The extracellular nucleoside adenosine reduces tissue inflammation and is generated by irreversible dephosphorylation of adenosine monophosphate (AMP) mediated by the ectonucleotidase CD73. The pro-inflammatory nucleotides adenosine triphosphate, nicotinamide adenine dinucleotide, and cyclic guanosine -monophosphate-AMP (cGAMP), which are produced in the tumor microenvironment (TME) during therapy-induced immunogenic cell death and activation of innate immune signaling, can be converted into AMP by ectonucleotidases CD39, CD38, and CD203a/ENPP1. Thus, ectonucleotidases shape the TME by converting immune-activating signals into an immunosuppressive one. Ectonucleotidases also hinder the ability of therapies including radiation therapy, which enhance the release of pro-inflammatory nucleotides in the extracellular milieu, to induce immune-mediated tumor rejection. Here, we review the immunosuppressive effects of adenosine and the role of different ectonucleotidases in modulating antitumor immune responses. We discuss emerging opportunities to target adenosine generation and/or its ability to signal via adenosine receptors expressed by immune and cancer cells in the context of combination immunotherapy and radiotherapy..

Radiation therapy (RT) increases tumor response to CTLA-4 inhibition (CTLA4i) in mice and in some patients, yet deep responses are rare. To identify rational combinations of immunotherapy to improve responses we use models of triple negative breast cancer highly resistant to immunotherapy in female mice. We find that CTLA4i promotes the expansion of CD4+ T helper cells, whereas RT enhances T cell clonality and enriches for CD8+ T cells with an exhausted phenotype. Combination therapy decreases regulatory CD4+ T cells and increases effector memory, early activation and precursor exhausted CD8+ T cells. A combined gene signature comprising these three CD8+ T cell clusters is associated with survival in patients. Here we show that targeting additional immune checkpoints expressed by intratumoral T cells, including PD1, is not effective, whereas CD40 agonist therapy recruits resistant tumors into responding to the combination of RT and CTLA4i, indicating the need to target different immune compartments..

Immune-checkpoint inhibitors (ICI), although revolutionary in improving long-term survival outcomes, are mostly effective in patients with immune-responsive tumors. Most patients with cancer either do not respond to ICIs at all or experience disease progression after an initial period of response. Treatment resistance to ICIs remains a major challenge and defines the biggest unmet medical need in oncology worldwide. In a collaborative workshop, thought leaders from academic, biopharma, and nonprofit sectors convened to outline a resistance framework to support and guide future immune-resistance research. Here, we explore the initial part of our effort by collating seminal discoveries through the lens of known biological processes. We highlight eight biological processes and refer to them as immune resistance nodes. We examine the seminal discoveries that define each immune resistance node and pose critical questions, which, if answered, would greatly expand our notion of immune resistance. Ultimately, the expansion and application of this work calls for the integration of multiomic high-dimensional analyses from patient-level data to produce a map of resistance phenotypes that can be utilized to guide effective drug development and improved patient outcomes..

Most patients with non-small cell lung cancer (NSCLC) do not achieve durable clinical responses from immune checkpoint inhibitors, suggesting the existence of additional resistance mechanisms. Nicotinamide adenine dinucleotide (NAD)-induced cell death (NICD) of P2X7 receptor (P2X7R)-expressing T cells regulates immune homeostasis in inflamed tissues. This process is mediated by mono-adenosine 5'-diphosphate (ADP)-ribosyltransferases (ARTs). We found an association between membranous expression of ART1 on tumor cells and reduced CD8 T cell infiltration. Specifically, we observed a reduction in the P2X7R+ CD8 T cell subset in human lung adenocarcinomas. In vitro, P2X7R+ CD8 T cells were susceptible to ART1-mediated ADP-ribosylation and NICD, which was exacerbated upon blockade of the NAD+-degrading ADP-ribosyl cyclase CD38. Last, in murine NSCLC and melanoma models, we demonstrate that genetic and antibody-mediated ART1 inhibition slowed tumor growth in a CD8 T cell-dependent manner. This was associated with increased infiltration of activated P2X7R+CD8 T cells into tumors. In conclusion, we describe ART1-mediated NICD as a mechanism of immune resistance in NSCLC and provide preclinical evidence that antibody-mediated targeting of ART1 can improve tumor control, supporting pursuit of this approach in clinical studies..

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Accumulating preclinical and clinical evidence indicates that high degrees of heterogeneity among malignant cells constitute a considerable obstacle to the success of cancer therapy. This calls for the development of approaches that operate - or enable established treatments to operate - despite such intratumoral heterogeneity (ITH). In this context, oncolytic peptides stand out as promising therapeutic tools based on their ability to drive immunogenic cell death associated with robust anticancer immune responses independently of ITH. We review the main molecular and immunological pathways engaged by oncolytic peptides, and discuss potential approaches to combine these agents with modern immunotherapeutics in support of superior tumor-targeting immunity and efficacy in patients with cancer..

LTX-315 is a nonameric oncolytic peptide in early clinical development for the treatment of solid malignancies. Preclinical and clinical evidence indicates that the anticancer properties of LTX-315 originate not only from its ability to selectively kill cancer cells, but also from its capacity to promote tumor-targeting immune responses. Here, we investigated the therapeutic activity and immunological correlates of intratumoral LTX-315 administration in three syngeneic mouse models of breast carcinoma, with a focus on the identification of possible combinatorial partners. We found that breast cancer control by LTX-315 is accompanied by a reconfiguration of the immunological tumor microenvironment that supports the activation of anticancer immunity and can be boosted by radiation therapy. Mechanistically, depletion of natural killer (NK) cells compromised the capacity of LTX-315 to limit local and systemic disease progression in a mouse model of triple-negative breast cancer, and to extend the survival of mice bearing hormone-accelerated, carcinogen-driven endogenous mammary carcinomas. Altogether, our data suggest that LTX-315 controls breast cancer progression by engaging NK cell-dependent immunity..

Cancer patients with low or absent pre-existing anti-tumour immunity ("cold" tumours) respond poorly to treatment with immune checkpoint inhibitors (ICPI). In order to render these patients susceptible to ICPI, initiation of de novo tumour-targeted immune responses is required. This involves triggering of inflammatory signalling, innate immune activation including recruitment and stimulation of dendritic cells (DCs), and ultimately priming of tumour-specific T cells. The ability of tumour localised therapies to trigger these pathways and act as in situ tumour vaccines is being increasingly explored, with the aspiration of developing combination strategies with ICPI that could generate long-lasting responses. In this effort, it is crucial to consider how therapy-induced changes in the tumour microenvironment (TME) act both as immune stimulants but also, in some cases, exacerbate immune resistance mechanisms. Increasingly refined immune monitoring in pre-clinical studies and analysis of on-treatment biopsies from clinical trials have provided insight into therapy-induced biomarkers of response, as well as actionable targets for optimal synergy between localised therapies and ICB. Here, we review studies on the immunomodulatory effects of novel and experimental localised therapies, as well as the re-evaluation of established therapies, such as radiotherapy, as immune adjuvants with a focus on ICPI combinations..

The ability of focal radiotherapy to promote priming of tumor-specific CD8+ T cells and increase responses to immunotherapy is dependent on infiltration of the tumor by Batf3-dependent conventional dendritic cell type 1 (cDC1) cells. Such infiltration is driven by radiotherapy-induced IFN type I (IFN-I). Other signals may also modulate cDC1 infiltration of irradiated tumors. Here we found increased expression of adenosine-generating enzymes CD38 and CD73 in irradiated mouse and human breast cancer cells and increased adenosine in mouse tumors following radiotherapy. CD73 blockade alone had no effect. CD73 blockade with radiotherapy restored radiotherapy-induced cDC1 infiltration of tumors in settings where radiotherapy induction of IFN-I was suboptimal. In the absence of radiotherapy-induced IFN-I, blockade of CD73 was required for rejection of the irradiated tumor and for systemic tumor control (abscopal effect) in the context of cytotoxic T-lymphocyte-associated protein 4 blockade. These results suggest that CD73 may be a radiation-induced checkpoint, and that CD73 blockade in combination with radiotherapy and immune checkpoint blockade might improve patient response to therapy..

Exercise is associated with favorable changes in circulating immune cells and improved survival in early-stage breast cancer patients, but the mechansims remain to be fully elucidated. Preclinical studies indicate that physical activity started before tumor injection reduces tumor incidence and progression. Here we tested whether exercise has anti-tumor effects in mice with established 4T1 mammary carcinoma, a mouse model of triple negative breast cancer. Exercise slowed tumor progression and reduced the tumor-induced accumulation of myeloid-derived suppressor cells (MDSCs). The reduction in MDSCs was accompanied by a relative increase in natural killer and CD8 T cell activation, suggesting that exercise restores a favorable immune environment. Consistently, exercise improved responses to a combination of programmed cell death protein 1 (PD-1) blockade and focal radiotherapy. These data support further investigations of exercise in breast cancer patients treated with combinations of immunotherapy and cytotoxic agents to improve cancer outcomes..

Exosomes are small extracellular vesicles released by prokaryotic and eukaryotic cells with a crucial role in cell-to-cell communication in both physiological and pathological conditions. Exosomes contain and transfer active biomolecules, including nucleic acids, proteins and lipids to target recipient cells. In the last decade, many methodologies have been developed for isolating specific exosomal components. In this chapter, we will detail methods to isolate exosomal DNA, considering the crucial role of exosomal DNA in regulating the behavior of recipient cells in multiple settings, including the response of malignant cells to chemo-, radio- and immunotherapy..

Preclinical and clinical data emerging over the past year demonstrate that cancer cells suppress the cytotoxic functions of natural killer cells by a variety of mechanisms. These findings reveal a new arsenal of actionable therapeutic targets to drive clinically relevant immune responses against cancer..

Immune checkpoint inhibitors activate T cells to reject tumors. Unique tumor mutations are key T-cell targets, but a comprehensive understanding of the nature of a successful antitumor T-cell response is lacking. To investigate the T-cell receptor (TCR) repertoire associated with treatment success versus failure, we used a well-characterized mouse carcinoma that is rejected by CD8 T cells in mice treated with radiotherapy (RT) and anti-CTLA-4 in combination, but not as monotherapy, and comprehensively analyzed tumor-infiltrating lymphocytes (TILs) by high-throughput sequencing of the TCRΒ CDR3 region. The combined treatment increased TIL density and CD8/CD4 ratio. Assessment of the frequency of T-cell clones indicated that anti-CTLA-4 resulted in fewer clones and a more oligoclonal repertoire compared with untreated tumors. In contrast, RT increased the CD8/CD4 ratio and broadened the TCR repertoire, and when used in combination with anti-CTLA-4, these selected T-cell clones proliferated. Hierarchical clustering of CDR3 sequences showed a treatment-specific clustering of TCRs that were shared by different mice. Abundant clonotypes were commonly shared between animals and yet treatment-specific. Analysis of amino-acid sequence similarities revealed a significant increase in the number and richness of dominant CDR3 motifs in tumors treated with RT + anti-CTLA-4 compared with control. The repertoire of TCRs reactive with a single tumor antigen recognized by CD8+ T cells was heterogeneous but highly clonal, irrespective of treatment. Overall, data support a model whereby a diverse TCR repertoire is required to achieve tumor rejection and may underlie the synergy between RT and CTLA-4 blockade. Cancer Immunol Res; 6(2); 139-50. ©2017 AACR..

Focal radiation therapy enhances systemic responses to anti-CTLA-4 antibodies in preclinical studies and in some patients with melanoma1-3, but its efficacy in inducing systemic responses (abscopal responses) against tumors unresponsive to CTLA-4 blockade remained uncertain. Radiation therapy promotes the activation of anti-tumor T cells, an effect dependent on type I interferon induction in the irradiated tumor4-6. The latter is essential for achieving abscopal responses in murine cancers6. The mechanisms underlying abscopal responses in patients treated with radiation therapy and CTLA-4 blockade remain unclear. Here we report that radiation therapy and CTLA-4 blockade induced systemic anti-tumor T cells in chemo-refractory metastatic non-small-cell lung cancer (NSCLC), where anti-CTLA-4 antibodies had failed to demonstrate significant efficacy alone or in combination with chemotherapy7,8. Objective responses were observed in 18% of enrolled patients, and 31% had disease control. Increased serum interferon-β after radiation and early dynamic changes of blood T cell clones were the strongest response predictors, confirming preclinical mechanistic data. Functional analysis in one responding patient showed the rapid in vivo expansion of CD8 T cells recognizing a neoantigen encoded in a gene upregulated by radiation, supporting the hypothesis that one explanation for the abscopal response is radiation-induced exposure of immunogenic mutations to the immune system..

Ionizing irradiation has been extensively employed for the clinical management of solid tumors, with therapeutic or palliative intents, for decades. Until recently, radiation therapy (RT) was believed to mediate antineoplastic activity mostly (if not only) as a consequence of cancer cell-intrinsic effects. Indeed, the macromolecular damage imposed to malignant cells by RT initiates one or multiple signal transduction cascades that drive a permanent proliferative arrest (cellular senescence) or regulated cell death. Both these phenomena show a rather linear dose-response correlation. However, RT also mediates consistent immunological activity, not only as an "on-target effect" originating within irradiated cancer cells, but also as an "off-target effect" depending on the interaction between RT and stromal, endothelial, and immune components of the tumor microenvironment. Interestingly, the immunological activity of RT does not exhibit linear dose-response correlation. Here, we discuss the mechanisms whereby RT alters the capacity of the immune system to recognize and eliminate irradiated cancer cells, either as an "on-target" or as on "off-target" effect. In particular, we discuss the antagonism between the immunostimulatory and immunosuppressive effects of RT as we delineate combinatorial strategies to boost the former at the expenses of the latter..

BACKGROUND: Adoptive natural killer (NK) cell transfer is being increasingly used as cancer treatment. However, clinical responses have so far been limited to patients with hematological malignancies. A potential limiting factor in patients with solid tumors is defective homing of the infused NK cells to the tumor site. Chemokines regulate the migration of leukocytes expressing corresponding chemokine receptors. Various solid tumors, including renal cell carcinoma (RCC), readily secrete ligands for the chemokine receptor CXCR2. We hypothesize that infusion of NK cells expressing high levels of the CXCR2 chemokine receptor will result in increased influx of the transferred NK cells into tumors, and improved clinical outcome in patients with cancer. METHODS: Blood and tumor biopsies from 14 primary RCC patients were assessed by flow cytometry and chemokine analysis. Primary NK cells were transduced with human CXCR2 using a retroviral system. CXCR2 receptor functionality was determined by Calcium flux and NK cell migration was evaluated in transwell assays. RESULTS: We detected higher concentrations of CXCR2 ligands in tumors compared with plasma of RCC patients. In addition, CXCL5 levels correlated with the intratumoral infiltration of CXCR2-positive NK cells. However, tumor-infiltrating NK cells from RCC patients expressed lower CXCR2 compared with peripheral blood NK cells. Moreover, healthy donor NK cells rapidly lost their CXCR2 expression upon in vitro culture and expansion. Genetic modification of human primary NK cells to re-express CXCR2 improved their ability to specifically migrate along a chemokine gradient of recombinant CXCR2 ligands or RCC tumor supernatants compared with controls. The enhanced trafficking resulted in increased killing of target cells. In addition, while their functionality remained unchanged compared with control NK cells, CXCR2-transduced NK cells obtained increased adhesion properties and formed more conjugates with target cells. CONCLUSIONS: To increase the success of NK cell-based therapies of solid tumors, it is of great importance to promote their homing to the tumor site. In this study, we show that stable engineering of human primary NK cells to express a chemokine receptor thereby enhancing their migration is a promising strategy to improve anti-tumor responses following adoptive transfer of NK cells..

The immunostimulatory properties of radiation therapy (RT) have recently generated widespread interest due to preclinical and clinical evidence that tumor-localized RT can sometimes induce antitumor immune responses mediating regression of non-irradiated metastases (abscopal effect). The ability of RT to activate antitumor T cells explains the synergy of RT with immune checkpoint inhibitors, which has been well documented in mouse tumor models and is supported by observations of more frequent abscopal responses in patients refractory to immunotherapy who receive RT during immunotherapy. However, abscopal responses following RT remain relatively rare in the clinic, and antitumor immune responses are not effectively induced by RT against poorly immunogenic mouse tumors. This suggests that in order to improve the pro-immunogenic effects of RT, it is necessary to identify and overcome the barriers that pre-exist and/or are induced by RT in the tumor microenvironment. On the one hand, RT induces an immunogenic death of cancer cells associated with release of powerful danger signals that are essential to recruit and activate dendritic cells (DCs) and initiate antitumor immune responses. On the other hand, RT can promote the generation of immunosuppressive mediators that hinder DCs activation and impair the function of effector T cells. In this review, we discuss current evidence that several inhibitory pathways are induced and modulated in irradiated tumors. In particular, we will focus on factors that regulate and limit radiation-induced immunogenicity and emphasize current research on actionable targets that could increase the effectiveness of radiation-induced in situ tumor vaccination..

Treatment of hematological malignancies by adoptive transfer of activated natural killer (NK) cells is limited by poor postinfusion persistence. We compared the ability of interleukin-2 (IL-2) and IL-15 to sustain human NK-cell functions following cytokine withdrawal to model postinfusion performance. In contrast to IL-2, IL-15 mediated stronger signaling through the IL-2/15 receptor complex and provided cell function advantages. Genome-wide analysis of cytosolic and polysome-associated messenger RNA (mRNA) revealed not only cytokine-dependent differential mRNA levels and translation during cytokine activation but also that most gene expression differences were primed by IL-15 and only manifested after cytokine withdrawal. IL-15 augmented mammalian target of rapamycin (mTOR) signaling, which correlated with increased expression of genes related to cell metabolism and respiration. Consistently, mTOR inhibition abrogated IL-15-induced cell function advantages. Moreover, mTOR-independent STAT-5 signaling contributed to improved NK-cell function during cytokine activation but not following cytokine withdrawal. The superior performance of IL-15-stimulated NK cells was also observed using a clinically applicable protocol for NK-cell expansion in vitro and in vivo. Finally, expression of IL-15 correlated with cytolytic immune functions in patients with B-cell lymphoma and favorable clinical outcome. These findings highlight the importance of mTOR-regulated metabolic processes for immune cell functions and argue for implementation of IL-15 in adoptive NK-cell cancer therapy..

MELANOMA BRIDGE 2015 KEYNOTE SPEAKER PRESENTATIONS Molecular and immuno-advances K1 Immunologic and metabolic consequences of PI3K/AKT/mTOR activation in melanoma Vashisht G. Y. Nanda, Weiyi Peng, Patrick Hwu, Michael A. Davies K2 Non-mutational adaptive changes in melanoma cells exposed to BRAF and MEK inhibitors help the establishment of drug resistance Gennaro Ciliberto, Luigi Fattore, Debora Malpicci, Luigi Aurisicchio, Paolo Antonio Ascierto, Carlo M. Croce, Rita Mancini K3 Tumor-intrinsic beta-catenin signaling mediates tumor-immune avoidance Stefani Spranger, Thomas F. Gajewski K4 Intracellular tumor antigens as a source of targets of antibody-based immunotherapy of melanoma Yangyang Wang, Soldano Ferrone Combination therapies K5 Harnessing radiotherapy to improve responses to immunotherapy in cancer Claire Vanpouille-Box, Erik Wennerberg, Karsten A. Pilones, Silvia C. Formenti, Sandra Demaria K6 Creating a T cell-inflamed tumor microenvironment overcomes resistance to checkpoint blockade Haidong Tang, Yang Wang, Yang-Xin Fu K7 Biomarkers for treatment decisions? Reinhard Dummer K8 Combining oncolytic therapies in the era of checkpoint inhibitors Igor Puzanov K9 Immune checkpoint blockade for melanoma: should we combine or sequence ipilimumab and PD-1 antibody therapy? Michael A. Postow News in immunotherapy K10 An update on adjuvant and neoadjuvant therapy for melanom Ahmad Tarhini K11 Targeting multiple inhibitory receptors in melanoma Joe-Marc Chauvin, Ornella Pagliano, Julien Fourcade, Zhaojun Sun, Hong Wang, Cindy Sanders, John M. Kirkwood, Tseng-hui Timothy Chen, Mark Maurer, Alan J. Korman, Hassane M. Zarour K12 Improving adoptive immune therapy using genetically engineered T cells David F. Stroncek Tumor microenvironment and biomarkers K13 Myeloid cells and tumor exosomes: a crosstalk for assessing immunosuppression? Veronica Huber, Licia Rivoltini K14 Update on the SITC biomarker taskforce: progress and challenges Magdalena Thurin World-wide immunoscore task force: an update K15 The immunoscore in colorectal cancer highlights the importance of digital scoring systems in surgical pathology Tilman Rau, Alessandro Lugli K16 The immunoscore: toward an integrated immunomonitoring from the diagnosis to the follow up of cancer’s patients Franck Pagès Economic sustainability of melanoma treatments: regulatory, health technology assessment and market access issues K17 Nivolumab, the regulatory experience in immunotherapy Jorge Camarero, Arantxa Sancho K18 Evidence to optimize access for immunotherapies Claudio Jommi ORAL PRESENTATIONS Molecular and immuno-advances O1 Ipilimumab treatment results in CD4 T cell activation that is concomitant with a reduction in Tregs and MDSCs Yago Pico de Coaña, Maria Wolodarski, Yuya Yoshimoto, Giusy Gentilcore, Isabel Poschke, Giuseppe V. Masucci, Johan Hansson, Rolf Kiessling O2 Evaluation of prognostic and therapeutic potential of COX-2 and PD-L1 in primary and metastatic melanoma Giosuè Scognamiglio, Francesco Sabbatino, Federica Zito Marino, Anna Maria Anniciello, Monica Cantile, Margherita Cerrone, Stefania Scala, Crescenzo D’alterio, Angela Ianaro, Giuseppe Cirino, Paolo Antonio Ascierto, Giuseppina Liguori, Gerardo Botti O3 Vemurafenib in patients with BRAFV600 mutation–positive metastatic melanoma: final overall survival results of the BRIM-3 study Paul B. Chapman, Caroline Robert, James Larkin, John B. Haanen, Antoni Ribas, David Hogg, Omid Hamid, Paolo Antonio Ascierto, Alessandro Testori, Paul Lorigan, Reinhard Dummer, Jeffrey A. Sosman, Keith T. Flaherty, Huibin Yue, Shelley Coleman, Ivor Caro, Axel Hauschild, Grant A. McArthur O4 Updated survival, response and safety data in a phase 1 dose-finding study (CA209-004) of concurrent nivolumab (NIVO) and ipilimumab (IPI) in advanced melanoma Mario Sznol, Margaret K. Callahan, Harriet Kluger, Michael A. Postow, RuthAnn Gordan, Neil H. Segal, Naiyer A. Rizvi, Alexander Lesokhin, Michael B. Atkins, John M. Kirkwood, Matthew M. Burke, Amanda Ralabate, Angel Rivera, Stephanie A. Kronenberg, Blessing Agunwamba, Mary Ruisi, Christine Horak, Joel Jiang, Jedd Wolchok Combination therapies O5 Efficacy and correlative biomarker analysis of the coBRIM study comparing cobimetinib (COBI) + vemurafenib (VEM) vs placebo (PBO) + VEM in advanced BRAF-mutated melanoma patients (pts) Paolo A. Ascierto, Grant A. McArthur, James Larkin, Gabriella Liszkay, Michele Maio, Mario Mandalà, Lev Demidov, Daniil Stoyakovskiy, Luc Thomas, Luis de la Cruz-Merino, Victoria Atkinson, Caroline Dutriaux, Claus Garbe, Matthew Wongchenko, Ilsung Chang, Daniel O. Koralek, Isabelle Rooney, Yibing Yan, Antoni Ribas, Brigitte Dréno O6 Preliminary clinical safety, tolerability and activity results from a Phase Ib study of atezolizumab (anti-PDL1) combined with vemurafenib in BRAFV600-mutant metastatic melanoma Ryan Sullivan, Omid Hamid, Manish Patel, Stephen Hodi, Rodabe Amaria, Peter Boasberg, Jeffrey Wallin, Xian He, Edward Cha, Nicole Richie, Marcus Ballinger, Patrick Hwu O7 Preliminary safety and efficacy data from a phase 1/2 study of epacadostat (INCB024360) in combination with pembrolizumab in patients with advanced/metastatic melanoma Thomas F. Gajewski, Omid Hamid, David C. Smith, Todd M. Bauer, Jeffrey S. Wasser, Jason J. Luke, Ani S. Balmanoukian, David R. Kaufman, Yufan Zhao, Janet Maleski, Lance Leopold, Tara C. Gangadhar O8 Primary analysis of MASTERKEY-265 phase 1b study of talimogene laherparepvec (T-VEC) and pembrolizumab (pembro) for unresectable stage IIIB-IV melanoma Reinhard Dummer, Georgina V. Long, Antoni Ribas, Igor Puzanov, Olivier Michielin, Ari VanderWalde, Robert H.I. Andtbacka, Jonathan Cebon, Eugenio Fernandez, Josep Malvehy, Anthony J. Olszanski, Thomas F. Gajewski, John M. Kirkwood, Christine Gause, Lisa Chen, David R. Kaufman, Jeffrey Chou, F. Stephen Hodi News in immunotherapy O9 Two-year survival and safety update in patients (pts) with treatment-naïve advanced melanoma (MEL) receiving nivolumab (NIVO) or dacarbazine (DTIC) in CheckMate 066 Victoria Atkinson, Paolo A. Ascierto, Georgina V. Long, Benjamin Brady, Caroline Dutriaux, Michele Maio, Laurent Mortier, Jessica C. Hassel, Piotr Rutkowski, Catriona McNeil, Ewa Kalinka-Warzocha, Celeste Lebbé, Lars Ny, Matias Chacon, Paola Queirolo, Carmen Loquai, Parneet Cheema, Alfonso Berrocal, Karmele Mujika Eizmendi, Luis De La Cruz-Merino, Gil Bar-Sela, Christine Horak, Joel Jiang, Helene Hardy, Caroline Robert O10 Efficacy and safety of nivolumab (NIVO) in patients (pts) with advanced melanoma (MEL) who were treated beyond progression in CheckMate 066/067 Georgina V. Long, Jeffrey S. Weber, James Larkin, Victoria Atkinson, Jean-Jacques Grob, Reinhard Dummer, Caroline Robert, Ivan Marquez-Rodas, Catriona McNeil, Henrik Schmidt, Karen Briscoe, Jean-François Baurain, F. Stephen Hodi, Jedd D. Wolchok Tumor microenvironment and biomarkers O11 New biomarkers for response/resistance to BRAF inhibitor therapy in metastatic melanoma Rosamaria Pinto, Simona De Summa, Vito Michele Garrisi, Sabino Strippoli, Amalia Azzariti, Gabriella Guida, Michele Guida, Stefania Tommasi O12 Chemokine receptor patterns in lymphocytes mirror metastatic spreading in melanoma and response to ipilimumab Nicolas Jacquelot, David Enot, Caroline Flament, Jonathan M. Pitt, Nadège Vimond, Carolin Blattner, Takahiro Yamazaki, Maria-Paula Roberti, Marie Vetizou, Romain Daillere, Vichnou Poirier-Colame, Michaëla Semeraro, Anne Caignard, Craig L Slingluff Jr, Federica Sallusto, Sylvie Rusakiewicz, Benjamin Weide, Aurélien Marabelle, Holbrook Kohrt, Stéphane Dalle, Andréa Cavalcanti, Guido Kroemer, Anna Maria Di Giacomo, Michaele Maio, Phillip Wong, Jianda Yuan, Jedd Wolchok, Viktor Umansky, Alexander Eggermont, Laurence Zitvogel O13 Serum levels of PD1- and CD28-positive exosomes before Ipilimumab correlate with therapeutic response in metastatic melanoma patients Passarelli Anna, Tucci Marco, Stucci Stefania, Mannavola Francesco, Capone Mariaelena, Madonna Gabriele, Ascierto Paolo Antonio, Silvestris Franco O14 Immunological prognostic factors in stage III melanomas María Paula Roberti, Nicolas Jacquelot, David P Enot, Sylvie Rusakiewicz, Michaela Semeraro, Sarah Jégou, Camila Flores, Lieping Chen, Byoung S. Kwon, Ana Carrizossa Anderson, Caroline Robert, Christophe Borg, Benjamin Weide, François Aubin, Stéphane Dalle, Michele Maio, Jedd D. Wolchok, Holbrook Kohrt, Maha Ayyoub, Guido Kroemer, Aurélien Marabelle, Andréa Cavalcanti, Alexander Eggermont, Laurence Zitvogel POSTER PRESENTATIONS Molecular and immuno-advances P1 Human melanoma cells resistant to B-RAF and MEK inhibition exhibit mesenchymal-like features Anna Lisa De Presbiteris, Fabiola Gilda Cordaro, Rosa Camerlingo, Federica Fratangelo, Nicola Mozzillo, Giuseppe Pirozzi, Eduardo J. Patriarca, Paolo A. Ascierto, Emilia Caputo P2 Anti-proliferative and pro-apoptotic effect of ABT888 on melanoma cell lines and its potential role in the treatment of melanoma resistant to B-RAF inhibitors Federica Fratangelo, Rosa Camerlingo, Emilia Caputo, Maria Letizia Motti, Rosaria Falcone, Roberta Miceli, Mariaelena Capone, Gabriele Madonna, Domenico Mallardo, Maria Vincenza Carriero, Giuseppe Pirozzi and Paolo Antonio Ascierto P3 Involvement of the L-cysteine/CSE/H2S pathway in human melanoma progression Elisabetta Panza, Paola De Cicco, Chiara Armogida, Giuseppe Ercolano, Rosa Camerlingo, Giuseppe Pirozzi, Giosuè Scognamiglio, Gerardo Botti, Giuseppe Cirino, Angela Ianaro P4 Cancer stem cell antigen revealing pattern of antibody variable region genes were defined by immunoglobulin repertoire analysis in patients with malignant melanoma Beatrix Kotlan, Gabriella Liszkay, Miri Blank, Timea Balatoni, Judit Olasz, Emil Farkas, Andras Szollar, Akos Savolt, Maria Godeny, Orsolya Csuka, Szabolcs Horvath, Klara Eles, Yehuda Shoenfeld and Miklos Kasler P5 Upregulation of Neuregulin-1 expression is a hallmark of adaptive response to BRAF/MEK inhibitors in melanoma Debora Malpicci, Luigi Fattore, Susan Costantini, Francesca Capone, Paolo Antonio Ascierto, Rita Mancini, Gennaro Ciliberto P6 HuR positively regulates migration of HTB63 melanoma cells Farnaz Moradi, Pontus Berglund, Karin Leandersson, Rickard Linnskog, Tommy Andersson, Chandra Prakash Prasad P7 Prolyl 4- (C-P4H) hydroxylases have opposing effects in malignant melanoma: implication in prognosis and therapy Cristiana Lo Nigro, Laura Lattanzio, Hexiao Wang, Charlotte Proby, Nelofer Syed, Marcella Occelli, Carolina Cauchi, Marco Merlano, Catherine Harwood, Alastair Thompson, Tim Crook P8 Urokinase receptor antagonists: novel agents for the treatment of melanoma Maria Letizia Motti, Katia Bifulco, Vincenzo Ingangi, Michele Minopoli, Concetta Ragone, Federica Fratangelo, Antonello Pessi, Gennaro Ciliberto, Paolo Antonio Ascierto, Maria Vincenza Carriero P9 Exosomes released by melanoma cell lines enhance chemotaxis of primary tumor cells Francesco Mannavola, Stella D’Oronzo, Claudia Felici, Marco Tucci, Antonio Doronzo, Franco Silvestris P10 New insights in mitochondrial metabolic reprogramming in melanoma Anna Ferretta, Gabriella Guida, Stefania Guida, Imma Maida, Tiziana Cocco, Sabino Strippoli, Stefania Tommasi, Amalia Azzariti, Michele Guida P11 Lenalidomide restrains the proliferation in melanoma cells through a negative regulation of their cell cycle Stella D’Oronzo, Anna Passarelli, Claudia Felici, Marco Tucci, Davide Quaresmini, Franco Silvestris Combination therapies P12 Chemoimmunotherapy elicits polyfunctional anti-tumor CD8 + T cells depending on the activation of an AKT pathway sustained by ICOS Ornella Franzese, Belinda Palermo, Cosmo Di Donna, Isabella Sperduti, MariaLaura Foddai, Helena Stabile, Angela Gismondi, Angela Santoni, Paola Nisticò P13 Favourable toxicity profile of combined BRAF and MEK inhibitors in metastatic melanoma patients Andrea P. Sponghini, Francesca Platini, Elena Marra, David Rondonotti, Oscar Alabiso, Maria T. Fierro, Paola Savoia, Florian Stratica, Pietro Quaglino P14 Electrothermal bipolar vessel sealing system dissection reduces seroma output or time to drain removal following axillary and ilio-inguinal node dissection in melanoma patients: a pilot study Di Monta Gianluca, Caracò Corrado, Di Marzo Massimiliano, Marone Ugo, Di Cecilia Maria Luisa, Mozzillo Nicola News in immunotherapy P15 Clinical and immunological response to ipilimumab in a metastatic melanoma patient with HIV infection Francesco Sabbatino, Celeste Fusciello1, Antonio Marra, Rosario Guarrasi, Carlo Baldi, Rosa Russo, Di Giulio Giovanni, Vincenzo Faiola, Pio Zeppa, Stefano Pepe P16 Immunotherapy and hypophysitis: a case report Elisabetta Gambale, Consiglia Carella, Alessandra Di Paolo, Michele De Tursi Tumor microenvironment and biomarkers P17 New immuno- histochemical markers for the differential diagnosis of atypical melanocytic lesions with uncertain malignant potential Laura Marra, Giosuè Scognamiglio, Monica Cantile, Margherita Cerrone, Fara De Murtas, Valeria Sorrentino, Anna Maria Anniciello, Gerardo Botti P18 Utility of simultaneous measurement of three serum tumor markers in melanoma patients Angela Sandru, Silviu Voinea, Eugenia Panaitescu, Madalina Bolovan, Adina Stanciu, Sabin Cinca P19 The significance of various cut-off levels of melanoma inhibitory activity in evaluation of cutaneous melanoma patients Angela Sandru, Silviu Voinea, Eugenia Panaitescu, Madalina Bolovan, Adina Stanciu, Sabin Cinca P20 The long noncoding RNA HOTAIR is associated to metastatic progression of melanoma and it can be identified in the blood of patients with advanced disease Chiara Botti, Giosuè Scognamiglio, Laura Marra, Gabriella Aquino, Rosaria Falcone, Annamaria Anniciello, Paolo Antonio Ascierto, Gerardo Botti, Monica Cantile Other P21 The effect of Sentinel Lymph Node Biopsy in melanoma mortality: timing of dissection Cristina Fortes, Simona Mastroeni, Alessio Caggiati, Francesca Passarelli, Alba Zappalà, Maria Capuano, Riccardo Bono, Maurizio Nudo, Claudia Marino, Paola Michelozzi P22 Epidemiological survey on related psychopathology in melanoma Valeria De Biasio, Vincenzo C. Battarra IMMUNOTHERAPY BRIDGE KEYNOTE SPEAKER PRESENTATIONS Immunotherapy beyond melanoma K19 Predictor of response to radiation and immunotherapy Silvia Formenti K20 Response and resistance to PD-1 pathway blockade: clues from the tumor microenvironment Maria Libera Ascierto, Tracee L. McMiller, Alan E. Berger, Ludmila Danilova, Robert A. Anders, George J. Netto, Haiying Xu, Theresa S. Pritchard, Jinshui Fan, Chris Cheadle, Leslie Cope, Charles G. Drake, Drew M. Pardoll, Janis M. Taube and Suzanne L. Topalian K21 Combination immunotherapy with autologous stem cell transplantation, protein immunization, and PBMC reinfusion in myeloma patients Sacha Gnjatic, Sarah Nataraj, Naoko Imai, Adeeb Rahman, Achim A. Jungbluth, Linda Pan, Ralph Venhaus, Andrew Park, Frédéric F. Lehmann, Nikoletta Lendvai, Adam D. Cohen, and Hearn J. Cho K22 Anti-cancer immunity despite T cell “exhaustion” Speiser Daniel Immunotherapy in oncology (I-O): data from clinical trial K23 The Checkpoint Inhibitors for the Treatment of Metastatic Non-small Cell Lung Cancer (NSCLC) Vera Hirsh.

Adoptive infusion of natural killer (NK) cells is being increasingly explored as a therapy in patients with cancer, although clinical responses are thus far limited to patients with hematological malignancies. Inadequate homing of infused NK cells to the tumor site represents a key factor that may explain the poor anti-tumor effect of NK cell therapy against solid tumors. One of the major players in the regulation of lymphocyte chemotaxis is the chemokine receptor chemokine (C-X-C motif) receptor 3 (CXCR3) which is expressed on activated NK cells and induces NK cell migration toward gradients of the chemokine (C-X-C motif) ligand (CXCL9, 10 and 11). Here, we show that ex vivo expansion of human NK cells results in a tenfold increased expression of the CXCR3 receptor compared with resting NK cells (p = 0.04). Consequently, these NK cells displayed an improved migratory capacity toward solid tumors, which was dependent on tumor-derived CXCL10. In xenograft models, adoptively transferred NK cells showed increased migration toward CXCL10-transfected melanoma tumors compared with CXCL10-negative wild-type tumors, resulting in significantly reduced tumor burden and increased survival (median survival 41 vs. 32 days, p = 0.03). Furthermore, administration of interferon-gamma locally in the tumor stimulated the production of CXCL10 in subcutaneous melanoma tumors resulting in increased infiltration of adoptively transferred CXCR3-positive expanded NK cells. Our findings demonstrate the importance of CXCL10-induced chemoattraction in the anti-tumor response of adoptively transferred expanded NK cells against solid melanoma tumors..

Pharmacologic manipulation of the immune system is emerging as a viable and robust treatment for some cancer patients. Exercise-induced modulation of the immune system may be another adjunctive strategy for inhibiting tumor initiation and progression. In healthy individuals, exercise has been shown to modulate a number of cell subsets involved in innate and adaptive immunity. Here, we provide an overview of the current state of knowledge pertaining to exercise modulation of the inflammation-immune axis in cancer. The current evidence suggests that exercise may be a promising adjunctive strategy that can favorably alter numerous components of the immune system, which, in turn, may modulate tumorigenesis. However, many important knowledge gaps are evident. To this end, we propose a framework to guide future research efforts investigating the immune effects of exercise in cancer..

Targeting immune checkpoint receptors has emerged as an effective strategy to induce immune-mediated cancer regression in the subset of patients who have significant pre-existing anti-tumor immunity. For the remainder, effective anti tumor responses may require vaccination. Radiotherapy, traditionally used to achieve local tumor control, has acquired a new role, that of a partner for immunotherapy. Ionizing radiation has pro-inflammatory effects that facilitate tumor rejection. Radiation alters the tumor to enhance the concentration of effector T cells via induction of chemokines, cytokines and adhesion molecules. In parallel, radiation can induce an immunogenic death of cancer cells, promoting cross-presentation of tumor-derived antigens by dendritic cells to T cells. Newly generated anti-tumor immune responses have been demonstrated post-radiation in both murine models and occasional patients, supporting the hypothesis that the irradiated tumor can become an in situ vaccine. It is in this role, that radiation can be applied to induce anti-tumor T cells in lymphocyte-poor tumors, and possibly benefit patients who would otherwise fail to respond to immune checkpoint inhibitors. This review summarizes preclinical and clinical data demonstrating that radiation acts in concert with antibodies targeting the immune checkpoint cytotoxic T-lymphocyte antigen-4 (CTLA-4), to induce therapeutically effective anti-tumor T cell responses in tumors otherwise non responsive to anti-CTLA-4 therapy..

Gap junctions (GJs) mediate intercellular communication between adjacent cells. Previously, we showed that connexin 43 (Cx43), the main GJ protein in the immune system, mediates Ag transfer between human dendritic cells (DCs) and is recruited to the immunological synapse during T cell priming. This crosstalk contributed to T cell activation, intracellular Ca(2+) responses, and cytokine release. However, the role of GJs in NK cell activation by DCs and NK cell-mediated cytotoxicity against tumor cells remains unknown. In this study, we found polarization of Cx43 at the NK/DC and NK/tumor cell-contact sites, accompanied by the formation of functional GJs between NK/DCs and NK/tumor cells, respectively. Cx43-GJ-mediated intercellular communication (GJIC) between human NK and DCs was bidirectional. Blockage of Cx43-GJIC inhibited NK cell activation, though it affected neither the phenotype nor the function of DCs. Cx43 knockdown or inhibition using mimetic peptides greatly reduced CD69 and CD25 expression and IFN-γ release by DC-stimulated NK cells. Moreover, blocking Cx43 strongly inhibited the NK cell-mediated tumor cell lysis associated with inhibition of granzyme B activity and Ca(2+) influx. Our data identify a novel and active role for Cx43-GJIC in human NK cell activation and antitumor effector functions that may be important for the design of new immune therapeutic strategies..

Given the critical role of Fc gamma receptors (FcγR) as primary targets for autoantibody-mediated effects an important issue is how the FcγR pathway is affected in autoimmune disorders. Here we investigated the FcγR function in monocytes from rheumatoid arthritis (RA) patients in relation to immunoglobulin levels and disease activity. Peripheral blood was obtained from 30 RA patients with clinical acute joint synovitis (active RA), 28 RA patients with no clinical signs of acute joint synovitis (non-active RA) and 34 healthy controls. Prior the functional studies the monocytes were characterized of their FcγRI (CD64), II (CD32), IIb (CD32b) and III (CD16) expression as well as their cell surface bound IgG. The monocytic FcγR function was assessed by binding of human IgG1 and IgG3 immune complexes (IC) and TNF secretion in vitro. IgG anti-citrullinated peptide antibodies (ACPA) were analyzed in the plasma. We found that monocytes from active RA patients had increased levels of FcγRI, II and cell surface IgG concurrently with impaired FcγR function. This was evident by reduced IgG1-IC binding and decreased TNF secretion in response to IgG3-IC. In contrast, monocytes from non-active RA patients displayed a normal FcγR function and had increased FcγRIIb expression together with elevated FcγRI, II and cell surface IgG. The ACPA levels did not differ in active and non-active RA patients but correlated with the monocytic FcγRIII expression in the patients. In conclusion, active RA patients display a dysregulated FcγR function that may represent a novel phenotypic and likely pathogenetic marker for active RA. A disease and FcγR function controlling effect is suggested by the increased inhibitory FcγRIIb in non-active RA..

PURPOSE: Anaplastic thyroid carcinoma (ATC) is one of the most aggressive forms of cancer with no curative therapies available. To date, strategies to target ATC by immunotherapy have not been evaluated. We investigated whether ATC would be a suitable target for natural killer (NK) cell-based immunotherapy. EXPERIMENTAL DESIGN: We first established seven new cell lines from ATC tumors, three from papillary thyroid carcinoma tumors and analyzed them together with eight additional ATC cell lines. Cells were analyzed for sensitivity to lysis by NK cells and their ability to chemoattract and regulate the activity of NK cells. In addition, fresh tumor samples and peripheral blood from six patients with ATC were analyzed for NK cell infiltration and phenotype. RESULTS: We observed that ATC cell lines are sensitive to lysis by ex vivo expanded NK cells and that the lysis was abrogated upon blockade of NKG2D. Sensitivity of thyroid cancer cell lines to NK cell-mediated lysis correlated with surface expression of UL16-binding protein 2 on tumor cells. Moreover, ATC cell lines produced high levels of CXCL10 and stimulated migration of expanded NK cells and ATC tumors were enriched for NK cells expressing the cognate chemokine receptor CXCR3. However, compared with NK cells in peripheral blood, ATC tumor-derived NK cells displayed a suppressed phenotype with a downregulated expression of NKG2D. In vitro, suppression of NK cell-mediated lysis and NKG2D expression by ATC cells was restored upon neutralization of prostaglandin-E2. CONCLUSIONS: ATC cell lines are sensitive to NK cell-mediated lysis via ULBP2/5/6 and chemoattract CXCR3-positive NK cells. Patients with ATC may benefit from NK cell-based immunotherapy..

Tumors can suppress the host immune system by employing a variety of cellular immune modulators, such as regulatory T cells, tumor-associated macrophages, and myeloid-derived suppressor cells (MDSC). In the peripheral blood of patients with advanced stage melanoma, there is an accumulation of CD14(+)HLA-DR(lo/-) MDSC that suppress autologous T cells ex vivo in a STAT-3-dependent manner. However, a precise mechanistic basis underlying this effect is unclear, particularly with regard to whether the MDSC induction mechanism relies on cell-cell contact of melanoma cells with CD14(+) cells. Here, we show that early-passage human melanoma cells induce phenotypic changes in CD14(+) monocytes, leading them to resemble MDSCs characterized in patients with advanced stage melanoma. These MDSC-like cells potently suppress autologous T-cell proliferation and IFN-γ production. Notably, induction of myeloid-suppressive functions requires contact or close proximity between monocytes and tumor cells. Further, this induction is largely dependent on production of cyclooxygenase-2 (COX-2) because its inhibition in these MDSC-like cells limits their ability to suppress T-cell function. We confirmed our findings with CD14(+) cells isolated from patients with advanced stage melanoma, which inhibited autologous T cells in a manner relying up prostaglandin E2 (PGE2), STAT-3, and superoxide. Indeed, PGE2 was sufficient to confer to monocytes the ability to suppress proliferation and IFN-γ production by autologous T cells ex vivo. In summary, our results reveal how immune suppression by MDSC can be initiated in the tumor microenvironment of human melanoma..

Doxorubicin (DOX) is an anthracycline antibiotic that is widely used to treat different types of malignancy. In this study, it was studied whether DOX could be used to render tumor cells susceptible to apoptosis by NK and T cells. Pretreatment with subapoptotic doses of DOX sensitized tumor cell lines of various histotypes to both NK and T cells resulting in a 3.7 to 32.7% increase in lysis (2.5 mean fold increase, p < 0.0001) and a 2.9 to 14.2% increase in lysis (3.0 mean-fold increase, p < 0.05), respectively. The sensitizing effect of the drug was primarily dependent on the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)/TRAIL-receptor signaling, but not on Fas-ligand, perforin, NKG2D or DNAM-1. The central role of the TRAIL signaling pathway was further supported by an increased expression of TRAIL-R2 on DOX-treated tumor cells and by downregulation of cellular FLICE inhibitory protein, the inhibitors of death receptor-mediated apoptosis. Compared to untreated cells, pretreatment of tumor cells with DOX showed increased processing and activation of caspase-8 on coculture with NK or T cells. The significance of this treatment strategy was confirmed using a xenogeneic tumor-bearing mouse model. Tumor progression was delayed in mice that received either NK cells (p < 0.05) or T cells (p < 0.0001) following DOX treatment compared to mice receiving either cell type alone. Moreover, combined infusion of both NK and T cells following DOX treatment not only delayed tumor progression but also significantly improved the long-term survival (p < 0.01). Based on these findings, it was proposed that DOX can be used to improve the efficacy of adoptive cell therapy in patients with cancer..

Natural killer (NK) cells are innate lymphocytes that are able to directly kill tumor cells through different mechanisms including ligation of TNF-related apoptosis-inducing ligand (TRAIL) receptors. Zoledronic acid (ZA) is a bisphosphonate known to upregulate the expression of TRAIL on human γδ T cells. Here, we investigated whether exposure to ZA would upregulate TRAIL expression on human NK cells and augment their cytotoxicity against tumor cells. When cocultured with monocytes, treatment with ZA and IL-2 resulted in a significant upregulation of TRAIL expression on human NK cells (p = 0.002). Consequently, ZA-primed NK cells were significantly more cytotoxic against TRAIL sensitive tumor cells (p < 0.0001). In the presence of ZA and IL-2, monocytes produced high levels of IFN-γ; when cultured in the presence of neutralizing antibodies to IFN-γ, TRAIL expression and TRAIL-mediated cytotoxicity of NK cells were significantly reduced. Furthermore, in tumor-bearing SCID/Beige mice, a significant delayed tumor progression and prolonged survival was observed after infusion of ZA-primed NK cells compared with that observed in mice infused with unprimed NK cells. These findings represent a novel approach to potentiate TRAIL-mediated apoptosis by adoptively infused NK cells that could improve the outcome in patients with cancer..

The proteasome inhibitor bortezomib simultaneously renders tumor cells sensitive to killing by natural killer (NK) cells and resistant to killing by tumor-specific T cells. Here, we show that b-AP15, a novel inhibitor of proteasome deubiquitinating activity, sensitizes tumors to both NK and T cell-mediated killing. Exposure to b-AP15 significantly increased the susceptibility of tumor cell lines of various origins to NK (p < 0.0002) and T cell (p = 0.02)-mediated cytotoxicity. Treatment with b-AP15 resulted in increased tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) receptor-2 expression (p = 0.03) and decreased cFLIP expression in tumor cells in vitro. In tumor-bearing SCID/Beige mice, treatment with b-AP15 followed by infusion of either human NK cells or tumor-specific T cells resulted in a significantly delayed tumor progression compared with mice treated with NK cells (p = 0.006), T cells (p < 0.0001) or b-AP15 alone (p = 0.003). Combined infusion of NK and T cells in tumor-bearing BALB/c mice following treatment with b-AP15 resulted in a significantly prolonged long-term survival compared with mice treated with b-AP15 and NK or T cells (p ≤ 0.01). Our findings show that b-AP15-induced sensitization to TRAIL-mediated apoptosis could be used as a novel strategy to augment the anticancer effects of adoptively infused NK and T cells in patients with cancer..

Oncogenes have been traditionally viewed as molecular drivers for tumor growth and survival. Recent evidence indicates that oncogenes may facilitate the escape of malignant cells from immune recognition and elimination. In this article, we discuss the implications of the overexpression of epidermal growth factor receptor (EGFR) family members on immune escape of tumors and immunotherapy..

Overexpression of the receptor tyrosine kinases HER2 and HER3 is associated with a poor prognosis in several types of cancer. Presently, HER2- as well as HER3-targeted therapies are in clinical practice or evaluated within clinical trials, including treatment with mAbs mediating growth inhibition and/or activation of Ab-induced innate or adaptive cellular immunity. A better understanding of how HER2/HER3 signaling in tumors influences cellular immune mechanisms is therefore warranted. In this study, we demonstrate that HER2/HER3 signaling regulates the expression of MHC class I-related chain A and B (MICA and MICB) in breast cancer cell lines. The MICA and MICB (MICA/B) molecules act as key ligands for the activating receptor NK group 2, member D (NKG2D) and promote NK cell-mediated recognition and cytolysis. Genetic silencing of HER3 but not HER2 downregulated the expression of MICA/B, and HER3 overexpression significantly enhanced MICA expression. Among the major pathways activated by HER2/HER3 signaling, the PI3K/AKT pathway was shown to predominantly regulate MICA/B expression. Treatment with the HER3-specific ligand neuregulin 1β promoted the expression in a process that was antagonized by pharmacological and genetic interference with HER3 but not by the ataxia-telangiectasia-mutated (ATM) and ATM and Rad3-related protein kinases inhibitor caffeine. These observations further emphasize that HER2/HER3 signaling directly, and not via genotoxic stress, regulates MICA/B expression. As anticipated, stimulating HER2/HER3 enhanced the NKG2D-MICA/B-dependent NK cell-mediated cytotoxicity. Taken together, we conclude that signaling via the HER2/HER3 pathway in breast carcinoma cell lines may lead to enhanced NKG2D-MICA/B recognition by NK cells and T cells..