bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract A053: Therapy with a non-blocking monoclonal antibody targeting soluble NKG2D ligand MIC revamps endogenous innate and adaptive anti-tumor responses and eliminates primary and metastatic tumors
Authors: Wu Jennifer
Published: May 2016

The human tumor-derived soluble NKG2D ligand, the MHC I-chain related molecule (sMIC), is highly immune suppressive in cancer patients and correlates with poor prognosis. However, the therapeutic effect of targeting sMIC has not been determined, due to the limitation that mice do not express homologs of human MIC. With a clinically relevant transgenic mouse models, we aimed to determine the therapeutic efficacy of a non-blocking sMIC-neutralizing anti-MIC mAb antibody. Treatment of the engineered MIC-expressing “humanized” TRAMP/MIC bi-transgenic mice at advanced disease stages with a sMIC-neutralizing non-blocking mAb effectively induced regression of primary tumors and eliminated metastasis without inducing systemic toxicity. The therapeutic effect is conferred by revamping endogenous anti-tumor immune responses, exemplified by restoring NK cell homeostasis and function, enhancing susceptibility of MIC+-tumor cells to NK cell killing, reviving and sustaining antigen-specific CD8 T cell responses, augmenting CD4 T cells to Th1 responses, priming dendritic cells for antigen presentation, and remodeling tumor microenvironment to be more immune reactive. With a transplantable syngeneic sMIC-expressing B16 melanoma model, we also demonstrated that therapy with the sMIC-neutralizing mAb significantly enhanced the anti-tumor responses of adoptively transferred antigen-specific CD8 and CD4 T cells. We conclude that therapy with a sMIC-neutralizing non-blocking anti-MIC mAb can effectuate anti-tumor immune responses against advanced MIC+ tumors. Our study provided strong rationale for translating sMIC-neutralizing therapeutic mAb into clinics, either alone or in combination with current ongoing standard immunotherapies.

Citation Format: Jennifer Wu. Therapy with a non-blocking monoclonal antibody targeting soluble NKG2D ligand MIC revamps endogenous innate and adaptive anti-tumor responses and eliminates primary and metastatic tumors. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr A053.
Abstract A055: Potent therapeutic and immunological effects of the first T-BiTE derived from a TCR-mimic antibody targeting intracellular oncoprotein WT1
Authors: Dao Tao , Pankov Dmitry , Scott Andrew , Korontsvit Tatyana , Zakhaleva Victoriya , Guerrerio Manuel Direito de Morais , Xu Yiyang , Xiang Jingyi , Yan Su , Veomett Nicholas , Veomett Nicholas , Dubrovsky Leonid , Curcio Michael , Doubrovina Ekaterina , Liu Cheng , O'Reilly Richard J. , Scheinberg David A.
Published: May 2016

Bi-specific T cell engager antibody (BiTE) therapy has recently emerged as an effective immunotherapy by redirecting polyclonal T cell cytotoxicity against cell surface protein on tumor cells. We generated the first BiTE construct derived from a TCR-mimic monoclonal antibody (mAb), ESK1, specific for a peptide from an intracellular oncoprotein, WT1, in the context of HLA-A*02:01 molecules. Despite the low density peptide/HLA-A2 complex on the cell surface, ESK-BiTE was able to selectively activate and induce proliferation of cytolytic human T cells to kill multiple leukemias and cancers in vitro and in mice. Surprisingly, we also discovered that in an autologous setting, ESK-BiTE induced a robust secondary CD8 T cell response specific for antigens other than WT1, including HLA-A2-restricted her2-neu-derived peptide 369-377, in patients with her2- positive ovarian cancer. Therefore, the study demonstrated a new vaccinal mechanism for BiTE mAb action that could contribute to more effective long-term therapeutic activity of BiTE's and further broaden their reach to other tumor antigens not previously known or originally targeted.

Citation Format: Tao Dao, Dmitry Pankov, Andrew Scott, Tatyana Korontsvit, Victoriya Zakhaleva, Manuel Direito de Morais Guerrerio, Yiyang Xu, Jingyi Xiang, Su Yan, Nicholas Veomett, Nicholas Veomett, Leonid Dubrovsky, Michael Curcio, Ekaterina Doubrovina, Cheng Liu, Richard J. O'Reilly, David A. Scheinberg. Potent therapeutic and immunological effects of the first T-BiTE derived from a TCR-mimic antibody targeting intracellular oncoprotein WT1. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr A055.
Abstract A073: Carrier-free delivery of cytokine to specifically expand adoptively transferred T cells for enhanced cancer immunotherapy
Authors: Tang Li , Zheng Yiran , Mabardi Llian , Irvine Darrell J.
Published: May 2016

Adoptive cell transfer (ACT) with autologous tumor-reactive T cells is a promising strategy in cancer immunotherapy, but treatment of solid tumors is limited by the rapid decline in function of the transplanted T cells. In order to maintain high numbers of viable antigen-specific cytotoxic T cells in tumors, co-administration of supporting immunostimulant agents together with transferred cells is often necessary in clinical practice. However, the high systemic doses of such agents needed to enhance T cell functionality can also result in serious side effects. Here, we developed a carrier-free strategy to deliver cytokines specifically to adoptively transferred T cells for cancer immunotherapy. IL2-Fc or an IL-15 superagonist were chemically crosslinked with a disulfide linker to form protein nanogels (NGs), which were conjugated to the plasma membrane of ACT T-cells. These NGs had exceptionally high loading of cytokines (~70 wt%) and released native protein in physiological conditions in a sustained manner through breakdown of the degradable disulfide linker in response to the activated T cell surface reduction activity. Cytokine-NGs were chemically conjugated onto the plasma membrane of donor T cells, enabling continuous pseudo-autocrine release of cytokine for stimulation of transferred CD8+ T cells. Transferred pmel-1 CD8+ T cells with optimized number of NGs conjugated per cell showed enhanced expansion and long persistence in B16F10 tumor bearing mice. Quantification of transferred Thy1.1+CD8+ T cells in tumors at Day 13 showed that T cells with conjugated cytokine-NGs expanded ~80 fold more than the T cells with systemically administered free cytokine. We demonstrated that the cytokine-NG-T cell conjugation strategy could augment transferred T-cell expansion efficiently and specifically in vivo, and thus improve the therapeutic efficacy. This T cell-NG “back pack” approach provides a readily generalizable strategy to provide autocrine protein drug support to donor cells to enhance the safety and efficacy of ACT.

Citation Format: Li Tang, Yiran Zheng, Llian Mabardi, Darrell J. Irvine. Carrier-free delivery of cytokine to specifically expand adoptively transferred T cells for enhanced cancer immunotherapy. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr A073.
Abstract A075: Immunotherapy of malignant pleural mesothelioma using cMET specific T-cells
Authors: Thayaparan Thivyan , Stegen Sjoukje J.C. van der , Puri Ana C. Parente Pereira , Petrovic Roseanna Maria , Spicer James , Maher John
Published: May 2016

Background: Malignant pleural mesothelioma (MPM) is an incurable cancer predominantly induced by asbestos exposure. This aggressive tumour commonly presents at an advanced stage of disease. Although surgery, combination chemotherapy and radiotherapy may be used in disease management, median survival from diagnosis is less than 12 months. New therapeutic approaches are required to improve outcome in this disease.

Chimeric antigen receptors (CAR) are fusion molecules that couple the HLA- independent binding of a selected cell surface target antigen to the delivery of a tailored T-cell activating signal. Using CAR technology, we aim to develop a novel immunotherapy for MPM that is both safe and effective. These molecules are delivered to patient T-cells using retroviral gene-transfer, thereby stably re-directing their specificity for antigen. The receptor tyrosine kinase MET is overexpressed in >80% of MPM patients making it an attractive candidate for CAR directed immunotherapy.

Methods: Three second-generation cMet-targeted CARs (containing a fused CD28/CD3ζ endodomain) have been developed, distinguished by peptide-binding motifs. Functionality of MET-re targeted T-cells has been assessed by co-cultivation of genetically enhanced test and control T-cells with MPM cell lines that express MET at various levels.

Results: Studies to date have shown that human T-cells engineered to express cMet CARs can destroy mesothelioma tumour cell monolayers, accompanied by T-cell proliferation and cytokine production. To further potentiate the activity of the cMet targeted CARs, a dual targeting approach to both cMet and the ErbB family is currently under evaluation. The second advantage of this approach is in diminishing the potential toxicity risks associate with “on target, off tumour” toxicity. An MPM xenograft model has been established utilising bioluminescence to further evaluate functionality and toxicity in vivo.

Conclusions: These findings demonstrate proof of concept for the utility of CAR engineered T-cells to recognise and destroy cMet-expressing MPM tumour cells. We envisage that regional i.e. intrapleural delivery of human CAR positive T-cells could be used to maximise therapeutic index of this approach.

Citation Format: Thivyan Thayaparan, Sjoukje J.C. van der Stegen, Ana C. Parente Pereira Puri, Roseanna Maria Petrovic, James Spicer, John Maher. Immunotherapy of malignant pleural mesothelioma using cMET specific T-cells. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr A075.
Abstract A080: Targeted genome modifications for improved adoptive immunotherapy
Authors: Valton Julien , Gautron Anne-Sophie , Juillerat Alexandre , Duchateau Philippe , Poirot Laurent
Published: May 2016

Chimeric antigen receptor (CAR)-redirected T-cells have given rise to long-term durable remissions and remarkable objective response rates in patients with refractory leukemia, raising hopes that a wider application of CAR technology may lead to a new paradigm in cancer treatment. Similarly, transcription activator-like effector nuclease (TALEN™)-mediated gene editing has emerged as powerful strategy to introduce targeted mutations and holds great promise in therapeutics and offers multiple opportunities to improve CAR T-cell therapies. The knockout of the TCR alpha gene eliminates TCR expression and abrogates the donor T-cell's potential for graft-versus-host disease (GvHD) while maintaining a potent anti-tumoral activity. Thus it is possible to manufacture T-cells from third-party healthy donors to generate allogeneic “off-the-shelf” engineered CAR T-cells. Disruption of CD52 or deoxycytidine kinase genes may be a useful approach to makes T-cells compatible with concurrent oncology treatments such as alemtuzumab or Fludarabine while the bypass of key immune checkpoint regulators such PD1/PDL1 by inactivation of T-cells receptors would potentiate the antitumor T-cell response by impairing the interaction of the inhibitory receptor PD-1 on T cells with PD-L1 expressed on tumor cells. Here, we will present in vitro and in vivo proof of concepts demonstrating the potential of TALEN™-mediated gene editing for adoptive T-cell therapy.

Citation Format: Julien Valton, Anne-Sophie Gautron, Alexandre Juillerat, Philippe Duchateau, Laurent Poirot. Targeted genome modifications for improved adoptive immunotherapy. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr A080.
Abstract A083: Modulation of the immune system as a strategy to treat EGFR mutant lung adenocarcinoma
Authors: Ayeni Deborah , Ho Ping-Chih , Perry Curtis , Kaech Susan , Politi Katerina
Published: May 2016

Fifteen percent of lung adenocarcinomas harbor mutations in the Epidermal Growth Factor Receptor (EGFR). Although EGFR mutant tumors show sensitivity to specific tyrosine kinase inhibitors (TKIs) like erlotinib, resistance develops after an average of 12 months and there are currently no approved therapeutic strategies to overcome resistance. Therefore, novel approaches to delay resistance and improve patient survival are crucial. Recent discoveries in tumor immunology have revealed the potential of immune-based therapies to treat lung malignancies. In particular, immune checkpoint inhibitors such as anti-PD-1 have shown efficacy in a subset of patients with metastatic lung adenocarcinoma with minimal toxicity. These promising data led us to investigate the benefit of immune modulatory agents in EGFR mutant lung cancer. As a first step, we set out to explore the role of the immune system in this lung adenocarcinoma subset using a tetracycline-inducible mouse model of EGFR mutant lung cancer. We found, in these models, that lung-specific expression of mutant EGFR and consequent tumor formation leads to the establishment of an immunosuppressive tumor microenvironment characterized by an overall decrease in CD4 T cells, infiltration of Tregs, up-regulation of PD-1 expression on both helper and cytotoxic T cells and a diminished cytokine production by these T cells. Additionally, by flow cytometry and quantitative PCR of FACS-sorted cells, we have observed increased expression of PD-L1 on alveolar macrophages, which represent over 60% of the CD45+ cells in these tumors, suggesting an engagement of the adaptive and innate arms of the immune system to mediate immunosuppression via the PD-1/PD-L1 axis. Furthermore, when the tumor suppressor gene p53 was deleted, we observed a marked decrease in tumor infiltrating CD8 T cells when compared to p53 wild-type tumors. Currently, we are evaluating the functional role of elements of the immune system in these models to delineate their effects on tumor progression and therapeutic response. Moreover, we are investigating whether the observed immunosuppression in these tumors can be altered by immunomodulatory agents such as the anti-PD-1 and anti-PD-L1 immune checkpoint inhibitors alone or in combination with EGFR TKIs.

Citation Format: Deborah Ayeni, Ping-Chih Ho, Curtis Perry, Susan Kaech, Katerina Politi. Modulation of the immune system as a strategy to treat EGFR mutant lung adenocarcinoma. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr A083.
Abstract A088: Increase lymphocyte infiltration overcomes tumor resistance to checkpoint blockade
Authors: Tang Haidong , Wang Yang , Fu Yang-Xin
Published: May 2016

Spontaneous T cell-inflamed tumor microenvironment is associated with clinical responses to immunotherapies, including immune checkpoint blockades. However, majority of established tumors often inhibit peripheral T cells entering tumor tissues for tumor destruction and/or prevent effective T cell priming. Previous studies in our lab have shown that upregulation of the tumor necrosis factor superfamily member LIGHT (also known as TNFSF14) in peripheral tissues results in T cell activation and migration into non-lymphoid tissues and formation of lymphoid-like structures, which lead to rapid T cell-mediated tissue destruction. Furthermore, local expression of LIGHT by tumor cells may promote the formation of lymphoid-like structures for direct T-cell sequestration and activation, leading to tumor regression. Those data suggest LIGHT as an interesting candidate to create T cell-inflamed tumor environment. To better evaluate the therapeutic efficacy of human LIGHT protein in both murine and human systems, we engineered human LIGHT by random mutation using yeast-display system, and were able to generate a human LIGHT mutant which binds to both murine and human receptors while remains stable. To specifically target LIGHT to tumor tissues, an antibody-LIGHT fusion protein was generated. In different mouse models, we found that antibody-LIGHT induces a T cell inflamed tumor environment. This is correlated with an upregulation of inflammatory cytokines and adhesion molecules, and leads to the rejection of established tumors. More importantly, we observed that LIGHT-mediated T cell inflamed environment is critical for restoring the efficacy of checkpoint blockade therapy. When we blocked lymphocyte trafficking, a tumor previously responding to checkpoint blockade became resistant to therapy. This process can be reversed by treating with LIGHT. Our study indicates that targeting LIGHT may be an effective strategy for cancer immunotherapy, especially those who do not response to checkpoint blockade due to the lack of infiltration.

Citation Format: Haidong Tang, Yang Wang, Yang-Xin Fu. Increase lymphocyte infiltration overcomes tumor resistance to checkpoint blockade. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr A088.
Abstract A100: Cooperative defense against acute Clostridium difficile infection is mediated by two innate lymphoid cell subsets
Authors: Abt Michael C. , Lewis Brittany B. , Ling Lilan , Carter Rebecca A. , Susac Boj , Pamer Eric G.
Published: May 2016

Clostridium difficile, an opportunistic pathogen that infects the gastrointestinal tract following perturbation of the microbiota, damages the intestinal epithelium and can cause debilitating and potentially fatal colitis. Antibiotic treatment of C. difficile is often ineffective and whether innate immune defenses can be exploited to promote C. difficile clearance is unknown. Innate lymphoid cells (ILCs) are early responders to enteric infection, however, their role during C. difficile infection is undefined. To identify immune pathways that mediate recovery from C. difficile infection, we compared C57BL/6, Rag1-/-, and Rag2-/- Il2rg-/- (Ragγc-/-) mice challenged with C. difficile. In contrast to C57BL/6 and Rag1-/- mice, ILC-deficient Ragγc-/- mice rapidly succumbed to infection. Protection against infection was restored by transferring ILCs into Ragγc-/- mice. While ILC3s made a minor contribution to resistance, loss of T-bet-expressing ILC1s or IFN-γ in Rag1-/- mice increased susceptibility to C. difficile. These data demonstrate a critical role for ILC1s in defense against C. difficile.

Citation Format: Michael C. Abt, Brittany B. Lewis, Lilan Ling, Rebecca A. Carter, Boj Susac, Eric G. Pamer. Cooperative defense against acute Clostridium difficile infection is mediated by two innate lymphoid cell subsets. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr A100.
Abstract A109: Exploring neo-antigens and immunological response in GBM patients after individualized Prophage vaccination
Authors: Castle John , Levey Dan , Drouin Elise , Wilson Nicholas , Schoenfeld Steven , Bloch Orin , Buell Jennifer
Published: May 2016

The Prophage therapeutic platform generates an individualized therapeutic cancer vaccine for each patient. The vaccine for a patient is generated by isolating heat-shock proteins (HSPs) from the patient's individual tumor. Tumor HSPs are complexed to the milieu of material in the tumor, such as mutation neo-antigens. We use NGS, bioinformatics, computational immunology, and immuno-monitoring to explore the ‘omics space of GBM tumors and blood from patients treated with Prophage. We find between 104 and 214 non-synonymous mutations per tumor, including mutations in BRCA1 and EGFR, such as EGFRvIII, and large DNA copy number variations. Integrating patient HLA types, we predict mutation immunogenicity and prioritize mutations as neo-antigens. We correlate neo-antigens to clinical response. Using longitudinal blood samples taken pre- and post-vaccination, we explore both spontaneous and vaccine-induced immunogenicity to neo-antigens. Across the tumors, there are no neo-antigens in common, underscoring the need for individualized vaccination.

Citation Format: John Castle, Dan Levey, Elise Drouin, Nicholas Wilson, Steven Schoenfeld, Orin Bloch, Jennifer Buell. Exploring neo-antigens and immunological response in GBM patients after individualized Prophage vaccination. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr A109.
Abstract A130: Immune regulation of EMT and metastatic competence in breast tumor progression
Authors: Joseph Robiya , Soundararajan Rama , Paranjape Anurag , Mani Sendurai
Published: May 2016

Dynamic interactions between cancer cells and their surrounding microenvironment influence tumor survival, growth and metastasis. The tumor microenvironment harbors a complex variety of cells including lymphocytes and macrophages that produce a host of cytokines, chemokines, growth factors or interleukins, all of which presumably work in coordination to determine net tumor biology. Immune cells can offer a critical check-point in tumor progression. Interestingly however, infiltration of the tumor by immune cells appears to have dual functionality - they can reportedly either be pro-metastatic or anti-metastatic in their contribution. These clearly conflicting roles of immune cells limit our comprehension of their actual input to tumor advancement. The presence of tumor infiltrating lymphocytes has emerged as a good prognostic marker for a variety of cancers. However, the key molecular factors that regulate the cross-talk between tumor cells and lymphocytes, and the underlying signaling pathways are still ill-defined. Moreover, the impact of lymphocytes of the inflammatory tumor microenvironment, on the epithelial-mesenchymal plasticity and associated metastatic traits in breast cancer cells, is incompletely understood. We previously demonstrated that two key EMT/CSC factors - FOXC2 and Twist - are critical requirements for breast carcinoma cells to metastasize. The objective of this study is to systematically investigate the role of immune cells in EMT/CSC-dictated breast tumor progression using two isogenic breast cancer cell lines (67NR and 4T1) that form primary mammary tumors similarly, but differ drastically in their ability to metastasize.

Citation Format: Robiya Joseph, Rama Soundararajan, Anurag Paranjape, Sendurai Mani. Immune regulation of EMT and metastatic competence in breast tumor progression. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr A130.
Abstract A133: Imaging in cancer immunology: Phenotyping of multiple immune cell subsets in-situ in FFPE tissue sections
Authors: Mansfield James R. , Hoyt Clifford C. , Stack Edward , Feldman Michael , Bifulco Carlo , Fox Bernard
Published: May 2016

There has been a rapid grown in the field of tumor immunobiology in recent years as a result of recent successes in cancer immunotherapies, and it is clear that immune cells play many sometimes conflicting roles in the tumor microenvironment. However, obtaining phenotypic information about the various immune cells in and around the tumor has been a challenge. Existing methods can deliver phenotypic information on homogenous samples (e.g., flow cytometry or PCR) or morphologic information in single stain IHC. We present here a methodology for delivering quantitative per-cell marker expression and phenotyping, analogous to that obtained from flow cytometry, but from cells imaged in situ in FFPE tissue sections. This methodology combines: the sequential multi-marker labeling of up to 6 antigens using antibodies all of the same species (with a goal of reaching 8 markers); automated multispectral imaging to remove problematic FFPE tissue autofluorescence and correct cross-talk between fluorescent channels; and an automated image analysis that can quantitate the per-cell marker expression, determine the cellular phenotype, count these cells separately in the tumor compartment and in the stroma, provide high-resolution images of their distributions and provide x,y coordinate data from which spatial distance calculations can be made. We will show a 6-plex assay in breast cancer showing the application of the multiplexed staining, per-cell quantitation and cellular phenotyping in FFPE tissue sections, as well as methods to explore the spatial distributions of the phenotyped cells in and around the tumor.

Citation Format: James R. Mansfield, Clifford C. Hoyt, Edward Stack, Michael Feldman, Carlo Bifulco, Bernard Fox. Imaging in cancer immunology: Phenotyping of multiple immune cell subsets in-situ in FFPE tissue sections. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr A133.
Abstract A140: Viral-like nanoparticles for tumor immunotherapy by in situ vaccination mediate potent antitumor immunity
Authors: Lizotte Patrick , Wen Amy , Steinmetz NIcole , Fiering Steven
Published: May 2016

Tumors are recognized by the immune system, but tumors that reach clinically relevant size have established mechanisms to suppress the immune response and protect themselves from immune attack. One approach to enable effective immune response is to change the immunosuppressive tumor microenvironment into an immunostimulatory environment by introducing immunostimulatory reagents directly into tumors. This is essentially an antitumor therapeutic “in situ vaccination”, because the tumors provide the antigens and the adjuvants are the immunostimulatory reagents. The overall goal of the approach is to not only stimulate an anti-tumor immune response against the directly treated tumor, but more importantly to stimulate a systemic anti-tumor response to treat unseen metastases. There are many immunostimulatory reagents that can be used and each has different capabilities. Here we report on plant-derived viral-like nanoparticles from Cowpea Mosaic Virus used in mouse cancer models. These particles are only composed of viral capsid proteins, have no nucleic acids and have no recognized immunostimulatory reagents. However, they are strongly immunostimulatory through unknown pathways and cause dramatic changes in the tumor microenvironment that lead to primary tumor reduction and resistance to metastatic tumors. The treatment is immune-mediated since it requires IFN-γ, IL-12, and adaptive immunity and also involves neutrophils. Tumor reduction or elimination occurs in many anatomic locations and with multiple tumor types. Most importantly, treatment of a primary tumor by direct intratumoral injection mediates robust rejection of a rechallenge with the same tumor. The mechanisms and pathways of immunostimulation are under investigation. In addition to the inherent immunostimulatory adjuvant properties of these nanoparticles, they are a versatile platform to which other reagents for immune modulation can be attached. This demonstration of the value of viral-like nanoparticles for treatment of cancer opens a new avenue of cancer immunotherapy.

Citation Format: Patrick Lizotte, Amy Wen, NIcole Steinmetz, Steven Fiering. Viral-like nanoparticles for tumor immunotherapy by in situ vaccination mediate potent antitumor immunity. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr A140.
Abstract A142: An in vivo functional genomics screen identifies molecular determinants of adaptive immune rejection
Authors: Shuptrine Casey W. , Fertig Elana J. , Salcie-Gautreaux Marsha , Weiner Louis M.
Published: May 2016

The complex cross-talk occurring among cells in the tumor microenvironment influences the anti-cancer immune response. Here we employed an RNAi screen of a murine cancer cell line syngeneic to C57Bl/6 mice to parse out the ability of the immune system to identify and eliminate malignant cells. To identify rate-limiting immune modulators, the EO771 mammary cancer cell line was transduced with a barcoded genome-wide shRNA library and engrafted in immune-competent as well as immune-deficient mice. Analysis of tumors grown in the presence of a functional adaptive immune system compared to those grown in immune-deficient mice, revealed cancer cell autonomous genes that modulate immune recognition. Pathway analysis identified enrichment of shRNAs targeting previously identified immune regulators including the TGF-BR pathway and MHC class I antigen processing. Among the candidates, we selected CD47, Tex9, Yif1a, EMP2, Pex14, and Sgpl1 for validation based on consistency between independent screens and known association with immune regulation. The roles of CD47, Tex9, Pex14, and Sgpl1 were validated for T cell-dependent recognition and elimination of EO771 tumors. CD47, a known inhibitor of target cell phagocytosis by macrophages, also regulated the adaptive immune response in this novel system. Two previously understudied molecules, Pex14 and Sgpl1, have immune inhibitory functions, as their respective knockdown suppressed EO771 tumor growth and increased survival in immunocompetent mice. Tex9 serves as a potential tumor antigen or immune stimulant, as reduction of expression enhances tumor growth when EO771 tumors are grown in immunocompetent mice. Therefore, this functional in vivo screening approach enabled the discovery of CD47, Pex14, Sgpl1, and Tex9 as novel tumor-based modulators of anti-tumor adaptive immunity. To the best of our knowledge, we are the first to report the successful utilization of an in vivo functional genomics approach to identify novel tumor cell-based mediators of immune regulation.

Note:This abstract was not presented at the conference.

Citation Format: Casey W. Shuptrine, Elana J. Fertig, Marsha Salcie-Gautreaux, Louis M. Weiner. An in vivo functional genomics screen identifies molecular determinants of adaptive immune rejection. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr A142.
Abstract A147: Sunitinib upregulates IFNγ-STAT1 signaling to modulate the tumor immune microenvironment in renal cell carcinoma
Authors: Liu Xian-De , Hoang Anh , Sun Mianen , Lijun Zhou , Ding Zhiyong , Zhang Xuesong , Bai Shanshan , Tannir Nizar , Jonasch Eric
Published: May 2016

Antiangiogenic therapy is the current mainstay of treatment for renal cell carcinoma (RCC). Recently we reported that antiangiogenic therapy-treated primary tumors demonstrated both increased infiltration of CD4 and CD8 T cells and higher expression of the immune checkpoint ligand PD-L1, all of which were associated with therapy resistance. The underlying mechanism remains unknown. IFNγ-STAT1 signaling pathway drives the expression of both immunosuppressive PD-L1, and immunostimulatory chemoattractants, adhesion molecules and class I antigen presentation components. We studied the effects of sunitinib on the IFNγ-STAT1 signaling pathway. We found that sunitinib treatment magnified IFNγ-induced STAT1 activity. Sunitinib not only increased the activity of janus kinase (JAK) and the tyrosine phosphorylation of STAT1, but also decreased the protein level of PIAS and SOCS, negative regulators of STAT1 signaling. These results indicate that sunitinib treatment potently activates IFNγ-mediated STAT1 signaling by modulating both activators and inhibitors of STAT1. Further investigation is underway into the precise signaling pathways involved in sunitinib mediated regulation of upstream regulators of STAT1, and on the effect of sunitinib mediated STAT1 signaling on other immunostimulatory molecules in the tumor cell. Understanding the impact of STAT1 activation on target proteins after stimulation by antiangiogenic therapy will guide us to develop predictive biomarkers for combination antiangiogenic and immunomodulatory therapy, and devise precise interventions to overcome tumor cell specific immunosuppressive signaling.

Citation Format: Xian-De Liu, Anh Hoang, Mianen Sun, Zhou Lijun, Zhiyong Ding, Xuesong Zhang, Shanshan Bai, Nizar Tannir, Eric Jonasch. Sunitinib upregulates IFNγ-STAT1 signaling to modulate the tumor immune microenvironment in renal cell carcinoma. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr A147.
Abstract A173: Inhibition of the STING pathway by the AIM2 inflammasome
Authors: Corrales Leticia , Woo Seng-Ryong , Gajewski Thomas F.
Published: May 2016

Recognition of tumor-derived DNA by the cGAS/STING pathway in the cytosol of antigen-presenting cells leads to production of type I IFN, facilitating adaptive immunity against tumors. But cytosolic DNA is also recognized by AIM2, leading to the assembly of the AIM2 inflammasome and the production of mature IL-1 and IL-18. As stimulation of the STING pathway by endogenous tumor-derived DNA or exogenous therapeutic agonists have shown to trigger an immune response against tumors, a key question was whether the AIM2 inflammasome would have a positive or negative regulatory role, given the sharing of the same ligand by both pathways. In vivo, sorted CD45+ cells from implanted B16 tumors in AIM2-/- animals showed a higher IFN-β expression than the same cells sorted from WT mice, suggesting that AIM2 plays a negative role in the induction of type I IFN in vivo. Experiments in vitro confirmed that macrophages and dendritic cells from AIM2-, ASC-, or caspase-1-deficient mice produced substantially higher IFN-β in response to tumor-derived DNA. Biochemical analysis revealed that all steps in the STING pathway were enhanced in the inflammasome deficient cells: generation of cGAMP, aggregation of STING, and phosphorylation of TBK1 and IRF3. Studies investigating the biological mechanism by which activation of the AIM2 inflammasome inhibits the STING pathway revealed that pyroptosis induced by activation of the AIM2 inflammasome was critically involved. Pre-incubation with a caspase-1 inhibitor abolished cell death, and recovered a significant proportion of phosphorylation of TBK1/IRF3 and production of IFN-β. Our data suggest that the activation of AIM2 inflammasome inhibits the STING pathway mainly by cell death derived from the activation of the inflammasome. This crosstalk may have potential consequences for anti-tumor immunity which should be explored in vivo.

Citation Format: Leticia Corrales, Seng-Ryong Woo, Thomas F. Gajewski. Inhibition of the STING pathway by the AIM2 inflammasome. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr A173.
Abstract A174: Mechanistic elucidation of activation-induced deaminase (AID) in immunity and cancer
Authors: Qiao Qi , Wang Li , Meng Feilong , Wu Hao
Published: May 2016

Activation-induced cytidine deaminase (AID) plays a critical role in human immune system. It initiates both somatic hypermutation (SHM) and class switch recombination (CSR) of immunoglobulin (Ig) genes and possibly performs destructive mutations on non-Ig genes, related in cancer generation and development. Due to the aggregation behavior and extremely low activity of AID protein in vitro, the molecular basis of its function is still unclear. Using protein engineer approach, we successfully produced fully functional monomeric human AID mutants with dramatically elevated activity in vitro and intact CSR ability in vivo. Biochemistry data showed structured DNA with single strands joint feature, like G-quadruplex or partially branched DNA, can provide 10-20 fold AID affinity and 50-100 fold deaminase activity, suggests such structure can perform as direct AID recruiters in vivo. AID self-assembly upon DNA binding was observed and likely to be important for CSR. Stable AID-DNA complexes were purified in constant stoichiometry. Using crystallography method, we solved structures of AID alone and in complex with different DNA components in atomic resolution. Analyze on substrate binding interface and potential self-oligomerization interface together with abundant assay results support a structure based AID targeting and processing model during CSR and potential AID recruiting mechanism in causing off-target mutations. For the first time, our study reveals a closer look at this mystery protein, and provides solid basis for further investigation in AID function in antibody production and related diseases.

Citation Format: Qi Qiao, Li Wang, Feilong Meng, Hao Wu. Mechanistic elucidation of activation-induced deaminase (AID) in immunity and cancer. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr A174.
Abstract A182: Zbtb7b is involved in the association of EBF1 enhancer to the nuclear lamina during early B cell commitment
Authors: Zhu Yina , Murre Cornelis
Published: May 2016

It is well established that E2A proteins activate the expression of tumor suppressors, EBF1, PAX5 and FOXO1, to promote the B cell fate. E2A and EBF1 are frequently mutated either by chromosomal translocations, point mutations or gene deletions in B-cell precursor acute lymphoblastic leukemia. However, it remains an enigma why EBF1 is not transcribed in multipotent progenitors, in which E2A is expressed at high levels. It has been shown that, by HiC and 3D-fluorescence in situ hybridization (3D-FISH), in multipotent progenitors the EBF1 locus was located at the nuclear lamina, in pro-B cells the EBF1 locus was located away from the lamina. In this study, using gain-of-function approaches, we show that enforced Zbtb7b expression inhibited B cell differentiation and caused rapid loss of EBF1 and Pax5 mRNA. Notably, Using 3D-FISH, we found enforced expression of Zbtb7b sequestered EBF1 locus to the nuclear lamina, and using live cell imaging, we show that, Zbtb7b primarily localized at nuclear lamina. We are now investigating whether and how the nuclear envelope and its interaction with the genome change during early B cell commitment using Damseq; and anti-Zbtb7b ChIP-seq provide fine mapping of potential interaction regions with nuclear lamina. These data indicate a novel role of Zbtb7b in B cell lineage commitment and potentially link EBF1 and Zbtb7b into a common pathway. Experiments are ongoing to further examine how sequestration of genes to the nuclear lamina relates to the development of lymphoid cells.

Citation Format: Yina Zhu, Cornelis Murre. Zbtb7b is involved in the association of EBF1 enhancer to the nuclear lamina during early B cell commitment. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr A182.
Abstract B004: The importance of quality standards to support test performance for the purpose of treatment decision making
Authors: Midha Anita , Walker Jill , Rebelatto Marlon C. , Sabalos Costi , Mistry Amita , Schechter Nicole
Published: May 2016

The role of PD-L1 as a patient selection biomarker is emerging, with clinical outcome data from numerous studies demonstrating enrichment of responders. PD-L1 expression as a continuous variable measured via IHC presents a number of challenges to the clinical community including: 1) the relevant expression levels for treatment decision making 2) how well the cut-off can be deployed routinely in the clinical setting and 3) the lack of a ‘gold standard’ that establishes PD-L1 truth, and against which assays in development can compare.

To fully determine the clinical utility of PD-L1 as a predictor of response, it is critical to first remove concerns that relate to test performance. During companion diagnostic development, the assay undergoes a comprehensive analysis of performance and evaluation in the population of intended use. Prior to pre market approval (PMA), the assay must demonstrate that it meets the criteria for safe and effective use as determined through statistically relevant acceptance criteria established by the sponsor.

Following commercialisation of the assay, performance is assessed in the real world setting through various external quality assurance schemes with the goal of reducing inter-laboratory variation and establishing assay standardisation. The latter is critical to the maintenance of test quality and ensuring patient care.

We will present a detailed overview of the quality standards observed for IHC-based companion diagnostic approvals. Previously approved PMA and cleared 510(k) assay summaries of safety and effectiveness data (SSED) will be reviewed. Published EQA Quality assessments will be compared to data obtained from SSED. Set against this is the quality level that has been achieved with the Ventana SP263 PD-L1 assay.

Citation Format: Anita Midha, Jill Walker, Marlon C. Rebelatto, Costi Sabalos, Amita Mistry, Nicole Schechter. The importance of quality standards to support test performance for the purpose of treatment decision making. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr B004.
Abstract B008: Design and development of a novel series of PI3K-p110beta/delta-selective inhibitors with combined tumor immunotherapeutic, growth inhibition, and anti-metastatic activity
Authors: Shuttleworth Stephen J.
Published: May 2016

The phosphatidylinositide 3-kinases (PI3Ks) have emerged as important therapeutic targets for the treatment of solid and hematological malignancies. In solid tumor therapy, the majority of clinical activity has centered on pan-class I (p110alpha, beta, delta and gamma) inhibitors of limited selectivity, or pan-class I/mTOR dual inhibitors, whereas targeting p110delta and p110gamma has been the main focus for hematological cancer treatment. Our research at Karus has focused on the emerging role of p110beta and p110delta in both cancer types, though increasingly in solid tumors, in which overexpression, mutation and PTEN-defectiveness have been shown to be key features in disease pathogenesis and progression. We have designed and developed a uniquely-selective series of orally-active molecules that inhibit the p110beta/delta isoforms, and which display extremely high specificity in the human kinome. The design of such molecules has enabled us to interrogate the function of p110delta in solid tumor immunotherapy and p110beta in primary tumor growth and metastasis, with our lead compounds showing promising oral activity in syngeneic models, in which they inhibit tumor growth and metastatic spread whilst also impacting on downstream biomarker levels. Additionally, through our ability to tune selectivity over p110alpha and p110gamma, elimination of the mechanism-related toxicities associated with those isoforms can be realized, making selective dual p110beta/delta inhibition, described herein for our lead compound, KA2237, potentially more conducive to combination therapy than for pan-inhibitors, including with signal transduction pathway inhibitors and other immunotherapeutics. KA2237, an orally-active, potent and selective small molecule p110beta/delta inhibitor, has completed GLP toxicology and will enter Phase I studies in 2015.

Citation Format: Stephen J. Shuttleworth. Design and development of a novel series of PI3K-p110beta/delta-selective inhibitors with combined tumor immunotherapeutic, growth inhibition, and anti-metastatic activity. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr B008.