Systemic adoptive T-cell immunotherapy in recurrent and metastatic carcinoma of the head and neck: a phase 1 study

The role of granulocyte-macrophage colony-stimulating factor in head and neck cancer

OBJECTIVE

To review the molecular mechanisms and biological roles of granulocyte-macrophage colony-stimulating factor (GM-CSF) in head and neck squamous cell carcinoma, highlighting its potential clinical applications.

DESIGN

The search terms "granulocyte-macrophage colony-stimulating factor", "GM-CSF", "CSF2″ and "head and neck squamous cell carcinoma" or "head and neck cancer" were queried in the PubMed/MEDLINE and Scopus databases.

RESULTS

Despite of being a widely expressed cytokine, the number of studies investigating the specific roles of GM-CSF in head and neck cancer was limited. Most of them investigated GM-CSF in conjunction with other cytokines. When studied alone, conflicting findings were observed in head and neck squamous cell carcinoma. GM-CSF has been shown to induce angiogenesis and local tumor invasion. Additionally, it has also been implicated in immune evasion. On the other hand, GM-CSF stimulated the differentiation of dendritic cells, which are responsible for presenting tumor antigens, and for the regulation of T cell function. Even with these paradoxical effects, there are few studies investigating the potential of GM-CSF as adjuvant therapy in head and neck cancer.

CONCLUSION

The effects of GM-CSF in head and neck cancer may be pro- or antitumor. Understanding how one arm and not the other is activated is essential to assess the applicability and the safety of this cytokine as a therapeutic agent.

Advanced Imaging Techniques for Differentiating Pseudoprogression and Tumor Recurrence After Immunotherapy for Glioblastoma

Glioblastoma (GBM) is the most common malignant tumor of the central nervous system with poor prognosis. Although the field of immunotherapy in glioma is developing rapidly, glioblastoma is still prone to recurrence under strong immune intervention. The major challenges in the process of immunotherapy are evaluating the curative effect, accurately distinguishing between treatment-related reactions and tumor recurrence, and providing guidance for clinical decision-making. Since the conventional magnetic resonance imaging (MRI) is usually difficult to distinguish between pseudoprogression and the true tumor progression, many studies have used various advanced imaging techniques to evaluate treatment-related responses. Meanwhile, criteria for efficacy evaluation of immunotherapy are constantly updated and improved. A standard imaging scheme to evaluate immunotherapeutic response will benefit patients finally. This review mainly summarizes the application status and future trend of several advanced imaging techniques in evaluating the efficacy of GBM immunotherapy.

Immunotherapy for Head and Neck Cancer

Head and neck squamous cell carcinomas (HNSCC) remain an important cause of global cancer morbidity and mortality. Historically, outcomes for patients with recurrent or metastatic disease were poor with limited treatment options. In recent decades, the demographic profile of this disease has evolved with an increase in human papilloma virus-associated oropharyngeal carcinoma and a decrease in tobacco-related disease. The treatment paradigm for HNSCC has rapidly evolved with identification of novel, immune-directed, therapeutic strategies that take advantage of immune dysregulation commonly seen in HNSCC. This review summarizes recent developments in this field and discusses emerging strategies for future therapies.

Immune deserts in head and neck squamous cell carcinoma: A review of challenges and opportunities for modulating the tumor immune microenvironment

Immunotherapy revolutionized cancer treatment but has yet to elicit durable responses in the majority of patients with head and neck squamous cell carcinoma (HNSCC). HNSCC is generally characterized by a high tumor mutational burden, which has translated to a large neoantigen load that could prime the immune system to recognize and eliminate malignant cells. Studies are increasingly showing, however, that HNSCC is an "immune desert" tumor that can hijack multiple parts of the tumor immunity cycle in order to evade immune recognition and suppress immune system activation. Herein we will review how HNSCC tumors modulate their architecture, cellular composition, and cytokine milieu to maximize immunosuppression; as well as relevant therapeutic opportunities and emerging issues facing the field of HNSCC immuno-oncology.

γδ T Cells: The Ideal Tool for Cancer Immunotherapy

γδ T cells have recently gained considerable attention as an attractive tool for cancer adoptive immunotherapy due to their potent anti-tumor activity and unique role in immunosurveillance. The remarkable success of engineered T cells for the treatment of hematological malignancies has revolutionized the field of adoptive cell immunotherapy. Accordingly, major efforts are underway to translate this exciting technology to the treatment of solid tumors and the development of allogeneic therapies. The unique features of γδ T cells, including their major histocompatibility complex (MHC)-independent anti-cancer activity, tissue tropism, and multivalent response against a broad spectrum of the tumors, render them ideal for designing universal 'third-party' cell products, with the potential to overcome the challenges of allogeneic cell therapy. In this review, we describe the crucial role of γδ T cells in anti-tumor immunosurveillance and we summarize the different approaches used for the ex vivo and in vivo expansion of γδ T cells suitable for the development of novel strategies for cancer therapy. We further discuss the different transduction strategies aiming at redirecting or improving the function of γδ T cells, as well as, the considerations for the clinical applications.

Heterogeneity of the Head and Neck Squamous Cell Carcinoma Immune Landscape and Its Impact on Immunotherapy

Head and neck squamous cell carcinomas (HNSCCs) are highly aggressive, multi-factorial tumors in the upper aerodigestive tract affecting more than half a million patients worldwide each year. Alcohol, tobacco, and human papillomavirus (HPV) infection are well known causative factors for HNSCCs. Current treatment options for HNSCCs are surgery, radiotherapy, chemotherapy, or combinatorial remedies. Over the past decade, despite the marked improvement in clinical outcome of many tumor types, the overall 5-year survival rate of HNSCCs remained ∼40–50% largely due to poor availability of effective therapeutic options for HNSCC patients with recurrent disease. Therefore, there is an urgent and unmet need for the identification of specific molecular signatures that better predict the clinical outcomes and markers that serve as better therapeutic targets. With recent technological advances in genomic and epigenetic analyses, our knowledge of HNSCC molecular characteristics and classification has been greatly enriched. Clinical and genomic meta-analysis of multicohort HNSCC gene expression profile has clearly demonstrated that HPV⁺ and HPV^- HNSCCs are not only derived from tissues of different anatomical regions, but also present with different mutation profiles, molecular characteristics, immune landscapes, and clinical prognosis. Here, we briefly review our current understanding of the biology, molecular profile, and immunological landscape of the HPV⁺ and HPV^- HNSCCs with an emphasis on the diversity and heterogeneity of HNSCC clinicopathology and therapeutic responses. After a review of recent advances and specific challenges for effective immunotherapy of HNSCCs, we then conclude with a discussion on the need to further enhance our understanding of the unique characteristics of HNSCC heterogeneity and the plasticity of immune landscape. Increased knowledge regarding the immunological characteristics of HPV⁺ and HPV^- HNSCCs would improve therapeutic targeting and immunotherapy strategies for different subtypes of HNSCCs.

Emerging patient-specific treatment modalities in head and neck cancer - a systematic review

INTRODUCTION

Head and neck cancer (HNC) is an immunosuppressive disease that demonstrates heterogeneous molecular characteristics and features of tumor-host interaction. Beside radiotherapy and surgery, the current standard of care in systemic treatment involves the use of cytotoxic chemotherapy, monoclonal antibodies (mAbs), and tyrosine kinase inhibitors (TKIs). There are also other modalities being developed under the category of immunotherapy, but they are overshadowed by the recent advancements of immune checkpoint inhibitors.

AREAS COVERED

This systematic review covers recent advancements in 'patient-specific' treatment modalities, which can be only administered to a given patient.

EXPERT OPINION

Currently, patient-specific treatment modalities in HNC mainly consist of active immunotherapy using adoptive cell therapies and/or gene engineered vectors. Despite the slow pace of development, the interest continues in these treatment modalities. The future of HNC treatment is expected to be guided by biomarkers and personalized approaches with tailored combinations of local treatments (radiotherapy, surgery), systemic agents and immune system modulation. Systematic research is required to generate robust data and obtain a high-level of evidence for the effectiveness of such treatment modalities.

Gamma Delta T Cell Therapy for Cancer: It Is Good to be Local

Human gamma delta T cells have extraordinary properties including the capacity for tumor cell killing. The major gamma delta T cell subset in human beings is designated Vγ9Vδ2 and is activated by intermediates of isoprenoid biosynthesis or aminobisphosphonate inhibitors of farnesyldiphosphate synthase. Activated cells are potent for killing a broad range of tumor cells and demonstrated the capacity for tumor reduction in murine xenotransplant tumor models. Translating these findings to the clinic produced promising initial results but greater potency is needed. Here, we review the literature on gamma delta T cells in cancer therapy with emphasis on the Vγ9Vδ2 T cell subset. Our goal was to examine obstacles preventing effective Vγ9Vδ2 T cell therapy and strategies for overcoming them. We focus on the potential for local activation of Vγ9Vδ2 T cells within the tumor environment to increase potency and achieve objective responses during cancer therapy. The gamma delta T cells and especially the Vγ9Vδ2 T cell subset, have the potential to overcome many problems in cancer therapy especially for tumors with no known treatment, lacking tumor-specific antigens for targeting by antibodies and CAR-T, or unresponsive to immune checkpoint inhibitors. Translation of amazing work from many laboratories studying gamma delta T cells is needed to fulfill the promise of effective and safe cancer immunotherapy.

Rescue of iCIKs transfer from PD-1/PD-L1 immune inhibition in patients with resectable tongue squamous cell carcinoma (TSCC)

OBJECTIVES

The purpose of this study is to evaluate the therapeutic efficacy and the role of PD-1/PD-L1 pathway in tongue squamous cell carcinoma (TSCC) patients treated with radical operation combined with chemotherapy and improving cytokine induced killer cells (iCIKs) transfer.

METHODS

Thirteen patients who received radical resection and chemotherapy were enrolled in this study. PD-1/PD-L1 expression was evaluated in TSCC patients. ICIKs were cultured from patient-derived peripheral blood mononuclear cells (PBMCs) in vitro. The immunological differences underlying iCIKs transfer were investigated through phenotype, cytokine secretion and PD-1/PD-L1 inhibition analysis.

RESULTS

The serum PD-L1 levels were elevated in the TSCC patients. PD-L1 was detected on both human TSCC cells and tumour tissue sections. PD-1 expression was much higher on the PBMCs of TSCC patients than on in vitro cultured iCIKs. Interruption of PD-1/PD-L1 interaction enhanced the cytotoxicity of iCIKs in vitro. CD3 + CD8+ T cell proportion and cytokine IL-6 secretion decreased after chemotherapy. The infusion of iCIKs effectively reversed the immunosuppression through the upregulation of the CD3 + CD8+ T cell proportion and Th cell cytokine secretion (IFN-γ, TNF-α, IL-4 and IL-6). Twelve responders are currently alive (95.7+ months), another patient 83 months.

CONCLUSION

Our findings indicated that the PD-1/PD-L1 interaction contributes to the immunosuppression in TSCC patients. ICIKs transfer is an effective therapy to reverse the immunosuppression caused by surgical procedures and chemotherapy and improve immune system function.

Head and Neck Carcinoma Immunotherapy: Facts and Hopes

Cancer of the head and neck (HNC) is a heterogeneous disease of the upper aerodigestive tract, encompassing distinct histologic types, different anatomic sites, and human papillomavirus (HPV)-positive as well as HPV-negative cancers. Advanced/recurrent HNCs have poor prognosis with low survival rates. Tumor-mediated inhibition of antitumor immune responses and a high mutational burden are common features of HNCs. Both are responsible for the successful escape of these tumors from the host immune system. HNCs evolve numerous mechanisms of evasion from immune destruction. These mechanisms are linked to genetic aberrations, so that HNCs with a high mutational load are also highly immunosuppressive. The tumor microenvironment of these cancers is populated by immune cells that are dysfunctional, inhibitory cytokines, and exosomes carrying suppressive ligands. Dysfunctional immune cells in patients with recurrent/metastatic HNC can be made effective by the delivery of immunotherapies in combination with conventional treatments. With many promising immune-based strategies available, the future of immune therapies in HNC is encouraging, especially as methods for genetic profiling and mapping the immune landscape of the tumor are being integrated into a personalized approach. Efficiency of immune therapies is expected to rapidly improve with the possibility for patients' selection based on personal immunogenomic profiles. Noninvasive biomarkers of response to therapy will be emerging as a better understanding of the various molecular signals co-opted by the tumors is gained. The emerging role of immunotherapy as a potentially beneficial addition to standard treatments for recurrent/metastatic HNC offers hope to the patients for whom no other therapeutic options exist. Clin Cancer Res; 24(1); 6-13. ©2017 AACR.

The emerging role of immunotherapy in head and neck squamous cell carcinoma (HNSCC): anti-tumor immunity and clinical applications

Head and neck squamous cell carcinoma (HNSCC) carries a poor prognosis, with low survival rates for advanced stage tumors and minimal improvement in survival trends through the past decades. It is becoming increasingly clear that HNSCC oncogenesis and evolution is characterized by profound immune defects, as cancer cells evade immunosurveillance due to accumulation of genetic mutations and tumor heterogeneity. Improved understanding of the role of the immune system in cancer has led to the identification of novel therapeutic targets, which are being investigated for their potential to provide durable responses. In this review, we will summarize the role of the immune system in HNSCC, the rationale behind immunotherapy strategies and their clinical applications.

Phase I/II study of adjuvant immunotherapy with sentinel lymph node T lymphocytes in patients with colorectal cancer

Although the development of multi-disciplinary management has improved the survival of colorectal cancer (CRC), the prognosis of metastatic CRC patients remains poor. Accumulating evidence has demonstrated that immunotherapy with cancer vaccines and adoptive T cell transfusions may improve outcomes as an adjuvant to current standard CRC treatment. In this phase I/II study, 71 CRC patients who underwent radical surgery (stage I-III, n = 46) or palliative surgery (stage IV with non-resectable synchronous metastases, n = 25) were included. In the first part of this study, sentinel lymph nodes (SLNs) were intraoperatively identified in 55 patients (46 with stage I-III CRC and 9 with stage IV CRC). SLN-T lymphocytes were expanded ex vivo for a median of 28.5 days (range 23-33 days). Thereafter, a median of 153 × 10(6) cells (range 20.7-639.0 × 10(6)) were transfused. No treatment-related toxicity was observed. In the second part of this study, the stage IV patients were routinely followed. The 24-month survival rate of the SLN-T lymphocyte group was significantly higher than that of the control group: 55.6 versus 17.5% (p = 0.02). The median overall survival of the SLN-T lymphocyte and control groups was 28 and 14 months, respectively. Our study showed that adjuvant SLN-T lymphocyte immunotherapy is feasible and safe for postoperative CRC patients. Additionally, this therapy may improve the long-term survival of metastatic CRC. Further investigation of the clinical efficacy and anti-tumor immunity is warranted.

The immune system and head and neck squamous cell carcinoma: from carcinogenesis to new therapeutic opportunities

Head and neck squamous cell carcinomas (HNSCCs) exhibit complex interactions with the host immune system that may simultaneously explain resistance to various therapeutic modalities and that may also provide opportunities for therapeutic intervention. Discoveries in immunologic research over the last decade have led to an increased understanding of these interactions as well as the development of a multitude of investigational immunotherapies. Here, we describe the interaction between HNSCC and the immune system, including a discussion of immune cells involved with tumor carcinogenesis and the role of immune-modulating factors derived from tumors. We also describe the current immunotherapeutic approaches being investigated for HNSCC, including a discussion of the successes and limitations. With this review, we hope to present HNSCC as a model to guide future research in cancer immunology.

Systemic therapy strategies for head-neck carcinomas: Current status

Head and neck cancers, most of which are squamous cell tumours, have an unsatisfactory prognosis despite intensive local treatment. This can be attributed, among other factors, to tumour recurrences inside or outside the treated area, and metastases at more distal locations. These tumours therefore require not only the standard surgical and radiation treatments, but also effective systemic modalities. The main option here is antineoplastic chemotherapy, which is firmly established in the palliative treatment of recurrent or metastatic stages of disease, and is used with curative intent in the form of combined simultaneous or adjuvant chemoradiotherapy in patients with inoperable or advanced tumour stages. Neoadjuvant treatment strategies for tumour reduction before surgery have yet to gain acceptance. Induction chemotherapy protocols before radiotherapy have to date been used in patients at high risk of distant metastases or as an aid for decision-making ("chemoselection") in those with extensive laryngeal cancers, prior to definitive chemoradiotherapy or laryngectomy. Triple-combination induction therapy (taxanes, cisplatin, 5-fluorouracil) shows high remission rates with significant toxicity and, in combination with (chemo-)radiotherapy, is currently being compared with simultaneous chemoradiotherapy; the current gold standard with regards to efficacy and long-term toxicity.A further systemic treatment strategy, called "targeted therapy", has been developed to help increase specificity and reduce toxicity. An example of targeted therapy, EGFR-specific antibodies, can be used in palliative settings and, in combination with radiotherapy, to treat advanced head and neck cancers. A series of other novel biologicals such as signal cascade inhibitors, genetic agents, or immunotherapies, are currently being evaluated in large-scale clinical studies, and could prove useful in patients with advanced, recurring or metastatic head and neck cancers. When developing a lasting, individualised systemic tumour therapy, the critical evaluation criteria are not only efficacy and acute toxicity but also (long-term) quality-of-life and the identification of dedicated predictive biomarkers.

[Immunotherapy of head and neck cancer. Current developments]

In order to improve the prognosis for patients with head and neck squamous cell cancer (HNSCC) the introduction of new therapeutic strategies is necessary. The concept of immunotherapy has been applied and improved for several years and recent studies have used tumor-specific antigens which facilitates targeted oncologic therapy. However, immunotherapy is hampered by the fact that immunosuppressive mechanisms are pronounced and relevant effector cells are suppressed, especially in patients with HNSCC. Successful immunotherapy could induce an antitumor immune response by restitution of these cell populations. Current anti-tumor immunotherapy includes unspecific immune stimulation, genetic modification of tumor and immune cells, the use of monoclonal antibodies, e.g. cetuximab, adoptive cell transfer and tumor vaccination. In the future, these biologic therapies alone or in combination with conventional therapeutic regimens could present a valuable therapeutic option for HNSCC patients.

Expansion of melanoma-specific T cells from lymph nodes of patients in stage III: implications for adoptive immunotherapy in treating cancer

BACKGROUND

Adoptive immunotherapy for patients with metastatic melanoma has yielded encouraging results. However, methods of expanding melanoma-specific T cells from stage III are limited. The objective of this study was to determine whether melanoma-specific T cells could be generated from the melanoma-draining lymph nodes (MDLNs) of patients in stage III.

METHODS

Patients in stage III who were undergoing completion lymphadenectomy were enrolled into a protocol approved by the institutional review board. MDLN cells were tested for ability to undergo cryopreservation, expand ex vivo in IL-2 or IL-2 and IL-7, and mediate melanoma-specific antitumor responses in vitro.

RESULTS

Cryopreservation produced no significant differences from fresh cultures in terms of cell growth and cellular phenotype. IL-2 and IL-2/IL-7 cultures resulted in similar growth rates, and functional studies revealed the presence of T cells that secreted interferon gamma in response to melanoma antigen peptides. Both IL-2- and IL-2/IL-7-cultured MDLN cells mediated significant apoptosis of human melanoma cell lines as compared to breast and brain tumor lines in vitro. Overall, there did not seem to be a benefit of adding IL-7. Both CD4+ and CD8+ T cells appear to mediate tumor cell apoptosis.

CONCLUSION

This study demonstrates that melanoma antigen-specific T cells can be generated from regional melanoma-draining lymph nodes and expanded ex vivo from patients with stage III disease.

Immunotherapy for head and neck cancer: advances and deficiencies

The concept of immunotherapy as a treatment for cancer patients has been in existence for decades. However, more recent immune therapeutic approaches have involved targeting of tumor-specific antigens. Although improvements have been made in using such immune stimulatory treatment strategies for a variety of solid cancers, the use of these strategies for patients with head and neck squamous cell carcinoma (HNSCC) is lagging behind. Immunotherapeutic approaches for HNSCC are particularly complicated by the profound immune suppression that is induced by HNSCC, which potentially decreases the effectiveness of immune stimulatory efforts. Trials involving patients with various solid cancers have shown the enhanced effectiveness of combining various immunotherapeutic approaches or combining immunotherapy with chemotherapy or radiation therapy. Treatment of HNSCC with such combination approaches has not been extensively investigated and has the added challenge of the need to overcome the HNSCC-induced immune suppression. This study focuses on clinical trials that have tested immunotherapeutic approaches for HNSCC patients and the challenges associated with such approaches. In addition, it will call attention to immunotherapeutic strategies that have been shown to be successful in the treatment of other solid cancers to identify potential strategies that may apply to the treatment of HNSCC.

Better understanding tumor-host interaction in head and neck cancer to improve the design and development of immunotherapeutic strategies

Head and neck cancers are heavily infiltrated by immune cells, the significance of which is complex. The natural immune response against head and neck tumors, including anti-human papillomavirus (HPV) T cells, and humoral responses has been clearly documented. However, during the course of tumor progression, co-option of the immune system by tumor cells for their own advantage and increased resistance of tumor cells to immune attack also occur. Inflammation and immune subversion to support angiogenesis are key factors promoting tumor growth. Only a better understanding of this tumor-host interaction will permit a rational design of new immunotherapeutic approaches combining immunostimulation with drugs endowed with the ability to counteract immunoevasion mechanisms.

Use of alpha,25-dihydroxyvitamin D3 treatment to stimulate immune infiltration into head and neck squamous cell carcinoma

Prior studies have shown that treatment of head and neck squamous cell carcinoma (HNSCC) patients with 1alpha,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)] reduced intratumoral levels of immune inhibitory CD34(+) progenitor cells while increasing levels of mature progeny dendritic cells. This finding was extended to a pilot study to determine whether 1,25(OH)(2)D(3) treatment concurrently increases levels of intratumoral CD4(+) and CD8(+) T cells, increases intratumoral levels of immune cells expressing the early activation marker CD69, and prolongs time to HNSCC recurrence. The clinical trial comprised 16 patients with newly diagnosed HNSCC being untreated and 16 patients being treated with 1,25(OH)(2)D(3) during the 3-week interval between cancer diagnosis and surgical treatment. Immunologic effects of treatment were monitored by immunohistochemical analyses of surgically removed HNSCC. Clinical effectiveness of 1,25(OH)(2)D(3) treatment in this study was measured by the time to HNSCC recurrence. HNSCC tissues of patients who received treatment with 1,25(OH)(2)D(3) contained increased levels of CD4(+) cells and, more significantly, CD8(+) T cells. Also prominent was an increase in cells expressing the lymphoid activation marker CD69. Results of this pilot study suggest that patients treated with 1,25(OH)(2)D(3) had a lengthier time to tumor recurrence compared with patients who were not treated before surgery.

Immunotherapy of head and neck cancer: current and future considerations

Patients with head and neck squamous cell carcinoma (HNSCC) are at considerable risk for death, with 5-year relative survival rates of approximately 60%. The profound multifaceted deficiencies in cell-mediated immunity that persist in most patients after treatment may be related to the high rates of treatment failure and second primary malignancies. Radiotherapy and chemoradiotherapy commonly have severe acute and long-term side effects on immune responses. The development of immunotherapies reflects growing awareness that certain immune system deficiencies specific to HNSCC and some other cancers may contribute to the poor long-term outcomes. Systemic cell-mediated immunotherapy is intended to activate the entire immune system and mount a systemic and/or locoregional antitumor response. The delivery of cytokines, either by single cytokines, for example, interleukin-2, interleukin-12, interferon-γ, interferon-α, or by a biologic mix of multiple cytokines, such as IRX-2, may result in tumor rejection and durable immune responses. Targeted immunotherapy makes use of monoclonal antibodies or vaccines. All immunotherapies for HNSCC except cetuximab remain investigational, but a number of agents whose efficacy and tolerability are promising have entered phase 2 or phase 3 development.

Tumor-induced CD11b+Gr-1+ myeloid cells suppress T cell sensitization in tumor-draining lymph nodes

Suppression of tumor-specific T cell sensitization is a predominant mechanism of tumor escape. To identify tumor-induced suppressor cells, we transferred spleen cells from mice bearing progressive MCA205 sarcoma into sublethally irradiated mice. These mice were then inoculated subdermally with tumor cells to stimulate T cell response in the tumor-draining lymph-node (TDLN). Tumor progression induced splenomegaly with a dramatic increase (22.1%) in CD11b(+)Gr-1(+) myeloid-derived suppressor cells (MDSC) compared with 2.6% of that in normal mice. Analyses of therapeutic effects by the adoptive immunotherapy revealed that the transfer of spleen cells from tumor-bearing mice severely inhibited the generation of tumor-immune T cells in the TDLN. We further identified MDSC to be the dominant suppressor cells. However, cells of identical phenotype from normal spleens lacked the suppressive effects. The suppression was independent of CD4(+)CD25(+) regulatory T cells. Intracellular IFN-gamma staining revealed that the transfer of MDSC resulted in a decrease in numbers of tumor-specific CD4(+) and CD8(+) T cells. Transfer of MDSC from MCA207 tumor-bearing mice also suppressed the MCA205 immune response indicating a lack of immunologic specificity. Further analyses demonstrated that MDSC inhibited T cell activation that was triggered either by anti-CD3 mAb or by tumor cells. However, MDSC did not suppress the function of immune T cells in vivo at the effector phase. Our data provide the first evidence that the systemic transfer of MDSC inhibited and interfered with the sensitization of tumor-specific T cell responses in the TDLN.

Immunotherapy in head and neck cancer: current practice and future possibilities

The survival of patients with head and neck squamous cell carcinoma has changed little over the last 30 years. However, with recent advances in the fields of cellular and molecular immunology, there is renewed optimism with regards to the development of novel methods of early diagnosis, prognosis estimation and treatment improvement for patients with head and neck squamous cell carcinoma. Here, we present a critical review of the recent advances in tumour immunology, and of the current efforts to apply new immunotherapeutic techniques in the treatment of head and neck squamous cell carcinoma.

Tumor Antigen–Specific T-Cell Expansion Is Greatly Facilitated by In vivo Priming

PURPOSE

Adoptive T-cell therapy is a promising strategy for the treatment of patients with established tumors but is often limited to specific cancers where tumor-infiltrating lymphocytes, the source of T cells for ex vivo culture, can be obtained. In this study, we evaluated the feasibility of expanding HER-2/neu-specific T cells derived from peripheral blood ex vivo following in vivo priming with a HER-2/neu peptide vaccine.

EXPERIMENTAL DESIGN

Peripheral blood mononuclear cells from cytomegalovirus (CMV)-seronegative and CMV-seropositive donors as well as HER-2/neu-positive cancer patients who had or had not been vaccinated with a HER-2/neu peptide-based vaccine was used as a source of T lymphocytes. Antigen-specific T-cell lines were generated by in vitro stimulation with antigen followed by nonspecific expansion on CD3/CD28 beads. The ability to expand antigen-specific T cells was assessed using IFN-gamma and granzyme B enzyme-linked immunosorbent spot. The phenotype of the resultant T-cell lines was evaluated by flow cytometry, including the presence of FOXP3-expressing CD4(+) T cells.

RESULTS

The frequencies of CMV-specific T cells generated from CMV(+) donors were >11-fold higher than the frequencies from CMV(-) donors (P = 0.001), with 22-fold increase of total number of CD3(+) T cells. The frequencies of HER-2/neu-specific T cells generated from the primed patients were >25-fold higher than the frequencies from unvaccinated patients (P = 0.006), with an average of a 19-fold increase of total number of CD3(+) T cells. Using peripheral blood as the source of T cells did not result in concurrent expansion of FOXP3(+)CD4(+) regulatory T cells despite the use of interleukin-2 in in vitro culture. Both CD4(+) and CD8(+) HER-2/neu-specific T cells could be expanded. The extent of ex vivo expansion correlated with the magnitude of immunity achieved during immunization (P = 0.008).

CONCLUSION

Tumor-specific T cells can be efficiently expanded from the peripheral blood ex vivo following in vivo priming with a vaccine. This approach provides an effective method to generate tumor-specific polyclonal T cells for therapeutic use that could be applied to cancer patients with any tumor type.

Synergism between GM-CSF and IFNgamma: enhanced immunotherapy in mice with glioma

Glioblastoma multiforme is the most common malignant primary brain tumor and also one of the most therapy-resistant tumors. Because of the dismal prognosis, various therapies modulating the immune system have been developed in experimental models. Previously, we have shown a 37-70% cure in a rat glioma model where rats were peripherally immunized with tumor cells producing IFNgamma. On the basis of these results, we wanted to investigate whether a combination of GM-CSF and IFNgamma could improve the therapeutic effect in a mouse glioma model, GL261 (GL-wt). Three biweekly intraperitoneal (i.p.) immunizations with irradiated GM-CSF-transduced GL261 cells (GL-GM) induced a 44% survival in mice with intracranial glioma. While treatment of GL-wt and GL-GM with IFNgamma in vitro induced upregulation of MHC I and MHC II on the tumor cells, it could not enhance survival after immunization. However, immunizations with GL-GM combined with recombinant IFNgamma at the immunization site synergistically enhanced survival with a cure rate of 88%. Tumors from mice receiving only 1 immunization on Day 10 after tumor inoculation were sectioned on Day 20 for analysis of leukocyte infiltration. Tumor volume was reduced and the infiltration of macrophages was denser in mice immunized with GL-GM combined with IFNgamma compared with that of both wildtype and nonimmunized mice. To our knowledge, this is the first study to demonstrate a synergy between GM-CSF and IFNgamma in experimental immunotherapy of tumors, by substantially increasing survival as well as inducing a potent anti-tumor response after only 1 postponed immunization.

Protective mechanisms of head and neck squamous cell carcinomas from immune assault

Head and neck squamous cell carcinoma (HNSCC) is an aggressive malignancy that is the sixth most common neoplasm in the world. Despite advances in treatments involving surgery, radiation, and chemotherapy, the 5-year survival has remained at less than 50% for the past 30 years, primarily because of local recurrences. Thus, the possibility of immunotherapeutic approaches for patients with HNSCC has gained interest. Unfortunately, patients with HNSCC have profound immune defects that are associated with increased recurrence. This review aims to provide an overview of both the defensive and immune subversive mechanisms by which patients with HNSCC can protect themselves from immune antitumor assault.

Plattenepithelkarzinome des Kopf-Hals-Bereichs

Biologic therapies able to induce or up-regulate anti-tumor immune responses could represent a complementary approach to improve the conventional treatment of squamous cell carcinomas of the head and neck (SCCHN). Patients with SCCHN are frequently immunocompromised due to the elimination and dysfunction of critical immune effector cells. Therefore, it might be necessary to restore these immune functions to allow for the generation of effective anti-tumor host responses. Simultaneously, to prevent tumor escape from immunological recognition and destruction, it might also be necessary to alter antigenic and immunogenic attributes of the malignant cells. The present overview summarizes general aspects, historical data, and recent advances in the field of immunotherapy of SCCHN, including non-specific immune stimulation, transfer of immunocompetent cells, gene therapy, use of monoclonal antibodies, and anti-cancer vaccines.

Immunological aspects of head and neck cancer: biology, pathophysiology and therapeutic mechanisms

Advanced cancer and head and neck cancer, in particular, remains a major clinical challenge with its associated morbidity and inevitable mortality. Local control of early disease is achievable in many solid tumours with current surgical and radiotherapeutic techniques but metastatic disease is associated with poor outcome and prognosis. It is known that, by the time of presentation, many patients will already have occult microscopic metastatic disease, and surgery and radiotherapy will not result in long-term survival. What little effect modern chemotherapeutic agents have on microscopic disease is, however, limited by systemic toxicity and multi-drug resistance. Immune surveillance is postulated to be operative in man. There is evidence, however, that patients with progressive tumour growth have failure of host defences both locally and systemically. Various possible defects and tumour escape mechanisms are discussed in the review. Immunotherapy and, in particular adoptive T cell therapy and DC therapy, show promise as putative tumour-specific therapy with clinical benefits. These techniques are undergoing development and evaluation in phase 1 clinical trials. Preliminary data suggest that the treatments are well tolerated. Unfortunately, there is limited evidence of significant and prolonged improvements in clinical outcome. Further developments of beneficial protocols (adjuvants, mode and frequency of vaccination etc) and multicentre studies of the use of immunotherapy in cancer are now required.

Prolonged Culture of Vaccine-Primed Lymphocytes Results in Decreased Antitumor Killing and Change in Cytokine Secretion

Adoptive transfer of effector T cells has been used successfully to eliminate metastases in animal models. Because antitumor activity depends on the number of effector cells transferred, some human trials have used in vitro-repetitive activation and expansion techniques to increase cell number. We hypothesized that the prolonged culture period might contribute to the lack of human trial success by decreasing the potency of the effector T cells. Lymph nodes draining a progressively growing murine melanoma tumor transduced to secrete granulocyte/macrophage colony-stimulating factor were harvested and activated in vitro with anti-CD3 monoclonal antibody followed by expansion in IL-2 for a total of 5 days in culture. Some lymphocytes were reactivated and further expanded for a total of 9 days in culture. In vivo activity of the effector T cells was measured by the reduction in lung metastases and is shown to be dose dependent. The prolonged culture period resulted in nearly 3-fold more T cells but at least 8-fold less antitumor activity. This was accompanied by decreased secretion of the proinflammatory cytokine, IFN-gamma, and increased secretion of the anti-inflammatory cytokine, IL-10. Thus, although increased cell number is important to maximize the effectiveness of adoptive immunotherapy, some culture conditions may actually be counterproductive in that decreases in cell potency can outweigh the benefits of increased cell numbers. The T-cell cytokine secretion pattern predicts decreased effector cell function and may explain the decreased antitumor effect.

Targeting the immune system: novel therapeutic approaches in squamous cell carcinoma of the head and neck

Despite advances in surgery, radiotherapy, and chemotherapy, the overall survival rates for patients with squamous cell carcinoma of the head and neck (SCCHN) have not changed over the last decades. Clearly, novel therapeutic strategies are needed for this cancer, which is highly immunosuppressive. Therefore, biologic therapies able to induce and/or up-regulate antitumor immune responses could represent a complementary approach to conventional treatments. Because patients with SCCHN are frequently immunocompromised due to the elimination or dysfunction of critical effector cells of the immune system, it might be necessary to restore these immune functions to allow for the generation of more effective antitumor host responses. Simultaneously, to prevent tumor escape, it might be necessary to alter attributes of the malignant cells. The present review summarizes recent advances in the field of immunotherapy of SCCHN, including techniques of nonspecific immune stimulation, the use of monoclonal antibodies, advances in adoptive immunotherapy and genetic engineering, as well as anticancer vaccines. These biologic therapies, alone or in combination with conventional treatment, are likely to develop into useful future treatment options for patients with SCCHN.

Role of NKG2D signaling in the cytotoxicity of activated and expanded CD8+ T cells

Activating and expanding T cells using T-cell receptor (TCR) cross-linking antibodies and interleukin 2 (IL-2) results in potent cytotoxic effector cells capable of recognizing a broad range of malignant cell targets, including autologous leukemic cells. The mechanism of target cell recognition has previously been unknown. Recent studies show that ligation of NKG2D on natural killer (NK) cells directly induces cytotoxicity, whereas on T cells it costimulates TCR signaling. Here we demonstrate that NKG2D expression is up-regulated upon activation and expansion of human CD8+ T cells. Antibody blocking, redirected cytolysis, and small interfering RNA (siRNA) studies using purified CD8+ T cells demonstrate that cytotoxicity against malignant target cells occurs through NKG2D-mediated recognition and signaling and not through the TCR. Activated and expanded CD8+ T cells develop cytotoxicity after 10 to 14 days of culture, coincident with the expression of the adapter protein DAP10. T cells activated and expanded in low (30 U/mL) and high (300 U/mL) concentrations of IL-2 both up-regulated NKG2D expression equally, but only cells cultured in high-dose IL-2 expressed DAP10 and were cytotoxic. Collectively these results establish that NKG2D triggering accounts for the majority of major histocompatibility complex (MHC)-unrestricted cytotoxicity of activated and expanded CD8+ T cells, likely through DAP10-mediated signaling.

Adoptive-cell-transfer therapy for the treatment of patients with cancer

Adoptive immunotherapy--the isolation of antigen-specific cells, their ex vivo expansion and activation, and subsequent autologous administration--is a promising approach to inducing antitumour immune responses. The molecular identification of tumour antigens and the ability to monitor the persistence and transport of transferred cells has provided new insights into the mechanisms of tumour immunotherapy. Recent studies have shown the effectiveness of cell-transfer therapies for the treatment of patients with selected metastatic cancers. These studies provide a blueprint for the wider application of adoptive-cell-transfer therapy, and emphasize the requirement for in vivo persistence of the cells for therapeutic efficacy.

Depletion of CD4+ CD25+ regulatory cells augments the generation of specific immune T cells in tumor-draining lymph nodes

Recent studies have identified a unique population of CD4+CD25+ regulatory T cells that is crucial for the prevention of spontaneous autoimmune diseases. Further studies demonstrated that depletion of CD4+CD25+ T cells enhances immune responses to nonself antigens. Because immune responses to malignant tumors are weak and ineffective, depletion of regulatory T cells has been reported to result in tumor regression. In the current study, using the weakly immunogenic MCA205 sarcoma and the poorly immunogenic B16/BL6/D5 (D5) melanoma, depletion of CD4+CD25+ T cells by the administration of anti-CD25 monoclonal antibodies (mAb), PC61 induced some tumor growth retardation, but all mice eventually succumbed to tumors. In our laboratory, immunotherapy by the transfer of tumor-immune T cells has demonstrated potent antitumor effects. A reliable source of tumor-reactive T cells has been lymph nodes (LN) draining progressive tumors. Therapeutic effector T cells can be generated by in vitro activation of draining LN cells with anti-CD3 mAb followed by culture in interleukin-2. In this system, PC61 mAb depletion of CD4+CD25+ T cells before or on day 8 of tumor growth resulted in increased sensitization in the draining LN. The therapeutic efficacy of activated tumor-draining LN cells from mAb depleted mice increased approximately three fold while maintaining specificity when tested in adoptive immunotherapy of established pulmonary metastases. Specific interferon-gamma secretion by LN T cells from mice treated with PC61 mAb 1 day before tumor inoculation increased significantly. However, this increase was not demonstrated with LN T cells from mice treated on day 8 despite their enhanced therapeutic reactivities. Our results indicate that although the antitumor immunity enhanced by the depletion of CD4+CD25+ T cells is insufficient to eradicate tumors, it augments the sensitization of immune T cells in the draining LN, thus, facilitating adoptive immunotherapy.

Current status of adoptive immunotherapy of malignancies

Adoptive immunotherapy involves the transfer of immune effectors with antitumour activity into the tumour bearing host. Early approaches such as lymphokine activator killer (LAK) cells and tumour infiltrating lymphocytes (TILs) have yielded occasional clinical responses. More recently, attempts to stimulate and/or select antigen-specific T-cells in vitro have demonstrated that tumour-specific adoptive immunotherapy is possible. These approaches require complicated and time consuming in vitro stimulation procedures. Therefore, genetic modification of bulk T-cell populations is an attempt to create a large population of T-cells with a single specificity. In addition to work being done to develop the most potent effector, other studies are working on improving T-cell trafficking to tumours and interfering with the tumour-induced immunosuppression that can impair in vivo T-cell activity.

Adoptive T-cell therapy for the treatment of solid tumours

Solid tumours can be eradicated by infusion of large amounts of tumour-specific T-cells in animal models. The successes seen in preclinical models, however, have not been adequately translated to human disease due, in part, to the inability to expand tumour antigen-specific T-cells ex vivo. Polyclonality and retention of antigen-specificity are two important properties of infused T-cells that are necessary for successful eradication of tumours. Investigators are beginning to evaluate the impact of attempting to reconstitute full T-cell immunity representing both major T-cell subsets, cytolytic T-cells and T-helper (Th) cells. One of the more important and often overlooked steps of successful adoptive T-cell therapy is the ex vivo expansion conditions, which can dramatically alter the phenotype of the T-cell. A number of cytokines and other soluble activation factors that have been characterised over the last decade are now available to supplement in vitro antigen presentation and IL-2. Newer molecular techniques have been developed and are aimed at genetically altering the characteristics of T-cells including their antigen-specificity and growth in vivo. In addition, advanced imaging techniques, such as positron emission tomography (PET), are being implemented in order to better define the in vivo function of ex vivo expanded tumour-specific T-cells.

Potent effector function of tumor-sensitized L-selectin(low) T cells against subcutaneous tumors requires LFA-1 co-stimulation

OBJECTIVE

Animal tumor models have demonstrated that adoptive transfer of tumor-draining lymph node (TDLN) T lymphocytes can cure established tumors in many anatomic sites. However, subcutaneous tumors are relatively refractory and have required maximally tolerated doses of cells. The goals of this study were to determine whether a subset of TDLN T lymphocytes varying in expression of the cell adhesion molecule L-selectin (CD62L) had augmented therapeutic efficacy and to determine the co-stimulatory requirements for trafficking and anti-tumor effector function.

STUDY DESIGN

TDLNs were recovered from mice bearing progressive MCA 205 fibrosarcomas, and the T lymphocytes were segregated into CD62L(low) and CD62L(high) subsets and activated ex vivo with anti-CD3 mAb and IL-2. Mice bearing established subcutaneous MCA 205 tumors were treated with activated T cell subsets and in some experiments with additional mAb against cell adhesion molecules.

RESULTS

Adoptive transfer of as few as 5 x 10(6) activated cells cured mice bearing 3-day subcutaneous MCA 205 tumors initiated with 6 x 10(6) cells, and the tumors demonstrated a dense infiltrate of CD62L(low) cells. In marked contrast, adoptive transfer of 10 times as many T cells derived from the reciprocal CD62L(high) compartment had no effect on tumor growth. The effector function of the CD62L(low) T cells was clearly dependent on co-stimulation through the cell adhesion molecule LFA-1, because anti-LFA-1 mAb completely abrogated the anti-tumor reactivity of the transferred cells against subcutaneous tumors and inhibited tumor infiltration. In contrast, blockade of ICAM-1, VLA-4, or VCAM-1 had no inhibitory effect on the anti-tumor function.

CONCLUSION

These studies demonstrate the high therapeutic activity of the CD62L(low) subset of tumor-draining LN T cells against subcutaneous tumors, a relatively refractory site, and confirm the essential role of LFA-1 for effector T cell function.

SIGNIFICANCE

Identification of the phenotype and requirements for effector function of T lymphocytes sensitized to tumor antigens has implications for clinical trials of adoptive immunotherapy for head and neck carcinoma using a similar approach.

Immunobiology and immunotherapy of head and neck cancer

The development of head and neck cancer (HNC) is strongly influenced by the host immune system. Immunoselection of tumors resistant to immune attack and the ability of established tumors to disarm or eliminate immune cells favor tumor progression. Recent evidence for local as well as systemic apoptosis of T lymphocytes, the paucity of dendritic cells (DC) at the tumor site, or the presence of signaling defects in T lymphocytes of patients with HNC emphasizes the fact that their antitumor responses are compromised. The clinical and biologic importance of these immune biomarkers is revealed by the finding that they appear to independently predict 5-year survival in patients with oral carcinoma. Whereas the mechanisms responsible for immune dysfunction in HNC are being investigated, new immunotherapeutic strategies, including antitumor vaccines and DC-based interventions, aim at the restoration of tumor-targeted immune responses. These novel biologic therapies, alone or in combination with conventional therapies, might be expected to protect immune cells from dysfunction or death and to enhance their antitumor activity.