Immune escape associated with functional defects in antigen-processing machinery in head and neck cancer

The relevance between the immune response-related gene module and clinical traits in head and neck squamous cell carcinoma

Purpose

Head and neck squamous cell carcinoma (HNSCC) is the sixth most prevalent cancer in the world, accounting for more than 90% of head and neck malignant tumors. However, its molecular mechanism is largely unknown. To help elucidate the potential mechanism of HNSCC tumorigenesis, we investigated the gene interaction patterns associated with tumorigenesis.

Methods

Weighted gene co-expression network analysis (WGCNA) can help us to predict the intrinsic relationship or correlation between gene expression. Additionally, we further explored the combination of clinical information and module construction.

Results

Sixteen modules were constructed, among which the key module most closely associated with clinical information was identified. By analyzing the genes in this module, we found that the latter may be related to the immune response, inflammatory response and formation of the tumor microenvironment. Sixteen hub genes were identified-ARHGAP9, SASH3, CORO1A, ITGAL, PPP1R16B, TBC1D10C, IL10RA, ITK, AKNA, PRKCB, TRAF3IP3, GIMAP4, CCR7, P2RY8, GIMAP7, and SP140. We further validated these genes at the transcriptional and translation levels.

Conclusion

The innovative use of a weighted network to analyze HNSCC samples provides new insights into the molecular mechanism and prognosis of HNSCC. Additionally, the hub genes we identified can be used as biomarkers and therapeutic targets of HNSCC, laying the foundation for the accurate diagnosis and treatment of HNSCC in clinical and research in the future.

Tumor-derived exosomes (TDEs): How to avoid the sting in the tail

Exosomes are abundantly secreted extracellular vesicles that accumulate in the circulation and are of great interest for disease diagnosis and evaluation since their contents reflects the phenotype of their cell of origin. Tumor‐derived exosomes (TDEs) are of particular interest for cancer diagnosis and therapy, since most tumor demonstrate highly elevated exosome secretion rates and provide specific information about the genotype of a tumor and its response to treatment. TDEs also contain regulatory factors that can alter the phenotypes of local and distant tissue sites and alter immune cell functions to promote tumor progression. The abundance, information content, regulatory potential, in vivo half‐life, and physical durability of exosomes suggest that TDEs may represent a superior source of diagnostic biomarkers and treatment targets than other materials currently under investigation. This review will summarize current information on mechanisms that may differentially regulate TDE biogenesis, TDE effects on the immune system that promote tumor survival, growth, and metastasis, and new approaches understudy to counteract or utilize TDE properties in cancer therapies.

Surrogates of immunologic cell death (ICD) and chemoradiotherapy outcomes in head and neck squamous cell carcinoma (HNSCC)

OBJECTIVES

Chemoradiation can induce immunogenic (ICD) or tolerogenic cell death. ICD relies on the generation of damage-associated molecular patterns which can stimulate toll-like receptors (TLRs). We sought to determine whether we can predict responses to chemoradiation by measuring surrogate biomarkers of ICD in a cohort of patients with locally advanced (LA) head and neck squamous cell carcinoma (HNSCC).

MATERIALS AND METHODS

In a cohort of 113 LA HNSCC pts we evaluated expression of TLR4, TLR7 and TLR9 in the EpCAM + circulating tumor cell (CTC) fraction at baseline and after cisplatin chemoradiation. We also quantified changes in chemokines CXCL10, CXCL16 and IL-2R in the serum.

RESULTS

Seventy three patients had evaluable specimens. Among cases with biomarker assessment at baseline and post treatment, 36.8% had an increase in CXCL10 levels (p = 0.022), 73.7% had an increase in CXCL16 levels (p = 0.002) and 63.8% had an increase in IL2Ra levels (p = 0.032) with treatment. 52.0% of evaluable cases at baseline and post-treatment had an increase in TLR4 levels (p = 0.996), 42.9% had an increase in TLR7 levels (p = 0.042) and 27.7% had increase in TLR9 levels (p = 0.011) with treatment. CXCL10 levels at baseline were significantly associated with PFS and OS (p = 0.010 and p = 0.032, respectively).

CONCLUSIONS

Our results suggest that chemoradiation leads to quantifiable effects in surrogate markers of ICD. These effects may inform trials combining chemoradiation with immune checkpoint inhibitors. In addition, CXCL10 has prognostic effect in pts treated with chemoradiation.

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.

Immune Evasion by Head and Neck Cancer: Foundations for Combination Therapy

Head and neck cancer is disfiguring and deadly, and contemporary treatment has fallen short in terms of morbidity and mortality. The rich immune infiltrate within these tumors designates them as prime candidates for immunotherapy and success with these drugs has been documented for recurrent and metastatic head and neck cancer. Still, single-agent immunotherapy has generated either only transient responses or durable response in only a minority subset of patients. Mapping the immune escape mechanisms enacted by head and neck cancer within the tumor microenvironment allows for rational design of strategies to overcome this tolerance. We outline the immune pathway derangements within the head and neck cancer microenvironment and discuss combination treatment strategies to overcome the limitations of immunologic monotherapy.

Modulators of Redox Metabolism in Head and Neck Cancer

SIGNIFICANCE

Head and neck squamous cell cancer (HNSCC) is a complex disease characterized by high genetic and metabolic heterogeneity. Radiation therapy (RT) alone or combined with systemic chemotherapy is widely used for treatment of HNSCC as definitive treatment or as adjuvant treatment after surgery. Antibodies against epidermal growth factor receptor are used in definitive or palliative treatment. Recent Advances: Emerging targeted therapies against other proteins of interest as well as programmed cell death protein 1 and programmed death-ligand 1 immunotherapies are being explored in clinical trials.

CRITICAL ISSUES

The disease heterogeneity, invasiveness, and resistance to standard of care RT or chemoradiation therapy continue to constitute significant roadblocks for treatment and patients' quality of life (QOL) despite improvements in treatment modality and the emergence of new therapies over the past two decades.

FUTURE DIRECTIONS

As reviewed here, alterations in redox metabolism occur at all stages of HNSCC management, providing opportunities for improved prevention, early detection, response to therapies, and QOL. Bioinformatics and computational systems biology approaches are key to integrate redox effects with multiomics data from cells and clinical specimens and to identify redox modifiers or modifiable target proteins to achieve improved clinical outcomes. Antioxid. Redox Signal.

PD-1 Haplotype Combinations and Susceptibility of Patients to Squamous Cell Carcinomas of Head and Neck

INTRODUCTION

Head and neck squamous cell carcinomas (HNSCCs) are the most common cancers of head and neck and the sixth most common malignancy worldwide. Programmed cell death 1 (PD-1) is an immune inhibitory molecule which through interaction with its ligands recruits protein phosphatase resulting in immune response inhibition. Expression of PD-1 ligands on tumor cells is considered as one of the crucial immune evasion mechanisms. This study aimed to investigate the association of PD-1 gene polymorphisms at positions PD1.3 (rs11568821), PD1.5 (rs2227981) and PD1.9 (rs2227982) with susceptibility to HNSCCs.

SUBJECTS AND METHODS

150 patients pathologically confirmed to suffer from HNSCCs and 150 age-sex matched healthy controls were recruited in this study. Genomic DNA was extracted from white blood cells of all participants. Restricted fragment length polymorphisms (RFLP)-PCR was performed using site specific primers to determine the genotypes in each position.

RESULTS

Statistical analyses indicated no significant differences in the frequencies of genotypes, alleles as well as haplotypes between patients and controls (P > 0.05), however, haplotype combination differed significantly between two groups. GCC/GCT, GCC/GCC and GCT/GCC were higher in the HNSCC patients than the control group (P < 0.05). On the other hand, in the controls, GCT/GCT, GCT/ACC, GCT/ACT and ACC/GCT were more frequent. No significant association was found with various HNSCC clinicopathological characteristics.

DISCUSSION

Our results suggested that although PD-1 gene polymorphisms at three investigated positions are not solely associated with susceptibility to HNSCCs, haplotype combinations emerged from these three loci may render susceptibility.

Expression of Programmed Death-Ligand 1 in Laryngeal Carcinoma and its Effects on Immune Cell Subgroup Infiltration

To study the expression of programmed death-ligand 1 (PD-L1), and its effects on CD8⁺ tumor infiltrating lymphocytes (TILs) and tumor associated macrophages (TAMs) in human laryngeal squamous cell carcinoma. Sixty-nine patients with laryngeal carcinoma and 10 with vocal cord leukoplakia received tumor resection at Neck Surgery Department in the Second Affiliation Hospital of Jilin University (Changchun, Jilin) from Jan. 2010 to Dec. 2015. The expressions of PD-L1, CD8, CD16 and CD206 in laryngeal carcinoma, paracancerous and vocal cord leukoplakia tissues were detected with immunohistochemistry. The associations between PD-L1 expression and clinicopathologic features, expression of TAMs and CD8⁺ T cell infiltration were analyzed. Expression of PD-L1 is significantly higher in laryngeal carcinoma than in paracancerous or leukoplakia tissue. The expression of PD-L1 is closely associated with stage of laryngeal cancer, histological differentiation and neck lymphatic metastasis. PD-L1 expression is negatively correlated with the number of CD8⁺ TILs and CD16⁺ cells (M1 type TAMs), while is positively associated with CD206⁺ (M2 type TAMs). PD-L1 is highly expressed in the laryngeal cancer with the tumor microenvironment immunosuppression.

Inflammatory Arthritis Induced by Pembrolizumab in a Patient With Head and Neck Squamous Cell Carcinoma

Introduction: T cell checkpoint inhibitors targeting Programmed cell Death protein-1 (PD-1) have emerged as novel immunotherapy agents showing remarkable efficacy in head and neck squamous cell carcinoma (HNSCC). Despite important clinical benefits, they are associated with side effects that occur as a consequence of general immunological stimulation due to loss of T cell inhibition. Herein, we report the unusual case of inflammatory arthritis induced by anti-PD-1 agent pembrolizumab.

Case report: A 55-years old male was treated with pembrolizumab at a dose of 200 mg every 3 weeks for a metastatic hypopharyngeal carcinoma. Following two cycles of immunotherapy, and while complete response of lung metastases was achieved, the patient presented with stiffness, swelling and pain of the right knee. Clinical examination and synovial fluid analysis revealed a seronegative inflammatory arthritis. Pembrolizumab therapy was interrupted and low-dose prednisone was administered with remarkable clinical improvement. Pembrolizumab was reintroduced, but after the fifth cycle, the patient developed inflammatory polyarthritis involving both knees and interphalangeal joints of both hands resulting in severe clinical deterioration. At that time, treatment with pembrolizumab was permanently discontinued. High-dose prednisone and methotrexate treatment led to remission of clinical symptoms.

Conclusion: Pembrolizumab-induced inflammatory arthritis is an unusual rheumatic immune-related adverse event that physicians are likely to encounter as ICI use expands. Multidisciplinary management and rheumatology consultation are necessary to provide immediate treatment and avoid permanent joint damage.

Exosomes in HNSCC plasma as surrogate markers of tumour progression and immune competence

Exosomes in plasma of head and neck squamous cell carcinoma (HNSCC) patients comprise subsets of vesicles derived from various cells. Recently, we separated CD3⁽⁺⁾ from CD3^(-) exosomes by immune capture. CD3^(-) exosomes were largely tumour-derived (CD44v3⁺ ). Both subsets carried immunosuppressive proteins and inhibited functions of human immune cells. The role of these subsets in immune cell reprogramming by the tumour was investigated by focusing on the adenosine pathway components. Spontaneous adenosine production by CD3⁽⁺⁾ or CD3^(-) exosomes was measured by mass spectrometry, as was the production of adenosine by CD4⁺ CD39⁺ regulatory T cells (T_reg ) co-incubated with these exosomes. The highest level of CD39/CD73 ectoenzymes and of adenosine production was found in CD3^(-) exosomes in patients with the stages III/IV HNSCCs). Also, the production of 5'-AMP and purines was significantly higher in T_reg co-incubated with CD3^(-) than CD3⁽⁺⁾ exosomes. Consistently, CD26 and adenosine deaminase (ADA) levels were higher in CD3⁽⁺⁾ than CD3^(-) exosomes. ADA and CD26 levels in CD3⁽⁺⁾ exosomes were significantly higher in patients with early (stages I/II) than advanced (stages III/IV) disease. HNSCC patients receiving and responding to photodynamic therapy had increased ADA levels in CD3⁽⁺⁾ exosomes with no increase in CD3^(-) exosomes. The opposite roles of CD3⁽⁺⁾ ADA⁺ CD26⁺ and CD3^(-) CD44v3⁺ adenosine-producing exosomes in early versus advanced HNSCC suggest that, like their parent cells, these exosomes serve as surrogates of immune suppression in cancer.

WEE1 kinase inhibition reverses G2/M cell cycle checkpoint activation to sensitize cancer cells to immunotherapy

Intrinsic resistance to cytotoxic T-lymphocyte (CTL) killing limits responses to immune activating anti-cancer therapies. Here, we established that activation of the G2/M cell cycle checkpoint results in tumor cell cycle pause and protection from granzyme B-induced cell death. This was reversed with WEE1 kinase inhibition, leading to enhanced CTL killing of antigen-positive tumor cells. Similarly, but at a later time point, cell cycle pause following TNFα exposure was reversed with WEE1 kinase inhibition, leading to CTL transmembrane TNFα-dependent induction of apoptosis and necroptosis in bystander antigen-negative tumor cells. Results were reproducible in models of oral cavity carcinoma, melanoma and colon adenocarcinoma harboring variable Tp53 genomic alterations. WEE1 kinase inhibition sensitized tumors to PD-1 mAb immune checkpoint blockade in vivo, resulting in CD8⁺-dependent rejection of established tumors harboring antigen-positive or mixed antigen-positive and negative tumor cells. Together, these data describe activation of the G2/M cell cycle checkpoint in response to early and late CTL products as a mechanism of resistance to CTL killing, and provide pre-clinical rationale for the clinical combination of agents that inhibit cell cycle checkpoints and activate anti-tumor immunity.

Checkpoint inhibitors in head and neck cancer: current knowledge and perspectives

The emergence of immunotherapy has provided significant clinical improvements in the treatment of metastatic solid tumors. Recurrent/metastatic head and neck squamous cell carcinoma (HNSCC) has dismal prognosis with median survival ranging between 6and12 months. Our aim is to review the current knowledge on the role of the immune system and immune checkpoint inhibitors in HNSCC. We will focus on the landmark trials that led to the regulatory approvals of pembrolizumab and nivolumab, and discuss a few promising contenders in clinical development and highlight the need to identify better biomarkers other than programmed death-ligand 1 to improve patient selection and help predict response.

Injectable Hydrogels Coencapsulating Granulocyte-Macrophage Colony-Stimulating Factor and Ovalbumin Nanoparticles to Enhance Antigen Uptake Efficiency

The combination of an antigen and adjuvant has synergistic effects on an immune response. Coadministration of an antigen and a granulocyte-macrophage colony-stimulating factor (GM-CSF) hydrogel delivery system will afford a novel strategy for enhancement of an immune response because of the dual role of the hydrogel as a vaccine carrier with a sustained release and a platform for recruiting dendritic cells (DCs). Herein, an injectable poly(caprolactone)-poly(ethylene glycol)-poly(caprolactone) thermosensitive hydrogel coencapsulating GM-CSF and ovalbumin nanoparticles was developed to enhance antigen uptake efficiency. The GM-CSF released from the hydrogel ensured accumulation of DCs; this effect improved the antigen uptake efficiency with the targeted delivery to antigen-presenting cells. Furthermore, the dual delivery system induced a stronger immune effect, including higher CD8⁺ T proportion, interferon γ secretion, and a greater cytotoxic T lymphocyte response, which may benefit from the recruitment of DCs, increasing antigen residence time, and the controllable antigen release owing to the combined effect of the hydrogel and nanoparticles. Meanwhile, the real-time antigen delivery process in vivo was revealed by a noninvasive fluorescence imaging method. All of the results indicated that the visible dual delivery system may have a greater potential for the efficient and trackable vaccine delivery.

Understanding Immune Tolerance of Cancer: Re-Purposing Insights from Fetal Allografts and Microbes

Cancer cells seem to exploit mechanisms that evolve as part of physiological tolerance, which is a complementary and often beneficial form of defense. The study of physiological systems of tolerance can therefore provide insights into the development of a state of host tolerance of cancer, and how to break it. Analysis of these models has the potential to improve our understanding of existing immunological therapeutic targets, and help to identify future targets and rational therapeutic combinations. The treatment of cancer with immune checkpoint inhibitors aims to reverse the progression to tolerance of cancer, and achieve an immunogenic, rather than tolerogenic, homeostasis. Broadening the efficacy and durability of checkpoint inhibitors focuses on reversing tolerance and stimulating immunogenicity in the cancer, host, and environment. Two examples of important physiological states of tolerance that may inform tolerance of cancer are microbial infection and placental reproduction. These states of tolerance result from bilateral shaping of host and non-self, akin to immunoediting in cancer, and offer reliable models to study the immune tolerance paradigm.

Blockage of the NLRP3 inflammasome by MCC950 improves anti-tumor immune responses in head and neck squamous cell carcinoma

The NLRP3 inflammasome is a critical innate immune pathway responsible for producing active interleukin (IL)-1β, which is associated with tumor development and immunity. However, the mechanisms regulating the inflammatory microenvironment, tumorigenesis and tumor immunity are unclear. Herein, we show that the NLRP3 inflammasome was over-expressed in human HNSCC tissues and that the IL-1β concentration was increased in the peripheral blood of HNSCC patients. Additionally, elevated NLRP3 inflammasome levels were detected in tumor tissues of Tgfbr1/Pten 2cKO HNSCC mice, and elevated IL-1β levels were detected in the peripheral blood serum, spleen, draining lymph nodes and tumor tissues. Blocking NLRP3 inflammasome activation using MCC950 remarkably reduced IL-1β production in an HNSCC mouse model and reduced the numbers of myeloid-derived suppressor cells (MDSCs), regulatory T cells (Tregs) and tumor-associated macrophages (TAMs). Moreover, inhibiting NLRP3 inflammasome activation increased the numbers of CD4+ and CD8+ T cells in HNSCC mice. Notably, the numbers of exhausted PD-1+ and Tim3+ T cells were significantly reduced. A human HNSCC tissue microarray showed that NLRP3 inflammasome expression was correlated with the expression of CD8 and CD4, the Treg marker Foxp3, the MDSC markers CD11b and CD33, and the TAM markers CD68 and CD163, PD-1 and Tim3. Overall, our results demonstrate that the NLRP3 inflammasome/IL-1β pathway promotes tumorigenesis in HNSCC and inactivation of this pathway delays tumor growth, accompanied by decreased immunosuppressive cell accumulation and an increased number of effector T cells. Thus, inhibition of the tumor microenvironment through the NLRP3 inflammasome/IL-1β pathway may provide a novel approach for HNSCC therapy.

Checkpoint immunotherapy in head and neck cancers

Checkpoint inhibitors have recently gained FDA approval for the treatment of cisplatin-resistant recurrent and metastatic head and neck squamous cell carcinoma (HNSCC) by outperforming standard of care chemotherapy and inducing durable responses in a subset of patients. These monoclonal antibodies unleash the patient's own immune system to target cancer cells. HNSCC is a good target for these agents as there is ample evidence of active immunosurveillance in the head and neck and a number of immune evasion mechanisms by which HNSCCs form progressive disease including via the PD-1/PD-L1 axis. As HNSCCs typically possess a moderately high mutation burden, they should express numerous mutation-derived antigen targets for immune detection. However, with response rates less than 20% in clinical trials, there is a need for biomarkers to screen patients as well as clinical trials evaluating novel combinations to improve outcomes. The aim of this review is to provide historical and mechanistic context for the use of checkpoint inhibitors in head and neck cancer and provide a perspective on the role of novel checkpoints, biomarkers, and combination therapies that are evolving in the near term for patients with HNSCC.

Immunotherapy in head and neck cancers: A new challenge for immunologists, pathologists and clinicians

Cancer occurrence can be understood as the result of dysfunctions in immune tumoral microenvironment. Here we review the recent understandings of those microenvironment changes, regarding their causes and prognostic significance in head and neck (HN) carcinoma. We will focus on HN squamous cell cancer (SCC) and nasopharyngeal carcinomas (NPC). Their overall poor prognosis may be improved with immunotherapy in a subset of patients, as supported by current clinical trials. However, finding reliable markers of therapeutic response is crucial for patient selection, due to potential severe adverse reactions and high costs. Half of HNSCC exhibit PD-L1 expression, this expression being higher in HPV-positive tumors. In recent clinical trials, a better therapeutic response to anti-PD-1 was obtained in patients with higher PD-L1 expression. The Food and Drug Administration (FDA) approved the use of these therapeutics without stating a need for patient selection regarding PD-L1 status. Activation status, density and localization of TIL as well as PD-L2, γ-interferon, inflammatory cytokines, epithelial-mesenchymal transition phenotype and mutational burden may all be potential therapeutic response markers. In Epstein-Barr Virus (EBV)-induced nasopharyngeal non-keratinizing cancer, PD-L1 is over-expressed compared to EBV-negative tumors. A 22% response rate has been observed under anti-PD-1 treatment among PD-L1-positive NPC patients. A better understanding of immune checkpoint regulation processes may allow patients to benefit from these promising immunotherapies.

Head and neck squamous cell carcinoma: Genomics and emerging biomarkers for immunomodulatory cancer treatments

Head and neck squamous cell carcinoma (HNSCC) comprises a heterogeneous group of tumors that arise from the squamous epithelium of the oral cavity, oropharynx, larynx and hypopharynx. While many HNSCCs are related to classical etiologic factors of smoking and alcohol, a clinically, genomically, and immunologically distinct subgroup of tumors arise from the epithelium of the tonsil and the base of tongue as a result of infection with Human Papilloma Virus (HPV). In this review we describe the genomic and immunologic landscape of HNSCC, highlighting differences between HPV-positive and HPV-negative HNSCC. While HPV-negative tumors are characterized by tobacco-associated mutations in genes including TP53 and CDKN2A, in HPV-positive HNSCC integration of viral genome from HPV into the host cellular genome results in expression of the E6 and E7 viral oncoproteins, with consequent degradation of p53 and functional inactivation of Rb. The immune microenvironment of HNSCC is characterized by changes in immune cell populations, immune checkpoints, as well as tumor or microenvironmental factors that alter the balance of the immune milieu in favor of immunosuppression, allowing tumor evasion and escape from immune surveillance. Immune therapies, in particular those targeting the PD1 receptor or its ligand PD-L1, including nivolumab, pembrolizumab, durvalumab, and atezolizumab have shown significant efficacy in subsets of patients with HNSCC. Current trials are evaluating the efficacy of these agents in combination with chemotherapy, radiotherapy and other immune therapies including CTLA-4 and IDO-1 inhibitors. While biomarkers including PD-L1 expression, PD-L2 expression and the interferon-gamma gene signature show potential to predict benefit from checkpoint inhibitor therapy - it is hoped that improved understanding of the genomic and immune landscape will lead to ways to improved strategies to stratify patients and to select which HNSCC are most likely to benefit from these therapies.

Therapeutic Implications of the Genetic Landscape of Head and Neck Cancer

Large-scale sequencing studies of head and neck squamous cell carcinoma (HNSCC) have elucidated the genetic changes that characterize HNSCC. These findings have supported the development of therapeutic strategies that target key components of aberrant signaling pathways and immune dysregulation. Cumulative evidence suggests that these agents in combination with radiotherapy may have synergistic effects. This review highlights the predictive biomarkers that have been identified from HNSCC genomic studies and implications on the development of molecular-targeting agents that may effectively treat patients with HNSCC, especially when used in combination with radiation.

Clinical Significance of PD-L1+ Exosomes in Plasma of Head and Neck Cancer Patients

Purpose: The microenvironment of head and neck squamous cell carcinomas (HNSCC) is highly immunosuppressive. HNSCCs expressing elevated levels of PD-L1 have especially poor outcome. Exosomes that carry PD-L1 and suppress T-cell functions have been isolated from plasma of patients with HNSCC. The potential contributions of PD-L1⁺ exosomes to immune suppression and disease activity are evaluated.Experimental Design: Exosomes isolated from plasma of 40 HNSCC patients by size exclusion chromatography were captured on beads using anti-CD63 Abs, stained for PD-1 and PD-L1 and analyzed by flow cytometry. The percentages and mean fluorescence intensities (MFI) of PD-L1⁺ and PD-1⁺ exosome/bead complexes were correlated with the patients' clinicopathologic data. PD-L1^high or PD-L1^low exosomes were incubated with activated CD69⁺ human CD8⁺ T cells ± PD-1 inhibitor. Changes in CD69 expression levels on T cells were measured. Patients' plasma was tested for soluble PD-L1 (sPD-L1) by ELISA.Results: Levels of PD-L1 carried by exosomes correlated with patients' disease activity, the UICC stage and the lymph node status (P = 0.0008-0.013). In contrast, plasma levels of sPD-L1 or exosome PD-1 levels did not correlate with any clinicopathologic parameters. CD69 expression levels were inhibited (P < 0.03) by coincubation with PD-L1^high but not by PD-L1^low exosomes. Blocking of PD-L1⁺ exosome signaling to PD-1⁺ T cells attenuated immune suppression.Conclusions: PD-L1 levels on exosomes, but not levels of sPD-L1, associated with disease progression in HNSCC patients. Circulating PD-L1⁺ exosomes emerge as useful metrics of disease and immune activity in HNSCC patients.

SIGNIFICANCE

Circulating PD-L1^high exosomes in HNC patients' plasma but not soluble PD-L1 levels associate with disease progression. Clin Cancer Res; 24(4); 896-905. ©2017 AACR.

Genetic defects of the IRF1-mediated major histocompatibility complex class I antigen presentation pathway occur prevalently in the JAK2 gene in non-small cell lung cancer

Recognition of major histocompatibility complex (MHC) class I antigens on tumor cells by cytotoxic T cells is involved in T cell-mediated tumor immune surveillance and immune checkpoint therapy. The interferon-γ (IFNγ)-IRF1 signaling pathway regulates MHC class I antigen presentation. To examine genetic defects of the IFNγ-IRF1 pathway in non-small cell lung cancer (NSCLC), we analyzed The Cancer Genome Atlas (TCGA) lung adenocarcinoma (LuAd) and lung squamous cell carcinoma (LuSc) data. Loss-of-function (LOF) genetic alterations of the IFNγ-IRF1 pathway genes (IFNGR1, IFNGR2, JAK1, JAK2, STAT1, IRF1) were found in 64 (6.3%) of 1,016 patients. These genetic defects occur prevalently in JAK2 (33 cases) and often through deletions (29 cases) of chromosome 9p24.1. JAK2 deletions were frequently, but not always, associated with deletions of PD-L1 gene (CD274), PD-L2 gene (PDCD1LG2), PTPRD, and CDKN2A/CDKN2B at the chromosome 9p24.1-9p21.3 region. IRF1 expression was correlated with immune cytolytic activity markers GZMA and PRF1 in NSCLC. IFNγ induced IRF1 expression and cell surface HLA-A/HLA-B/HLA-C (HLA-ABC) in A549, H661, H292, and H2172 cells that contained the wildtype JAK2, but not in H1573 and H1623 cells that were JAK2 defective. Deletion of JAK2 or inhibition of the JAK2 kinase activity resulted in loss of IFNγ-induced IRF1 and cell surface HLA-ABC in JAK2 wildtype NSCLC cells, whereas expression of exogenous JAK2 in H1573 cells restored the IFNγ responses. These findings show that JAK2 deficiency is the major mechanism of genetic defects of the IFNγ-IRF1 pathway in NSCLC and reveal a previously unrecognized significance of chromosome 9p deletion in NSCLC.

Profile of pembrolizumab in the treatment of head and neck squamous cell carcinoma: design development and place in therapy

Head and neck squamous cell cancer (HNSCC) is the sixth most common malignancy worldwide, and despite advances in cytotoxic, surgical and radiation techniques, outcomes are still poor in those with both locally advanced and metastatic diseases. The need for development of better therapeutics along with a greater understanding of the relationship between the immune system and malignancies has led to a new therapeutic modality, immune modulators, particularly checkpoint inhibitors in HNSCC. It is now well recognized that HNSCC circumvents crucial pathways utilized by the immune system to escape surveillance. These hijacked pathways include impairing tumor antigen presentation machinery and co-opting checkpoint receptors. This understanding has led to the development of monoclonal antibodies targeting checkpoint receptors and has resulted in promising outcomes in HNSCC. This article describes the mechanisms that HNSCC utilizes to escape immune surveillance, clinical impact of checkpoint inhibitors (with a focus on pembrolizumab), ongoing studies, and future directions.

Immunotherapy as a Potential Treatment for Chordoma: a Review

Chordoma is a locally aggressive primary malignancy of the axial skeleton. The gold standard for treatment is en bloc resection, with some centers now advocating for the use of radiation to help mitigate the risk of recurrence. Local recurrence is common, and salvaging local failures is quite difficult. Chemotherapy has been ineffective and small molecule targeted therapy has had only marginal benefits in small subsets of patients with rare tumor phenotypes or refractory disease. Recent successes utilizing immunotherapy in a variety of cancers has led to a resurgence of interest in modifying the host immune system to develop new ways to treat tumors. This review will discuss these studies and will highlight the early studies employing immune strategies for the treatment of chordoma.

Head and neck cancer: improving outcomes with a multidisciplinary approach

For early-stage head and neck cancer (HNC), surgery (S) or radiotherapy (RT) is a standard treatment. The multidisciplinary approach, which includes multimodality treatment with S followed by RT, with or without chemotherapy (CT) or concurrent chemoradiotherapy (CRT), is required for locally advanced head and neck cancer (LAHNC). CRT improves prognosis, locoregional control (LRC), and organ function in LAHNC, compared to RT alone. Prognosis in recurrent/metastatic HNC (R/M HNC) is dismal. Platinum-based CT, combined with the anti-Epidermal Growth Factor Receptor (EGFR) antibody (Ab) cetuximab, is used in first-line setting, while no further validated options are available at progression. The complexity of disease is, in part, due to the heterogeneity of organs and functions involved and the need for a multimodality approach. In addition, the patient population (often elderly and/or patients with smoking and alcohol habits) argues for an individually tailored treatment plan. Furthermore, treatment goals - which include cure, organ, and function preservation, quality of life and palliation - must also be considered. Thus, optimal management of patients with HNC should involve a range of healthcare professionals with relevant expertise. The purpose of the present review is to 1) highlight the importance and necessity of the multidisciplinary approach in the treatment of HNC; 2) update the knowledge regarding modern surgical techniques, new medical and RT treatment approaches, and their combination; 3) identify the treatment scenario for LAHNC and R/M HNC; and 4) discuss the current role of immunotherapy in HNC.

Checkpoint Inhibitors in Head and Neck Cancer: Rationale, Clinical Activity, and Potential Biomarkers

OPINION STATEMENT

The discovery and antibody targeting of immune regulatory molecules such as programmed cell death protein 1 (PD-1) and cytotoxic T lymphocyte antigen 4 (CTLA-4) pathways have led to clinically meaningful anti-cancer results. Rapid advances are being made in a variety of tumor types resulting in regulatory approvals in melanoma, non small cell lung cancer, and renal cell cancer. Numerous ongoing studies are expected to establish the worth of PD-1 pathway inhibitors in other tumor types as well as in combinations with approved agents. Head and neck squamous cell carcinoma (HNSCC) represents a complex group of malignancies characterized by profound immunosuppression and is an excellent candidate for investigation in this exciting field. However, given the fact that a subset of patients will likely benefit, it is critical to focus on biomarker development for appropriate patient selection and facilitation of trial design. As immunotherapy is settling in cancer treatment, immune checkpoint inhibitors are emerging as one of the most promising agents.

Suppression of Lymphocyte Functions by Plasma Exosomes Correlates with Disease Activity in Patients with Head and Neck Cancer

Purpose: Head and neck cancers (HNCs) often induce profound immunosuppression, which contributes to disease progression and interferes with immune-based therapies. Body fluids of patients with HNC are enriched in exosomes potentially engaged in negative regulation of antitumor immune responses. The presence and content of exosomes derived from plasma of patients with HNC are evaluated for the ability to induce immune dysfunction and influence disease activity.Experimental Design: Exosomes were isolated by size-exclusion chromatography from plasma of 38 patients with HNC and 14 healthy donors. Morphology, size, numbers, and protein and molecular contents of the recovered exosomes were determined. Coculture assays were performed to measure exosome-mediated effects on functions of normal human lymphocyte subsets and natural killer (NK) cells. The results were correlated with disease stage and activity.Results: The presence, quantity, and molecular content of isolated, plasma-derived exosomes discriminated patients with HNC with active disease (AD) from those with no evident disease (NED) after oncologic therapies. Exosomes of patients with AD were significantly more effective than exosomes of patients with NED in inducing apoptosis of CD8⁺ T cells, suppression of CD4⁺ T-cell proliferation, and upregulation of regulatory T-cell (Treg) suppressor functions (all at P < 0.05). Exosomes of patients with AD also downregulated NKG2D expression levels in NK cells.Conclusions: Exosomes in plasma of patients with HNC carry immunosuppressive molecules and interfere with functions of immune cells. Exosome-induced immune suppression correlates with disease activity in HNC, suggesting that plasma exosomes could be useful as biomarkers of HNC progression. Clin Cancer Res; 23(16); 4843-54. ©2017 AACR.

Immunotherapy for head and neck cancer: the future of treatment?

INTRODUCTION

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide with >500,000 cases diagnosed each year. HNSCC patients often present to the clinic with advanced disease and are managed with a multi-disciplinary approach consisting of surgery, chemotherapy, and/or radiation. Morbidity and quality of life issues are major challenges in this patient population due to the debilitating effects of standard of care treatment paradigms. There is a critical need for new therapeutic approaches to manage HNSCC with better anti-tumor activities and toxicity profiles. Immunotherapy has gained traction as a precision medicine initiative to manage solid malignancies. Areas covered: The authors review current knowledge of immune escape mechanisms and discuss key immunotherapies in HNSCC with an emphasis on clinical trials data. Expert opinion: The excitement over the potential of immunotherapy to manage solid malignancies, including HNSCC is high and warranted based on the impressive clinical data accrued to date. Research in immunity and immune modulation in cancer has been invigorated and offers the potential to reveal novel vulnerabilities that may be exploitable pharmacologically. The evolution of immunotherapy will continue and move toward rational combinations with other immunotherapies or molecularly-targeted agents in the first-line, adjuvant, and recurrent/metastatic settings in HNSCC.

Biological mechanisms of immune escape and implications for immunotherapy in head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is an aggressive malignancy with high morbidity and mortality. Despite advances in cytotoxic therapies and surgical techniques, overall survival (OS) has not improved over the past few decades. This emphasises the need for intense investigation into novel therapies with good tumour control and minimal toxicity. Cancer immunotherapy has led this endeavour, attempting to improve tumour recognition and expand immune responses against tumour cells. While various forms of HNSCC immunotherapy are in preclinical trials, the most promising direction thus far has been with monoclonal antibodies (mAbs), targeting growth factor and immune checkpoint receptors. Preclinical and early phase trials have shown unprecedented efficacy with minimal adverse effects. This article will review biological mechanisms of immune escape and implications for immunotherapy in HNSCC.

Surveilling the Potential for Precision Medicine-driven PD-1/PD-L1-targeted Therapy in HNSCC

Immunotherapy is becoming an accepted treatment modality for many patients with cancer and is now approved for use in platinum-refractory recurrent or metastatic head and neck squamous cell carcinoma (HNSCC). Despite these successes, a minority of patients with HNSCC receiving immunotherapy respond to treatment, and few undergo a complete response. Thus, there is a critical need to identify mechanisms regulating immune checkpoints in HNSCC such that one can predict who will benefit, and so novel combination strategies can be developed for non-responders. Here, we review the immunotherapy and molecular genetics literature to describe what is known about immune checkpoints in common genetic subsets of HNSCC. We highlight several highly recurrent genetic lesions that may serve as biomarkers or targets for combination immunotherapy in HNSCC.

T-cell immunoglobulin mucin 3 blockade drives an antitumor immune response in head and neck cancer

T‐cell immunoglobulin mucin 3 (TIM3) contributes to immune suppression during progression of many cancers, but the precise role of TIM3 in head and neck squamous cell carcinoma (HNSCC) is not clearly understood. In this study, we report that TIM3 expression was significantly up‐regulated in patients with HNSCC and associated with lymph node metastasis. Additionally, TIM3 expression was increased in patients with recurrent HNSCC and patients with preradiotherapy or prechemotherapy. We also characterized CD8⁺ T cells and CD11b⁺CD33⁺ myeloid‐derived suppressor cells (MDSCs) in human HNSCC, and found that their expression was positively correlated with TIM3 expression. To determine the underlying mechanism of TIM3 in immune response during HNSCC progression, we utilized the Tgfbr1/Pten 2cKO HNSCC mouse model with TIM3 overexpression. Treatment with anti‐TIM3 monoclonal antibody effectively suppressed tumor growth through restoring effector T‐cell function by targeting CD4⁺TIM3⁺ cells and CD8⁺TIM3⁺ cells and decreasing MDSCs. Our findings demonstrate TIM3 expression in patients with HNSCC and suggest anti‐TIM3 immunotherapy as a novel therapeutic approach for effective treatment of HNSCC.

Understanding the Impact of ErbB Activating Events and Signal Transduction on Antigen Processing and Presentation: MHC Expression as a Model

Advances in molecular pathology have changed the landscape of oncology. The ability to interrogate tissue samples for oncogene amplification, driver mutations, and other molecular alterations provides clinicians with an enormous level of detail about their patient's cancer. In some cases, this information informs treatment decisions, especially those related to targeted anti-cancer therapies. However, in terms of immune-based therapies, it is less clear how to use such information. Likewise, despite studies demonstrating the pivotal role of neoantigens in predicting responsiveness to immune checkpoint blockade, it is not known if the expression of neoantigens impacts the response to targeted therapies despite a growing recognition of their diverse effects on immunity. To realize the promise of 'personalized medicine', it will be important to develop a more integrated understanding of the relationships between oncogenic events and processes governing anti-tumor immunity. One area of investigation to explore such relationships centers on defining how ErbB/HER activation and signal transduction influences antigen processing and presentation.

The rationale for including immune checkpoint inhibition into multimodal primary treatment concepts of head and neck cancer

Background

Treatment of locally advanced squamous cell carcinomas of the head and neck (SCCHN) remains unsatisfactory. Although the addition of concurrent radiochemotherapy (RCT) or the combination of radiotherapy with blockade of the epidermal growth factor receptor (EGFR) have improved outcomes over radiotherapy alone, further optimization is urgently needed. The introduction of immune checkpoint inhibitors is currently revolutionizing cancer treatment. Clinical evidence has recently been provided in melanoma that immune checkpoint blockade may cooperate with radiation. Therefore, we searched in the literature for the evidence of combining immune checkpoint inhibitors with radiotherapy in primary treatment of SCCHN.

Discussion

A substantial amount of previous studies has dissected the molecular mechanisms of immune evasion in SCCHN. The biological effects of radio- and chemotherapy in tumor cells and the immune cell microenvironment were characterized in detail, revealing significant interference of both types of treatment with anti-tumor immunity. This extensive review of the literature revealed considerable amount of evidence that addition of immune checkpoint inhibitors might boost the immunomodulatory potential of radiotherapy and RCT regimens in SCCHN.

Summary

Promising activity of immune checkpoint inhibitors has already been reported for metastatic/recurrent SCCHN. Given the immunogenic effect of radiotherapy and its enhancement by chemotherapy, combination of radiotherapy or RCT with this new type of immunotherapy might represent a valuable option for improvement of curative treatment modalities in SCCHN.

CD137 Stimulation Enhances Cetuximab-Induced Natural Killer: Dendritic Cell Priming of Antitumor T-Cell Immunity in Patients with Head and Neck Cancer

PURPOSE

Cetuximab, an EGFR-specific antibody (mAb), modestly improves clinical outcome in patients with head and neck cancer (HNC). Cetuximab mediates natural killer (NK) cell:dendritic cell (DC) cross-talk by cross-linking FcγRIIIa, which is important for inducing antitumor cellular immunity. Cetuximab-activated NK cells upregulate the costimulatory receptor CD137 (4-1BB), which, when triggered by agonistic mAb urelumab, might enhance NK-cell functions, to promote T-cell-based immunity.

EXPERIMENTAL DESIGN

CD137 expression on tumor-infiltrating lymphocytes was evaluated in a prospective cetuximab neoadjuvant trial, and CD137 stimulation was evaluated in a phase Ib trial, in combining agonistic urelumab with cetuximab. Flow cytometry and cytokine release assays using NK cells and DC were used in vitro, testing the addition of urelumab to cetuximab-activated NK, DC, and cross presentation to T cells.

RESULTS

CD137 agonist mAb urelumab enhanced cetuximab-activated NK-cell survival, DC maturation, and tumor antigen cross-presentation. Urelumab boosted DC maturation markers, CD86 and HLA DR, and antigen-processing machinery (APM) components TAP1/2, leading to increased tumor antigen cross-presentation. In neoadjuvant cetuximab-treated patients with HNC, upregulation of CD137 by intratumoral, cetuximab-activated NK cells correlated with FcγRIIIa V/F polymorphism and predicted clinical response. Moreover, immune biomarker modulation was observed in an open label, phase Ib clinical trial, of patients with HNC treated with cetuximab plus urelumab.

CONCLUSIONS

These results suggest a beneficial effect of combination immunotherapy using cetuximab and CD137 agonist in HNC. Clin Cancer Res; 23(3); 707-16. ©2016 AACR.

The role of antagonists of the PD-1:PD-L1/PD-L2 axis in head and neck cancer treatment

We review the current clinical knowledge surrounding one of the most promising immune checkpoint pathways currently investigated in head and neck squamous cell carcinoma patients, programmed cell death-1 (PD-1) and its ligands (PD-L1 and PD-L2). We review ongoing clinical trials and associated clinical responses observed with targeting the receptor, PD-1, and its ligand, PD-L1. A recent phase III clinical trial (Checkmate 141) demonstrated an improved overall survival in head and neck cancer patients treated with anti-PD-1 monotherapy as compared to standard of care for recurrent and/or metastatic disease, which raises questions on how best to incorporate immunotherapy in the context of standard of care. We discuss biomarkers of response to this class of novel drugs, which is an area of active investigation. Lastly, we project future directions in the field wherein understanding how the Fc portions of the various monoclonal antibodies may impact their clinical efficacy as well as discuss areas where our next advances may take place, such as combination strategies.

A review of drugs in development for the personalized treatment of head and neck squamous cell carcinoma

INTRODUCTION

Head and neck squamous cell carcinoma remains a highly morbid and fatal disease, with poor survival rates among patients with advanced and recurrent disease. Recent advances in next generation sequencing, targeted therapeutics, and precision medicine trials are expanding treatment options for head and neck cancers; thus greater awareness of this rapidly evolving field is important.

AREAS COVERED

Recent next-generation sequencing studies in head and neck squamous cell carcinoma, targeted therapy clinical trials involving head and neck squamous cell carcinoma.

EXPERT COMMENTARY

This review discusses the current state of head and neck cancer treatment, and considerations and implications for the incorporation of personalized medicine and targeted therapy for head and neck cancers in a dynamic clinical landscape.

The promise of immunotherapy in head and neck squamous cell carcinoma

Squamous cell cancers of the head and neck (HNSCC) comprise a diverse group of malignancies that includes tobacco-related tumors in addition to an increasing number of human papillomavirus-associated cancers. Independently of cause, there is a growing body of evidence supporting that the immune system plays a pivotal role in HNSCC development, as tumor cells evade immunosurveillance by exploiting inhibitory checkpoint pathways that suppress anti-tumor T-cell responses. HNSCC cells have the ability to manipulate the immune system through a variety of different mechanisms, forcing it to promote tumor growth and spread. Over the last decade, discoveries in immunologic research resulted in increased understanding of complex interactions between HNSCC and the host immune system as well as T-cell regulatory mechanisms, promoting the development of a variety of novel immunotherapies. Following the availability of novel immunotherapeutic strategies, the challenge for clinicians is to understand how and in which clinical setting to use these agents in order to provide greater clinical benefit for patients. Combination of immunotherapies with standard treatment approaches also represents an evolving field of research. Herein, we provide a comprehensive review of immune escape mechanisms in HNSCC, as well as current immunotherapy approaches under investigation.

Immunological and clinical significance of HLA class I antigen processing machinery component defects in malignant cells

Experimental as well as clinical studies demonstrate that the immune system plays a major role in controlling generation and progression of tumors. The cancer immunoediting theory supports the notion that tumor cell immunogenicity is dynamically shaped by the immune system, as it eliminates immunogenic tumor cells in the early stage of the disease and then edits their antigenicity. The end result is the generation of a tumor cell population able to escape from immune recognition and elimination by tumor infiltrating lymphocytes. Two major mechanisms, which affect the target cells and the effector phase of the immune response, play a crucial role in the editing process. One is represented by the downregulation of tumor antigen (TA) processing and presentation because of abnormalities in the HLA class I antigen processing machinery (APM). The other one is represented by the anergy of effector immune infiltrates in the tumor microenvironment caused by aberrant inhibitory signals triggered by immune checkpoint receptor (ICR) ligands, such as programmed death ligand-1 (PD-L1). In this review, we will focus on tumor immune escape mechanisms caused by defects in HLA class I APM component expression and/or function in different types of cancer, with emphasis on head and neck cancer (HNC). We will also discuss the immunological implications and clinical relevance of these HLA class I APM abnormalities. Finally, we will describe strategies to counteract defective TA presentation with the expectation that they will enhance tumor recognition and elimination by tumor infiltrating effector T cells.

Immunotherapy for Head and Neck Squamous Cell Carcinoma

Head and neck squamous cell carcinoma has been found to be an immunosuppressive malignancy, with many defects in the host immune system contributing to the progression of disease. A greater understanding of these defects has lead to the identification and investigation of new therapeutic strategies, targeting immune system dysfunction in an effort to improve the outcomes of this disease. This article provides a brief review of the knowledge regarding the immune defects present in head and neck cancer, as well as a review of the current therapeutic strategies being investigated for use.

Clinical relevance of the tumor microenvironment and immune escape of oral squamous cell carcinoma

BACKGROUND

Changes in the tumor microenvironment and immune surveillance represent crucial hallmarks of various kinds of cancer, including oral squamous cell carcinoma (OSCC), and a close crosstalk of hypoxia regulating genes, an activation of chemokines and immune cells has been described.

METHODS

A review about the pivotal role of HIF-1, its crosstalk to various cornerstones in OSCC tumorigenesis is presented.

RESULTS

Hypoxia is a frequent event in OSCC and leads to a reprogramming of the cellular metabolism in order to prevent cell death. Hypoxic OSCC cells induce different adaptive changes such as anaerobic glycolysis, pH stabilisation and alterations of the gene and protein expression profile. This complex metabolic program is orchestrated by the hypoxia inducible factor (HIF)-1, the master regulator of early tumor progression. Hypoxia-dependent and -independent alterations in immune surveillance lead to different immune evasion strategies, which are partially mediated by alterations of the tumor cells, changes in the frequency, activity and repertoire of immune cell infiltrates and of soluble and environmental factors of the tumor micromilieu with consecutive generation of an immune escape phenotype, progression of disease and poor clinical outcome of OSCC patients.

CONCLUSIONS

This review focusses on the importance of HIF-1 in the adaption and reprogramming of the metabolic system to reduced oxygen values as well as on the role of the tumor microenvironment for evasion of OSCC from immune recognition and destruction.

Changing the paradigm: the potential for targeted therapy in laryngeal squamous cell carcinoma

Laryngeal squamous cell carcinoma (LSCC) remains a highly morbid and fatal disease. Historically, it has been a model example for organ preservation and treatment stratification paradigms. Unfortunately, survival for LSCC has stagnated over the past few decades. As the era of next-generation sequencing and personalized treatment for cancer approaches, LSCC may be an ideal disease for consideration of further treatment stratification and personalization. Here, we will discuss the important history of LSCC as a model system for organ preservation, unique and potentially targetable genetic signatures of LSCC, and methods for bringing stratified, personalized treatment strategies to the 21(st) century.

TAP-independent self-peptides enhance T cell recognition of immune-escaped tumors

Tumor cells frequently escape from CD8+ T cell recognition by abrogating MHC-I antigen presentation. Deficiency in processing components, like the transporter associated with antigen processing (TAP), results in strongly decreased surface display of peptide/MHC-I complexes. We previously identified a class of hidden self-antigens known as T cell epitopes associated with impaired peptide processing (TEIPP), which emerge on tumor cells with such processing defects. In the present study, we analyzed thymus selection and peripheral behavior of T cells with specificity for the prototypic TEIPP antigen, the "self" TRH4 peptide/Db complex. TEIPP T cells were efficiently selected in the thymus, egressed with a naive phenotype, and could be exploited for immunotherapy against immune-escaped, TAP-deficient tumor cells expressing low levels of MHC-I (MHC-Ilo). In contrast, overt thymus deletion and functionally impaired TEIPP T cells were observed in mice deficient for TAP1 due to TEIPP antigen presentation on all body cells in these mice. Our results strongly support the concept that TEIPPs derive from ubiquitous, nonmutated self-antigens and constitute a class of immunogenic neoantigens that are unmasked during tumor immune evasion. These data suggest that TEIPP-specific CD8+ T cells are promising candidates in the treatment of tumors that have escaped from conventional immunotherapies.

Innovative perspectives of immunotherapy in head and neck cancer. From relevant scientific rationale to effective clinical practice

It is now well established that head and neck cancer carcinogenesis is characterized by genetic instability and several immune defects, leading to unique host-tumor interactions. In such condition, recent improved comprehension and relevant findings could lead to identification of innovative molecular therapeutic targets, achieving considerable clinical and translational research. This review aims to summarize and to highlight most recent and relevant scientific rationale in this era of immunotherapy revival, and to correlate it to the near future clinical practice for the management of this challenging disease.

Anti-Tumor Immunity in Head and Neck Cancer: Understanding the Evidence, How Tumors Escape and Immunotherapeutic Approaches

Many carcinogen- and human papilloma virus (HPV)-associated head and neck cancers (HNSCC) display a hematopoietic cell infiltrate indicative of a T-cell inflamed phenotype and an underlying anti-tumor immune response. However, by definition, these tumors have escaped immune elimination and formed a clinically significant malignancy. A number of both genetic and environmental mechanisms may allow such immune escape, including selection of poorly antigenic cancer cell subsets, tumor produced proinflammatory and immunosuppressive cytokines, recruitment of immunosuppressive immune cell subsets into the tumor and expression of checkpoint pathway components that limit T-cell responses. Here, we explore concepts of antigenicity and immunogenicity in solid tumors, summarize the scientific and clinical data that supports the use of immunotherapeutic approaches in patients with head and neck cancer, and discuss immune-based treatment approaches currently in clinical trials.

Immunology and Immunotherapy of Head and Neck Cancer

The immune system plays a key role in the development, establishment, and progression of head and neck squamous cell carcinoma (HNSCC). A greater understanding of the dysregulation and evasion of the immune system in the evolution and progression of HNSCC provides the basis for improved therapies and outcomes for patients. HNSCC cells evade the host immune system through manipulation of their own immunogenicity, production of immunosuppressive mediators, and promotion of immunomodulatory cell types. Through the tumor's influence on the microenvironment, the immune system can be exploited to promote metastasis, angiogenesis, and growth. This article provides a brief overview of key components of the immune infiltrating cells in the tumor microenvironment, reviewing immunological principles related to head and neck cancer, including the concept of cancer immunosurveillance and immune escape. Current immunotherapeutic strategies and emerging results from ongoing clinical trials are presented.