. 53 months; p = 0.006, respectively). Among the advanced-stage patients, the 3-year PFS and OS rates of arm 1 were significantly higher than those of arm 2 (6 vs. 3 %; p < 0.001 and 31 vs. 3 %; p < 0.001, respectively); the median PFS and OS times in arm 1 were also significantly longer than those in arm 2 (13 vs. 6 months; p = 0.001 and 24 vs. 10 months; p < 0.001, respectively). Multivariate analyses indicated that the frequency of CIK cell immunotherapy was significantly associated with prolonged PFS (HR = 0.91; 95 % CI 0.85-0.98; p = 0.012) and OS (HR = 0.83; 95 % CI, 0.74-0.93; p = 0.001) in the arm 1.

CONCLUSIONS

The data suggested that CIK cell immunotherapy could improve the efficacy of conventional chemotherapy in NSCLC patients, and increased frequency of CIK cell treatment could further enhance the beneficial effects. A multi-center randomized trial is being carried out in our hospital to further validate these findings.

Antitumor T-cell responses contribute to the effects of dasatinib on c-KIT mutant murine mastocytoma and are potentiated by anti-OX40

Targeted and immune-based therapies are thought to eradicate cancer cells by different mechanisms, and these approaches could possibly complement each other when used in combination. In this study, we report that the in vivo antitumor effects of the c-KIT inhibitor, dasatinib, on the c-KIT mutant P815 mastocytoma tumor were substantially dependent on T cell-mediated immunity. We found that dasatinib treatment significantly decreased levels of Tregs while specifically enhancing tumor antigen-specific T-cell responses. We sought to further enhance this therapy with the addition of anti-OX40 antibody, which is known to provide a potent costimulatory signal to T cells. The combination of dasatinib and anti-OX40 antibody resulted in substantially better therapeutic efficacy compared with either drug alone, and this was associated with enhanced accumulation of tumor antigen-specific T cells in the tumor microenvironment. Furthermore, the combination regimen inhibited the function of Tregs and also resulted in significantly up-regulated expression of the IFN-γ-induced chemokines CXCL9, 10, and 11 in the tumor microenvironment, which provides a feasible mechanism for the enhanced intratumoral CTL infiltration. These studies delineate a strategy by which targeted therapy and immunotherapy may be combined to achieve superior antitumor responses in cancer patients.

Eradication of metastatic renal cell carcinoma after adenovirus-encoded TNF-related apoptosis-inducing ligand (TRAIL)/CpG immunotherapy

Despite evidence that antitumor immunity can be protective against renal cell carcinoma (RCC), few patients respond objectively to immunotherapy and the disease is fatal once metastases develop. We asked to what extent combinatorial immunotherapy with Adenovirus-encoded murine TNF-related apoptosis-inducing ligand (Ad5mTRAIL) plus CpG oligonucleotide, given at the primary tumor site, would prove efficacious against metastatic murine RCC. To quantitate primary renal and metastatic tumor growth in mice, we developed a luciferase-expressing Renca cell line, and monitored tumor burdens via bioluminescent imaging. Orthotopic tumor challenge gave rise to aggressive primary tumors and lung metastases that were detectable by day 7. Intra-renal administration of Ad5mTRAIL+CpG on day 7 led to an influx of effector phenotype CD4 and CD8 T cells into the kidney by day 12 and regression of established primary renal tumors. Intra-renal immunotherapy also led to systemic immune responses characterized by splenomegaly, elevated serum IgG levels, increased CD4 and CD8 T cell infiltration into the lungs, and elimination of metastatic lung tumors. Tumor regression was primarily dependent upon CD8 T cells and resulted in prolonged survival of treated mice. Thus, local administration of Ad5mTRAIL+CpG at the primary tumor site can initiate CD8-dependent systemic immunity that is sufficient to cause regression of metastatic lung tumors. A similar approach may prove beneficial for patients with metastatic RCC.

Chronic inflammation and immunologic-based constraints in malignant disease

Acute inflammatory reactions benefit the host by supporting the effective clearance of pathogens and fostering wound healing, in addition to other self-preservative processes. However, when the inflammatory program is not resolved, becoming chronic in nature, it creates an environment conducive to cancer development and progression. Therefore, minimizing exposure to risk factors that contribute to chronic inflammation and reconditioning the host towards a state of (at least locoregional) acute inflammation would meaningfully impact cancer incidence and its treatment, respectively. Regarding cancer therapy, combinational treatments that both disrupt chronic inflammation and install specific adaptive type I immunity are predicted to enhance quality of life and extend the overall survival of patients.

Randomized study of autologous cytokine-induced killer cell immunotherapy in metastatic renal carcinoma

PURPOSE

The therapeutic benefit of the cytokine-induced killer (CIK) cells was unknown in the renal cell carcinoma (RCC). This prospectively randomized study was conducted to evaluate the effects of autologous CIK cell immunotherapy in patients with metastatic clear cell RCCs.

EXPERIMENTAL DESIGN

From June 2005 to June 2008, 148 patients with metastatic clear cell RCC were randomized to autologous CIK cell immunotherapy (arm 1, n = 74), or interleukin-2 treatment combination with IFN-α-2a (arm 2, n = 74). The primary endpoint was overall survival (OS) and secondary endpoint was progression-free survival (PFS) evaluated by Kaplan-Meier analyses and treatment HRs with the Cox proportional hazards model.

RESULTS

The 3-year PFS and OS in arm 1 were 18% and 61%, as compared with 12% and 23% in arm 2 (P = 0.031 and <0.001, respectively). The median PFS and OS in arm 1 were significantly longer than those in arm 2 (PFS, 12 vs. 8 months, P = 0.024; OS, 46 vs. 19 months, P < 0.001). Multivariate analyses indicated that the cycle count of CIK cell immunotherapy as a continuous variable was significantly associated with prolonged PFS [HR = 0.88; 95% confidence interval (CI), 0.84-0.93; P < 0.001] and OS (HR = 0.58; 95% CI, 0.48-0.69; P < 0.001) in arm 1.

CONCLUSION

The data suggested that CIK cell immunotherapy could improve the prognosis of metastatic clear cell RCC, and increased cycle count of CIK cell treatment could further enhance the beneficial effects.

Dendritic cell internalization of α-galactosylceramide from CD8 T cells induces potent antitumor CD8 T-cell responses

Dendritic cells (DC) present α-galactosylceramide (αGalCer) to invariant T-cell receptor-expressing natural killer T cells (iNKT) activating these cells to secrete a variety of cytokines, which in turn results in DC maturation and activation of other cell types, including NK cells, B cells, and conventional T cells. In this study, we showed that αGalCer-pulsing of antigen-activated CD8 T cells before adoptive transfer to tumor-bearing mice caused a marked increase in donor T-cell proliferation, precursor frequency, and cytotoxic lymphocyte activity. This effect was interleukin (IL)-2 dependent and involved both natural killer T cells (NKT) and DCs, as mice lacking IL-2, NKTs, and DCs lacked any enhanced response to adoptively transferred αGalCer-loaded CD8 T cells. iNKT activation was mediated by transfer of αGalCer from the cell membrane of the donor CD8 T cells onto the αGalCer receptor CD1d which is present on host DCs. αGalCer transfer was increased by prior activation of the donor CD8 T cells and required AP-2-mediated endocytosis by host DCs. In addition, host iNKT cell activation led to strong IL-2 synthesis, thereby increasing expansion and differentiation of donor CD8 T cells. Transfer of these cells led to improved therapeutic efficacy against established solid tumors in mice. Thus, our findings illustrate how αGalCer loading of CD8 T cells after antigen activation in vitro may leverage the therapeutic potential of adoptive T-cell therapies.

Immunotherapy of prostate cancer: identification of new treatments and targets for therapy, and role of WAP domain-containing proteins

Prostate adenocarcinoma is present in over 80% of men over the age of 80 and is by far the most common cancer of men. Although radical prostatectomy is curative in early disease, the risks of incontinence and impotence can affect the quality of life of patients. Early intervention with localized immunotherapy represents a potential solution as lymphocyte infiltration does occur in prostate cancer lesions, and immunotherapy with dendritic cell vaccines can significantly increase survival in late stage disease. However, lymphocytic infiltrates in the cancerous prostates have an anergic character arising from the suppressive effects of the microenvironment resulting from a conversion of effector cells into regulatory T-cells. Although TGFβ (transforming growth factor β) and IL-10 (interleukin-10) are known to be strong suppressor molecules associated with prostate cancer, they are among many possible suppressive factors. We discuss the possible role of alternative suppressor molecules, including the WAP (whey acidic protein) homologue ps20 that is expressed on prostate stroma and other WAP domain-containing proteins in the immunosuppressive prostate cancer milieu and discuss novel immunotherapeutic strategies to combat this disease.

Is adoptive T-cell therapy for solid tumors coming of age?

Among the novel biological therapeutics that will increase our ability to cure human cancer in years to come, adoptive cellular therapy is one of the most promising approaches. Although this is a complex and challenging field, there have been major advances in basic and translational research resulting in clinical trial activity that is now beginning to confirm this promise. The results obtained with tumor-infiltrating lymphocytes therapy for melanoma, and virus-specific CTLs for EBV-associated malignancies are encouraging in terms of both ability to obtain clinical benefit and limited toxicity profile. In both settings, objective responses were obtained in at least 50% of treated patients. However, improvements to the clinical protocols, in terms of better patient selection and timing of administration, as well as cell product quality and availability, are clearly necessary to further ameliorate outcome, and logistical solutions are warranted to extend T-cell therapy beyond academic centers. In particular, there is a need to simplify cell production, in order to decrease costs and ease preparation. Promising implementations are underway, including harnessing the therapeutic potential of T cells transduced with TCRs directed against shared tumor antigens, and delineating strategies aimed at targeting immune evasion mechanisms exerted by tumor cells.

Therapeutic vaccines in renal cell carcinoma

Metastatic renal cell carcinoma (mRCC) is a lethal disease. The advent of tyrosine kinase inhibitors (TKIs) has changed the disease process, yet the majority of patients will develop treatment-resistant disease. IL-2 based immunotherapy in mRCC is the only US FDA-approved treatment with curative results. Immunotherapeutic vaccine approaches to mRCC have been under investigation for several decades with mixed results. The recent FDA-approval of the first cellular immunotherapy in prostate cancer (Provenge(®)) has reinvigorated the search for similar vaccines approaches in mRCC. This review introduces the concepts and different features required for a successful anticancer vaccine approach.

T cell therapy for nasopharyngeal carcinoma

Among the novel biologic therapeutics that will increase our ability to cure human cancer in the years to come, T cell therapy is one of the most promising approaches. However, with the possible exception of tumor-infiltrating lymphocytes therapy for melanoma, clinical trials of adoptive T-cell therapy for solid tumors have so far provided only clear proofs-of-principle to build on with further development. Epstein-Barr virus (EBV)-associated malignancies offer a unique model to develop T cell-based immune therapies, targeting viral antigens expressed on tumor cells. In the last two decades, EBV-specific cytotoxic T-lymphocytes (CTL) have been successfully employed for the prophylaxis and treatment of EBV-related lymphoproliferative disorders in immunocompromised hosts. More recently, this therapeutic approach has been applied to the setting of EBV-related solid tumors, such as nasopharyngeal carcinoma. The results are encouraging, although further improvements to the clinical protocols are clearly necessary to increase anti-tumor activity. Promising implementations are underway, including harnessing the therapeutic potential of CTLs specific for subdominant EBV latent cycle epitopes, and delineating strategies aimed at targeting immune evasion mechanisms exerted by tumor cells.

Molecular imaging of cell-based cancer immunotherapy

Cell-based cancer immunotherapy represents a new and powerful weapon in the arsenal of anticancer treatments. Non-invasive monitoring of the disposition, migration and destination of therapeutic cells will facilitate the development of cell based therapy. The therapeutic cells can be modified intrinsically by a reporter gene or labeled extrinsically by introducing imaging probes into the cells or on the cell surface before transplant. Various advanced non-invasive molecular imaging techniques are playing important roles in optimizing cellular therapy by tracking cells and monitoring the therapeutic effects of transplanted cells in vivo. This review will summarize the application of multiple molecular imaging modalities in cell-based cancer immunotherapy.

Program death-1 signaling and regulatory T cells collaborate to resist the function of adoptively transferred cytotoxic T lymphocytes in advanced acute myeloid leukemia

Tumor-induced immune defects can weaken host immune response and permit tumor cell growth. In a systemic model of murine acute myeloid leukemia (AML), tumor progression resulted in increased regulatory T cells (Treg) and elevation of program death-1 (PD-1) expression on CD8(+) cytotoxic T cells (CTLs) at the tumor site. PD-1 knockout mice were more resistant to AML despite the presence of similar percentage of Tregs compared with wild type. In vitro, intact Treg suppression of CD8(+) T-cell responses was dependent on PD-1 expression by T cells and Tregs and PD-L1 expression by antigen-presenting cells. In vivo, the function of adoptively transferred AML-reactive CTLs was reduced by AML-associated Tregs. Anti-PD-L1 monoclonal antibody treatment increased the proliferation and function of CTLs at tumor sites, reduced AML tumor burden, and resulted in long-term survivors. Treg depletion followed by PD-1/PD-L1 blockade showed superior efficacy for eradication of established AML. These data demonstrated that interaction between PD-1 and PD-L1 can facilitate Treg-induced suppression of T-effector cells and dampen the antitumor immune response. PD-1/PD-L1 blockade coupled with Treg depletion represents an important new approach that can be readily translated into the clinic to improve the therapeutic efficacy of adoptive AML-reactive CTLs in advanced AML disease.

T-cell receptor gene-modified T cells with shared renal cell carcinoma specificity for adoptive T-cell therapy

PURPOSE

Adoptive therapy with genetically engineered T cells carrying redirected antigen specificity is a new option for the treatment of cancer. This approach is not yet available for metastatic renal cell carcinoma (RCC), due to the scarcity of therapeutically useful reagents. We analyzed tumor-infiltrating lymphocytes (TIL) from RCC to identify T-cell specificities with shared tumor-specific recognition to develop T-cell receptor (TCR)-engineered T lymphocytes for adoptive therapy of RCC.

EXPERIMENTAL DESIGN

We established a T-cell clone from TIL that recognized a human leukocyte antigen (HLA)-A2-restricted tumor antigen. The TCR alpha- and beta-chain genes were isolated, modified by codon optimization and murinization, and retrovirally transduced into peripheral blood lymphocytes (PBL). A TCR-expressing indicator line (B3Z-TCR53) was established to screen for antigen prevalence in RCC, other malignancies, and normal cell counterparts.

RESULTS

TCR53-engineered PBL recapitulated the specificity of the TIL and showed tumor-specific HLA-A2-restricted effector activities (IFN-gamma, tumor necrosis factor-alpha, interleukin-2, macrophage inflammatory protein-1beta, cytotoxicity). PBL-TCR53 of healthy donors and RCC patients exhibited similar transduction efficiency, expansion, and polyfunctional profile. Using B3Z-TCR53 cells, 130 tumor and normal cells were screened and shared TCR53 peptide: MHC expression was found in >60% of RCC and 25% of tumor lines of other histology, whereas normal tissue cells were not recognized.

CONCLUSIONS

To date, TCR53 is the only TCR with shared HLA-A2-restricted recognition of RCC. It fulfills the criteria for utilization in TCR gene therapy and advances T cell-based immunotherapy to patients with RCC and other malignancies expressing the TCR ligand.