bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract A04: An inflammatory gene signature distinguishes neurofibroma Schwann cells and macrophages from cells in the normal peripheral nervous system
Authors: Choi Kwangmin , Komurov Kakajan , Fletcher Jonathan S. , Jousma Edwin , Cancelas Jose A. , Wu Jianqiang , Ratner Nancy
Published: March 2017

Neurofibromas are benign peripheral nerve tumors driven by NF1 loss in Schwann cells (SCs). Current evidence suggests that an inflammatory environment is critical for neurofibroma development and growth, however the roles of intercellular interactions between SCs and other cells in neurofibroma microenvironment are not clear yet. Neurofibromas contain numerous macrophages. We analyzed gene expression in FACS-sorted SCs and macrophages from wild type nerve and neurofibroma. Nerve macrophage transcriptomes differed from previously defined macrophage sub-populations. In 1-month-old Nf1 mutant nerve, neither SCs nor macrophages significantly differed from their counterparts in normal mice. In 7-month-old neurofibromas, macrophages showed significantly altered gene expression, as did neurofibroma SCs. Computational reconstruction of SC-macrophage molecular networks based on the gene expression data revealed extensive inflammatory-associated signaling and possible interplay between macrophages and Schwann cells. Among these were previously implicated pathways and novel paracrine and autocrine loops involving cytokines, chemokines, and growth factors. Specifically, the data predicted increased cytokine expression and imbalanced type-I/type-II interferon signaling, which were confirmed by protein profiling, and normalized in neurofibroma-bearing mice treated with PEGylated interferon-α2b. These studies identify Nf1 mutant SCs interactions with macrophages, which result in chronic inflammation and neurofibroma, and provide a system in which to study early changes in benign tumorigenesis.

Citation Format: Kwangmin Choi, Kakajan Komurov, Jonathan S. Fletcher, Edwin Jousma, Jose A. Cancelas, Jianqiang Wu, Nancy Ratner. An inflammatory gene signature distinguishes neurofibroma Schwann cells and macrophages from cells in the normal peripheral nervous system. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2016 Oct 20-23; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2017;5(3 Suppl):Abstract nr A04.
Abstract A23: Development of a novel preclinical model to delineate the role of tumor microenvironment on mechanism of action and efficacy of PD-1 checkpoint blockade
Authors: Chakravarthy Kalyan , Sevilla Raquel , Caniga Michael , Zhang Weisheng , Murtaza Anwar , Moy Lily , Cicmil Milenko
Published: March 2017

Background: The cellular environment in which the tumor exists, also known as tumor microenvironment, includes surrounding blood vessels, immune cells, fibroblasts, signaling molecules, and the extracellular matrix. This microenvironment can contribute to the growth and metastases of tumors, potentially influencing the efficacy of therapeutic agents. Thus, understanding the contribution of the microenvironment on tumorigenesis may enable us to investigate biology and kinetics between tumor and surrounding environment and improve target selection for standalone or combination therapies.

Methods: To interrogate the role of the microenvironment we developed a tumor model in which the tumors can grow inside an air-pouch created in the dorsal part of the mouse. The air-pouch serves as the local microenvironment, which can be modulated by pro or anti-inflammatory stimuli to study the impact of local cells and cytokines on tumor growth as well as the efficacy of therapeutic agents.

Results: Using luciferized mouse colon carcinoma (mc38-LUC2) syngeneic cells, we demonstrate that the kinetics of tumor growth within the air-pouch is similar to standard subcutaneously induced tumor models and was quantified via bioluminescence imaging. Additionally, further characterization of the tumor microenvironment was performed using MR and CT imaging, cytokine expression, and cell phenotyping. Furthermore, we also evaluated checkpoint inhibitor agent targeting the PD-1pathway to evaluate its effect on tumor growth and impact on cellular and cytokine microenvironment.

Conclusions: Taken together, our novel model can facilitate innovative assessment of the mechanism of action of immunomodulatory agents across multiple oncological malignancies and evaluation of next generation therapeutics.

Citation Format: Kalyan Chakravarthy, Raquel Sevilla, Michael Caniga, Weisheng Zhang, Anwar Murtaza, Lily Moy, Milenko Cicmil. Development of a novel preclinical model to delineate the role of tumor microenvironment on mechanism of action and efficacy of PD-1 checkpoint blockade. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2016 Oct 20-23; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2017;5(3 Suppl):Abstract nr A23.
Abstract A25: High-resolution visualization of immune response across the intact melanoma tumor
Authors: Kumari Sudha , Moynihan Kelly , Irvine Darrell J.
Published: March 2017

Tumor immunotherapy relies on improved anti-tumor activity of the immune cells. Efficacious immunotherapy often correlates with increased CD8+ T cell infiltration within the tumor, subsequently resulting into reduction in tumor growth and morphological remodeling. However, pan- melanoma visualization of immune cell infiltration and associated macro-scale alterations in tumor morphology and vasculature remains extremely challenging. This is largely owing to the dense pigmentation, thick extracellular matrix deposition and friable texture of the tumor, rendering it optically inaccessible using the routine histology and organ clarification techniques. Here, we describe a rapid and inexpensive optical clarification technique that enables examination of immune infiltration as well as vascular changes, both at tissue level as well as single cell-resolution within an intact tumor. The aforementioned technique, termed Tumor-optimized three-dimensional imaging of solvent cleared organs (T-DISCO), combines in vivo fluorescent labeling of the endogenous immune cells with organic solvents-based tissue clarification and eventual image acquisition using a standard confocal microscope. This technique when applied to the B16F10 melanoma model undergoing a multi-component immunotherapy, revealed changes within the tumor microenvironment, including vascular normalization and intra-tumoral trafficking of the T cells. Thus, T-DISCO represents a powerful tool to examine and investigate immune cell behavior deep within the intact tumor.

Citation Format: Sudha Kumari, Kelly Moynihan, Darrell J. Irvine. High-resolution visualization of immune response across the intact melanoma tumor. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2016 Oct 20-23; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2017;5(3 Suppl):Abstract nr A25.
Abstract A34: Beyond immune checkpoint: First-in-class antibody targeting soluble NKG2D ligand sMIC for cancer immunotherapy
Authors: Wu Jennifer D. , Zhang Jinyu D. , Basher Fahmin , Rubinstein Mark
Published: March 2017

In response to oncogenic insult, human cells were induced to express a family of MHC I-chain related molecules A and B (MICA and MICB, generally termed MIC) on the surface which serve as the ligands for the activating immune receptor NKG2D expressed by all human NK and cytotoxic T cells. Theoretically, engagement of NKG2D by tumor cell surface MIC is deemed to signal and provoke the immune system to eliminate transformed cells. Clinically, almost all advanced tumors in cancer patients produce soluble MIC through proteolytic shedding mediated by metalloproteases, or by release in exosomes derived from the cell membrane. Tumor-derived sMIC is known to be highly immune suppressive and profoundly insults the immune system by downregulating receptor NKG2D expression on effector NK and T cells, driving the expansion of tumor-favoring myeloid suppression cells, skewing macrophages into alternatively activated phenotypes, and perturbing NK cell peripheral maintenance. High levels of serum sMIC significantly correlate with advanced diseases of many types of cancer. These observations clearly endorse sMIC to be a cancer immune therapeutic target. However, due to mice lack homologues to human MIC, this concept was not proven until our recent studies. Using a “humanized” MIC-transgenic spontaneous mouse model which recapitulates the NKG2D-mediated onco-immune dynamics of human cancer patients, we show that neutralizing circulating sMIC with a first-in-field non-blocking antibody B10 that does not block the interaction of MIC with NKG2D revamps endogenous innate and antigen-specific CD8 T cell responses. We show that therapy with the non-blocking sMIC-neutralizing antibody results in effectively debulk of primary tumor and elimination of metastasis, with no observed toxicity. Furthermore, we show that clearing sMIC with the first-in-class neutralizing antibody B10 also enhanced the efficacy of other cancer immunotherapeutic modalities, such as immune checkpoint blockade or adoptive cell-based therapy pre-clinically. Our study has launched a new avenue of cancer immunotherapy which can be readily translated into clinical trials.

Note: This abstract was not presented at the conference.

Citation Format: Jennifer D. Wu, Jinyu D. Zhang, Fahmin Basher, Mark Rubinstein. Beyond immune checkpoint: First-in-class antibody targeting soluble NKG2D ligand sMIC for cancer immunotherapy. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2016 Oct 20-23; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2017;5(3 Suppl):Abstract nr A34.
Abstract A52: Eradication of large established tumors with combination immunotherapy engaging innate and adaptive immunity
Authors: Moynihan Kelly Dare , Opel Cary , Szeto Gregory , Tzeng Alice , Eric Zhu , Engreitz Jesse , Robert Williams , Rakhra Kavya , Zhang Michael , Rothschilds Adrienne , Kumari Sudha , Kelly Ryan L. , Kwan Byron , Abraham Wuhbet , Hu Kevin , Mehta Naveen , Kauke Monique , Suh Heikyung , Lauffenburger Douglas A. , Wittrup K. Dane , Irvine Darrell J.
Published: March 2017

Checkpoint blockade against CTLA-4 or PD-1 has demonstrated that an endogenous immune response can be stimulated to elicit durable regressions in advanced cancer, but these dramatic responses are currently confined to a minority of patients. This outcome is probably due in part to the complex network of immunosuppressive pathways present in advanced tumors, which are unlikely to be overcome by intervention at a single signaling checkpoint, requiring a counter-directed network of pro-immunity signals. Here we demonstrate a combination immunotherapy that recruits a diverse set of innate and adaptive immune effectors, enabling robust elimination of tumor burdens that to our knowledge have not previously been curable by treatments relying on endogenous immunity. Maximal anti-tumor efficacy required four components: a tumor antigen targeting antibody, an extended half-life IL-2, anti-PD-1, and a powerful T-cell vaccine. This combination elicited durable cures in a majority of animals, formed immunological memory in multiple transplanted tumor models, and induced sustained tumor regression in an autochthonous BRrafV600E/Pten-/- melanoma model. Multiple innate immune cell subsets, CD8+ T-cells, and cross-presenting dendritic cells were critical to successful therapy. Treatment induced high levels of intratumoral inflammatory cytokines and immune cell infiltration, enhanced antibody-mediated tumor antigen uptake, and promoted antigen spreading. These results demonstrate the capacity of an elicited endogenous immune response to destroy large, established tumors and elucidate essential characteristics of combination immunotherapies capable of curing a majority of tumors in experimental settings typically viewed as intractable.

Citation Format: Kelly Dare Moynihan, Cary Opel, Gregory Szeto, Alice Tzeng, Zhu Eric, Jesse Engreitz, Williams Robert, Kavya Rakhra, Michael Zhang, Adrienne Rothschilds, Sudha Kumari, Ryan L. Kelly, Byron Kwan, Wuhbet Abraham, Kevin Hu, Naveen Mehta, Monique Kauke, Heikyung Suh, Douglas A. Lauffenburger, K. Dane Wittrup, Darrell J. Irvine. Eradication of large established tumors with combination immunotherapy engaging innate and adaptive immunity. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2016 Oct 20-23; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2017;5(3 Suppl):Abstract nr A52.
Abstract A64: Mast cell expressed FcεR beta subunit (MS4A2) is prognostic in lung adenocarcinoma
Authors: Ly Dalam , Zhu Chang-Qi , Cabanero Michael , Tsao Ming-Sound , Zhang Li
Published: March 2017

Background: The context of immune cell infiltrates within the tumor is associated with cancer prognosis. The type of immune cells and their activation state can provide mediators that either promote or inhibit tumor growth. A growing body of evidence suggest the presence of innate immune cells play a role in shaping early tumor growth. In attempts to gain insight into the immune networks that regulate tumorigenesis, we used genome wide expression datasets of patients with resected early stage non-small cell lung cancer (NSCLC) to identify immune-related genes associated with patient survival.

Methods: Gene expression analysis was conducted on microarray datasets from 128 early-stage NSCLC adenocarcinoma resected tumor samples. Limiting analysis to immune-related genes, we identified a minimum gene set that is prognostic for lung adenocarcinoma and validated the gene signature in additional published microarray NSCLC datasets. Using pathway analysis and immunohistochemistry (IHC), we identified a role for mast cell-expressed IgE receptor beta subunit, MS4A2, in lung adenocarcinoma progression.

Results: From an immune-related gene list, we identified a minimal gene signature that was able to separate patients into high or low-risk survival groups. This gene signature was shown to be prognostic for NSCLC adenocarcinoma in nine validation datasets (n=1264, hazard ratio 2.07, 95% confidence interval 1.69-2.53, p<0.0001). Pathway analysis of differentially expressed genes within high or low-risk survival subgroups reveals gene ontologies and immune signatures that are enriched for IgE receptor signaling and mast cells in patients with favourable prognosis. Univariate analysis shows that the IgE receptor complex genes, as well as mast cell specific protease, mast cell carboxypeptidase A, are highly prognostic for survival. We are currently using IHC of matched patient samples to validate receptor localization.

Conclusion: By limiting gene expression analysis to immune-related genes, we identified a minimal gene set that indicate an important role for IgE receptor signaling and mast cells in favourable lung cancer prognosis. Our data highlights the importance of innate immune cells in shaping lung cancer development.

Citation Format: Dalam Ly, Chang-Qi Zhu, Michael Cabanero, Ming-Sound Tsao, Li Zhang. Mast cell expressed FcεR beta subunit (MS4A2) is prognostic in lung adenocarcinoma. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2016 Oct 20-23; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2017;5(3 Suppl):Abstract nr A64.
Abstract A67: Phenotypic and functional dynamics of CD4+CD25+FOXP3+ regulatory T cells in patients with tobacco-related oral squamous cell carcinoma
Authors: Das Satya N. , Aggarwal Sadhna , Sharma Suresh C.
Published: March 2017

Background: Oral squamous cell carcinoma (OSCC) is one of the most common head and neck cancers worldwide. Dysregulation of immune response plays a major role in establishment and development of cancer. CD4+CD25+FoxP3+ regulatory T cells (Tregs) have been reported to downregulate effector immune functions and its inactivation have been associated with development of autoimmune diseases. We therefore investigated the phenotypic and functional dynamics of CD4+CD25+FoxP3+ (Tregs) cells in tobacco-related OSCC patients.

Aim: Aim of the study was to investigate the phenotypic and functional characteristics of Tregs cells in OSCC patients in terms of their subsets, expression of functional markers and cytokine profile etc.

Methods: The phenotypic and functional characteristics of Treg subsets in patients with OSCC were assessed by multicolour flowcytometry. The levels of TGFβ were assessed by realtime PCR and western blot.

Results: An increased (p<0.05) prevalence of Tregs phenotypes (CD4+CD25+, CD4+FoxP3+, CD8+FoxP3+, CD4+CD25+FoxP3+) was observed in the peripheral circulation of OSCC patients that positively correlated with clinicopathological features. The increased frequency of CD4+CD8+CD25+FoxP3+, a unique T cells subset also showed significantly higher prevalence in OSCC patients. Functionally CD4+FoxP3+ Tregs showed skewed expression of IL-2, IL-10 and IL-35 in patients as compared with the normal controls. Higher expression of TGF-β in tumour tissues suggests their dominant role in upregulation of differentiation of Tregs from naive T cells in tumour bearing host. Further enhanced expression of CCR5 and CCR7 on Tregs with upregulation of their ligands (CCL5, CCL19 and CCL21) in tumour cells indicate efficient recruitment and trafficking of Tregs to the tumour site.

Conclusions: Accumulation of heterogeneous subsets of Tregs in the peripheral circulation indicates their suggestive role in immuno-suppression leading to growth and proliferation of OSCC. Therefore manipulation of Tregs can be added to the therapeutic armamentarium for enhancing anti-tumour immunity in OSCC patients.

Note: This abstract was not presented at the conference.

Citation Format: Satya N. Das, Sadhna Aggarwal, Suresh C. Sharma. Phenotypic and functional dynamics of CD4+CD25+FOXP3+ regulatory T cells in patients with tobacco-related oral squamous cell carcinoma. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2016 Oct 20-23; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2017;5(3 Suppl):Abstract nr A67.
Abstract B03: Integrin agonists reduce infiltration of tumor-associated macrophages to promote T-cell mediated anti-tumor immunity
Authors: Khan Samia Q. , Faridi Mohd. H. , Khaliqdina Shehryar J. , Barbosa Antonio J. , Varner Judith A. , Gupta Vineet
Published: March 2017

Tumors associated macrophages (TAMs) mediate neovascularization and promote tumor growth. Integrin CD11b/CD18 is highly expressed on cells of myeloid and granulocytic lineage and mediates their adhesion, migration and tissue recruitment functions. CD11b+ TAMs are present at high numbers in several types of human cancers, including breast and non-small cell lung cancer, and are associated with reduced T-cell mediated anti-tumor immunity. This suggests that reducing infiltration of CD11b+ TAMs could have a therapeutic benefit. Recently, we have developed a novel small molecule CD11b agonist termed leukadherin-1 (LA1) that binds to and allosterically activates integrin CD11b on leukocytes. We also reported that CD11b activation is a more effective strategy for reducing CD11b+ cell tissue infiltration, as compared to integrin antagonists. LA1 binding transiently increases leukocyte adhesion to the vascular endothelium and reduces their transmigration in vivo. Here, we show that LA1 mediated CD11b activation reduced the number of CD11b+ TAMs in two different murine tumor models that was accompanied with diminished primary tumor growth. LA1 treated animals also had significantly reduced tumor angiogenesis and prolonged survival. These improved aspects were accompanied with reduction in vessel density as indicated by reduced intratumoral expression levels of CD31 and αSMA and increased numbers of CD8+ T cells indicating an anti-tumor immune profile response fostering tumor suppression. Our data provide a rationale for using allosteric CD11b agonists to target TAMs as a novel therapeutic approach for treating cancer.

Citation Format: Samia Q. Khan, Mohd. H. Faridi, Shehryar J. Khaliqdina, Antonio J. Barbosa, Judith A. Varner, Vineet Gupta. Integrin agonists reduce infiltration of tumor-associated macrophages to promote T-cell mediated anti-tumor immunity. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2016 Oct 20-23; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2017;5(3 Suppl):Abstract nr B03.
Abstract B07: The loss function of BP180 (Collagen type XVII) in skin, leads to a mast cell dependent pro-inflammatory microenvironment which promotes melanoma progression
Authors: Hwang Bin-Jin , Peng Bin , Zhang Yang , Brozowski Jaime Marie , Lin Lin , Williams Scott E. , Li Ning , Liu Zhen , Su Maureen , Thomas Nancy E. , Diaz Luis A. , Liu Zhi
Published: March 2017

BP180, also known as type 17 collagen, is a transmembrane glycoprotein located in the hemidesmosome of epidermal basal keratinocytes. BP180 is a critical cell/matrix adhesion molecule in dermal-epidermal junction of the skin. Various clinical reports indicated that the altered expression of hemidesmosomal protein BP180 is associated with melanoma progression. However, it is unclear whether BP180 is directly involved in melanoma progression. To investigate the role of BP180 in melanoma progression, we generated novel mouse strains lacking BP180 functions in whole body (by crossing floxed mice with germline Cre), in the local skin (tamoxifen-inducible Cre), or in basal keratinocytes (K14-driven Cre). These BP180 functional knockout mice showed dermal-epidermal junction separation in the skin, indicating that the cell/cell matrix adhesion mediated by BP180 is impaired. Loss of BP180 function also lead to a proinflammatory microenvironment in skin accompanied with an influx of immune cells including mast cells, neutrophils and T cells. When tested in B16 mouse melanoma model BP180 functional deficient mice (globally, in the local skin, or in basal keratinocytes) showed significantly increased melanoma progression. These results demonstrated that BP180 deficiency limited in local skin microenvironment or basal keratinocyte is sufficient to promote melanoma progression. To determine whether increased neutrophil or mast cells are required for the accelerated melanoma progression in BP180 functional deficient mice, we injected B16 melanoma cells into mice lacking both mast cells and BP180 function. Mast cell deficiency drastically reduced the inflammation, neutrophil influx into skin and melanoma progression caused by loss of BP180 function. These findings provide the first evidence suggesting that BP180, as a hemidesmosomal cell-cell matrix adhesion protein, plays a vital role in host defense against melanoma progression through modulating basal keratinocytes, neutrophil and mast cells in local tumor microenvironment.

Citation Format: Bin-Jin Hwang, Bin Peng, Yang Zhang, Jaime Marie Brozowski, Lin Lin, Scott E. Williams, Ning Li, Zhen Liu, Maureen Su, Nancy E. Thomas, Luis A. Diaz, Zhi Liu. The loss function of BP180 (Collagen type XVII) in skin, leads to a mast cell dependent pro-inflammatory microenvironment which promotes melanoma progression. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2016 Oct 20-23; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2017;5(3 Suppl):Abstract nr B07.
Abstract B12: Independent comparison of the state of the art in-silico HLA typing software
Authors: Ng Alvin , Rozen Steve
Published: March 2017

To accurately characterize the neo-antigen repertoire in tumors, identifying the HLA alleles of the patient is paramount. The binding of the neo-antigens to the patient's specific HLA alleles HLA-restriction has to be determined to identify neo-antigens that might play a role in stimulating an immune response in immunotherapy. The information on the patient's HLA alleles is captured in the next-generation sequencing (NGS) data and has to be accurately teased out using in-silico HLA typing software. However, to our knowledge, until now an independent study of HLA typing software has not been carried out. In this study, five publicly available HLA typing software packages were compared using 106 whole exome sequencing samples from the 1000 Genomes Project and a published dataset of 56 Asian nasopharyngeal tumor-normal pairs with experimentally determined HLA types. Whole exome sequencing samples of varying depth and coverage were chosen to simulate real-world data and test the robustness of the HLA typing software.

Citation Format: Alvin Ng, Steve Rozen. Independent comparison of the state of the art in-silico HLA typing software. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2016 Oct 20-23; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2017;5(3 Suppl):Abstract nr B12.
Abstract B13: Integrative genomic and transcriptomic analysis of 775 human cancer cell lines reveals tumor-derived immune programs and their regulators
Authors: Villani Alexandra-Chloe , Chun Ye , Raychowdhury Raktima , Li Weibo , Eisenhaure Thomas , Regev Aviv , Hacohen Nir
Published: March 2017

The role of tumor cell-derived immune factors in the development of cancer and tumor immunity remains poorly understood. We hypothesized that tumors express recurrent and stable immunoregulatory programs that impact cancer growth and immunity. To identify these programs, we performed an unbiased integrative analysis of chromosomal copy number aberrations and gene expression analysis on 775 primary solid tumor cell lines, derived from 23 different tissues of origin. Using modified versions of GISTIC 2.0 and CONEXIC, a Bayesian module network method, we identified cancer drivers that correlated with specific transcriptional regulatory programs across multiple cell lines (after considering confounding variables, including histology, sub-histology, ethnicity, gender, center of collection, experimental batches and unknown variables using Surrogate Variable Analysis). We identified a total of 60 amplified and 222 deleted somatic regions, of which 52% contained a candidate driver gene whose expression was associated with the expression of a target module. The driver genes consisted of putative novel and known cancer drivers, including deletions in CDKN2A-CDKN2B (q< 4.2E-176), WWOX (q< 5.3E-100), and amplifications in MYC (q< 2.1E-81) and CCND1 (q< 1.4E-44) genes. The target modules were enriched for known cancer-dysregulated processes, including cell cycle (q< 2.1E-91) and DNA damage/repair (q< 9.3E-50), validating the analysis. We identified and focused on immune programs common to several tissues of origin, including a type I interferon-related program (q<9.8E-26), which is likely to impact the tumor immune microenvironment. To validate our predictions, we functionally investigated 8 cell lines with high versus 8 with low expression of the interferon-related immune regulatory program. We validated activation of the pathway at the protein level and found that it was sustained by secreted factors. We found drivers of this program using CRISPR/Cas9 single guide RNAs and small molecule inhibitors, and showed that cancer cells expressing this program modulated activation of co-cultured immune cells. The finding of a stable tumor-derived immune program should help point to new targets for cancer therapy.

Note: This abstract was not presented at the conference.

Citation Format: Alexandra-Chloe Villani, Ye Chun, Raktima Raychowdhury, Weibo Li, Thomas Eisenhaure, Aviv Regev, Nir Hacohen. Integrative genomic and transcriptomic analysis of 775 human cancer cell lines reveals tumor-derived immune programs and their regulators. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2016 Oct 20-23; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2017;5(3 Suppl):Abstract nr B13.
Abstract B42: Role of TRAIL signaling in tumor killing
Authors: Siao Shih-Hong , Hsu Ping-Ning
Published: March 2017

TRAIL (tumor necrosis factor-related apoptosis-inducing ligand) is an endogenous ligand, which plays role in immune surveillance and anti-tumor immunity. Binding of TRAIL to its death receptor (DR4 or DR5) leads to receptor oligomerization and recruitment of the death-inducing signaling complex (DISC), activates the caspase-8 and its downstream caspase cascade and ultimately leads to cell death. Although TRAIL induces apoptosis in many tumor cell lines, almost all normal cells are insensitive to TRAIL-induced cell death. The physiological role of TRAIL remains to be elucidated. Recently, scientists have turned their attention to the emerging role of TRAIL in modulating immune responses. TRAIL administration induced anti-inflammatory effects in several autoimmune animal models. All these results suggest an apoptosis-independent role of TRAIL in the immune system. In this study, we studied the role of TRAIL signaling in immune resistance to tumor growth by using the TRAILR-R knockout mice. We demonstrated TRAIL suppressed T cell activation stimulated by anti-CD3/CD28. T cells from TRAIL-R knockout mice resisted to these effects and were with higher proliferation and cytokine production capability to anti-CD3/CD28 stimulation. However, when the melanoma cell lines B16-F10 were inoculated, there was enhanced tumor growth in TRAIL-R knockout mice compared to the wild type control. This finding suggests TRAIL/TRAIL-R interaction may play a role in host against tumor growth. The immunophenotype of the tumor infiltrating lymphocytes and cytokine production are analyzed. Apoptosis and activation of caspases of tumor cells and infiltrating immune cells are also characterized. This study will help to elucidate the role of TRAIL signaling in tumor killing and immune surveillance.

Citation Format: Shih-Hong Siao, Ping-Ning Hsu. Role of TRAIL signaling in tumor killing. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2016 Oct 20-23; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2017;5(3 Suppl):Abstract nr B42.
Abstract B44: Selective stimulation of RIG-I with a novel synthetic RNA induces strong anti-tumor immunity in mouse tumor models
Authors: Barsoum Jim , Renn Marcel , Schuberth Christine , Jakobs Christopher , Schwickart Anna , Schlee Martin , Boorn Jasper van den , Hartmann Gunther
Published: March 2017

We describe a novel immunotherapy approach in which a natural viral defense system is harnessed to stimulate anti-tumor immunity. Cancer immunotherapy has revolutionized oncology in recent years, yet many tumors become resistant or do not respond to current treatments such as checkpoint inhibitors. Stimulation of the innate immune system opens a new therapeutic strategy that could be combined effectively with other immunotherapeutic regimens. The ubiquitously expressed cytosolic RNA receptor retinoic acid inducible gene I (RIG-I) recognizes double-stranded RNA bearing a 5'-triphosphate. RIG-I plays a prominent role in antiviral defense. Its activation induces apoptosis preferentially in tumor cells and simultaneously activates the innate immune system via type I interferon (IFN) signaling. We developed an optimized, fully synthetic oligonucleotide, designated RGT100, which is a RIG-I selective ligand. RGT100 activates the RIG-I pathway leading to the induction of cytokines, including IFN-α and IFN-β. The treatment of tumor-bearing mice with RGT100 induced potent anti-tumor activity against large established B16 melanoma and CT26 colon carcinoma tumors. RGT100 also was efficacious in a spontaneous melanoma model. Histological and flow cytometric analysis of the tumors revealed infiltration and activation of immune cells after RGT100 treatment. RGT100 induced a strong and durable type I IFN response in tumors. Treatment of subcutaneous tumors by intratumor injection led to efficacy of both the treated tumors as well as untreated contralateral tumors. Furthermore, systemic delivery of RGT100 was efficacious against both local subcutaneous B16 melanoma as well as lung metastases. Data support both rapid natural killer (NK) cell-mediated and long-term T cell-mediated anti-tumor activities. Depletion of NK cells blocked the immediate anti-tumor activity of RGT100. In summary, Rigontec's RIG-I-selective ligand RGT100 shows strong anti-tumor activity in several clinically relevant mouse tumor models, while bearing an advantageous safety profile. RGT100 is rapidly progressing toward clinical evaluation in cancer patients. This agent will be evaluated both for single-agent activity as well as in combination with checkpoint inhibitors.

Citation Format: Jim Barsoum, Marcel Renn, Christine Schuberth, Christopher Jakobs, Anna Schwickart, Martin Schlee, Jasper van den Boorn, Gunther Hartmann. Selective stimulation of RIG-I with a novel synthetic RNA induces strong anti-tumor immunity in mouse tumor models. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2016 Oct 20-23; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2017;5(3 Suppl):Abstract nr B44.
Abstract B51: Targeting galectin-1 to improve therapeutic efficacy in head and neck cancers
Authors: Nambiar Dhanya K. , Cao Hongbin , Le Quynh Thu
Published: March 2017

Head and neck cancers (HNC) are associated with significant changes in the immune profile, with lower systemic absolute lymphocyte count and reduced tumor-infiltrating lymphocytes (TILs), which are inversely correlated with overall survival. Galectin-1(Gal-1), which is a carbohydrate binding protein, is secreted at high level by cancer cells, including HNC, and contributes to tumor-immune escape and disease progression. Our group has shown that both hypoxia and radiotherapy (RT) can individually stimulate tumor Gal-1 secretion, which is detrimental to therapeutic efficacy. Targeting Gal-1 in HNC therefore may synergize with radiotherapy and/or immunotherapy. Using the CRISPR/Cas9 deletion approach, we developed an orthotopic model of HNC with/without Gal-1 expression. We found that Gal-1 KO tumors showed a marked decrease in tumor growth and nodal metastases. Gal-1 WT tumors had very low infiltration of CD4+/CD8+ T cells (TILs) compared to Gal-1 null tumors. The decrease in TILs was due to both Gal-1-induced apoptosis of activated T cells and Gal-1 inhibition of trans-endothelial T-cell migration, which was confirmed by in vitro assays. Endothelial cells within Gal-1 WT tumors showed uniformed staining of PD-L1 expression by immunohistochemistry, that was not present in Gal-1 null tumors. Similarly, isolated tumor endothelial cells (TECs) from Gal-1 WT tumors showed significantly higher expression of PD-L1 (PD1 ligand) and Gal-9 (Tim-3 ligand) than TECs from Gal-1 null tumor. Concurrently, there were more PD1+ and Tim3+ intra-tumoral T cells within the Gal-1 WT than Gal-1 null tumors. Our study therefore suggest that in addition to T-cell apoptosis, tumor Gal-1 can impede transendothelial T cell migration, leading to less TIL, resulting in immune escape and possible resistance to immune check point therapy. Therefore, a combined approach of targeting Gal-1 with immune checkpoint inhibitors may lead to better therapeutic efficacy in HNC patients.

(Acknowlegement: NIH Grant-R01CA161585-03)

Citation Format: Dhanya K. Nambiar, Hongbin Cao, Quynh Thu Le. Targeting galectin-1 to improve therapeutic efficacy in head and neck cancers. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2016 Oct 20-23; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2017;5(3 Suppl):Abstract nr B51.
Abstract B69: Antitumor effects of combining hemocoagulase with the blocking-microvascular action of microbubbles enhanced ultrasound cavitation on rabbit VX2 liver tumors
Authors: Yang Qian , Tang Peng , Liu Liwen , Ge Shuping , Zhou Xiaodong
Published: March 2017

Substantial effort is being directed toward investigating the use of microbubble enhanced ultrasound cavitation (MEUC) to promote penetrate vascular wall and disrupting circulation in liver tumor. In this study we propose and investigate a new method for combining MEUC with hemocoagulase (HC) atrox, which is effectively a vascular targeting to induce embolism effects and combine these with an antiangiogenic treatment strategy. HC was administered was inserted precisely into the tumor under the guidance of real- time ultrasound with a 21-gauge needle. MEUC were conducted at1 MHz frequency probe (with a 400-cycle pulse length and a pulse repetition frequency of 9 Hz) at peak positive pressure of 1 MPa in combination with the commercial microbubble agent SonoVue. MEUC treatments were performed on 10 min on and off periods and HC was administered for 1KU. Rabbits were implanted VX2 tumor mass to establish a liver tumor model. 7 days after tumor implantation, rabbits presented with single liver tumor were randomly divided into 4 study groups: (1) control group were given injections of saline use micro- pump intravenously. (2) HC only injection. (3) MEUC treatment. (4) MEUC+HC treatment. The MEUC induced an acute reduction of blood flow as confirmed with contrast enhanced ultrasound (CEUS) imaging. QontraXt software quantitative analysis time intensity curve (TIC) of the tumor blood perfusion and microvascular changes. The MEUC+HC treatment group showed significant growth inhibition relative to the MEUC-only (p < 0.01) and HC-only treatment groups (p < 0.01). These results indicate the feasibility of a new approach to combining microbubble enhanced ultrasound cavitation with hemocoagulase.

Citation Format: Qian Yang, Peng Tang, Liwen Liu, Shuping Ge, Xiaodong Zhou. Antitumor effects of combining hemocoagulase with the blocking-microvascular action of microbubbles enhanced ultrasound cavitation on rabbit VX2 liver tumors. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2016 Oct 20-23; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2017;5(3 Suppl):Abstract nr B69.
Abstract B80: Natural killer and dendritic cells collaborate in the immune response induced by Cetuximab and IL-15 against triple negative breast cancer
Authors: Juliá Estefanía P. , Pampena María Betina , Rocca Yamila S. , Mordoh José , Levy Estrella M.
Published: March 2017

Background: While the majority of Triple Negative Breast Cancer (TNBC) overexpress epidermal growth factor receptor (EGFR), EGFR inhibition as a monotherapy with Cetuximab is not effective. The study of its mechanism of action is important to find out potentially synergistic combinations. Previously, we demonstrated that Cetuximab can trigger antibody-dependent NK cell-mediated cytotoxicity against TNBC cells. The aim of this study was to investigate the effect of NK cell activation by Cetuximab-coated TNBC cells on Dendritic Cell (DC) function, and the result of its combination with IL-15.

Methods: Human monocyte-derived DCs were co-cultured with autologous isolated NK cells, TNBC cells, Cetuximab and/or IL-15 for 24hs. Costimulatory molecule and activation marker expression in DC and NK cells were analyzed by flow cytometry, and cytokine concentration in culture supernatants was assessed by ELISA. DCs obtained after co-cultures were incubated for 24hs with CD40 ligand transfected fibroblasts to mimic the interaction with CD40L expressing Th cells, and IL-12 was analyzed in culture supernatants by ELISA.

Results: Cetuximab treatment of TNBC cells enhanced DC maturation only when NK cells were present in the co-culture (%CD83+: 6.6±0.7 vs 61.0±17, p<0.001; CD86 MIF: 121±36 vs 1868±833, p<0.01). In concert, NK cells were activated by Cetuximab showing increased CD25 expression and IFN-γ production, a cytokine known to induce DC activation. After subsequent CD40 ligand stimulation, DCs that where co-cultured with Cetuximab activated NK cells had an increased ability to produce IL-12p70. Furthermore, IL-15 combination with Cetuximab not only promoted NK cell cytotoxic activity against TNBC cells, but also induced IFN-γ production and DC maturation.

Conclusions: Our results suggest that besides its anti-proliferative mechanism of action, Cetuximab has immunological effects in an in vitro model of TNBC, promoting NK cell activation and DC maturation, which could be potentiated by the combination with IL-15. This could ultimately result in the priming of T cell-based immunity, which will be evaluated in further studies.

Citation Format: Estefanía P. Juliá, María Betina Pampena, Yamila S. Rocca, José Mordoh, Estrella M. Levy. Natural killer and dendritic cells collaborate in the immune response induced by Cetuximab and IL-15 against triple negative breast cancer. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2016 Oct 20-23; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2017;5(3 Suppl):Abstract nr B80.
Abstract B88: TGF-β pathway-mediated escape from VEGF blockade is linked with angiogenesis and immune-suppression in murine glioma models
Authors: Mangani Davide , Weller Michael , Sadr Emad Seyed , Willscher Edith , Seystahl Katharina , Reifenberger Guido , Tabatabai Ghazaleh , Binder Hans , Schneider Hannah
Published: March 2017

The vascular endothelial growth factor (VEGF) and transforming growth factor (TGF)-β are key target molecules in glioblastoma that are interdependently regulated. Both pathways drive key malignant features in glioma cells such as angiogenesis, invasiveness and immunosuppression. Here we explore whether TGF-β acts as an escape pathway from VEGF inhibition using gene expression profiling and in vitro and in vivo studies in a panel of syngeneic mouse glioma models. In vivo, single agent activity was observed for the VEGF antibody B20-4.1.1 in three (SMA-540, SMA-560 and GL-261), and for the TGF-β receptor I antagonist LY2157299 in two (SMA-540 and SMA-560) of four mouse glioma models. Transcriptomic profiling of the four mouse glioma models revealed that SMA-497 and GL-261, while unresponsive to LY2157299, were the most immunogenic tumors as defined by Gene Ontology; specifically, up-regulation of chemokine/chemoreceptors genes involved in immune cell recruitment and interferon-related genes were found. Co-targeting of VEGF and TGF-β was ineffective in one refractory model (SMA-497), in which no major changes in tumor immune-infiltrating cells were detected upon mono- or co-treatment settings. Significant prolongation of survival in the GL-261 model was associated with early stage increased infiltration of CD8+ cells, lower numbers of CD11b+ macrophages/microglia and sustained suppression of angiogenesis compared to anti-VEGF treatment alone. Phosphorylated SMAD2 was increased in both tumor cells and CD45+ leukocytes during anti-angiogenic treatment pointing to the possibility of a TGF-β-induced immunosuppressive micro-milieu that is efficiently counteracted by concomitant administration of LY2157299. In conclusion, our study highlights the biological heterogeneity of glioblastoma even among simple mouse models and illustrates that co-targeting of the VEGF and TGF-β pathways might lead to improved tumor control in subsets of glioblastoma linked with angiogenesis impairment and general reduction of the immune-suppressive phenotype.

Note: This abstract was not presented at the conference.

Citation Format: Davide Mangani, Michael Weller, Emad Seyed Sadr, Edith Willscher, Katharina Seystahl, Guido Reifenberger, Ghazaleh Tabatabai, Hans Binder, Hannah Schneider. TGF-β pathway-mediated escape from VEGF blockade is linked with angiogenesis and immune-suppression in murine glioma models. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2016 Oct 20-23; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2017;5(3 Suppl):Abstract nr B88.
Abstract IA21: Profiling immune cell subsets and immune responses using immunoPET
Authors: Wu Anna M.
Published: March 2017

The field of immuno-oncology is seeing striking successes, yet suffers from ongoing diagnostic challenges that are hampering progress in the development of novel and combination immunotherapies in patients. Non-invasive imaging using PET enables profiling tumor and immune system biology throughout the body. In vivo imaging provides a powerful and complementary approach to in vitro diagnostics, allowing profiling of biology in the context of an intact living organism. Given the challenges of tumor heterogeneity, as well as variability of immune responses, molecular imaging approaches are poised to provide essential information to enhance our understanding of immune responses and immunotherapy.

We have developed engineered antibody fragments to provide a versatile platform for non-invasive imaging of cells and tissues based on cell surface phenotype. Recombinant fragments such as minibodies and diabodies have been developed with accelerated clearance (enabling same-day or next-day imaging), limited or no biological activity (lacking complement/Fc receptor binding), and permitting site-specific conjugation. When labeled with positron-emitting radionuclides (such as I-124, Zr-89, Cu-64, F-18), minibodies and diabodies can be employed for high resolution, sensitive, quantitative imaging by immunoPET and provide highly specific molecular assessments of tumor biology and response to treatment. For example, an I-124 prostate stem cell antigen (PSCA)-specific minibody demonstrates sensitive imaging in mouse models of prostate cancer and provides a PET imaging readout of response to anti-androgens. Antibody-based targeting and imaging of CD markers (CD4 or CD8 on T lymphocytes; CD20 on B lymphocytes) broadens applications to assessment of immune cell subsets and monitoring responses to cancer immunotherapy. A Zr-89 anti-CD8 cys-diabody has been used to detect and image tumor infiltrating CD8+ T lymphocytes in tumor treatment models using anti-CD137 or anti-PD-L1 antibodies, and to detect adoptively-transferred OT-I T cells in mice. Applications extend beyond oncology, with recent visualization of CD4+ T lymphocytes in a mouse model of colitis.

Importantly, immunoPET using engineered antibody fragments can be readily translated, and can provide highly sensitive imaging of cell surface biomarkers in patients. ImmunoPET provides a broad approach for noninvasive, whole-body monitoring of key factors such as target expression in vivo, response to therapy, and immune responses, and stands to play an expanding role in the detection and management of cancer.

Citation Format: Anna M. Wu. Profiling immune cell subsets and immune responses using immunoPET. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2016 Oct 20-23; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2017;5(3 Suppl):Abstract nr IA21.