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

{"title":"Abstract A076: DSP107—a novel SIRPα-4-1BBL dual signaling protein (DSP) for cancer immunotherapy","authors":"Y. Gozlan, S. Hilgendorf, A. Aronin, Yehudith Sagiv, Liat Ben-gigi-Tamir, S. Amsili, A. Tamir, I. Pecker, Shirley Greenwald, A. Chajut, A. Foley-Comer, Y. Pereg, A. Peled, M. Dranitzki-Elhalel, E. Bremer","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A076","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A076","url":null,"abstract":"Background: The (re)activation of anticancer innate and adaptive immunity is at the forefront of developments in cancer therapy. Here, we report on a new immunotherapeutic fusion protein, termed Dual Signaling Protein 107 (DSP107). DSP107 was designed to combine activation of innate and adaptive immunity, by both blocking CD47/SIRPα interaction and activating 4-1BB. CD47 is overexpressed on cancer cells and upon binding to SIRPα on phagocytes transmits a “don’t eat me” signal, thereby suppressing innate immunity. 4-1BB is a costimulatory receptor that is transiently upregulated on tumor-infiltrating T-cells and is considered a surrogate marker for the tumor-reactive T-cell population. Activation of 4-1BB using its ligand or by agonistic antibodies reactivates anti-cancer T-cell immunity. In DSP107, the extracellular domains of SIRPα and 41BBL have been fused, yielding a dual function protein. DSP107 is produced as a homotrimer due to the trimerization property of 41BBL, an essential element for activating the 41BB receptor, a member of the TNF super-family of receptors. DSP107 was designed to bind to CD47 on tumor cells, thereby removing the inhibitory signal delivered to phagocytes. Simultaneously, CD47-mediated surface immobilization of DSP107 enables delivery of the 41BBL-4-1BB costimulatory signal to tumor localized T-cells. This dual immunomodulatory effect of DSP107 is designed to unleash both innate and adaptive immune responses targeted to the tumor site. Methods and Results: Trimeric DSP107 was successfully produced in a mammalian expression system. Both sides of DSP107 bound their cognate counterparts in kinetic Blitz binding assays and on human tumor and immune cell surfaces. The binding affinity of DSP107 was 1.6 nM for human CD47 and 0.69 nM for human 4-1BB as determined using BIAcore analysis. DSP107 blocked the interaction of SIRPα with CD47 in an ELISA-based competition assay (EC50 of 0.03 nM). DSP107 induced granulocyte- and macrophage-mediated phagocytosis of several lymphoma, leukemia and carcinoma cell lines in vitro. Further, DSP107 treatment triggered phagocytosis of primary AML cells by autologous macrophages. Co-treatment with DSP107 and therapeutic tumor-targeting antibodies, i.e., rituximab or cetuximab, resulted in enhanced phagocytosis of lymphoma or carcinoma cells, respectively. In a reporter assay measuring IL-8 secretion upon binding to/activation of 4-1BB, DSP107 activated 4-1BB signaling only in the presence of CD47-expressing cells. Further, DSP107 augmented the activation of purified T-cells activated by suboptimal concentrations of αCD3 + IL2 or αCD3/αCD28 Dynabeads in CD47 coated plates, as measured by percentage of CD25 expressing cells (up to 3-fold). When PBMCs were co-cultured with or without CD47-expressing cancer cells and stimulated with suboptimal concentrations of αCD3 + IL2, DSP107 treatment resulted in increased secretion of IFNg up to 2-fold), and increased T-cell proliferation (up to 2-fold). Con","PeriodicalId":22141,"journal":{"name":"Tackling the Tumor Microenvironment: Beyond T-cells","volume":"304 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79798023","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 A100: ROBO2 is a stroma suppressor gene in the pancreas through regulation of TGF-β","authors":"Andreia V. Pinho, M. V. Bulck, L. Chantrill, M. Arshi, D. Herrmann, C. Vennin, A. Gill, P. Timpson, A. Biankin, Jianmin Wu, I. Rooman","doi":"10.1158/2326-6074.cricimteatiaacr18-a100","DOIUrl":"https://doi.org/10.1158/2326-6074.cricimteatiaacr18-a100","url":null,"abstract":"Pancreatic ductal adenocarcinoma (PDAC) has a dismal prognosis, being predicted to become the second leading cause of cancer-related death by 2030. Chronic pancreatitis is a risk factor for PDAC and both diseases are characterized by a strong desmoplastic response, comprised of activated myofibroblasts and immune cell infiltrates. Genomic aberrations in the SLIT-ROBO pathway are frequent in PDAC. Nevertheless, their role in the pancreas is unclear. We have used an integrative approach combining the study of murine models and PDAC patients with the objective of unraveling the function of the SLIT-ROBO signaling pathway in pancreatic disease. RNA expression of SLIT-ROBO genes was analyzed in murine normal pancreas, pancreatitis and PDAC. Primary cell cultures and experimental pancreatitis were studied using pancreas-specific Robo2 (Pdx1-Cre;Robo2F/F) and whole-body Slit1 (Slit1-/-) knockout mice. Gene and protein expression were assessed in a cohort of PDAC patients (n=109). In mouse pancreatitis and PDAC, epithelial Robo2 expression is lost while Robo1 expression becomes most prominent in the stroma. Pdx1Cre;Robo2F/F pancreatic cell cultures showed increased activation of Robo1-positive myofibroblasts and induction of TGF-β and Wnt pathways. Likewise, induction of pancreatitis in Pdx1Cre;Robo2F/F mice enhanced myofibroblast activation, collagen crosslinking, T-cell infiltration and tumorigenic immune markers. Similar results were obtained using Slit1-/- animals. Moreover, TGF-β inhibition using galunisertib treatment suppressed Robo2-mediated effects in the microenvironment. In patients, ROBO2 expression is overall low in PDAC, while ROBO1 is variably expressed in epithelium and high in the stroma. ROBO1 expression is correlated with markers of activated stroma, Wnt and TGF-β pathways. ROBO2low;ROBO1high subpopulation of patients present the poorest survival rates. In conclusion, Robo2 acts nonautonomously as a stroma suppressor gene by restraining myofibroblast activation and inflammation in the pancreatic microenvironment. ROBO1/2 expression is prognostic in PDAC patients and may guide therapy with TGF-β inhibitors or immunotherapies, currently being tested in clinical trials for advanced pancreatic cancer. Citation Format: Andreia V. Pinho, Mathias Van Bulck, Lorraine Chantrill, Mehreen Arshi, David Herrmann, Claire Vennin, APGI - Australian Pancreatic Cancer Genome Initiative, Anthony Gill, Paul Timpson, Andrew Biankin, Jianmin Wu, Ilse Rooman. ROBO2 is a stroma suppressor gene in the pancreas through regulation of TGF-β [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 A100.","PeriodicalId":22141,"journal":{"name":"Tackling the Tumor Microenvironment: Beyond T-cells","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85074994","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 A065: Genome-scale CRISPR screens identify essential genes for tumor sensitivity to NK cells","authors":"O. Dufva, J. Klievink, K. Saeed, M. Kankainen, Mette Ilander, Tiiina Hannunen, S. Lagström, P. Ellonen, Dean Anthony Lee, S. Mustjoki","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A065","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A065","url":null,"abstract":"Harnessing natural killer (NK) cells to attack tumors could improve immune-based cancer treatment strategies. However, mechanisms regulating sensitivity or resistance of cancer cells to the effector function of NK cells are incompletely understood. Here, we performed genome-scale CRISPR-Cas9 loss-of-function screens in human cancer cells to discover genes that influence susceptibility to primary human NK cells. To screen for genes essential for the interaction between NK cells and cancer cells, we infected human cancer cells expressing Cas9 with a genome-scale lentiviral guide RNA library. The resulting pool of knockout cells was exposed to NK cells expanded from peripheral blood of healthy donors. Enriched and depleted knockout clones were detected by next-generation sequencing of the integrated sgRNA cassettes, enabling identification of genes conferring resistance or susceptibility to NK cell-mediated lysis. The screens were performed in cell lines from diverse cancer types, including chronic myeloid leukemia (CML), B cell acute lymphoblastic leukemia, diffuse large B-cell lymphoma (DLBCL), and multiple myeloma. We recovered several known mechanisms of NK cell/cancer cell interactions, demonstrating feasibility of the screening approach. Loss of genes encoding components of the MHC class I complex (B2M, HLA-A, HLA-C, HLA-E) sensitized multiple cancer cell lines to NK cell-mediated lysis. This is consistent with missing-self recognition as a fundamental mechanism of NK cell activation. Furthermore, knockout of IFN-JAK-STAT signaling mediators led to increased tumor cell lysis, suggesting that MHC class I induction in response to NK cell-derived IFN gamma enables NK cell evasion by tumor cells. We also identified genes essential for effective NK cell-mediated lysis. NCR3LG1, encoding the B7-H6 ligand for the NKp30 activating NK cell receptor, was essential for NK cell lysis of CML cells. In contrast, knockout of apoptotic mediators and TRAIL pathway components conferred resistance to NK cell cytotoxicity in DLBCL cells, indicating heterogeneity in NK cell/cancer cell interactions between cancer types. Our data support a view that distinct mechanisms regulate sensitivity to NK cell cytotoxicity in different cancers. Importantly, our results indicate that loss-of-function mutations in the antigen-presenting machinery and the IFN-JAK-STAT pathway sensitize tumors to NK cell effector function. As alterations in these genes are associated with resistance to T-cell immunotherapies such as PD-1 blockade, NK cell-based therapies could be employed to overcome resistance in these patients. In summary, we suggest that systematic identification of mechanisms governing tumor immune susceptibility has the potential to uncover novel immunotherapy targets. Citation Format: Olli Dufva, Jay Klievink, Khalid Saeed, Matti Kankainen, Mette Ilander, Tiiina Hannunen, Sonja Lagstrom, Pekka Ellonen, Dean A Lee, Satu Mustjoki. Genome-scale CRISPR screens identify essenti","PeriodicalId":22141,"journal":{"name":"Tackling the Tumor Microenvironment: Beyond T-cells","volume":"46 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86597924","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 A053: Activated B cells in human primary tumors present antigen and increase antitumor function of CD4 T-cells in tertiary lymphoid structures","authors":"T. Bruno, A. Ruffin, A. Cillo, R. Ferris, D. Vignali","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A053","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A053","url":null,"abstract":"Immunotherapy, specifically anti-PD1, has improved patient survival in a range of tumor types including head and neck squamous cell carcinoma (HNSCC) and non-small cell lung cancer (NSCLC). Despite the success of anti-PD1 therapy, only 20% of patients produce a durable response to this treatment. Thus, a need exists to develop additional therapeutic strategies to treat these patients, which includes evaluation of other tumor-infiltrating immune cells that could further augment the CD8+ and CD4+ T-cell response. Tumor-infiltrating B cells (TIL-B) represent a possible target for immunotherapy due to their predominance in the tumor microenvironment (TME) and crucial role in the immune response. However, TIL-B function in cancer and in the context of immunotherapy has been understudied. In fact, conclusions on an anti- or protumor role for TIL-Bs in the TME is dependent on the study. However, in HNSCC and NSCLC patients, current evidence suggests an antitumor role for TIL-Bs. Specifically, detection of TIL-Bs within tertiary lymphoid structures (TLS) correlates with better prognosis. While TIL-Bs have been identified in HNSCC and NSCLC patients, their complete phenotypic signature and function in the TME has been understudied with no focus on their role as antigen presenting cells (APCs) and their influence on CD8+ and CD4+ tumor infiltrating lymphocytes (TILs). We hypothesize that TIL-Bs help generate potent, long-term immune responses against cancer by presenting tumor antigens to CD4 TILs within TLS.Using unmanipulated, primary human B cells from fresh tumor, we quantified and further characterized TIL-Bs in HNSCC and NSCLC utilizing single-cell RNAseq and multiparameter flow cytometry. We observed increased numbers of activated TIL-Bs in these primary tumors compared to other immune subsets, specifically CD27+ TIL-Bs. We further assessed the TIL-Bs by correlating phenotype of the TIL-B with its location in the TME, predominantly separating out differences between TIL-Bs within TLS and outside TLS. In addition, we generated a specific antigen presentation assay in vitro, and we observed three types of CD4+ TIL responses when TIL-Bs presented autologous tumor antigens. There were activated responder CD4+ TILs that proliferated when combined with TIL-Bs alone, which indicates stimulation with endogenous tumor antigens. There were antigen-associated responders that required exogenous autologous tumor lysate to elicit a CD4+ TIL response, and there were patient CD4 TILs that did not respond to antigen presentation by TIL-Bs. Within the activated and antigen-associated responders, the TIL-B phenotype influenced the CD4+ TIL phenotype; if the TIL-Bs were activated (CD27+), the CD4+ TILs were T helper (antitumor) CD4+ T-cells and if the TIL-Bs were non-activated (CD27-), the CD4+ TILs were T regulatory cells (protumor). These data suggest that TIL-Bs influence the phenotype and function of CD4+ TILs in patient tumors. In conclusion, activated TIL-Bs are ","PeriodicalId":22141,"journal":{"name":"Tackling the Tumor Microenvironment: Beyond T-cells","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86631772","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 A089: The effect of lactate dehydrogenase-A (LDH-A) knockdown and human prostate-specific membrane antigen (hPSMA) directed CAR T-cell treatment on hPSMA(+) Myc-CaP tumors","authors":"Mayuresh Mane, Khalid Shalaby, Ivan J. Cohen, Avi S. Albeg, Jenny N. Ijoma, M. Ko, Masatomo Maeda, K. Vemuri, J. Satagopan, A. Moroz, J. Zurita, L. Shenker, E. Ackerstaff, M. Shindo, Ekaterina Moroz, Maxim A. Moroz, I. Serganova, J. Koutcher, V. Ponomarev, R. Blasberg","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A089","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A089","url":null,"abstract":"Objective: Determine whether LDH-A knockdown enhances CAR T-cell tumor-targeting and treatment response.Background: It has been shown that T-cells are restricted from entering many human and murine solid tumors, including both murine and human prostate tumors. CD3(+) T-cells are restricted from Myc-CaP murine prostate tumors and localize around the periphery of the tumor nodules (1). Human prostate specific membrane antigen (hPSMA) targeted CAR T-cells are also restricted from hPSMA(+) Myc-CaP tumors and this is only partially reversed by anti-PD1 treatment (1). This report describes the benefit of LDH-A depletion and a greater response of CAR T-cells targeting Myc-CaP tumors with low expression of LDH-A. Methods: LDH-A depletion in hPSMA(+) Myc-CaP cells bearing a bioluminescence reporter (Renilla Luciferase), was achieved by shRNA knockdown (KD) (1). A scrambled IgG shRNA was used as a control (NC). LDH-A expression was quantified by digital droplet PCR (ddPCR), Western blotting and LDH enzyme activity. The glycolytic activity of KD and NC cells was measured using Seahorse XF96 and XFp analyzers. Intratumoral lactate levels were monitored by magnetic resonance spectroscopy (MRS). The preparation and characterization of “second generation” hPSMA-directed CAR T-cells and the hPSMA(+) Myc-CaP tumor models in SCID mice have been described (1). To monitor CAR T-cell trafficking, T-cells were transduced with a Click Beetle Red luciferase reporter to enable efficient visualization by bioluminescence imaging (BLI) of CAR T-cell trafficking, persistence and viability within the hPSMA(+)Myc-CaP tumor mass. Tumor volume was calculated from caliper measurements. CD31 and PD-L1 expression was quantified with immunofluorescent staining and Metamorph Offline image analysis. Results and Discussion: These studies demonstrated that LDH-A KD was the dominant factor in reducing tumor growth. The difference in tumor doubling time (DT) between KD and NC tumors in the presence of CAR T-cell therapy was significant (p Citation Format: Mayuresh M. Mane, Khalid Shalaby, Ivan Cohen, Avi Albeg, Jenny Ijoma, Myat Ko, Masatomo Maeda, Kiranmayi Vemuri, Jaya Satagopan, Anna Moroz, Juan Zurita, Larissa Shenker, Ellen Ackerstaff, Masahiro Shindo, Ekaterina Moroz, Maxim A. Moroz, Inna Serganova, Jason Koutcher, Vladimir Ponomarev, Ronald G. Blasberg. The effect of lactate dehydrogenase-A (LDH-A) knockdown and human prostate-specific membrane antigen (hPSMA) directed CAR T-cell treatment on hPSMA(+) Myc-CaP tumors [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 A089.","PeriodicalId":22141,"journal":{"name":"Tackling the Tumor Microenvironment: Beyond T-cells","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91130071","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 A056: Incessant ER stress responses promote dendritic cell dysfunction in ovarian cancer","authors":"Chang-Suk Chae","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A056","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A056","url":null,"abstract":"Harnessing the intrinsic ability of our immune system to recognize and eliminate malignanT-cells represents the most promising anticancer strategy since the development of chemotherapy. However, hostile microenvironmental conditions within aggressive solid tumors inhibit the optimal activity of protective immune cells. Targeting immunosuppression and re-programming immune cell function in the tumor microenvironment are thus fundamental requirements for developing successful cancer immunotherapies. Our CRI postdoctoral project aims at identifying, understanding and disabling the molecular mechanisms by which endoplasmic reticulum (ER) stress responses inhibit the natural function of dendritic cells (DCs) in the ovarian cancer microenvironment. The central hypothesis of this study is that ovarian tumors trigger ER stress and aberrant activation of the IRE1-XBP1 pathway in infiltrating DCs to cripple key immuno-metabolic processes and impede the development of protective T-cell responses. To determine how IRE1α-XBP1 overactivation defines regulatory DC phenotypes in the ovarian cancer microenvironment, metastatic ovarian tumors were developed in ER stress-Activated Indicator (ERAI) reporter mice. We found that DCs demonstrating IRE1 activation in the tumor microenvironment overexpress tolerogenic and immunosuppressive molecules. Next, to determine whether tumor-derived factors may affect DC metabolism, we optimized an ex vivo culture system that recreates the tumor microenvironment using malignant ascites samples from ovarian cancer patients. We treated human monocyte-derived DCs from healthy donors with patient-derived ovarian cancer malignant ascites supernatants and assessed the bioenergetic profile of DCs. Oxygen consumption rate (OCR), which measures mitochondrial respiration, ATP production and spare respiratory capacity, was increased in DCs exposed to ascites supernatants. We found that these metabolic changes upon ascites treatment relied on IRE1a-XBP1 pathway. Further, since therapeutic DC-based vaccines have shown limited effects in ovarian cancer patients, we tested the novel translational hypothesis that XBP1-deficient bone marrow-derived DCs (BMDCs) would be better equipped to endure and function in the tumor microenvironment when used as therapeutic vaccines. While adoptive transfer of WT BMDCs did not induce any therapeutic effect, treatment with XBP1-deficient BMDCs elicited a marked increase in overall host survival. This result suggest that compared with WT BMDCs, their XBP1-deficient counterparts were resistant to the immunosuppressive effects of the tumor microenvironment. Our results provide a unique mechanistic rationale for targeting the IRE1-XBP1 arm of the ER stress response as a potent approach to reprogram and enhance antitumor immune cell function in cancer. These findings should also pave the way for devising a new generation of cancer immunotherapies that may improve the dismal survival of >21,000 American women affect","PeriodicalId":22141,"journal":{"name":"Tackling the Tumor Microenvironment: Beyond T-cells","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88130813","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 A112: OncoPeptTUME: A novel computational approach analyzes the tumor microenvironment to predict response to checkpoint inhibitors","authors":"Xiaoshan Shi, M. Manoharan, Nitin Mandloi, S. Priyadharshini, L. Iyer, R. Gupta, Papia Chakraborty, Amitabha Chaudhuri, Ravi Gupta","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A112","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A112","url":null,"abstract":"Cancer immunotherapy is now an established treatment option for many cancers. Cancer immunotherapy boosts host antitumor immunity to provide long-term benefit; however, only a small fraction of the treated patients show a durable clinical response. The tumor microenvironment ecosystem, with its complex mixture of non-malignant and malignant cells, is a major contributor in regulating the response to checkpoint blockade and development of resistance. Ongoing efforts to characterize the tumor microenvironment to stratify patients for immunotherapy and find biomarkers of response often use methods that are limited by the availability of adequate tumor tissue from needle biopsy material and loss of tissue viability during sample processing that precludes the use of single-cell sequencing platforms. Therefore, genomic methods that use deconvolution to assess the relative proportion of different cell types and their phenotypes in the tumor microenvironment are desirable for clinical use. To this end, we have developed OncoPeptTUME, a novel computational approach that utilizes a proprietary minimal gene expression signature to assign immune scores for eight broad categories of immune cells present in the tumor microenvironment. To validate the approach, we used 9,640 TCGA gene expression datasets from 33 different tumors, defined their immune cell content, organized samples into clusters based on their immune cell content, and identified the molecular differences that predict survival in samples belonging to different clusters. We further performed a deeper analysis of samples enriched in infiltrating CD8+ T-cells to identify T-cell phenotype that correlated with a long-term survival benefit. A small set of genes associated with functional T-cell phenotype was used on a dataset of melanoma samples to show that higher expression of the genes discriminated responders from the nonresponders to nivolumab treatment. In conclusion, our analysis demonstrates that OncoPeptTUME is a powerful immunogenomic tool to predict patient prognosis, stratify patients who will benefit from cancer immunotherapy and identify pathways and novel biomarkers of long-term benefit from the use of cancer immunotherapy drugs. Citation Format: Xiaoshan Shi, Malini Manoharan, Nitin Mandloi, Sushri Priyadharshini, Laxman Iyer, Rohit Gupta, Papia Chakraborty, Amitabha Chaudhuri, Ravi Gupta. OncoPeptTUME: A novel computational approach analyzes the tumor microenvironment to predict response to checkpoint inhibitors [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 A112.","PeriodicalId":22141,"journal":{"name":"Tackling the Tumor Microenvironment: Beyond T-cells","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87399570","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 A114: Omental fat in ovarian cancer induces metabolic and immune alterations","authors":"M. Suarez-Carmona, N. Valous, P. Charoentong, Jakob Nikolas Kather, M. Hampel, B. Lenoir, D. Ferber, S. Schott, S. Kess, I. Zoernig, D. Jaeger, N. Halama","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A114","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A114","url":null,"abstract":"Epithelial ovarian cancer (EOC) is an immunogenic tumor entity, as evidenced by multiple correlative studies indicating the impact of intraepithelial tumor-infiltrating T lymphocyte (TIL) density on patient outcome. Immunotherapy trials have generated modest results so far and chemotherapy remains standard of care. In this study, we focus on EOC metastases invading the omentum. Our aim is to characterize their immune landscape with the goal of identifying specific targetable characteristics of these metastases, which are the most prevalent and relate to high morbidity.We used a cohort of 120 ovarian cancer specimens for histologic analysis, cytokine, or metabolic profiling. Furthermore, we developed an EOC tissue explant culture model and treated whole-tissue explants with drugs before assessing immune cell density, distribution, and activation status. Finally, we cultured macrophages isolated from patient-derived ascites to study their response to various treatments.Samples were classified into omental metastases and primary tumors (based on the presence of fat on histologic sections). We observed that omental metastases are characterized by an inflamed microenvironment orchestrated by macrophages and are infiltrated by high amounts of TILs with low expression of activation markers, and a skewed localization around fat patches. These TILs express high amounts of the tumor-supporting CCL5 chemokine. Macrophages storing fatty acids in the form of big vacuoles were found in these fatty tumors as well. Targeting macrophages using the CCR5 inhibitor maraviroc in whole tissue explants effectively restored T-cell distribution across the tissue and slightly affected macrophage polarization specifically in fat-containing tumors. Inhibiting fatty acid import in macrophages more dramatically affected the cytokine landscape, also specifically in fat-containing tumors, and established a Th1-supporting environment permeable to T-cell expansion and activation. In brief, omental metastases are characterized by: (a) a smoldering inflammatory reaction and high macrophage density, (b) increased T-cell accumulation around fatty areas away from cancer cells, and (c) T-cell exhaustion accompanied by CCL5 expression. Treatment of EOC explants revealed that macrophages infiltrating omental metastases can be repolarized in situ, leading to TIL expansion and activation. Citation Format: Meggy Suarez-Carmona, Nektarios A. Valous, Pornpimol Charoentong, Jakob N. Kather, Mareike Hampel, Benedicte M.A. Lenoir, Dyke Ferber, Sarah Schott, Sabine Kess, Inka Zoernig, Dirk Jaeger, Niels Halama. Omental fat in ovarian cancer induces metabolic and immune alterations [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 A114.","PeriodicalId":22141,"journal":{"name":"Tackling the Tumor Microenvironment: Beyond T-cells","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83003261","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 IA07: Using matrix protein affinity to modulate the tumor microenvironment","authors":"J. Ishihara, Ako Ishihara, Koichi Saskai, S. S. Lee, Mariko Yasui, Hiroyuki Abe, L. Potin, Peyman Hosseinchi, Kazuto Fukunaga, Michal M. Raczy, L. Gray, John-Michael Williford, M. Fukayama, Tiffany M. Marchell, A. Mansurov, A. T. Alpar, S. Kron, M. Swartz, J. Hubbell","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-IA07","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-IA07","url":null,"abstract":"Cancer immunotherapy with immune checkpoint inhibitors (CPI) and interleukin (IL)-2 has demonstrated clinical efficacy but is frequently accompanied with severe adverse events caused by excessive and systemic immune system activation. Here, we addressed this need by targeting both the CPI antibodies anti-cytotoxic T-lymphocyte antigen 4 antibody (CTLA4) + anti-programmed death-ligand 1 antibody (PD-L1) and the cytokine IL-2 to tumors via conjugation (for the antibodies) or recombinant fusion (for the cytokine) to a collagen-binding domain (CBD) derived from the blood protein von Willebrand factor (VWF) A3 domain, harnessing the exposure of tumor stroma collagen to blood components due to the leakiness of the tumor vasculature. We show that intravenously (i.v.) administered CBD protein accumulated mainly in tumors, for example 57% of total injected dose depositing in an orthotopic breast tumor model. The CBD was observed to localize throughout the tumor stroma, not merely in the subendothelial space. CBD conjugation or fusion decreased the systemic toxicity of both CTLA4+PD-L1 combination therapy and IL-2, for example eliminating hepatotoxicity with the CPI molecules and ameliorating capillary leak syndrome and pulmonary edema with IL-2. Both CBD-CPI and CBD-IL-2 significantly suppressed tumor growth compared to their unmodified forms in multiple murine cancer models, and both CBD-CPI and CBD-IL-2 increased tumor-infiltrating CD8+ T cells; increases in the ratio of effector CD8+ T cells to T regulatory cells were observed. In an orthotopic breast tumor model, combination treatment with CPI and IL-2 eradicated tumors in 9/13 animals with the CBD-modified drugs, whereas it did so in only 1/13 animals with the unmodified drugs. Thus, the A3 domain of von Willebrand factor can be used to engineer immunotherapies with high translational promise as systemically-administered tumor targeting drugs with improved safety and efficacy compared to their native forms. The targeting approach exploits vascular permeability in the tumor to render the ubiquitous extracellular matrix protein accessible in the tumor, while sparing most other tissues. Citation Format: Jun Ishihara, Ako Ishihara, Koichi Saskai, Steve Seung-Young Lee, Mariko Yasui, Hiroyuki Abe, Lambert Potin, Peyman Hosseinchi, Kazuto Fukunaga, Michal M. Raczy, Laura T. Gray, John-Michael Williford, Masashi Fukayama, Tiffany M. Marchell, Aslan Mansurov, Aaron T. Alpar, Stephen J. Kron, Melody Swartz, Jeffrey A. Hubbell. Using matrix protein affinity to modulate the tumor microenvironment [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 IA07.","PeriodicalId":22141,"journal":{"name":"Tackling the Tumor Microenvironment: Beyond T-cells","volume":"152 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79547561","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 A092: TAM receptors targeting unleashes antileukemic immunity and enables checkpoint blockade leading to eradication of leukemic cells","authors":"I. Tirado-González, A. Nevmerzhitskaya, Arnaud Descot, D. Soetopo, E. Członka, Maresa Weitmann, C. Wachtel, J. Slotta-Huspenina, Christine Tran-Quang, K. Götze, E. Alberto, C. Rothlin, J. Ghysdael, H. Medyouf","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A092","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A092","url":null,"abstract":"Background: TAM receptor tyrosine kinases—Tyro3, Axl and Mertk—and their ligands, Gas6 and Pros1, have been extensively studied for their cell-intrinsic pro-oncogenic function in cancer cells, including leukemia. However, much less is known about their indirect impact on tumor growth through their function as modulators of the immune system. In particular, no study has yet explored this aspect in the context of hematological malignancies. Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL) is the most aggressive human ALL subtype, in particular in adults, where it represents 30% of all ALL cases. The disease responds poorly to standard chemotherapy and has a very high risk of recurrence. Treatment relies on the use of a BCR-ABL1 tyrosine kinase inhibitor (TKI) with or without chemotherapy followed by an allogenic-SCT. Despite this intensive regimen a significant fraction (40%) of adult patients fails to achieve long-term disease-free survival, clearly pointing to an unmet clinical need. Methods: To explore the importance of TAM receptors and their ligands in the immune response against leukemia, we developed a very aggressive syngeneic model of Ph+ B-ALL. In this model, leukemia is driven by the expression of the fusion oncoprotein BCR-ABL1 and the loss of the Arf gene, often altered in human Ph+ ALL. Functional studies were carried out using small-molecule inhibitors and genetic mouse models. The latter allowed us to interrogate the importance of specific TAM receptors in defined immune cellular subsets. Lastly, we used pharmacologic inhibitors to explore the potential therapeutic benefit of targeting TAMR signaling alone or in combination with standard of care treatment (TKI) and checkpoint inhibitors. Results: Our study for the first time shows that Gas6, a high-affinity Axl ligand, promotes the establishment of an immune-suppressive milieu that contributes to the aggressive phenotype associated with Ph+ B-ALL. Importantly, Gas6 is not expressed by leukemic cells but rather produced by bone marrow associated stromal cells. Using genetic approaches, we demonstrate that Gas6 primarily acts through its high-affinity receptor, Axl, specifically on myeloid cells, to inhibit the anti-leukemic immune response. This immune-suppressive effect can be effectively blocked using an orally available selective Axl inhibitor or the genetic deletion of Axl in Csf1r expressing myeloid cells, leading to reduced leukemic burden and significantly prolonged survival of leukemia-challenged mice. In a subset of long-term survivors, progressive increase in PD1 expression limited the antileukemic effects associated with Axl deficiency, an effect that can be efficiently reverted by combination treatment with anti-PD1 checkpoint inhibitor.Mechanistically, the antileukemic effects promoted by Gas6/Axl blockade are mediated by an enhanced inflammatory response, followed by a potent adaptive immune response. This can be further potentiated by combinati","PeriodicalId":22141,"journal":{"name":"Tackling the Tumor Microenvironment: Beyond T-cells","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73622617","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}