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

{"title":"Abstract A088: Selective blockage of the innate immune checkpoint receptor CD47 on mesothelin (MSLN) positive solid tumor cells via dual targeting bispecific antibodies alters the tumor microenvironment to control tumor growth","authors":"S. Majocchi, V. Moine, X. Chauchet, Lucile Broyer, L. Cons, L. Chatel, E. Hatterer, V. Buatois, H. Haddouk, Gérard Didelot, G. Magistrelli, Y. Poitevin, U. Ravn, A. Papaioannou, F. Richard, L. Shang, M. Kosco-Vilbois, N. Fischer, W. Ferlin, K. Masternak","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A088","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A088","url":null,"abstract":"Up-regulation of CD47 is an immune evasion mechanism used by different cancers to evade immune surveillance. Through its interaction with signal-regulatory protein alpha (SIRPα) on myeloid cells, CD47 delivers a universal “don’t eat me” signal to phagocytes, which prevents immune cells from efficiently eliminating tumor cells. Blockade of the SIRPα–CD47 innate immune checkpoint has therefore emerged as a new way to treat cancer. Several CD47-targeting molecules are in development with encouraging results obtained with monoclonal antibodies (mAb). However, the pharmacologic properties and the safety profile of molecules indiscriminately blocking CD47 can be improved by selectively inhibiting CD47 only on tumor cells. For this purpose, we generated bispecific antibodies (bsAbs) capable of targeting blockade of CD47 specifically to malignanT-cells through the co-engagement of a tumor-associated antigen (TAA). The bsAb NI-1801 specifically targets mesothelin (MSLN)-positive tumors. NI-1801 was shown to bind to MSLN-positive tumor cells, but not to MSLN-negative cells expressing physiologic levels of CD47 (e.g., leukocytes, erythrocytes, platelets). NI-1801 blocks the CD47-SIRPα interaction in a MSLN-dependent manner and thus minimizes the side effects related to a nonspecific blockade of CD47 on healthy cells. Studying antibody-dependent cellular phagocytosis (ADCP) and antibody-dependent cellular cytotoxicity (ADCC) of various MSLN-positive human tumor cell lines revealed that NI-1801 markedly enhanced killing as compared to amatuximab (an anti-MSLN mAb in clinical trials) and to the corresponding anti-MSLN mAb, exemplifying the role of blocking the “don’t eat me” signal to target cancer. NI-1801 also showed efficacy in various xenograft tumor models and analysis of the tumor microenvironment (TME) revealed a significant increase in leukocyte subpopulations (macrophages/monocytes and NK cells) of NI-1801 treated mice, suggesting that NI-1801 mediates the recruitment of monocytes from blood. Additionally, NI-1801 treatment affected the ratio between MHC-II-low and MHC-II-high macrophages in the TME. Finally, nonhuman primate studies with NI-1801 demonstrated a linear elimination profile, minimal target-mediated drug disposition and no hematologic toxicity. Taken together, these results illustrate that this strategy possesses potent anticancer activities both in vitro and in vivo in conjunction with favorable pharmacologic and toxicologic profiles. Citation Format: Stefano Majocchi, Valery Moine, Xavier Chauchet, Lucile Broyer, Laura Cons, Laurence Chatel, Eric Hatterer, Vanessa Buatois, Hasnaa Haddouk, Gerard Didelot, Giovanni Magistrelli, Yves Poitevin, Ulla Ravn, Anne Papaioannou, Francoise Richard, Limin Shang, Marie H. Kosco-Vilbois, Nicolas Fischer, Walter G. Ferlin, Krzysztof Masternak. Selective blockage of the innate immune checkpoint receptor CD47 on mesothelin (MSLN) positive solid tumor cells via dual targeting bispecific antibodies alters","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":"91205405","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 A101: IDO2 host genetic status influences progression and radiotherapy response in pancreatic ductal adenocarcinoma","authors":"G. Prendergast, A. Nevler, A. Muller, E. Sutanto‐Ward, J. DuHadaway, K. Nagatomo, Eric Londin, K. O'Hayer, J. Cozzitorto, H. Lavu, T. Yeo, M. Curtis, Tatiana M. Villatoro, B. Leiby, J. Winter, C. Yeo, J. Brody","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A101","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A101","url":null,"abstract":"Sporadic pancreatic ductal adenocarcinoma (PDAC) develops into a lethal disease that has remained refractory to different treatment approaches including recent advances in cancer immunotherapy. Variations in host genetic status affecting the inflammatory microenvironment can impact cancer susceptibility, malignant progression and clinical outcomes. In this study, we present genetic evidence from mouse and human genetic studies supporting a role for IDO2, an immunometabolic modifier of B cell-mediated autoimmune responses, in promoting pancreatic ductal adenocarcinoma (PDAC). In an established transgenic mouse model of KRAS-induced pancreatic cancer, IDO2 genetic inactivation markedly reduced malignant progression. In retrospective clinical analyses of PDAC patients (N=200), the biallelic occurrence of either of two inactivating polymorphisms in the IDO2 coding region trended with favorable disease-free survival. In PDAC tissues, an inactive IDO2 host genotype corresponded with changes in expression of genes involved in tryptophan catabolism and immune modulation, along with a reduced neutrophil to lymphocyte ratio. Notably, subset analysis revealed a striking association of inactive IDO2 status with improved disease-free survival in patients who had received adjuvant radiotherapy, a treatment modality that has been highly debated due to its variable efficacy in patients. Accordingly, our findings suggest that host IDO2 genetic status may offer a simple incisive marker to stratify PDAC patients who stand to gain the most from adjuvant radiotherapy, addressing the long-standing debate of its benefits. Citation Format: George C. Prendergast, Avinoam Nevler, Alexander J. Muller, Erika Sutanto-Ward, James B. DuHadaway, Kei Nagatomo, Eric Londin, Kevin O9Hayer, Joseph A. Cozzitorto, Harish Lavu, Theresa P. Yeo, Mark Curtis, Tatiana Villatoro, Benjamin E. Leiby, Jordan M. Winter, Charles J. Yeo, Jonathan R. Brody. IDO2 host genetic status influences progression and radiotherapy response in pancreatic ductal adenocarcinoma [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 A101.","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":"90395981","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 A087: The immunosuppressive property of mesenchymal stem cell in an apoptotic tumor microenvironment","authors":"A. Li, C. J. Cao, G. C. Chan","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A087","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A087","url":null,"abstract":"Mesenchymal stem cells (MSCs) are a heterogeneous population of multipotenT-cells and are capable of differentiating into certain cell types. They can be found within tumor core and constitute part of the tumor microenvironment. Their role in tumor progression remains contradictory with both sides arguing pro- and anti-tumor function. In regarding to the pro-tumor effect, MSCs have shown to have immunoregulatory properties—suppressing T lymphocytes, B lymphocytes and dendritic cells, thereby helping tumor cells to escape from the immune surveillance. However there are some studies that showed certain microenvironment and stimulation can drive MSC into a proinflammatory phenotype. During cancer therapy, large amount of apoptotic cells are released to the tumor microenvironment. The aim of this study is to investigate how an apoptotic microenvironment can affect the function of MSC on naive T-cells. Apoptotic cells (ACs) were derived from the neuroblastoma cell line SK-N-LP treated with cisplatin for 24 hr; they were then co-cultured with the immortalised human MSC cell line (hTMSC). Naive T-cells were isolated from peripheral blood mononuclear cells of healthy donors and further co-cultured with either hTMSC alone or AC-treated hTMSC (hTMSC-AC) for 5 days. Cell proliferation and phenotype were analyzed by flow cytometry. We demonstrated that hTMSCs have the ability to phagocytose AC. After engulfment, the hTMSC-AC were able to increase T-cell proliferation compared to those co-cultured with untreated hTMSC. The T-cells co-cultured with hTMSC-AC also showed a decrease in CD45RA expression, suggesting an increase in T-cell activation. Moreover, these T-cells had a higher expression level of interferon-gamma (IFN-γ) and a lower expression of FoxP3, indicating a shift towards proinflammatory effector T-cells and a reduction of regulatory T-cells. Consistent with other literature, hTMSC has the ability to supress T-cells’ activation and proliferation. However in the presence of AC, hTMSC immunosuppressive property was impeded, thereby heightening the immune response. Therefore the microenvironment can play a major factor in determining the role of MSC on tumor. Further investigation of the interaction of MSC with immune cells in an apoptotic tumor microenvironment can lead to a potential immunotherapy for neuroblastoma. Citation Format: Anita K.Y. Li, Carmen J.M. Cao, Godfrey C.F. Chan. The immunosuppressive property of mesenchymal stem cell in an apoptotic 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 A087.","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":"84530801","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 A084: Towards combining androgen deprivation and immunotherapy to prevent progression to castration-resistant prostate cancer","authors":"J. Krolewski, K. Sha, M. Mastri, D. Tang, K. Eng, K. Nastiuk","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A084","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A084","url":null,"abstract":"Most prostate cancer (PCa) deaths are due to castration-resistant PCa (CRPC), following failure of androgen-deprivation therapy (ADT). ADT is the standard of care for patients with advanced PCa. However, nearly universal progression to castration-resistant prostate cancer (CRPC) occurs 2-3 years after ADT is initiated. Although there have been recent improvements in the treatment of CRPC, even the most promising therapies are still not curative. One approach to this problem is to improve the initial treatment of advanced prostate cancers, by combining complementary therapies with ADT, to prevent progression of such advanced cancers to CRPC. Immunotherapy with checkpoint inhibitors (CPIs) has not been effective in prostate cancers, perhaps because such cancers are “cold” (lacking cytolytic CD8 T-cells). Some cold tumors may be caused by infiltration of myeloid cell populations (tumor associated macrophages and myeloid-derived suppressor cells) into the tumor immune cell microenvironment (TIME). Recently, we found that in a PTEN-deficient mouse PCa model, castration induces an immunosuppressive state within the tumor that is concurrent with tumor recurrence. The response to castration/ADT is tri-phasic: a pro-apoptotic regression phase when tumor shrinks, followed by selection for a residual population of resistant tumor cells and finally recurrent growth as CRPC. Using PCa cell lines to model the first two phases of the response to ADT, we have shown that ADT induces apoptosis, thereby enriching for an ADT-resistant stem/progenitor population that we propose is the in vivo source of TNF. Mechanistically, in our model system the response to ADT is driven by the soluble mediators TNF and CCL2, which facilitate communication within the TIME. Specifically, a TNF-CCL2-CCR2 paracrine loop is induced between prostate cancer cells and non-tumor cells in the microenvironment: TNF produced by tumor cells acts on myofibroblasts to induce CCL2 production, which in turn recruits CCR2+ tumor-associated macrophages (TAMs). To investigate the ADT response within the TIME in an in vivo model of prostate cancer, we employed a prostate-specific PTEN-deficient mouse model (PbCre4 x PTENf/f). Castration caused the tumors to regress, consistent with initial phase of the response that is seen in the human disease. At late times post-castration (5-6 weeks), corresponding to the selection phase, we observed a coordinate increase in the stem/progenitor tumor cell population, as well as TNF and CCL2, within the TIME. Immunohistochemical staining of tumors 5 weeks post-castration revealed an increase in TAMs, and a decrease in CD8 T-cells, consistent with an immunosuppressive or immunoevasive state. This phenotype was reversed by a soluble receptor that binds TNF (etanercept). We also observed increased myeloid-derived suppressor cells (MDSC). Thus, following ADT, TNF derived from an ADT-resistant stem/progenitor epithelial tumor cell population promotes an immunosuppressive","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":"85988936","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 A111: Effects of ionizing radiation on brain metastasis-associated inflammation and its implication for immunotherapy","authors":"Michael Schulz, Katja Niesel, Anna Salamero Boix, Woongjoo Chae, Birgitta E. Michels, A. Schaeffer, Maja I. Strecker, T. Alekseeva, S. Stein, H. Farin, F. Roedel, P. Harter, K. Plate, L. Sevenich","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A111","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A111","url":null,"abstract":"Brain metastases represent the most common intracranial tumor in adults associated with poor prognosis and median survival of only a few months. Despite current success in the development of targeted or immuno-therapies against different cancer entities, those strategies are ineffective against brain metastases. Hence, treatment options for brain metastasis patients largely remain limited to surgical resection and radio- and/or chemotherapy. This paucity can in part be attributed to the immune-privileged status of the brain where the blood brain-barrier restricts the entry of blood-borne immune cells. However, recent insights into the immune landscape of primary brain cancers indicate that tumor progression leads to an infiltration of blood-borne immune cells into the brain. We employ a comprehensive set of experimental brain metastasis models to characterize the immune landscape of brain metastases from different primary cancer entities at distinct disease stages and in response to radiotherapy. Our data indicate that brain metastases induce massive infiltration of myeloid and lymphoid cell populations into the central nervous system. This leads to the establishment of a dynamic and highly complex tumor microenvironment that affects tumor progression and therapy response. Fractionated whole-brain radiotherapy leads to enhanced infiltration of blood-borne myeloid and lymphoid cells. Transcriptome analysis of brain-resident and recruited myeloid cells indicate a switch from a proinflammatory towards an immune-suppressive environment at advanced disease stages. Importantly, radiotherapy was found to induce gene signatures that are associated with proinflammatory innate immune responses that could revert the establishment of an immune-suppressive environment. Consequently, radiotherapy might sensitize brain metastases towards immuno-therapies. Our goal is to identify pathways or molecular targets that are induced by radiotherapy in the tumor microenvironment to overcome resistance against immuno-therapy. In this project, we seek to test strategies to maintain or induce proinflammatory immune responses for improved targeted or immuno-therapies against brain metastasis. Citation Format: Michael Schulz, Katja Niesel, Anna Salamero Boix, Woon Hyung Chae, Birgitta Michels, Alexander Schaeffer, Maja Strecker, Tijna Alekseeva, Stefan Stein, Henner Farin, Franz Roedel, Patrick Harter, Karlheinz Plate, and Lisa Sevenich. Effects of ionizing radiation on brain metastasis-associated inflammation and its implication for 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 A111.","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":"87051765","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 A119: Combating primary and secondary checkpoint blockade resistance using immunostimulatory CD40L/4-1BBL-encoding oncolytic virotherapy for melanoma","authors":"J. Wenthe, Mantas Šilanskas, E. Eriksson, A. Loskog","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A119","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A119","url":null,"abstract":"In recent years, cancer immunotherapies significantly advanced the clinical management of metastatic melanoma. In particular, treatment with immune checkpoint inhibitors increased survival rates compared with standard therapy. However, not all patients benefit from checkpoint blockade. Primary treatment resistance is connected to poor T-cell infiltration in the tumors. This can be due to limited activation of antigen-presentation cells such as dendritic cells (DCs) and the high threshold of activating low-affinity T-cells that may respond to the tumor antigens. CD27 signaling in T-cells during activation lowers the T-cell receptor signaling threshold, which may be important to activate tumor-targeting T-cells. Secondary resistance to checkpoint blockade therapy includes loss of MHC-I on the tumor cells. Hence, inducing natural killer (NK) cell activation in parallel to antitumor T-cells may be crucial. LOAd703 was designed to optimize antitumor immune activation. LOAd703 is an oncolytic adenovirus (serotype Ad5/35) carrying two immunostimulatory transgenes; a trimerized membrane-bound CD40 ligand (TMZ-CD40L) and the full-length 4-1BB ligand (4-1BBL) (patent filed: PCT/EP2015/057489). The viral replication is restricted to tumor cells with a hyperphosphorylated retinoblastoma pathway due to a deletion in E1A, but transgenes are expressed under the control of a cytomegalovirus (CMV) promoter, which enables transgene expression even in the surrounding tumor microenvironment. Herein, we investigated LOAd703 in a melanoma model and its immunostimulatory effect on DC maturation to induce antigen-specific T-cell responses. LOAd703 infected the human melanoma cell line 526-mel and efficiently induced tumor cell death as evaluated by MTS viability assay. The viability of infected cells was reduced to 15% at 72 hours post infection compared to uninfected cells. Transgene expression of both TMZ-CD40L and 4-1BBL was confirmed by flow cytometry post infection. To evaluate the immunostimulatory capacity of LOAd703, immature DCs were differentiated from CD14+ monocytes using granulocyte-macrophage colony-stimulating factor and interleukin-4 and infected with virus. LOAd703-infected DCs upregulated the expression of maturation markers, such as CD83, CD86 and MHC molecules as analyzed by flow cytometry. Interestingly, CD70 that is required for CD27 stimuli of T-cells was highly upregulated on the DCs using LOAd703. Furthermore, the chemokine receptor CCR7 and the adhesion molecule ICAM-1 were increased upon LOAd703 infection, which are crucial for lymph node homing and the initiation of a systemic response. Next, the functional capacity of LOAd703-matured DCs to induce antigen-specific T-cell responses was assessed in a CMV model, in which CMV-peptide pulsed DCs are utilized to induce expansion of CMV-specific T-cells. LOAd703-matured DCs from CMV+ donors were pulsed with CMV-peptide and co-cultured with autologous peripheral blood mononuclear cells for 11 days. ","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":"84024287","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 A063: Multidimensional cytometric analysis of colorectal cancer reveals novel and diverse mediators of antitumor immunity","authors":"N. Miranda, N. D. Vries, V. V. Unen, T. Abdelaal, M. Ijsselsteijn, R. V. D. Breggen, A. Fariña-Sarasqueta, K. Peeters, T. Höllt, B. Lelieveldt, F. Koning","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A063","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A063","url":null,"abstract":"Checkpoint blockade has revived the potential of immunotherapy for cancer treatment. For optimal application and development of cancer immunotherapies, a comprehensive understanding of the antitumor immune response is required. We unraveled local and systemic immune profiles of colorectal cancer by multidimensional mass cytometric analysis of 36 immune cell markers at the single-cell level in tumor tissues, tumor-associated lymph nodes, adjacent normal mucosa, and peripheral blood samples from CRC patients. We identified 218 phenotypically distinct immune cell clusters, including a previously neglected innate lymphoid cell (CD7+CD3-CD127-CD45RO+CD56+) population with cytotoxic potential. This subset demonstrated a tissue-resident (CD69+, CD103+) phenotype, and was most abundant in the immunogenic mismatch repair deficient (MMRd) cancers. Furthermore, tumor-resident immune cell populations were identified across the adaptive (CD4+ and CD8+) and innate (gammadelta) T-cell compartments showing a highly similar activated (HLA-DR+, CD38+, PD-1+) phenotype. PD-1 intermediate and PD-1 high CD8+ T-cell subsets represented distinct states of T-cell activation that further discriminated immunogenic from non-immunogenic colorectal cancers. Remarkably, activated gammadelta T-cells were specific for MMRd cancers, and their potential role in the response to PD-1 checkpoint blockade requires further clarification. The nonactivated counterparts of the tumor-resident CD103+PD-1+ cytotoxic and gammadelta T-cells were present in both tumor and healthy colorectal tissues. We did not detect any of the aforementioned tumor-resident immune cell populations in lymph node samples, with the exception of a tumor-positive lymph node. This indicates that the critical immune cell populations with antitumor activity reside in the colorectal mucosa, and that the role of lymph nodes in the antitumor immune response should be revisited. Finally, by applying imaging mass cytometry we demonstrated that the cytotoxic anti-tumor response in colorectal cancer is highly diverse and not restricted to cytotoxic T-cells, which opens new avenues for the management of this disease.The findings presented here advance the paradigm of antitumor immunity in colorectal cancer and provide a blueprint for the detailed characterization of the involved immune cell subsets. The coordinated action of innate and adaptive immune cell populations suggests a multitargeted exploitation of their antitumor properties in a therapeutic setting. Citation Format: Noel F. de Miranda, Natasja L. de Vries, Vincent van Unen, Tamim Abdelaal, Marieke E. Ijsselsteijn, Ruud van der Breggen, Arantza Farina-Sarasqueta, Koen C.M.J. Peeters, Thomas Hollt, Boudewijn P.F. Lelieveldt, Frits Koning. Multidimensional cytometric analysis of colorectal cancer reveals novel and diverse mediators of antitumor immunity [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translat","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":"88073481","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 A055: Lineage–tracing reveals a unique contribution of embryonic macrophages to NSCLC progression","authors":"M. Casanova","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A055","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A055","url":null,"abstract":"Macrophages are the professional phagocytes of the innate immune system required to remove cellular debris and maintain tissue homeostasis. However, they can also play a role in the pathophysiology of many diseases. In non-small-cell lung carcinoma (NSCLC), macrophages constitute one of the major leukocyte subsets founds in tumors and contribute to immunosuppression by releasing growth factors, inhibiting immune T-cell surveillance, and enhancing angiogenesis, among other mechanisms. Importantly, macrophages in the lung can arise from embryonic or from adult hematopoietic precursors derived from the bone marrow (BM). This dual source of phagocytes has long been ignored and their contribution to tumor progression and response to immunotherapy has remained largely unexplored. Here we propose to analyze the role of macrophages during early and late stages of NSCLC. Using lineage-tracing murine models, tumor spheroids, and high-dimensional techniques to capture macrophage heterogeneity within the lesions (scRNAseq), we found that embryonic macrophages are progressively excluded from the tumor mass, whereas BM-derived ones are evenly distributed. Depletion of embryonic macrophages in a pretumor implantation setting diminishes tumor size and metastasis and leads to an increase in T-cell infiltration and antitumor activity, whereas elimination of tissue-resident macrophages post-tumor implantation does not impact tumor burden or immunity. Importantly, early human NSCLC lesions (stage I) show reduced macrophage infiltrates within the tumor microenvironment, which correlate with poor T-cell infiltration. Our findings suggest that macrophage ontogeny plays a pivotal role in tumor immunity. In this context, we aim to develop novel immunotherapies that harness embryonic macrophages to prevent tumor progression during early phases of lung cancer. Citation Format: Maria Casanova. Lineage–tracing reveals a unique contribution of embryonic macrophages to NSCLC progression [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 A055.","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":"91073134","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 A115: Use of angiotensin system inhibitors is associated with immune activation and longer survival in pancreatic ductal adenocarcinoma patients","authors":"Nilesh P. Talele, Hao Liu, K. Naxerova, M. Pinter, J. Incio, Hang Lee, Kohei Shigeta, William W. Ho, T. Michelakos, T. Hong, Jeffrey W. Clark, Janet E. Murphy, D. Ryan, V. Deshpande, K. Lillemoe, C. F. Castillo, M. Downes, R. Evans, J. Michaelson, D. Duda, C. Ferrone, Yves Bouches, R. Jain","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A115","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A115","url":null,"abstract":"Purpose: Angiotensin system inhibitors (ASIs) can improve prognosis in multiple cancer types, including pancreatic ductal adenocarcinoma (PDAC). However, no study has examined the effect of ASIs alone or combined with adjuvant chemotherapy in resected PDAC patients. Experimental Design: We performed an analysis of the records of ASI users and non-user patients with PDAC seen at Massachusetts General Hospital between January 2006 and December 2010. To identify mechanisms of ASIs in PDAC, we performed RNA-Seq of resected primary lesions. In a prospective trial (NCT01821729), we investigated circulating biomarkers of losartan activity. Results: 794 consecutive patients were included. In 299 resected patients, ASI-users experienced longer overall survival (OS) in both univariate (median OS: 36.3 vs. 19.3 months, p=0.011) and adjusted multivariate (HR, 0.505; 95%CI, 0.339 - 0.750; p=0.001) analyses. Propensity score adjusted analysis also showed a longer median OS for chronic ASI users. In unresected patients, the beneficial effect of ASIs was significant in patients with locally advanced disease, but not in metastatic patients. RNA-Seq analysis revealed in tumors of ASI-users (lisinopril) a normalized extracellular matrix, a reduced expression of genes involved in PDAC progression (e.g., WNT and Notch signaling) and an increased expression of genes linked with the activity of T-cells and antigen-presenting cells. Finally, chronic use of ASI was associated with a gene expression signature that is predictive of survival in independent validation cohorts. Circulating biomarker data will be presented at the meeting. Conclusions: In patients with non-metastatic PDAC, chronic ASI use is associated with longer OS independently of chemotherapy. Our RNA-Seq analysis suggests that ASI reduce the malignant potential of cancer cells and stimulate the immune microenvironment in primary PDAC. Citation Format: Nilesh P. Talele, Hao Liu, Kamila Naxerova, Matthias Pinter, Joao Incio, Hang Lee, Kohei Shigeta, William W. Ho, Theodoros Michelakos, Theodore S. Hong, Jeffrey W. Clark, Janet E. Murphy, David P. Ryan, Vikram Deshpande, Kieth D. Lillemoe, Carlos Fernandez-del Castillo, Michael Downes, Ronald M. Evans, James Michaelson, Dan G. Duda, Cristina R. Ferrone, Yves Bouches, Rakesh Jain. Use of angiotensin system inhibitors is associated with immune activation and longer survival in pancreatic ductal adenocarcinoma patients [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 A115.","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":"83533993","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 A113: Harnessing lymphoid organ neogenesis as a novel prognostic biomarker and therapeutic target","authors":"K. Silina, A. Soltermann, Chiara Burkhardt, Farkhondeh Movahedian Attar, R. Casanova, A. Curioni-Fontecedro, H. Moch, F. Posch, T. Winder, N. V. Dijk, C. Voskuilen, M. S. Heijden, M. Broek","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A113","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A113","url":null,"abstract":"Lymphoid organ neogenesis takes place in chronically inflamed tissues including cancer and yields the development of tertiary lymphoid structures (TLS). TLS are ectopic lymphoid organs that activate antigen specific T-cells and B cells in infection and autoimmunity and correlate with prolonged survival in various cancer types. This suggests that TLS contribute to protective anti-tumor immunity. Therefore, promoting the development of tumor-associated TLS could be a novel immunotherapeutic approach. However, the molecular and cellular mechanisms of TLS development in human cancer or how TLS contribute to survival are largely not understood. Here we used multiparameter immunofluorescence and digital pathology to quantify TLS and to characterize their cellular composition and tissue context in cohorts of lung squamous cell carcinoma (LSCC, n=138), colorectal cancer (CRC, n=111), clear cell renal cell carcinoma (ccRCC, n=50) and bladder cancer (BC, n=33) patients. Furthermore, we established an experimental model to characterize TLS development and its impact on tumor-specific immunity. We discovered that TLS development and maturation followed the same steps in all analyzed tumor types as well as in the lungs of mice in our experimental model. First, B and T lymphocytes accumulated around blood vessels. Second, a network of follicular dendritic cells developed within the lymphocytic aggregate, and third, a germinal center (GC) reaction was activated. Additionally, we identified a niche of CXCL13+ perivascular stroma and CXCL12+LTB+ and PD-L1+ epithelial cells that were associated with TLS in LSCC. We found that the number of tumor-associated TLS was an independent prognostic factor for prolonged survival in untreated LSCC, CRC and BC, but not in ccRCC patients or in LSCC and BC patients who were treated with neoadjuvant chemotherapy. By comparing the chemotherapy-treated and untreated cohorts we observed that the number of TLS was not changed but TLS maturation (i.e. GC formation) was significantly impaired after chemotherapy. This difference was at least partially dictated by corticosteroids, which are commonly used to treat the side effects of chemotherapy of LSCC patients. We further studied the mechanisms underlying TLS development using the experimental model. We identified a combination of stimuli that induces the development of mature TLS in the lungs of mice. Besides inflammatory stimuli, a foreign antigen was necessary to achieve a significant increase in TLS numbers and maturation stage, suggesting that cognate interactions are crucial for lymphoid organ neogenesis. This is further supported by our observation that CRC patients with microsatellite instability, which presumably results in more neoantigens, had an increased proportion of mature TLS. The negative impact of corticosteroids on TLS development was confirmed in this model. In summary, we propose that GC+ TLS represent the relevant TLS phenotype contributing to survival in differe","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":"72650445","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}