Tackling the Tumor Microenvironment: Beyond T-cells最新文献

{"title":"Abstract A069: NIM15 blockade – A new stroma-targeting approach for the treatment of epithelial ovarian cancer","authors":"D. Ferber, M. Suarez-Carmona, F. Momburg, Marten Meyer, Rebecca Rothenheber, B. Lenoir, S. Schott, I. Zoernig, D. Jäger, N. Halama","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A069","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A069","url":null,"abstract":"Despite the immense research over the past decade in the cancer immunology field, which has led to several clinical trials and FDA and EMA approvals of biologicals for the reinvigoration of T-cell-mediated cancer cell killing in diverse tumor entities, the long-term survival of patients with advanced epithelial ovarian cancer is still devastating. These results therefore imply the need for a more intensive investigation of the tumor microenvironment in this cancer type in order to enhance disease outcome and improve the effectiveness of current immunotherapeutics. We herein show for the first time efficacy data of a novel treatment approach for the specific targeting of the stromal tumor compartment in a human tissue explant culture model of high-grade serous ovarian cancer. Antibody-mediated blockade of NIM15, a protein suspected to be predominantly expressed by tumor-associated macrophages and cancer-associated-fibroblasts in ovarian cancer, has the potential to polarize the immune landscape in a subset of patients from a stromal-dense and immunosuppressive one into a Th1-M1-supportive microenvironment, as measured by cytokine pattern analyses and semiautomated immune cell quantification. Abrogating the effects of secreted NIM15 unleashes in vitro proliferation of T-cell subsets and increases the production of cytokines and chemokines involved in innate and adaptive antitumor immune responses in our tissue culture explant model. In order to unravel the mechanistic relations behind the observed effects, we plan further experiments to prove whether these might be due to a disruption of the collagen-dense tumor stroma and a repolarization of the secretory profile of tumor-associated macrophages and fibroblasts. In summary, we hope to develop a pharmacologic tool that converts immune-depleted, “cold” cancer types into T-cell infiltrated ones and therewith provide a rationale for combination treatment approaches, like anti-PD1 blockade or adoptive cell transfer, to further ameliorate the so far poor response of metastasized, refractory ovarian cancer. Citation Format: Dyke Ferber, Meggy Suarez-Carmona, Frank Momburg, Marten Meyer, Rebecca Rothenheber, Benedicte M.A. Lenoir, Sarah Schott, Inka Zoernig, Dirk Jager, Niels Halama. NIM15 blockade – A new stroma-targeting approach for the treatment of epithelial ovarian cancer [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr A069.","PeriodicalId":22141,"journal":{"name":"Tackling the Tumor Microenvironment: Beyond T-cells","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74817347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstract A050: Intratumoral delivery of a novel STING agonist synergizes with checkpoint blockade to regress multifocal pancreatic cancer","authors":"C. Ager, M. D. Francesco, Philip D. Jones, M. Curran","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A050","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A050","url":null,"abstract":"Immunosuppressive myeloid populations including tumor-associated macrophages (TAM) and myeloid-derived suppressor cells (MDSC) are abundant within pancreatic adenocarcinoma (PDAC) tumors and play critical roles in constraining cytotoxic T-cell function in the tumor microenvironment. We hypothesized that intratumoral engagement of innate pathogen recognition receptors such as Stimulator of Interferon Genes (STING) could induce proinflammatory polarization of the myeloid stroma and liberate the antitumor T-cell response to regress refractory PDAC tumors in the presence of checkpoint blockade.We developed and characterized a novel cyclic dinucleotide (CDN) STING agonist IACS-8803, and found that 8803 activates downstream STING signaling in both human (THP-1) and murine (J774) myeloid reporter cells with over 10-fold greater potency than ML-RR-S2-CDA, the first-in-class CDN currently undergoing clinical evaluation (NCT02675439, NCT03172936). Intratumoral delivery of 8803 into subcutaneous B16 melanoma and PDAC tumors additionally revealed a greater capacity to induce tumor regression relative to ML-RR-S2-CDA. In order to evaluate the specific effects of 8803 on the phenotype and function of suppressive myeloid populations, we generated in vitro polarized human M2 macrophages and murine bone marrow-derived MDSC. Upon exposure to 8803, we observe downregulation of M2 markers CD163, LAP/TGF-β, and Arginase on human M2 macrophages, concomitant with upregulation of M1 markers CD86, CD80, and IL-6. Additionally, 8803-stimulated murine MDSC exhibit reduced T-cell suppressive capacity compared to unstimulated MDSC. In these studies, we consistently observe that the magnitude of phenotypic and functional repolarization by 8803 is superior to that of ML-RR-S2-CDA as well as other known CDN, 2’3’-cGAMP and c-di-GMP. Therefore, we describe IACS-8803 as a novel, highly potent STING agonist with the capacity to induce inflammatory repolarization in suppressive myeloid cells of both human and murine origin. We next investigated the capacity for intratumoral delivery of IACS-8803 to sensitize murine pancreatic cancer to checkpoint blockade and to mobilize systemic immunity against disseminated lesions. We utilized mT4-2D, a novel pancreatic cancer cell line from Kras+/LSL-G12D Tp53+/LSL-R172H Pdx1-Cre tumor organoids. We isolateda single cell clone of mT4-2D with reduced in vivo growth kinetics (termed mT4-LS), as well as a clone that maintains the aggressive nature of the parental line (termed mT4-LA). Mice bearing 10-day established orthotopic and subcutaneous mT4-LS tumors received standard regimens of αCTLA-4, αPD-1, or combined αCTLA-4/αPD-1 in the presence or absence of 8803 CDN injected into the orthotopic pancreatic tumor. We find single-agent treatment with 8803, αCTLA-4, αPD-1, or αCTLA-4/αPD-1 can cure 40-60% of mice of both orthotopic and subcutaneous tumors in this system; however, combining 8803 with checkpoint blockade completely eradicates both injec","PeriodicalId":22141,"journal":{"name":"Tackling the Tumor Microenvironment: Beyond T-cells","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79559243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstract A066: Expanding insights into the colorectal cancer tumor proteome; unbiased protein profiling reveals multiple proteomic-based tumor subtypes","authors":"N. Dupuis, J. Muntel, R. Bruderer, L. Reiter","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A066","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A066","url":null,"abstract":"Introduction: Recent approvals of microsatellite instability (MSI) or mismatch repair (MMR) testing, in addition to PD-L1 expression, expand the tools available to identify tumor characteristics that may help predict the likelihood of patient response to immunotherapy treatment. However, even in MSI positive subgroups, not all subjects achieve a durable response and research continues to identify tumor characteristics that further predict the likelihood of patient response. To support and advance this area of research, new tools are being developed that provide deeper and unbiased views of the tumor proteome. Here, we characterize the protein expression profiles of 95 colorectal cancer tumors (CRC) using SWATH acquisition mass spectrometry (SWATH MS) to further probe tumor phenotypic characteristics. Experimental Methods: FFPE colon tissue samples (10 healthy, 95 cancer) were obtained from commercial biobanks. Proteins were extracted from the tissue, processed to peptides with trypsin, and prepared for LC-MS analysis. Peptides for each sample were injected on a Triart C18 column (YMC) coupled to a NanoLC 425 system (SCIEX) using a 43min gradient at a flow rate of 5µl/min. The eluted peptides were then analyzed with a TripleTOF® 6600 system (SCIEX) operated in SWATH mode. Total run time per sample was 1 hour. Data were analyzed in Spectronaut Pulsar X (Biognosys) with a project specific library. All data were filtered with a 1% FDR on peptide and protein level. Results: Across all samples, >4,500 protein groups were quantified (approximately 3,600 per sample). Data analysis revealed a large number of proteins (~1,000) were differentially expressed in the cancer cohort. Consistent with increased tumor cell proliferation, proteins involved in protein translation were upregulated in the tumor samples. Unsupervised clustering of the data separated the healthy and the cancer cohort. Clustering also revealed three main proteomic subtypes within in the cancer cohort (A, B and C), which were largely distinguished by expression of cell adhesion proteins, including neuronal growth regulator 1 (NEGR1), a potential tumor suppressor. Interestingly, hepatocyte nuclear factor 4-alpha (HNF4A), a transcription factor which is known to be elevated in CRC, was only overexpressed in subtype B. Further analysis of key protein networks related to CRC treatment and immunotherapy development will be presented. Conclusions: High-throughput proteomic profiling of FFPE tissues using SWATH-MS enables the deepest phenotypic characterization of tumor tissue. Ultimately, analyses of this type will enable a functional understanding of interplay between the tumor microenvironment, expression of protein networks and response to immune-directed therapies. Citation Format: Nicholas Dupuis, Jan Muntel, Roland Bruderer, Lukas Reiter. Expanding insights into the colorectal cancer tumor proteome; unbiased protein profiling reveals multiple proteomic-based tumor subtypes [abstract]. In: ","PeriodicalId":22141,"journal":{"name":"Tackling the Tumor Microenvironment: Beyond T-cells","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79750649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstract A109: Matrix metalloproteinase-2 stimulates Toll-like receptor-2 on melanoma cells to induce immunosuppressive inflammation in the tumor microenvironment","authors":"Mansi Saxena, Keerthi Caroline Sadanala, L. Muniz-Bongers, N. Bhardwaj","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A109","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A109","url":null,"abstract":"Extracellular proteinases, such as matrix metalloproteinases (MMPs), support tumor progression through modulation of the tumor microenvironment (TME). MMP-2, in particular, is overexpressed in several cancers and high MMP-2 levels are associated with advanced tumor stages, increased dissemination and poorer survival/prognosis. Our lab has previously demonstrated that upon antigenic stimulation, MMP-2-specific CD4+ T-cells, derived from patients with melanoma, secrete inflammatory TH2 cytokines. We subsequently showed that active MMP-2 drives the differentiation of TH2 responses by inhibiting IL-12 production and up-regulating OX40L expression on dendritic cells (DCs). We published our novel discovery identifying MMP-2 as a ligand for TLR-2 and showed that MMP-2 mediated TLR-2 stimulation lead to up-regulation OX40L on DCs (Cell Reports 2014). This is particularly interesting as TLR-2 stimulating adjuvants are being tested for immunotherapy. However, the full spectrum of how TLR-2 activation affects tumor cells or immune cells remains unclear.The main purpose of this study is to characterize the role of TLR-2-MMP-2 axis in shaping the TME through its influence on tumor cells and tumor infiltrating immune cells. Towards this end we performed RNA sequencing to identify genes induced in human DCs upon MMP-2 stimulation. One of these targets is an atypical member of the canonical NFκB family, IkappaBzeta (NFKBIZ or IκBζ). We show that MMP-2 secreted by melanoma cells upregulates IκBζ in DCs through TLR-2 and promotes secretion of Th2 and Th17 inducing cytokines. Furthermore, we screened several human melanoma cell lines for high and low MMP-2 and TLR-2 expression. CRISPR/Cas9 technology was used to stably knock out TLR-2, TLR-4 and MMP-2 in tumor cell lines. Early data indicates a role for tumor cell intrinsic MMP-2 in promoting secretion of protumorigenic cytokines and chemokines from tumor cells that support immune evasion and tumor growth, both constitutively and upon TLR-2 stimulation. Moreover, IκBζ was found to positively regulate MMP-2 dependent protumorigenic inflammation. In summary, we have identified a novel role for MMP-2 as a TLR-2 alarmin with particular emphasis on induction of atypical signaling modulator IκBζ and have uncovered a new role for MMP-2 in modulating tumor cell-induced inflammation. Taken together, our previous research and current data indicate that MMP-2 acts simultaneously as an endogenous T-cell differentiation \"conditioner\" and a tumor-associated antigen. Therefore, delving into MMP-2 signaling mechanisms in the TME holds a strong potential for discovering novel therapeutic options for treating melanoma. Citation Format: Mansi Saxena, Keerthi Caroline Sadanala, Luciana Rebiero Muniz-Bongers, Nina Bhardwaj. Matrix metalloproteinase-2 stimulates Toll-like receptor-2 on melanoma cells to induce immunosuppressive inflammation in the tumor microenvironment [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR Intern","PeriodicalId":22141,"journal":{"name":"Tackling the Tumor Microenvironment: Beyond T-cells","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79326731","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstract A097: Complement system mutations in cancer: Uncovering new relationships between tumor hypoxia and complement","authors":"M. Olcina, N. Balanis, Ryan K. Kim, M. Thompson, T. Graeber, A. Giaccia","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A097","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A097","url":null,"abstract":"The complement system has been proposed to facilitate cancer hallmarks such as increased metastatic potential, proliferation and apoptosis evasion. Despite the association between complement and tumor progression, a detailed characterization of cancer genetic alterations in the complement system has not been performed to date. Here, we report a number of previously unappreciated mutations in complement system genes. Taken together as a pathway, mutations in complement genes occur at a relatively high frequency and across a number of cancer types. Notably, when grouping complement mutations into functionally relevant subgroups according to gene function, mutations and copy number alterations in genes within these subgroups are associated with changes in overall survival outcomes in a range of cancers. We use specific complement component mutations in colorectal cancer to uncover and experimentally validate crosstalk between complement and hypoxia, providing new associations between this innate immunity pathway and a prevalent component of the tumor microenvironment. Our data highlight the complex mechanism employed by cancers to manipulate the innate immune system and point to the potential use of complement system mutations in successful patient stratification into clinically and biologically relevant groups. Citation Format: Monica M. Olcina, Nikolas G. Balanis, Ryan K. Kim, Michael J. Thompson, Thomas G. Graeber, Amato J. Giaccia. Complement system mutations in cancer: Uncovering new relationships between tumor hypoxia and complement [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr A097.","PeriodicalId":22141,"journal":{"name":"Tackling the Tumor Microenvironment: Beyond T-cells","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89539039","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstract A054: Tumor cell intrinsic factors dictate immune cell infiltration and response to immunotherapy","authors":"Katelyn T. Byrne, Jinyang Li, R. Vonderheide, B. Stanger","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A054","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A054","url":null,"abstract":"The establishment of immune heterogeneity in the tumor microenvironment (TME) is poorly understood, despite recent data that the success of immunotherapies is dictated by the immune environment of the tumor site. Pancreatic ductal adenocarcinoma (PDA) is characteristically devoid of CD8 T-cells and resistant to therapeutic intervention. However, a small subset of patients (15%) have tumors highly infiltrated by CD8 T-cells, correlating with improved overall survival. To better elucidate the determinants of immune heterogeneity in the PDA TME, we generated clones from spontaneous tumors harvested from KrasG12D+/-;Trp53R172H+/-;Pdx-1 Cre (KPC) mice, a genetically engineered mouse model of PDA. Using a panel of 17 tumor clones, we found the clones segregated in to two groups with differential immune cell infiltration upon implantation in congenic C57BL/6 mice. 7/17 tumor clones were categorized as “T-cell high,” with an immune infiltrate comprising CD8 T-cells and CD103+ dendritic cells (DCs). In contrast, the remaining 10 tumor clones were categorized as “T-cell low” lines, with the TME dominated by myeloid cells and macrophages, especially granulocytic myeloid-derived suppressor cells. Hypothesizing that increased T-cell infiltrate would render PDA sensitive to therapy, we treated two T-cell high and two T-cell low tumor clones with combination immunotherapy. Mice bearing T-cell high clones responded to therapy (7/7 and 4/7 mice cured) and formed protective memory responses against secondary tumor challenge, while none of the mice bearing T-cell low tumors responded to treatment (0/7 and 0/7 mice cured). At baseline, T-cell high tumors had similar proportions of functional CD8 T-cells as in T-cell low tumors. However, the proportion of activated CD44hiPD-1+ CD8 T-cells was significantly increased in T-cell high tumors (62.2% vs. 35.1% in T-cell low clones, p Citation Format: Katelyn T. Byrne, Jinyang Li, Robert H. Vonderheide, Ben Stanger. Tumor cell intrinsic factors dictate immune cell infiltration and response to immunotherapy [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr A054.","PeriodicalId":22141,"journal":{"name":"Tackling the Tumor Microenvironment: Beyond T-cells","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85228412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstract A060: Targeting glioma-macrophage interplay via LOX in PTEN-deficient glioblastoma","authors":"Peiwen Chen, Alan Wang, R. DePinho","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A060","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A060","url":null,"abstract":"Glioblastoma multiforme (GBM) is the most lethal form of brain cancer in adults. The median survival of GBM patients is only about one year after initial diagnosis. Genomic profiling has stratified GBM into various subgroups, which are driven by specific genetic alternations of core signaling pathways, including RTK/RAS/PI3K/PTEN, P53/ARF/MDM2 and RB/CDKN2A pathways. However, targeted therapies, such as therapy against EGFR, have failed in the clinic, and no effective therapeutic drugs are available to target tumor suppressors. A key reason for therapeutic failure is inter- and intra-tumoral cancer cell genetic instability and heterogeneity, resulting in aberrant activation of multiple signaling pathways within and across tumors. Stromal/immune cells in the tumor microenvironment (TME) are genetically stable, which not only play a pivotal role in GBM progression by affecting multiple cancer hallmarks, but can also be educated by cancer cells. However, whether and how the behavior and function of specific stromal/immune cells in the TME are regulated by cancer cell with specific genetic alterations in GBM remain relatively undefined. Utilizing a large scale of bioinformatic analysis in TCGA GBM patients, we revealed that genetic alteration (deletion/mutation) of PTEN in GBM patients specifically triggers immune response by promoting macrophage recruitment, without affecting macroglia and other immune cells. Using unbiased transcriptome profiling following functional validation, we identified that lysyl oxidase (LOX) is preferentially secreted by PTEN-deficient cancer cells. In vitro transwell migration assay and in vivo Matrigel Plug assay demonstrated that LOX is a potent macrophage chemoattractant. Transcriptome profiling following Gene Set Enrichment Analysis (GSEA) and functional validation demonstrated that activation of SRC and AKT signaling pathways drives LOX upregulation in PTEN-deficient cancer cells. Genetic and pharmacologic inhibition of LOX in PTEN-deficient cancer cells does not affect tumor cell proliferation in vitro, but markedly inhibits macrophage density and tumor growth in vivo. Using the bioinformatics analysis in clinical GBM samples, we demonstrated that LOX is enriched in GBM patients with higher macrophage density, and that these patients show lower survival. Together, our findings highlight the significance of PTEN-LOX axis in macrophage infiltration in GBM, and demonstrate a possibility of improving GBM treatment by targeting this axis-mediated macrophage recruitment. Citation Format: Peiwen Chen, Alan Wang, Ronald DePinho. Targeting glioma-macrophage interplay via LOX in PTEN-deficient glioblastoma [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr A060.","PeriodicalId":22141,"journal":{"name":"Tackling the Tumor Microenvironment: Beyond T-cells","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91345935","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstract A099: Using high-throughput phenotypic screening to identify therapeutic targets for the inhibition of myeloid-derived suppressor cells","authors":"E. Petrova, Sandra Schäffner, J. Pieck, C. Herhaus, F. Rippmann, Oliver Pöschke, L. Helming","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A099","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A099","url":null,"abstract":"Myeloid-derived suppressor cells (MDSC) are a heterogeneous population of immature myeloid cells with immunosuppressive function, which inhibit the antitumor activity of T-cells and natural killer (NK) cells. MDSC number is greatly increased in tumor-bearing mice and in cancer patients, and in the clinic, MDSC accumulation is associated with cancer progression, recurrence, and poor response to chemo-, radio- and immunotherapies. The increasing evidence for the clinical significance of MDSC has triggered a strong interest in the therapeutic modulation of their function. To date, however, limited progress has been made in this direction, as a major challenge in the field remains the identification of suitable therapeutic targets for the development of novel drugs. Here, we describe a systematic approach in which a small-molecule high-throughput phenotypic screen was used to identify MDSC targets and pathways of therapeutic relevance. This screen was based on a validated in vitro mouse mononuclear MDSC (M-MDSC) model, in which hematopoietic progenitors, immortalized using a NUP98/HOXB4 transgene, were differentiated into immunosuppressive MDSC. Using this model, we developed a 384-well-based phenotypic screening assay, in which the suppressive effect of mouse M-MDSC on CD8+ T-cell proliferation and cytokine secretion was monitored. We screened a small molecule library, comprising 5000+ biologically active compounds with known target(s), and identified 116 compounds that potently disrupted MDSC suppression of T-cell function. With the help of chemoinformatics methods, reported target activities associated with the compounds were annotated, and a set of targets and pathways of potential significance for MDSC-driven immunosuppression was identified. Altogether, this work provides insight into the signaling nodes that could be of relevance for MDSC function, and offers a path forward for the therapeutic targeting of MDSC. Citation Format: Elissaveta Petrova, Sandra Schaffner, Jan-Carsten Pieck, Christian Herhaus, Friedrich Rippmann, Oliver Poschke, Laura Helming. Using high-throughput phenotypic screening to identify therapeutic targets for the inhibition of myeloid-derived suppressor cells [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr A099.","PeriodicalId":22141,"journal":{"name":"Tackling the Tumor Microenvironment: Beyond T-cells","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86185365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstract IA09: Harnessing natural and engineered properties of NKT cells for cancer immunotherapy","authors":"A. Heczey, Amy N. Courtney, Ho Ngai, Gengwen Tian, S. Robinson, G. Dotti, L. Metelitsa","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-IA09","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-IA09","url":null,"abstract":"Due to their natural anti-tumor properties and ability to preferentially localize to the neuroblastoma (NB) tumor site, Vα24-invariant natural killer T cells (NKTs) are promising candidate immune effectors for chimeric antigen receptor (CAR)-based immunotherapies targeting NB and other solid tumors. We have previously demonstrated that human NKTs expressing a CAR specific for ganglioside GD2 (CAR.GD2) mediated potent anti-tumor activity in a xenogeneic NB model in NOD/SCID/IL-2Rγnull mice. In comparison with CAR.GD2 T cells, CAR.GD2 NKTs localized more effectively to the tumor tissues and did not induce graft-versus-host disease (GvHD). Clinical development of NKT cell-based therapeutics requires overcoming two fundamental challenges: 1) the low frequency of NKTs in human peripheral blood, and 2) the limited ability of adoptively transfered NKTs/CAR-NKTs to persist in tumor-bearing animals. To address the first limitation, we have developed a cGMP protocol to isolate NKT cells from leukapheresis products using NKT-specific magnetic beads with the CliniMAX® system (Miltenyi). Isolated NKTs then undergo stimulation with CD1d-expressing antigen-presenting cells pulsed with α-galactosylceramide, retroviral transduction with a CAR-expressing vector, and rapid numeric expansion in cytokine-supplemented culture. This protocol routinely produces more than 109 CAR-NKTs within 17 days with average NKT cell purity and CAR expression of 96% and 54%, respectively. To overcome the second limitation, we incorporated the primary NKT homeostatic cytokine, IL-15, into the CAR.GD2 construct and evaluated its ability to enhance NKT cell in vivo persistence and therapeutic efficacy. Following adoptive transfer into mice bearing human NB xenografts, NKTs expressing CAR.GD2 were undetectable by three weeks whereas CAR.GD2/IL-15 NKTs underwent progressive expansion at sites of NB metastasis, reaching 32% of bone marrow cells two months after a single injection. Treatment with CAR.GD2/IL-15 NKTs resulted in a median survival of 70 days versus 48 days for mice treated with CAR.GD2 NKTs (P Citation Format: Andras Heczey, Amy N. Courtney, Ho Ngai, Gengwen Tian, Simon N. Robinson, Gianpietro Dotti, Leonid S. Metelitsa. Harnessing natural and engineered properties of NKT cells for cancer immunotherapy [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr IA09.","PeriodicalId":22141,"journal":{"name":"Tackling the Tumor Microenvironment: Beyond T-cells","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81423731","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstract PR10: Reprogramming myeloid cells in TME with pepinemab, first-in-class semaphorin 4D MAb, enhances combination immunotherapy","authors":"E. Evans, H. Bussler, C. Mallow, C. Reilly, Sebold Torno, Maria Scrivens, Alan P. Howell, Leslie Balch, J. Leonard, T. Fisher, C. Allen, Paúl E. Clavijo, Gregory Lesiniski, Christina Wu, S. Hu-Lieskovan, A. Ribas, Emily G Greengard, Ernest S. Smith, M. Zauderer","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-PR10","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-PR10","url":null,"abstract":"Purpose: Tumor growth inhibition by anti-semaphorin 4D (SEMA4D, CD100) blocking antibody is enhanced when combined with various immunotherapies in preclinical animal models. Immune checkpoint combinations with pepinemab (VX15/2503), a humanized anti-SEMA4D antibody, are currently being evaluated in several clinical trials. Methods: Expanded mechanistic studies in syngeneic preclinical models investigated the effect of SEMA4D blockade on immune contexture within the tumor microenvironment, as a single agent and in combination with various immunotherapy agents. Antitumor activity and immune response was characterized by immunohistochemistry, flow cytometry, functional assays, and cytokine, chemokine and gene expression analysis. Pepinemab (VX15/2503) is currently being evaluated as single agent or in combination with other immunotherapies in four clinical trials: (i) a phase 1b/2a combination trial of pepinemab with avelumab in NSCLC (CLASSICAL-Lung) (NCT03268057); (ii) a phase 1 combination trial of pepinemab with nivolumab or ipilimumab in melanoma patients who have progressed on any anti-PD-1/PD-L1 (NCT03373188); (iii) a neoadjuvant integrated biomarker trial in patients with metastatic colorectal and pancreatic cancers treated with pepinemab in combination with nivolumab or ipilimumab (NCT03373188); and (iv) a phase 1/2 trial of pepinemab in children with solid tumors and children and young adults with osteosarcoma (NCT03320330). Results: SEMA4D exerts multifaceted effects within the tumor microenvironment by creating a barrier at the tumor-stroma margin to restrict immune cell infiltration and promoting immunosuppressive activity of myeloid-derived cells. Blocking antibody to SEMA4D directly enhanced M1/M2 ratio and both reduced expression of chemokines that recruit MDSC and the ability of MDSC to suppress T-cell proliferation. Antibody blockade reduced the function of immunosuppressive myeloid and regulatory T-cells in the TME while simultaneously restoring the ability of dendritic cells and cytotoxic T-cells to migrate into the tumor in several syngeneic tumor models. Importantly, anti-SEMA4D MAb enhanced the activity of co-administered immunotherapies in murine colon, head and neck (HNSCC), and melanoma models. For example, anti-SEMA4D plus anti-CTLA-4 resulted in 100% survival and 90% complete tumor rejection (CR) (p Citation Format: Elizabeth E. Evans, Holm Bussler, Crystal Mallow, Christine Reilly, Sebold Torno, Maria Scrivens, Alan Howell, Leslie Balch, John E. Leonard, Terrence L. Fisher, Clint Allen, Paul Clavijo, Gregory Lesiniski, Christina Wu, Siwen Hu-Lieskovan, Antoni Ribas, Emily Greengard, Ernest S. Smith, Maurice Zauderer. Reprogramming myeloid cells in TME with pepinemab, first-in-class semaphorin 4D MAb, enhances combination immunotherapy [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphi","PeriodicalId":22141,"journal":{"name":"Tackling the Tumor Microenvironment: Beyond T-cells","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74387619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}