Document Detail

Immunologic monitoring of cellular responses by dendritic/tumor cell fusion vaccines.
Jump to Full Text
MedLine Citation:
PMID:  21541197     Owner:  NLM     Status:  MEDLINE    
Although dendritic cell (DC)- based cancer vaccines induce effective antitumor activities in murine models, only limited therapeutic results have been obtained in clinical trials. As cancer vaccines induce antitumor activities by eliciting or modifying immune responses in patients with cancer, the Response Evaluation Criteria in Solid Tumors (RECIST) and WHO criteria, designed to detect early effects of cytotoxic chemotherapy in solid tumors, may not provide a complete assessment of cancer vaccines. The problem may, in part, be resolved by carrying out immunologic cellular monitoring, which is one prerequisite for rational development of cancer vaccines. In this review, we will discuss immunologic monitoring of cellular responses for the evaluation of cancer vaccines including fusions of DC and whole tumor cell.
Shigeo Koido; Sadamu Homma; Akitaka Takahara; Yoshihisa Namiki; Hideo Komita; Eijiro Nagasaki; Masaki Ito; Keisuke Nagatsuma; Kan Uchiyama; Kenichi Satoh; Toshifumi Ohkusa; Jianlin Gong; Hisao Tajiri
Related Documents :
4396127 - Beta-adrenoceptor antagonist activity of 3-methoxyisoprenaline.
11429927 - Electrophilic nitration of aromatics in ionic liquid solvents.
21386997 - A rapid flp-in system for expression of secreted h5n1 influenza hemagglutinin vaccine i...
15823047 - Stable recognition of ta interruptions by triplex forming oligonucleotides containing a...
19797807 - Helicobacter pylori vaccine: mucosal adjuvant & delivery systems.
17368317 - Vitamin a supplementation and retinoic acid treatment in the regulation of antibody res...
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Review     Date:  2011-04-26
Journal Detail:
Title:  Journal of biomedicine & biotechnology     Volume:  2011     ISSN:  1110-7251     ISO Abbreviation:  J. Biomed. Biotechnol.     Publication Date:  2011  
Date Detail:
Created Date:  2011-05-04     Completed Date:  2011-08-26     Revised Date:  2013-06-30    
Medline Journal Info:
Nlm Unique ID:  101135740     Medline TA:  J Biomed Biotechnol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  910836     Citation Subset:  IM    
Division of Gastroenterology and Hepatology, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Cancer Vaccines / immunology*
Cell Fusion
Dendritic Cells / cytology*,  immunology*
Monitoring, Immunologic / methods*
Neoplasms / immunology*,  pathology*
T-Lymphocytes / immunology
Reg. No./Substance:
0/Cancer Vaccines

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Full Text
Journal Information
Journal ID (nlm-ta): J Biomed Biotechnol
Journal ID (publisher-id): JBB
ISSN: 1110-7243
ISSN: 1110-7251
Publisher: Hindawi Publishing Corporation
Article Information
Download PDF
Copyright © 2011 Shigeo Koido et al.
Received Day: 12 Month: 8 Year: 2010
Revision Received Day: 11 Month: 11 Year: 2010
Accepted Day: 27 Month: 2 Year: 2011
Print publication date: Year: 2011
Electronic publication date: Day: 26 Month: 4 Year: 2011
Volume: 2011E-location ID: 910836
ID: 3085507
PubMed Id: 21541197
DOI: 10.1155/2011/910836

Immunologic Monitoring of Cellular Responses by Dendritic/Tumor Cell Fusion Vaccines
Shigeo Koido1, 2, 3I2I3*
Sadamu Homma3
Akitaka Takahara1
Yoshihisa Namiki2
Hideo Komita1
Eijiro Nagasaki3
Masaki Ito3
Keisuke Nagatsuma1
Kan Uchiyama1
Kenichi Satoh1
Toshifumi Ohkusa1
Jianlin Gong4
Hisao Tajiri1
1Division of Gastroenterology and Hepatology, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo 105-8461, Japan
2Institute of Clinical Medicine and Research, The Jikei University School of Medicine, Tokyo 105-8461, Japan
3Department of Oncology, Institute of DNA Medicine, The Jikei University School of Medicine, Tokyo 105-8461, Japan
4Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA
Correspondence: *Shigeo Koido:
[other] Academic Editor: Theresa L. Whiteside

1. Introduction

The mechanism of action for most cancer vaccines is mainly mediated through cytotoxic T lymphocytes (CTLs). We are now gaining a clear understanding of the cellular events leading to an effective CTL-mediated antitumor immunity. The antigen-presenting cells (APCs) most suitable for cancer vaccines are dendritic cells (DCs), which can be distinguished from B cells and macrophages by their abundant expression of costimulatory molecules and abilities to initiate a strong primary immune response [1, 2]. DCs are specialized to capture and process tumor-associated antigens (TAAs), converting the proteins to peptides that are presented on major histocompatibility complex (MHC) class I and class II molecules [3]. After TAAs uptake and inflammatory stimulation, immature DCs in peripheral tissues undergo a maturation process characterized by the upregulation of costimulatory molecules [2, 3]. During this process, mature DCs migrate to T-cell areas of secondary lymphoid organs, where they present antigenic peptides to CD8+ and CD4+ T cells through MHC class I and class II pathways, respectively, and become competent to present antigens to T cells, thus initiating antigen-specific CTL responses [4]. Antigen-specific CTLs in turn can attack tumor cells that express cognate antigenic determinants or can provide help for B-cell responses that produce antibodies, which can also lead to tumor cell death in some cases [5]. Thus, the mechanism of action for cancer vaccines, based on harnessing host immune cells to infiltrate tumors and to exert CTL responses, is quite different from that of a traditional cytotoxic chemotherapy [6].

2. DC-Based Cancer Vaccines

A major area of investigation in induction of antitumor immunity involves the design of DC-based cancer vaccines [7]. DCs derive their potency from constitutive and inducible expression of essential costimulatory molecules including B7, ICAM-1, LFA-1, LFA-3, and CD40 on the cell surface [1, 8, 9]. These proteins function in concert to generate a network of secondary signals essential for reinforcing the primary antigen-specific signals in T-cell activation. Therefore, many strategies have been developed to load TAAs onto DCs and used as cancer vaccines. For example, DCs are pulsed with synthetic peptides derived from the known antigens [10], tumor lysates [11], tumor RNA [12, 13], and dying tumor cells [14] to induce antigen-specific antitumor immunity. Although the production of DC-based cancer vaccines for individual patients with cancer has currently been addressed in clinical trials, a major drawback of these strategies comes from the limited number of known antigenic peptides available in many HLA contexts. Moreover, the results of clinical trials using DCs pulsed with antigen-specific peptides show that clinical responses have been found in a small number of patients [15, 16]. To overcome this limitation, we have proposed the fusions of DCs and whole tumor cell (DC/tumor) to generate cell hybrids with the characteristics of APCs able to process endogenously provided whole TAAs [17]. The whole tumor cells may be postulated to serve as the best source of antigens [1721].

3. DC/Tumor Fusion Vaccines

The fusion of DC and tumor cell through chemical [17], physical [22], or biological means [23] creates a heterokaryon which combines DC-derived costimulatory molecules, efficient antigen-processing and -presentation machinery, and an abundance of tumor-derived antigens including those yet to be unidentified (Figure 1). Thus, the DC/tumor fusion cells combine the essential elements for presenting tumor antigens to host immune cells and for inducing effective antitumor responses. Now, it is becoming clear that the tumor antigens are processed along the endogenous pathway, through the antigen processing machinery of human DC. Thus, it is conceivable that tumor antigens synthesized de novo in the heterokaryon are processed and presented through the endogenous pathway. The advantage of DC/tumor fusion vaccines over pulsing DC with whole tumor lysates is that endogenously synthesized antigens have better access to MHC class I pathway [1821]. Indeed, it has been demonstrated that DC/tumor fusion vaccines are superior to those involving other methods of DC loaded with antigenic proteins, peptides, tumor cell lysates, or irradiated tumor cells in murine models [1821]. The efficacy of antitumor immunity induced by DC/tumor fusion vaccines has been demonstrated in murine models using melanoma [2432], colorectal [17, 30, 31, 3341], breast [4247], esophageal [48], pancreatic [49, 50], hepatocellular [5155], lung [22, 41, 5659], renal cell [60] carcinoma, sarcoma [6166], myeloma [6774], mastocytoma [75], lymphoma [76], and neuroblastoma [77]. The fusion cells generated with human DC and tumor cell also have the ability to present multiple tumor antigens, thus increasing the frequency of responding T cells and maximizing antitumor immunity capable of killing tumor targets such as colon [7884], gastric [85, 86], pancreatic [87], breast [47, 8893], laryngeal [94], ovarian [9597], lung [85, 98], prostate [99, 100], renal cell [101, 102], hepatocellular [103105] carcinoma, leukemia [106111], myeloma [112, 113], sarcoma [114, 115], melanoma [116119], glioma [120], and plasmacytoma [121].

4. Monitoring of DC/Tumor Fusion Cell Preparations

Despite the strong preclinical evidences supporting the use of DC/tumor fusions for cancer vaccination, the results of clinical trials so far reported are conflicting [1821]. One of the reasons is the evidence for fusion cell formation used as clinical trials is not definitive [23]. The levels of fusion efficiency, which can be quantified by determining the percentage of cells that coexpress tumor and DC antigens, are closely correlated with CTL induction in vitro [82, 83]. Another reason is immunosuppressive substances such as TGF-β derived from tumor cells used for fusion cell preparations [35, 47]. Although tumor-derived TGF-β reduces the efficacy of DC/tumor fusion vaccines via an in vivo mechanism [35], the reduction of TGF-β derived from the fusions inhibits the generation of Tregs and enhances antitumor immunity [47]. Moreover, the therapeutic effects in patients vaccinated by DC/tumor fusions are correlated with the characteristics of the DCs used as the fusion vaccines [82, 83]. Indeed, patient-derived fusions show inferior levels of MHC class II and costimulatory molecules and produce decreased levels of IL-12 and increased levels of IL-10, as compared with those obtained from fusions of tumor cell and DC from healthy donors [87, 103]. However, the fusion vaccines induce recovery of DC function in metastatic cancer patients [103]. Therefore, it is important to assess the phenotype and function of DC/tumor fusion cell preparations used in each vaccination.

5. In Vivo Monitoring

The delayed-type hypersensitivity (DTH) is an inflammatory reaction mainly mediated by CD4+ effector memory T cells that infiltrate the site of injection of an antigen against which the immune system has been primed by cancer vaccines [122]. Actually, soluble proteins, peptides, or antigens pulsed DCs have been injected intradermally, and the diameter of erythema or induration after 48–72 h is measured. CD4+ effector memory T cells that recognize the antigens presented on local APCs mediate the immune responses by releasing cytokines, resulting in an increased vascular permeability and the recruitment of monocytes and other inflammatory cells in the site. CD8+ T cells less frequently also mediate similar responses [123]. It has been reported that antigen-specific T cells can be readily detected in skin biopsies from DTH sites, much less in abdominal lymph nodes, and not in peripheral blood and tumor site [124]. Moreover, there is a significant correlation between favorable clinical outcome and the presence of vaccine-related antigen-specific T cells in biopsies from DTH sites [122]. Indeed, the increased DTH reactivity against tumor antigens has been observed in clinical responders by DC/tumor fusion vaccines [125]. In almost patients with cancer, T cells from lymph nodes and the tumor site itself are not readily available for monitoring purposes. Therefore, functional assessment of antigen-specific T cells from such DTH sites may serve as an additional strategy to evaluate antigen-specific antitumor immune responses [122, 126, 127].

6. T-Cell Monitoring In Vitro

The mechanism of cancer vaccines, based on inducing CTLs, infiltrating tumors, and exerting T-cell-mediated cytotoxic effects, is quite different from that of cytotoxic chemotherapy. As cancer vaccines do not work as quickly as chemotherapy which has a direct cytotoxic effect, the Response Evaluation Criteria in Solid Tumors (RECIST) and WHO criteria [128, 129], designed to detect early effects of cytotoxic chemotherapy, cannot appropriately evaluate the response patterns observed with cancer vaccines. The RECIST criteria are highly dependent upon measurement of tumor size. They presume that linear measures are an adequate substitute for 2-dimentional methods and register four response categories: CR (complete response), PR (partial response), SD (stable disease), and PD (progressive disease). However, in the solid tumors, there exist not only antigen-specific CTLs but also immune suppressive cells such as myeloid-derived suppressor cells (MDSCs) [130], immunosuppressive tumor-associated macrophages (TAMs) [131], and cancer associated fibroblasts (CAFs) [132] (Figure 2). After vaccination, the solid tumors may become heavily infiltrated by immune-related cells resulting in an apparent increase in size of lesions, which is, at least in part, due to the infiltration of CTLs induced by cancer vaccines. Therefore, the development of new response criteria, including immunologic cellular monitoring, is of great importance in the development of cancer vaccines.

In clinical trials, the peripheral blood T-cell responses are generally accessible for serial analyses. The currently used methods of assessing T-cells from patients treated with cancer vaccines are T-cell proliferation, cytokine profile, cytotoxic T lymphocyte assays (CTL assays), CTL-associated molecules (CD107, perforin, granzyme B, and CD154), multimer analysis, T-cell receptor (TCR) gene usage, and immune suppression assays (Table 1). While these assays can be also used for monitoring cellular immune responses induced by DC/tumor fusion vaccines, none has been standardized. As DC/tumor fusion vaccines can induce defined and undefined antigen-specific antitumor activities, immunologic cellular monitoring for the fusion vaccines is much more complex. Furthermore, as immune responses induced by DC/tumor fusion vaccines are a balanced mosaic of both immune stimulatory and suppressive responses [92], multiple monitoring assays for the clinical efficacy parameters may be needed to evaluate the antitumor immune responses.

6.1. T-Cell Proliferation

T-cell proliferation assay assesses the number and function at the level of the entire T-cell population in the culture. Therefore, the ability to detect T-cell responses is based on the proliferative potential of the cells in response to antigens. The most commonly used in vitro method for measuring antigen-specific T-cell proliferation is the assessment of T-cell clonal expansion following incubation of T-cells with antigens in the presence of a radio-labeled nucleotide (e.g., [3H] thymidine) in vitro. CFSE (5-(and-6)-carboxyfluorescein diacetate succinimidyl ester) staining can be also used to directly detect proliferative responses of T-cells [82]. Because CFSE is partitioned equally during cell division [133], this technique can monitor T-cell division and determine the relationship between T-cell division and differentiation in vitro and in vivo. The extensive T-cell proliferation can be demonstrated by the few undivided T-cells left and from proper accumulation of activated T cells, as shown by the increase in T-cell counts correlating with the decrease in CFSE label for each division. The CFSE-based assays are equivalent to traditional measures of antigen-specific T-cell responsiveness and have significant advantages for the ability to gate on a specific population of T-cells and the concomitant measurement of T-cell phenotype [134]. After vaccination, DC/tumor fusion cells can migrate to the T-cell area in the regional lymph nodes and form clusters with CD8+ and CD4+ T cells [34]. Simultaneous recognition of cognate peptides presented by MHC class I and class II molecules on DC/tumor fusion cell is essential in the induction of efficient CTLs. Therefore, measuring antigen-specific CD8+ and CD4+ T-cell proliferation is essential to evaluate the induction of vaccine-specific immune responses. Although T-cell proliferation assay is usefulness to detect immune responses in vitro, the results are strongly influenced by the in vitro stimulation procedures. Stimulation of naive T cells from healthy donors with DC/tumor fusions in vitro results in potent proliferation of CD4+ and CD8+ T cells [34, 80]. Therefore, to assess DC/tumor fusion vaccines, antigen-specific CD4+ and CD8+ T cells need to be expanded by stimulation with autologous tumor lysates [103]. In addition, the frozen peripheral blood mononuclear cells (PBMCs) obtained before and after vaccination must be processed in the same set of experiments [103, 135, 136]. As T-cell proliferation assay is biologically irrelevant and imprecise for the reasons stated above, this assay may not be emphasized in future studies.

6.2. Cytokine Production

There is a currently great interest in the assay of polyfunctional T cells, secreting multiple cytokines (e.g., secreting IFN-γ and TNF-α rather than either alone), or expressing multiple surface markers. As the release of Th1 cytokines such as IFN-γ and TNF-α is important to determine long-lasting antitumor immunity, a shift to Th1 response by cancer vaccines is essential for therapeutic potential in murine models [36, 37, 67, 77, 137, 138]. Therefore, it is important to test whether cancer vaccines can induce a Th1 response in the tumor-specific T cells, and what impact might this have on the clinical responses. Cytokine production by T cells in response to antigens can be detected in individual T cells by enzyme-linked immunospot (ELISPOT) assay [1821, 139]. Moreover, production of IFN-γ captured by antibodies bound to T-cell surface can be detected by flow cytometry analysis [96, 140]. The actual state of antigen specific T-cell reactivity directly from peripheral blood T cells can be quantified by IFN-γ ELISPOT assay and flow cytometry analysis [1821, 141]. As the IFN-γ ELISPOT assay shows highly reproducible results among different laboratories, the ELISPOT may be an ideal candidate for robust monitoring of T-cell activity [1821, 142]. Coculture of CD4+ and CD8+ T cells from healthy donors with DC/tumor fusions results in high levels of IFN-γ production and low levels of IL-10 production [50, 54, 80, 143]. Therefore, to assess DC/tumor fusion vaccines precisely, T cells obtained before and after vaccination might be directly quantified with stimulation of autologous tumor lysates in vitro [103]. In effective clinical responders, comparable levels of IFN-γ production in response to tumor lysates may be detected in PBMCs obtained before vaccination. A correlation between IFN-γ ELISPOT outcome and effective clinical responses (period free of relapse or survival) has been found in patients treated with cancer vaccines including DC/tumor fusions [103, 135, 136, 144].

6.3. CTL Assays

For immune monitoring of cancer vaccines, T-cell-mediated CTL assays are appealing because measurement of the ability of CTL to kill tumor targets is thought to be a relevant marker for antitumor activity. It has been assumed that the cytotoxicity has been measured in 51Cr-release assays in vitro. One drawback to the CTL assays is their relative insensitivity. Instead of 51Cr release assays, flow cytometry-based methods have been developed to assess CTL activity [145, 146]. Flow cytometry CTL assays can be predicated on measurement of CTL-induced caspase-3 or annexin-V activation in target cells through fluorescence detection, which are more sensitive to conventional 51Cr release assays [145147]. These assays show increased sensitivity at early time points after target/effector cell mixing and allow for analysis of target cells in real time at the single-cell level. However, it is unusual to detect antigen-specific killing by T cells directly isolated from the patients vaccinated with DC/tumor fusions even with the use of flow cytometry-based CTL assays [103, 148]. Therefore, there is a need to stimulate and expand the antigen-specific T cells in vitro for several days. These stimulations may distort the phenotype and function of the T-cell populations from tumor state. Moreover, it is difficult to obtain sufficient numbers of viable tumor cells from primary lesion due to the length of culture time and potential contamination of bacteria and fungus [79]. Thus, semiallogeneic targets with shared TAAs and MHC class I molecules are necessary instead of autologous targets. Importantly, a majority of the antigen-specific CD8+ CTLs in peripheral blood may not be tumor reactive due to various mechanisms such as downmodulation of MHC class I molecules on tumors and presence of Tregs at the tumor site. Indeed, cytotoxic activity against autologous targets has been observed in peripheral blood T cells from patients vaccinated with DC/tumor fusions by CTL assays [103, 148], but the clinical responses from early clinical trails in patients with melanoma, glioma, gastric, breast, and renal cancer are muted [103, 130, 134, 135, 142, 143, 148154]. The defects of the clinical responses may be caused by the immunosuppressive influences derived from the local tumor microenvironment [103]. In addition, therapeutic antitumor immunity depends on highly migratory CTLs capable of trafficking between lymphoid and tumor sites [155]. Therefore, localization of antigen-specific CTLs demonstrated by analysis of biopsy samples from tumor sites may be directly associated with clinical responses [155].

6.4. Tumor-Specific CD8+ and CD4+ T Cells

The population of CD8+ CTLs can destroy tumor cells through effector molecules (e.g., perforin and granzyme B) [156]. Degranulation of CD107a and b is a requisite process of perforin/granzyme B-dependent lytic fashions mediated by responding antigen-specific CTLs. These perforin/granzyme B-dependent lytic fashions require degranulation of CD107a and b in CD8+ CTLs [5]. Therefore, measurement of CD107a and b, perforin, or granzyme B expression by flow cytometric analysis can be combined with intracellular IFN-γ staining to more completely assess the functionality of CD8+ CTLs [83, 87]. Moreover, autologous tumor-induced de novo CD154 expression in CD4+ T cells is highly sensitive for tumor-specific Th cells [157]. The coupling of CD154 expression with multiplexed measurements of IFN-γ production provides a greater level of detail for the study of tumor-specific CD4+ T-cell responses. Although DC/tumor fusion vaccines have abilities to induce CD107+ IFN-γ+ CD8+ T cells and CD154+ IFN-γ+ CD4+ T cells upon autologous tumor encounter in vitro [83, 87], it has now been unclear the correlation of the assay with clinical outcome.

6.5. Multimer Assays

Now, it has become possible to analyze antigen-specific CD8+ and CD4+ T cells by flow cytometric analysis using multimeric MHC-peptide complexes, measuring the affinity of the TCR to a given epitope [158]. The MHC-peptide multimer analysis is more sensitive to conventional CTL assays [158]. Although DC/tumor fusion vaccines can induce defined and undefined antigens-specific CD8+ and CD4+ T cells, the multimer analysis can only be used to detect immune responses against defined antigenic epitopes expressing in tumor cells [21]. MHC-peptide multimers stably bind to the TCR exhibiting a certain minimal avidity. Hence, there are principal limitations of the multimeric analysis including the suitability and specificity of multimers and the lack of information about the functionality of multimer-positive T cells [158]. The specific role of the multimer-positive T cells for cancer vaccine efficacy has not yet been well established in the setting of clinical trials. Recent studies suggest that effective cancer vaccines not only stimulate CTL activity, but also sustain long-term memory T cells capable of mounting strong proliferative and functional responses to secondary tumor antigen challenge [159]. Therefore, it is more important to assess whether multimer-positive T cells are effector or effector-memory cells. Moreover, the combined use of multimers and functional assays such as IFN-γ analysis may have provided some insight into the functional activity of these cells. It has been demonstrated that cryopreserved PBMCs from melanoma patients vaccinated with gp100 peptide show that the majority of multimer-positive CD8+ T cells had either a long-term “effector” (CD45RA+ CCR7−) or an “effector-memory” (CD45RA− CCR7−) phenotype [160]. Interestingly, after vaccination, the resected melanoma patients can mount a significant antigen-specific CD8+ T cell immune response with a production of IFN-γ and high proliferation potential [160]. To date, no studies have evaluated the functional activity of multimer-positive T cells in the blood after vaccination with DC/tumor fusions.

6.6. TCR

Only T cells having a TCR specific for a given antigen are triggered by interaction with cancer vaccines. This activation results in the clonal expansion of antigen-specific T cells that can be followed by TCR Vβ gene usage. Recently, the availability of a large panel of monoclonal antibodies against TCRs, mainly Vβ epitopes, allows one to study the TCR repertoire by flow cytometry [161]. PCR techniques can also be used to detect a restricted TCR repertoire from small amounts of T cells without biases caused by ex vivo expansions [162]. Although DC/tumor fusion vaccines have resulted in selection and expansion of T-cell clones [87], the generation of antitumor immunity by CTLs has not correlated with clinical responses. Tumors may evade surveillance of CTLs by distinct mechanisms. Immunogenic tolerance to a particular set of antigens is the absence of an immune response to those antigens, which can be achieved by processes that result in T-cell anergy (antigen-specific unresponsiveness), T-cell unresponsiveness (generalized dysfunction), and T-cell deletion (apoptosis) [163]. Future fusion vaccine studies should be designed to determine whether T-cell dysfunction correlated with clinical outcome.

6.7. Immune Suppression Assays

Although antigen-specific CTLs can be generated and detected in the circulation of vaccinated patients, these do not usually act against the tumor. It has been documented that immune suppressive cells can counteract antitumor immune responses. In tumor microenvironment, there are not only CTLs but also many immune suppressive cells such as CD4+ CD25high+ Foxp3+ Tregs [103, 164], MDSCs [130], TAMs [131], and CAFs [132] (Figure 2). Moreover, tumor cells produce immunosuppressive substances such as transforming growth factor β (TGF-β) [165] vascular endothelial growth factor (VEGF) [166], IL-6 [167], IL-10 [167], soluble Fas ligand (Fas-L) [168], programmed death-1 ligand (PD-L1) [169], indolamine-2,3-dioxygenase (IDO) [170], and microvesicles [171]. Type 1 regulatory T cells (Tr1) expressing CD39 may mediate suppression by IL-10, TGF-β, and adenosine secretion, and whereby accumulation strongly correlates with the cancer progression [172]. The mechanisms that suppress the immune system provide a fundamental reason why cancer vaccines fail to induce consistently robust antitumor immune responses. In DC/tumor fusion vaccines, CD4+ CD25high+ Foxp3+ Tregs were promoted in the presence of the local tumor-related factors in vitro [103]. Moreover, increased CD4+ CD25high+ Foxp3+ Tregs impaired the effector function of CTLs induced by DC/tumor fusion vaccines [103]. Therefore, monitoring of immune suppressive cells in cancer patients vaccinated with DC/tumor fusions is also essential.

7. Conclusion

The development of assays for detecting immune responses associated with clinical outcome has been limited. A variety of assays had been introduced to provide monitoring tools necessary for following changes in the frequency of antigen-specific CTLs and to assess the impact of cancer vaccines on the immune system. As the mechanisms of immune response that cause tumor regression are not simple, the currently available assays may not actually measure a function with direct relevance to how tumors are actually attacked immunologically in cancer patients. A high reproducibility of results among different laboratories leads to the conclusion that cytokine flow cytometry or ELISPOT may be an ideal candidate for robust and reproducible monitoring of T-cell activity in vivo. However, the widely used ELISPOT assay often does not correlate the best with clinical outcome [173]. Therefore, it may be important to use a functional assay like cytokine flow cytometry or ELISPOT in combination with a quantitative assay like multimers for immune monitoring. Furthermore, it is necessary to understand the immune responses seen in peripheral blood versus the responses at the tumor site. Monitoring of antigen-specific CTLs at the tumor site may be directly associated with clinical responses [155]. However, T cells from lymph nodes and the tumor site itself are not readily available for monitoring purposes in almost all patients. Therefore, the ability to assess the function of antigen-specific T cells from DTH site may serve as an additional strategy to evaluate cancer vaccines [122, 126, 127]. In our opinion, monitoring of multimer-positive CD8+ (effector or effector memory) T cells from the DTH sites or PBMCs with IFN-γ production by flow cytometry may be sensitive markers particularly associated with overall survival. In addition, the DC/tumor fusion vaccine studies should be designed to determine whether T cell dysfunction in the tumor microenvironment correlated with clinical outcome. This informations may help us more fully understand the mechanisms of cancer vaccines and its potency to hasten the progress of efficient cancer vaccine strategies into the clinic.


The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the paper.


This work has been supported by Foundation for Promotion of Cancer Research, Mitsui Life Social Welfare Foundation, Grants-in-Aid for Scientific Research (B) from the Ministry of Education, Cultures, Sports, Science and Technology of Japan, Grant-in-Aid of the Japan Medical Association, Takeda Science Foundation, Pancreas Research Foundation of Japan, and Mitsui Life Social Welfare Foundation.

1. Inaba K,Pack M,Inaba M,Sakuta H,Isdell F,Steinman RM. High levels of a major histocompatibility complex II-self peptide complex on dendritic cells from the T cell areas of lymph nodesJournal of Experimental MedicineYear: 199718656656729271582
2. Banchereau J,Steinman RM. Dendritic cells and the control of immunityNatureYear: 199839266732452529521319
3. Steinman RM,Swanson J. The endocytic activity of dendritic cellsJournal of Experimental MedicineYear: 199518222832887629494
4. Steinman RM. The dendritic cell system and its role in immunogenicityAnnual Review of ImmunologyYear: 19919271296
5. Barry M,Bleackley RC. Cytotoxic T lymphocytes: all roads lead to deathNature Reviews ImmunologyYear: 200226401409
6. Wolchok JD,Hoos A,O’Day S,et al. Guidelines for the evaluation of immune therapy activity in solid tumors: immune-related response criteriaClinical Cancer ResearchYear: 200915237412742019934295
7. Banchereau J,Palucka AK. Dendritic cells as therapeutic vaccines against cancerNature Reviews ImmunologyYear: 200554296306
8. Inaba K,Witmer-Pack M,Inaba M,et al. The tissue distribution of the B7-2 costimulator in mice: abundant expression on dendritic cells in situ and during maturation in vitroJournal of Experimental MedicineYear: 19941805184918607525841
9. Young JW,Inaba K. Dendritic cells as adjuvants for class I major histocompatibility complex-restricted antitumor immunityJournal of Experimental MedicineYear: 199618317118551246
10. Celluzzi CM,Mayordomo JI,Storkus WJ,Lotze MT,Falo LD Jr.. Peptide-pulsed dendritic cells induce antigen-specific, CTL-mediated protective tumor immunityJournal of Experimental MedicineYear: 199618312832878551233
11. Nestle FO,Alijagic S,Gilliet M,et al. Vaccination of melanoma patients with peptide- or tumor lysate-pulsed dendritic cellsNature MedicineYear: 199843328332
12. Nair SK,Hull S,Coleman D,Gilboa E,Lyerly HK,Morse MA. Induction of carcinoembryonic antigen (CEA)-specific cytotoxic T-lymphocyte responses in vitro using autologous dendritic cells loaded with CEA peptide or CEA RNA in patients with metastatic malignancies expressing CEAInternational Journal of CancerYear: 1999821121124
13. Koido S,Kashiwaba M,Chen D,Gendler S,Kufe D,Gong J. Induction of antitumor immunity by vaccination of dendritic cells transfected with MUC1 RNAThe Journal of ImmunologyYear: 2000165105713571911067929
14. Palucka AK,Ueno H,Connolly J,et al. Dendritic cells loaded with killed allogeneic melanoma cells can induce objective clinical responses and MART-1 specific CD8+ T-cell immunityJournal of ImmunotherapyYear: 200629554555716971810
15. Thurner B,Haendle I,Röder C,et al. Vaccination with Mage-3A1 peptide-pulsed nature, monocyte-derived dendritic cells expands specific cytotoxic T cells and induces regression of some metastases in advanced stage IV melanomaJournal of Experimental MedicineYear: 1999190111669167810587357
16. Mackensen A,Herbst B Jr.,Chen JIL,et al. Phase I study in melanoma patients of a vaccine with peptide-pulsed dendritic cells generated in vitro from CD34+ hematopoietic progenitor cellsInternational Journal of CancerYear: 2000892385392
17. Gong J,Chen D,Kashiwaba M,Kufe D. Induction of antitumor activity by immunization with fusions of dendritic and carcinoma cellsNature MedicineYear: 199735558561
18. Koido S,Hara E,Homma S,Fujise K,Gong J,Tajiri H. Dendritic/tumor fusion cell-based vaccination against cancerArchivum Immunologiae et Therapiae ExperimentalisYear: 200755528128718219758
19. Gong J,Koido S,Calderwood SK. Cell fusion: from hybridoma to dendritic cell-based vaccineExpert Review of VaccinesYear: 2008771055106818767954
20. Koido S,Hara E,Homma S,et al. Cancer vaccine by fusions of dendritic and cancer cellsClinical and Developmental ImmunologyYear: 2009200913 pages Article ID 657369..
21. Koido S,Homma S,Hara E,et al. Antigen-specific polyclonal cytotoxic T lymphocytes induced by fusions of dendritic cells and tumor cellsJournal of Biomedicine and BiotechnologyYear: 2010201012 pages Article ID 752381..
22. Celluzzi CM,Falo LD Jr.. Physical interaction between dendritic cells and tumor cells results in an immunogen that induces protective and therapeutic tumor rejectionThe Journal of ImmunologyYear: 19981607308130859531260
23. Shu S,Zheng R,Lee WT,Cohen PA. Immunogenicity of dendritic-tumor fusion hybrids and their utility in cancer immunotherapyCritical Reviews in ImmunologyYear: 200727546348318197808
24. Wang J,Saffold S,Cao X,Krauss J,Chen W. Eliciting T cell immunity against poorly immunogenic tumors by immunization with dendritic cell-tumor fusion vaccinesThe Journal of ImmunologyYear: 199816110551655249820528
25. Cao X,Zhang W,Wang J,et al. Therapy of established tumour with a hybrid cellular vaccine generated by using granulocyte-macrophage colony-stimulating factor genetically modified dendritic cellsImmunologyYear: 199997461662510457215
26. Li J,Holmes LM,Franek KJ,Burgin KE,Wagner TE,Wei Y. Purified hybrid cells from dendritic cell and tumor cell fusions are superior activators of antitumor immunityCancer Immunology, ImmunotherapyYear: 2001509456462
27. Phan V,Errington F,Cheong SC,et al. A new genetic method to generate and isolate small, short-lived but highly potent dendritic cell-tumor cell hybrid vaccinesNature MedicineYear: 20039912151219
28. Shimizu K,Kuriyama H,Kjaergaard J,Lee W,Tanaka H,Shu S. Comparative analysis of antigen loading strategies of dendritic cells for tumor immunotherapyJournal of ImmunotherapyYear: 200427426527215235387
29. Kuriyama H,Watanabe S,Kjaergaard J,et al. Mechanism of third signals provided by IL-12 and OX-40R ligation in eliciting therapeutic immunity following dendritic-tumor fusion vaccinationCellular ImmunologyYear: 20062431304017207783
30. Ishida A,Tanaka H,Hiura T,et al. Generation of anti-tumour effector T cells from naïve T cells by stimulation with dendritic/tumour fusion cellsScandinavian Journal of ImmunologyYear: 200766554655417953530
31. Ko E,Luo W,Peng L,Wang X,Ferrone S. Mouse dendritic-endothelial cell hybrids and 4-1BB costimulation elicit antitumor effects mediated by broad antiangiogenic immunityCancer ResearchYear: 200767167875788417699794
32. Šalomskaite-Davalgiene S,Čepurniene K,Šatkauskas S,Venslauskas MS,Mir LM. Extent of cell electrofusion in vitro and in vivo is cell line dependentAnticancer ResearchYear: 20092983125313019661325
33. Gong J,Apostolopoulos V,Chen D,et al. Selection and characterization of MUC1-specific CD8+ T cells from MUC1 transgenic mice immunized with dendritic-carcinoma fusion cellsImmunologyYear: 2000101331632411106934
34. Koido S,Tanaka Y,Chen D,Kufe D,Gong J. The kinetics of in vivo priming of CD4 and CD8 T cells by dendritic/tumor fusion cells in MUC1-transgenic miceThe Journal of ImmunologyYear: 200216852111211711859096
35. Kao JY,Gong Y,Chen CM,Zheng QD,Chen JJ. Tumor-derived TGF-β reduces the efficacy of dendritic cell/tumor fusion vaccineThe Journal of ImmunologyYear: 200317073806381112646647
36. Iinuma T,Homma S,Noda T,Kufe D,Ohno T,Toda G. Prevention of gastrointestinal tumors based on adenomatous polyposis coli gene mutation by dendritic cell vaccineJournal of Clinical InvestigationYear: 200411391307131715124022
37. Suzuki T,Fukuhara T,Tanaka M,et al. Vaccination of dendritic cells loaded with interleukin-12-secreting cancer cells augments in vivo antitumor immunity: characteristics of syngeneic and allogeneic antigen-presenting cell cancer hybrid cellsClinical Cancer ResearchYear: 2005111586615671528
38. Kao JY,Zhang M,Chen CM,Chen JJ. Superior efficacy of dendritic cell-tumor fusion vaccine compared with tumor lysate-pulsed dendritic cell vaccine in colon cancerImmunology LettersYear: 2005101215415915993950
39. Xu F,Ye YJ,Cui ZR,Wang S. Allogeneic dendritomas induce anti-tumour immunity against metastatic colon cancerScandinavian Journal of ImmunologyYear: 200561436436915853920
40. Yasuda T,Kamigaki T,Kawasaki K,et al. Superior anti-tumor protection and therapeutic efficacy of vaccination with allogeneic and semiallogeneic dendritic cell/tumor cell fusion hybrids for murine colon adenocarcinomaCancer Immunology, ImmunotherapyYear: 200756710251036
41. Cho EI,Tan C,Koski GK,Cohen PA,Shu S,Lee WT. Toll-like receptor agonists as third signals for dendritic cell-tumor fusion vaccinesHead and NeckYear: 201032670070719908319
42. Gong J,Chen D,Kashiwaba M,et al. Reversal of tolerance to human MUC1 antigen in MUC1 transgenic mice immunized with fusions of dendritic and carcinoma cellsProceedings of the National Academy of Sciences of the United States of AmericaYear: 19989511627962839600956
43. Lindner M,Schirrmacher V. Tumour cell-dendritic cell fusion for cancer immunotherapy: comparison of therapeutic efficiency of polyethylen-glycol versus electro-fusion protocolsEuropean Journal of Clinical InvestigationYear: 200232320721711895473
44. Xia J,Tanaka Y,Koido S,et al. Prevention of spontaneous breast carcinoma by prophylactic vaccination with dendritic/tumor fusion cellsThe Journal of ImmunologyYear: 200317041980198612574367
45. Chen D,Xia J,Tanaka Y,et al. Immunotherapy of spontaneous mammary carcinoma with fusions of dendritic cells and mucin 1-positive carcinoma cellsImmunologyYear: 2003109230030712757626
46. Tamai H,Watanabe S,Zheng R,et al. Effective treatment of spontaneous metastases derived from a poorly immunogenic murine mammary carcinoma by combined dendritic-tumor hybrid vaccination and adoptive transfer of sensitized T cellsClinical ImmunologyYear: 20081271667718262845
47. Zhang M,Berndt BE,Chen JJ,Kao JY. Expression of a soluble TGF-β receptor by tumor cells enhances dendritic cell/tumor fusion vaccine efficacyThe Journal of ImmunologyYear: 200818153690369718714045
48. Guo GH,Chen SZ,Yu J,et al. In vivo anti-tumor effect of hybrid vaccine of dendritic cells and esophageal carcinoma cells on esophageal carcinoma cell line 109 in mice with severe combined immune deficiencyWorld Journal of GastroenterologyYear: 20081481167117418300341
49. Ziske C,Etzrodt PE,Eliu AS,et al. Increase of in vivo antitumoral activity by CD40L (CD154) gene transfer into pancreatic tumor cell-dendritic cell hybridsPancreasYear: 200938775876519546834
50. Yamamoto M,Kamigaki T,Yamashita K,et al. Enhancement of anti-tumor immunity by high levels of Th1 and Th17 with a combination of dendritic cell fusion hybrids and regulatory T cell depletion in pancreatic cancerOncology ReportsYear: 200922233734319578774
51. Homma S,Toda G,Gong J,Kufe D,Ohno T. Preventive antitumor activity against hepatocellular carcinoma (HCC) induced by immunization with fusions of dendritic cells and HCC cells in miceJournal of GastroenterologyYear: 2001361176477111757749
52. Zhang JK,Li J,Zhang J,Chen HB,Chen SB. Antitumor immunopreventive and immunotherapeutic effect in mice induced by hybrid vaccine of dendritic cells and hepatocarcinoma in vivoWorld Journal of GastroenterologyYear: 20039347948412632501
53. Iriei M,Homma S,Komita H,et al. Inhibition of spontaneous development of liver tumors by inoculation with dendritic cells loaded with hepatocellular carcinoma cells in C3H/HeNCRJ miceInternational Journal of CancerYear: 20041112238245
54. Zhang HM,Zhang LW,Liu WC,Cheng J,Si XM,Ren J. Comparative analysis of DC fused with tumor cells or transfected with tumor total RNA as potential cancer vaccines against hepatocellular carcinomaCytotherapyYear: 20068658058817148035
55. Sheng XIL,Zhang H. In-vitro activation of cytotoxic T lymphocytes by fusion of mouse hepatocellular carcinoma cells and lymphotactin gene-modified dendritic cellsWorld Journal of GastroenterologyYear: 200713445944595017990361
56. Šímová J,Bubeník J,Bieblová J,Indrová M,Jandlová T. Immunotherapeutic efficacy of vaccines generated by fusion of dendritic cells and HPV16-associated tumour cellsFolia BiologicaYear: 2005511192415783088
57. Savai R,Schermuly RT,Schneider M,et al. Hybrid-primed lymphocytes and hybrid vaccination prevent tumor growth of Lewis lung carcinoma in miceJournal of ImmunotherapyYear: 200629217518716531818
58. Savai R,Schermuly RT,Pullamsetti SS,et al. A combination hybrid-based vaccination/adoptive cellular therapy to prevent tumor growth by involvement of T cellsCancer ResearchYear: 200767115443545317545626
59. Ou X,Cai S,Liu P,et al. Enhancement of dendritic cell-tumor fusion vaccine potency by indoleamine-pyrrole 2,3-dioxygenase inhibitor, 1-MTJournal of Cancer Research and Clinical OncologyYear: 2008134552553317909857
60. Siders WM,Vergilis KL,Johnson C,Shields J,Kaplan JM. Induction of specific antitumor immunity in the mouse with the electrofusion product of tumor cells and dendritic cellsMolecular TherapyYear: 20037449850512727113
61. Kjaergaard J,Shimizu K,Shu S. Electrofusion of syngeneic dendritic cells and tumor generates potent therapeutic vaccineCellular ImmunologyYear: 20032252657414698141
62. Matsue H,Matsue K,Edelbaum D,Walters M,Morita A,Takashima A. New strategy for efficient selection of dendritic cell-tumor hybrids and clonal heterogeneity of resulting hybridsCancer Biology and TherapyYear: 20043111145115115539940
63. Kim GY,Chae HJ,Kim KH,et al. Dendritic cell-tumor fusion vaccine prevents tumor growth in vivoBioscience, Biotechnology and BiochemistryYear: 2007711215221
64. Yu Z,Ma B,Zhou Y,et al. Allogeneic tumor vaccine produced by electrofusion between osteosarcoma cell line and dendritic cells in the induction of antitumor immunityCancer InvestigationYear: 2007257535541
65. Zheng R,Cohen PA,Paustian CA,et al. Paired toll-like receptor agonists enhance vaccine therapy through induction of interleukin-12Cancer ResearchYear: 200868114045404918519662
66. Yanai S,Adachi Y,Fuijisawa JI,et al. Anti-tumor effects of fusion cells of type 1 dendritic cells and Meth A tumor cells using hemagglutinating virus of Japan-envelopeInternational Journal of OncologyYear: 200935224925519578737
67. Gong J,Koido S,Chen D,et al. Immunization against murine multiple myeloma with fusions of dendritic and plasmacytoma cells is potentiated by interleukin 12BloodYear: 20029972512251711895787
68. Zhang W,Yang H,Zeng H. Enhancing antitumor by immunization with fusion of dendritic cells and engineered tumor cellsJournal of Huazhong University of Science and Technology. Medical ScienceYear: 200222114
69. Liu Y,Zhang W,Chan T,Saxena A,Xiang J. Engineered fusion hybrid vaccine of IL-4 gene-modified myeloma and relative mature dendritic cells enhances antitumor immunityLeukemia ResearchYear: 200226875776312191571
70. Hao S,Bi X,Xu S,et al. Enhanced antitumor immunity derived from a novel vaccine of fusion hybrid between dendritic and engineered myeloma cellsExperimental OncologyYear: 200426430030615627063
71. Xia D,Li F,Xiang J. Engineered fusion hybrid vaccine of IL-18 gene-modified tumor cells and dendritic cells induces enhanced antitumor immunityCancer Biotherapy and RadiopharmaceuticalsYear: 200419332233015285878
72. Shi M,Su L,Hao S,Guo X,Xiang J. Fusion hybrid of dendritic cells and engineered tumor cells expressing interleukin-12 induces type 1 immune responses against tumorTumoriYear: 200591653153816457153
73. Quéant S,Sarde CO,Gobert MG,Kadouche J,Roseto A. Antitumor response against myeloma cells by immunization with mouse syngenic dendritomaHybridomaYear: 200524418218816120023
74. Alvarez E,Moga E,Barquinero J,Sierra J,Briones J. Dendritic and tumor cell fusions transduced with adenovirus encoding CD40L eradicate B-cell lymphoma and induce a Th17-type responseGene TherapyYear: 201017446947720010627
75. Lespagnard L,Mettens P,Verheyden AM,et al. Dendritic cells fused with mastocytoma cells elicit therapeutic antitumor immunityInternational Journal of CancerYear: 1998762250258
76. Wells JW,Cowled CJ,Darling D,et al. Semi-allogeneic dendritic cells can induce antigen-specific T-cell activation, which is not enhanced by concurrent alloreactivityCancer Immunology, ImmunotherapyYear: 2007561218611873
77. Iinuma H,Okinaga K,Fukushima R,et al. Superior protective and therapeutic effects of IL-12 and IL-18 gene-transduced dendritic neuroblastoma fusion cells on liver metastasis of murine neuroblastomaThe Journal of ImmunologyYear: 200617663461346916517714
78. Draube A,Beyer M,Schumer S,et al. Efficient activation of autologous tumor-specific T cells: a simple coculture technique of autologous dendritic cells compared to established cell fusion strategies in primary human colorectal carcinomaJournal of ImmunotherapyYear: 200730435936917457211
79. Koido S,Hara E,Homma S,et al. Dendritic cells fused with allogeneic colorectal cancer cell line present multiple colorectal cancer-specific antigens and induce antitumor immunity against autologous tumor cellsClinical Cancer ResearchYear: 200511217891790016278414
80. Koido S,Hara E,Torii A,et al. Induction of antigen-specific CD4- and CD8-mediated T-cell responses by fusions of autologous dendritic cells and metastatic colorectal cancer cellsInternational Journal of CancerYear: 20051174587595
81. Hock BD,Roberts G,McKenzie JL,et al. Exposure to the electrofusion process can increase the immunogenicity of human cellsCancer Immunology, ImmunotherapyYear: 2005549880890
82. Koido S,Hara E,Homma S,et al. Streptococcal preparation OK-432 promotes fusion efficiency and enhances induction of antigen-specific CTL by fusions of dendritic cells and colorectal cancer cellsThe Journal of ImmunologyYear: 2007178161362217182602
83. Koido S,Hara E,Homma S,et al. Synergistic induction of antigen-specific CTL by fusions of TLR-stimulated dendritic cells and heat-stressed tumor cellsThe Journal of ImmunologyYear: 200717974874488317878387
84. Yang JY,Cao DY,Ma LY,Liu WC. Dendritic cells fused with allogeneic hepatocellular carcinoma cell line compared with fused autologous tumor cells as hepatocellular carcinoma vaccinesHepatology ResearchYear: 201040550551320374301
85. Imura K,Ueda Y,Hayashi T,et al. Induction of cytotoxic T lymphocytes against human cancer cell lines using dendritic cell-tumor cell hybrids generated by a newly developed electrofusion techniqueInternational Journal of OncologyYear: 200629353153916865268
86. Matsumoto S,Saito H,Tsujitani S,Ikeguchi M. Allogeneic gastric cancer cell-dendritic cell hybrids induce tumor antigen (carcinoembryonic antigen) specific CD8+ T cellsCancer Immunology, ImmunotherapyYear: 2006552131139
87. Koido S,Hara E,Homma S,et al. Dendritic/pancreatic carcinoma fusions for clinical use: comparative functional analysis of healthy-versus patient-derived fusionsClinical ImmunologyYear: 2010135338440020226739
88. Gong J,Avigan D,Chen D,et al. Activation of antitumor cytotoxic T lymphocytes by fusions of human dendritic cells and breast carcinoma cellsProceedings of the National Academy of Sciences of the United States of AmericaYear: 20009762715271810688917
89. Zhang Y,Ma B,Zhou Y,et al. Dendritic cells fused with allogeneic breast cancer cell line induce tumor antigen-specific CTL responses against autologous breast cancer cellsBreast Cancer Research and TreatmentYear: 2007105327728617187233
90. Serhal K,Baillou C,Ghinea N,et al. Characteristics of hybrid cells obtained by dendritic cell/tumour cell fusion in a T-47D breast cancer cell line model indicate their potential as anti-tumour vaccinesInternational Journal of OncologyYear: 20073161357136517982663
91. Koido S,Tanaka Y,Tajiri H,Gong J. Generation and functional assessment of antigen-specific T cells stimulated by fusions of dendritic cells and allogeneic breast cancer cellsVaccineYear: 200725142610261917239504
92. Vasir B,Wu Z,Crawford K,et al. Fusions of dendritic cells with breast carcinoma stimulate the expansion of regulatory T cells while concomitant exposure to IL-12, CpG oligodeoxynucleotides, and Anti-CD3/CD28 promotes the expansion of activated tumor reactive cellsThe Journal of ImmunologyYear: 2008181180882118566447
93. Rosenblatt J,Wu Z,Vasir B,et al. Generation of tumor-specific t lymphocytes using dendritic cell/tumor fusions and anti-CD3/CD28Journal of ImmunotherapyYear: 201033215516620145548
94. Weise JB,Maune S,Görögh T,et al. A dendritic cell based hybrid cell vaccine generated by electrofusion for immunotherapy strategies in HNSCCAuris Nasus LarynxYear: 200431214915315121224
95. Gong J,Nikrui N,Chen D,et al. Fusions of human ovarian carcinoma cells with autologous or allogeneic dendritic cells induce antitumor immunityThe Journal of ImmunologyYear: 200016531705171110903782
96. Koido S,Ohana M,Liu C,et al. Dendritic cells fused with human cancer cells: morphology, antigen expression, and T cell stimulationClinical ImmunologyYear: 2004113326126915507391
97. Koido S,Nikrui N,Ohana M,et al. Assessment of fusion cells from patient-derived ovarian carcinoma cells and dendritic cells as a vaccine for clinical useGynecologic OncologyYear: 200599246247116137749
98. Cheong SC,Blangenois I,Franssen JD,et al. Generation of cell hybrids via a fusogenic cell lineJournal of Gene MedicineYear: 20068791992816602137
99. Lundqvist A,Palmborg A,Bidla G,Whelan M,Pandha H,Pisa P. Allogeneic tumor-dendritic cell fusion vaccines for generation of broad prostate cancer T-cell responsesMedical OncologyYear: 200421215516515299188
100. Kim TB,Park HK,Chang JH,et al. The establishment of dendritic cell-tumor fusion vaccines for hormone refractory prostate cancer cellKorean Journal of UrologyYear: 201051213914420414428
101. Gottfried E,Krieg R,Eichelberg C,Andreesen R,Mackensen A,Krause SW. Characterization of cells prepared by dendritic cell-tumor cell fusionCancer ImmunityYear: 20025111
102. Hu Z,Liu S,Mai X,Hu Z,Liu C. Anti-tumor effects of fusion vaccine prepared by renal cell carcinoma 786-O cell line and peripheral blood dendritic cells of healthy volunteers in vitro and in human immune reconstituted SCID miceCellular ImmunologyYear: 2010262211211920167310
103. Koido S,Homma S,Hara E,et al. In vitro generation of cytotoxic and regulatory T cells by fusions of human dendritic cells and hepatocellular carcinoma cellsJournal of Translational MedicineYear: 20086, article 51
104. Cao DY,Yang JY,Yue SQ,et al. Comparative analysis of DC fused with allogeneic hepatocellular carcinoma cell line HepG2 and autologous tumor cells as potential cancer vaccines against hepatocellular carcinomaCellular ImmunologyYear: 20092591132019545862
105. Xu F,Ye YJ,Liu W,Kong M,He Y,Wang S. Dendritic cell/tumor hybrids enhances therapeutic efficacy against colorectal cancer liver metastasis in SCID miceScandinavian Journal of GastroenterologyYear: 201045670771320205622
106. Galea-Lauri J,Darling D,Mufti G,Harrison P,Farzaneh F. Eliciting cytotoxic T lymphocytes against acute myeloid leukemia-derived antigens: evaluation of dendritic cell-leukemia cell hybrids and other antigen-loading strategies for dendritic cell-based vaccinationCancer Immunology, ImmunotherapyYear: 2002516299310
107. Kokhaei P,Rezvany MR,Virving L,et al. Dendritic cells loaded with apoptotic tumour cells induce a stronger T-cell response than dendritic cell-tumour hybrids in B-CLLLeukemiaYear: 200317589489912750703
108. Gong J,Koido S,Kato Y,et al. Induction of anti-leukemic cytotoxic T lymphocytes by fusion of patient-derived dendritic cells with autologous myeloblastsLeukemia ResearchYear: 200428121303131215475072
109. Banat GA,Usluoglu N,Hoeck M,Ihlow K,Hoppmann S,Pralle H. Dendritic cells fused with core binding factor-beta positive acute myeloid leukaemia blast cells induce activation of cytotoxic lymphocytesBritish Journal of HaematologyYear: 2004126459360115287954
110. Allgeier T,Garhammer S,Nößner E,et al. Dendritic cell-based immunogens for B-cell chronic lymphocytic leukemiaCancer LettersYear: 20072451-227528316516377
111. Lei Z,Zhang GM,Hong M,Feng ZH,Huang B. Fusion of dendritic cells and CD34+CD38 acute myeloid leukemia (AML) cells potentiates targeting AML-initiating cells by specific CTL inductionJournal of ImmunotherapyYear: 200932440841419342964
112. Raje N,Hideshima T,Davies FE,et al. Tumour cell/dendritic cell fusions as a vaccination strategy for multiple myelomaBritish Journal of HaematologyYear: 2004125334335215086415
113. Vasir B,Borges V,Wu Z,et al. Fusion of dendritic cells with multiple myeloma cells results in maturation and enhanced antigen presentationBritish Journal of HaematologyYear: 2005129568770015916692
114. Yu Z,Ma B,Zhou Y,Zhang M,Qiu X,Fan Q. Activation of antitumor cytotoxic T lymphocytes by fusion of patient-derived dendritic cells with autologous osteosarcomaExperimental OncologyYear: 200527427327816404346
115. Guo W,Guo Y,Tang S,Qu H,Zhao H. Dendritic cell-Ewing’s sarcoma cell hybrids enhance antitumor immunityClinical Orthopaedics and Related ResearchYear: 200846692176218318563501
116. Jantscheff P,Spagnoli G,Zajac P,Rochlitz C. Cell fusion: an approach to generating constitutively proliferating human tumor antigen-presenting cellsCancer Immunology, ImmunotherapyYear: 2002517367375
117. Parkhurst MR,DePan C,Riley JP,Rosenberg SA,Shu S. Hybrids of dendritic cells and tumor cells generated by electrofusion simultaneously present immunodominant epitopes from multiple human tumor-associated antigens in the context of MHC class I and class II moleculesThe Journal of ImmunologyYear: 2003170105317532512734382
118. Trevor KT,Cover C,Ruiz YW,et al. Generation of dendritic cell-tumor cell hybrids by electrofusion for clinical vaccine applicationCancer Immunology, ImmunotherapyYear: 2004538705714
119. Neves AR,Ensina LFC,Anselmo LB,et al. Dendritic cells derived from metastatic cancer patients vaccinated with allogeneic dendritic cell-autologous tumor cell hybrids express more CD86 and induce higher levels of interferon-gamma in mixed lymphocyte reactionsCancer Immunology, ImmunotherapyYear: 20055416166
120. Sloan AE,Parajuli P. Human autologous dendritic cell-glioma fusions: feasibility and capacity to stimulate T cells with proliferative and cytolytic activityJournal of Neuro-OncologyYear: 2003641-217718312952298
121. Sukhorukov VL,Reuss R,Endter JM,et al. A biophysical approach to the optimisation of dendritic-tumour cell electrofusionBiochemical and Biophysical Research CommunicationsYear: 2006346382983916780801
122. Aarntzen EHJG,Figdor CG,Adema GJ,Punt CJA,de Vries IJM. Dendritic cell vaccination and immune monitoringCancer Immunology, ImmunotherapyYear: 2008571015591568
123. Puccetti P,Bianchi R,Fioretti MC,et al. Use of a skin test assay to determine tumor-specific CD8+ T cell reactivityEuropean Journal of ImmunologyYear: 1994246144614528206103
124. Lesterhuis WJ,de Vries IJM,Schuurhuis DH,et al. Vaccination of colorectal cancer patients with CEA-loaded dendritic cells: antigen-specific T cell responses in DTH skin testsAnnals of OncologyYear: 200617697498016600979
125. Märten A,Renoth S,Heinicke T,et al. Allogeneic dendritic cells fused with tumor cells: preclinical results and outcome of a clinical phase I/II trial in patients with metastatic renal cell carcinomaHuman Gene TherapyYear: 200314548349412691613
126. Waanders GA,Rimoldi D,Liénard D,et al. Melanoma-reactive human cytotoxic T lymphocytes derived from skin biopsies of delayed-type hypersensitivity reactions induced by injection of an autologous melanoma cell lineClinical Cancer ResearchYear: 1997356856969815737
127. de Vries IJM,Bernsen MR,Lesterhuis WJ,et al. Immunomonitoring tumor-specific T cells in delayed-type hypersensitivity skin biopsies after dendritic cell vaccination correlates with clinical outcomeJournal of Clinical OncologyYear: 200523245779578716110035
128. Therasse P,Arbuck SG,Eisenhauer EA,et al. New guidelines to evaluate the response to treatment in solid tumors. European Organization for Research and Treatment of Cancer, National Cancer Institute of the United States, National Cancer Institute of CanadaJournal of the National Cancer InstituteYear: 200092320521610655437
129. Miller AB,Hoogstraten B,Staquet M,Winkler A. Reporting results of cancer treatmentCancerYear: 19814712072147459811
130. Morse MA,Hall JR,Plate JMD. Countering tumor-induced immunosuppression during immunotherapy for pancreatic cancerExpert Opinion on Biological TherapyYear: 20099333133919216622
131. Kormelink TG,Abudukelimu A,Redegeld FA. Mast cells as target in cancer therapyCurrent Pharmaceutical DesignYear: 200915161868187819519429
132. Fassnacht M,Lee J,Milazzo C,et al. Induction of CD4+ and CD8+ T-cell responses to the human stromal antigen, fibroblast activation protein: implication for cancer immunotherapyClinical Cancer ResearchYear: 200511155566557116061874
133. Hasbold J,Gett AV,Rush JS,et al. Quantitative analysis of lymphocyte differentiation and proliferation in vitro using carboxyfluorescein diacetate succinimidyl esterImmunology and Cell BiologyYear: 199977651652210571672
134. Tanaka Y,Koido S,Xia J,et al. Development of antigen-specific CD8+ CTL in MHC class I-deficient mice through CD4 to CD8 conversionThe Journal of ImmunologyYear: 2004172127848785815187169
135. Avigan D,Vasir B,Gong J,et al. Fusion cell vaccination of patients with metastatic breast and renal cancer induces immunological and clinical responsesClinical Cancer ResearchYear: 200410144699470815269142
136. Avigan DE,Vasir B,George DJ,et al. Phase I/II study of vaccination with electrofused allogeneic dendritic cells/autologous tumor-derived cells in patients with stage IV renal cell carcinomaJournal of ImmunotherapyYear: 200730774976117893567
137. Kikuchi T,Akasaki Y,Abe T,et al. Vaccination of glioma patients with fusions of dendritic and glioma cells and recombinant human interleukin 12Journal of ImmunotherapyYear: 200427645245915534489
138. Homma S,Kikuchi T,Ishiji N,et al. Cancer immunotherapy by fusions of dendritic and tumour cells and rh-IL-12European Journal of Clinical InvestigationYear: 200535427928615816998
139. Czerkinsky C,Andersson G,Ekre HP,Nilsson LA,Klareskog L,Ouchterlony O. Reverse ELISPOT assay for clonal analysis of cytokine production. I. Enumeration of gamma-interferon-secretion cellsJournal of Immunological MethodsYear: 1988110129363131436
140. Suni MA,Picker LJ,Maino VC. Detection of antigen-specific T cell cytokine expression in whole blood by flow cytometryJournal of Immunological MethodsYear: 1998212189989671156
141. Schmittel A,Keilholz U,Scheibenbogen C. Evaluation of the interferon-γ ELISPOT-assay for quantification of peptide specific T lymphocytes from peripheral bloodJournal of Immunological MethodsYear: 199721021671749520299
142. Schmittel A,Keilholz U,Thiel E,Scheibenbogen C. Quantification of tumor-specific T lymphocytes with the ELISPOT assayJournal of ImmunotherapyYear: 200023328929510838657
143. Rosenblatt J,Vasir B,Uhl L,et al. Vaccination with dendritic cell/tumor fusion cells results in cellular and humoral antitumor immune responses in patients with multiple myelomaBloodYear: 2011117239340221030562
144. Scheibenbogen C,Schmittel A,Keilholz U,et al. Phase 2 trial of vaccination with tyrosinase peptides and granulocyte-macrophage colony-stimulating factor in patients with metastatic melanomaJournal of ImmunotherapyYear: 200023227528110746554
145. Liu L,Chahroudi A,Silvestri G,et al. Visualization and quantification of T cell-mediated cytotoxicity using cell-permeable fluorogenic caspase substratesNature MedicineYear: 200282185189
146. Jerome KR,Sloan DD,Aubert M. Measuring T-cell-mediated cytotoxicity using antibody to activated caspase 3Nature MedicineYear: 20039145
147. Goldberg JE,Sherwood SW,Clayberger C. A novel method for measuring CTL and NK cell-mediated cytotoxicity using annexin V and two-color flow cytometryJournal of Immunological MethodsYear: 19992241-21910357200
148. Homma S,Matai K,Irie M,Ohno T,Kufe D,Toda G. Immunotherapy using fusions of autologous dendritic cells and tumor cells showed effective clinical response in a patient with advanced gastric carcinomaJournal of GastroenterologyYear: 2003381098999414614608
149. Kikuchi T,Akasaki Y,Irie M,Homma S,Abe T,Ohno T. Results of a phase I clinical trial of vaccination of glioma patients with fusions of dendritic and glioma cellsCancer Immunology, ImmunotherapyYear: 2001507337344
150. Trefzer U,Weingart G,Chen Y,et al. Hybrid cell vaccination for cancer immune therapy: first clinical trial with metastatic melanomaInternational Journal of CancerYear: 2000855618626
151. Trefzer U,Herberth G,Wohlan K,et al. Tumour-dendritic hybrid cell vaccination for the treatment of patients with malignant melanoma: immunological effects and clinical resultsVaccineYear: 20052317-182367237315755630
152. Krause SW,Neumann C,Soruri A,Mayer S,Peters JH,Andreesen R. The treatment of patients with disseminated malignant melanoma by vaccination with autologous cell hybrids of tumor cells and dendritic cellsJournal of ImmunotherapyYear: 200225542142812218780
153. Haenssle HA,Krause SW,Emmert S,et al. Hybrid cell vaccination in metastatic melanoma: clinical and immunologic results of a phase I/II studyJournal of ImmunotherapyYear: 200427214715514770086
154. Zhou J,Weng D,Zhou F,et al. Patient-derived renal cell carcinoma cells fused with allogeneic dendritic cells elicit anti-tumor activity: in vitro results and clinical responsesCancer Immunology, ImmunotherapyYear: 2009581015871597
155. Su H,Chang DS,Gambhir SS,Braun J. Monitoring the antitumor response of naive and memory CD8 T cells in RAG1−/− mice by positron-emission tomographyThe Journal of ImmunologyYear: 200617674459446716547284
156. Finn OJ. Molecular origins of cancer: cancer immunologyThe New England Journal of MedicineYear: 2008358252704271518565863
157. Chattopadhyay PK,Yu J,Roederer M. A live-cell assay to detect antigen-specific CD4+ T cells with diverse cytokine profilesNature MedicineYear: 2005111011131117
158. Altman JD,Moss PAH,Goulder PJR,et al. Phenotypic analysis of antigen-specific T lymphocytesScienceYear: 1996274528494968810254
159. Klebanoff CA,Gattinoni L,Restifo NP. CD8+ T-cell memory in tumor immunology and immunotherapyImmunological ReviewsYear: 200621121422416824130
160. Walker EB,Haley D,Miller W,et al. gp100(209-2M) peptide immunization of human lymphocyte antigen-A2+ stage I-III melanoma patients induces significant increase in antigen-specific effector and long-term memory CD8+ T cellsClinical Cancer ResearchYear: 200410266868014760090
161. Houtenbos I,Westers TM,Dijkhuis A,de Gruijl TD,Ossenkoppele GJ,van de Loosdrecht AA. Leukemia-specific T-cell reactivity induced by leukemic dendritic cells is augmented by 4-1BB targetingClinical Cancer ResearchYear: 200713130731517170077
162. Kalams SA,Johnson RP,Trocha AK,et al. Longitudinal analysis of T cell receptor (TCR) gene usage by human immunodeficiency virus 1 envelope-specific cytotoxic T lymphocyte clones reveals a limited TCR repertoireJournal of Experimental MedicineYear: 19941794126112718145043
163. Ramsdell F,Fowlkes BJ. Clonal deletion versus clonal anergy: the role of the thymus in inducing self toleranceScienceYear: 19902484961134213481972593
164. Law JP,Hirschkorn DF,Owen RE,Biswas HH,Norris PJ,Lanteri MC. The importance of Foxp3 antibody and fixation/permeabilization buffer combinations in identifying CD4+CD25+Foxp3+ regulatory T cellsCytometry Part AYear: 2009751210401050
165. Teicher BA. Transforming growth factor-β and the immune response to malignant diseaseClinical Cancer ResearchYear: 200713216247625117975134
166. Fricke I,Mirza N,Dupont J,et al. Vascular endothelial growth factor-trap overcomes defects in dendritic cell differentiation but does not improve antigen-specific immune responsesClinical Cancer ResearchYear: 200713164840484817699863
167. Elgert KD,Alleva DG,Mullins DW. Tumor-induced immune dysfunction: the macrophage connectionJournal of Leukocyte BiologyYear: 19986432752909738653
168. Houston A,Bennett MW,O’Sullivan GC,Shanahan F,O’Connell J. Fas ligand mediates immune privilege and not inflammation in human colon cancer, irrespective of TGF-β expressionBritish Journal of CancerYear: 20038971345135114520470
169. Takeda K,Kojima Y,Uno T,et al. Combination therapy of established tumors by antibodies targeting immune activating and suppressing moleculesThe Journal of ImmunologyYear: 2010184105493550120400706
170. Uyttenhove C,Pilotte L,Théate I,et al. Evidence for a tumoral immune resistance mechanism based on tryptophan degradation by indoleamine 2,3-dioxygenaseNature MedicineYear: 200391012691274
171. Szajnik M,Czystowska M,Szczepanski MJ,Mandapathil M,Whiteside TL. Tumor-derived microvesicles induce, expand and up-regulate biological activities of human regulatory T cells (Treg)PLoS OneYear: 201057 Article ID e11469..
172. Strauss L,Bergmann C,Szczepanski M,Gooding W,Johnson JT,Whiteside TL. A unique subset of CD4+CD25highFoxp3+T cells secreting interleukin-10 and transforming growth factor-β1 mediates suppression in the tumor microenvironmentClinical Cancer ResearchYear: 200713154345435417671115
173. Plebanski M,Katsara M,Sheng KC,Xiang SD,Apostolopoulos V. Methods to measure T-cell responsesExpert Review of VaccinesYear: 20109659560020518715

Article Categories:
  • Review Article

Previous Document:  Methotrexate toxicity in growing long bones of young rats: a model for studying cancer chemotherapy-...
Next Document:  Target therapies in lung cancer.