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

{"title":"Abstract A094: Characterization of pancreatic cancer endothelial cells: Approach to enhance immune cell infiltration for immunotherapy","authors":"K. Nakajima, Y. Ino, T. Iwasaki, N. Hiraoka","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A094","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A094","url":null,"abstract":"The hurdles in realizing immunotherapy success for cure stem from the fact that cancer patients are either refractory to immune response and/or develop resistance. We previously proposed that these phenomena are due, in part, to the deployment of tumor-associated antigens, or employment of tumor-associated endothelium acting as a gatekeeper for immune cell infiltration into the cancer tissue (Nakajima et al, Cancer Res 2017;77:5441-4). Here, an extensive study unveiled functional/molecular differences of endothelium derived from pancreatic cancer and normal pancreas. They were isolated from fresh surgical specimen by magnet-based selection. The primary culture of tumor-associated endothelial cells was confirmed by double positive expressions of endothelial markers, CD31 and ERG1. They showed the short vessel formations and the narrow area of capillary network, indicating the low potential of angiogenesis. Further, peripheral blood–derived lymphocytes were less adhering to the tumor-associated endothelial cells. To find the molecular differences, microarray analysis was performed, and identified 2748 molecules distinct from endothelial cells of noncancerous tissues (p Citation Format: Kosei Nakajima, Yashunori Ino, Toshimitsu Iwasaki, Nobuyoshi Hiraoka. Characterization of pancreatic cancer endothelial cells: Approach to enhance immune cell infiltration 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 A094.","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":"82085679","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 A048: Targeting the tumor microenvironment to enhance immunotherapy against cancer","authors":"C. Slaney, A. Oliver, M. Kershaw","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A048","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A048","url":null,"abstract":"Immunotherapies that harness the immune system against cancer are an attractive proposition for cancer treatment. While there have been some promising successes, only a small fraction of patients obtain clinical benefit. It has become clear that the immunosuppressive tumor microenvironment (TME) is a major obstacle for immunotherapies, because the TME suppresses immune responses, leading to reduced efficacy. We previously demonstrated that the site of tumor growth is a major determinant in sculpting the organ-specific TME, and thus predisposes treatment efficacy (1). In this project, we hypothesize that the TME of visceral tumors is more immunosuppressive than those of the tumors growing elsewhere. We investigated in murine models the difference in the TME in breast cancer growing orthotopically and the same breast cancer growing in the common metastatic sites, such as the lungs. Our findings showed that the breast cancer growing in the lungs was resistant to immunotherapies such as anti-PD1 and anti-CTLA-4, whereas the breast cancer growing orthotopically could be completely eradicated even when the cancer burden was greater. Through an institutional prospective community-based rapid autopsy program (CASCADE), we obtained genetically matched metastases and surrounding tissues from several sites in the same breast cancer patients and investigated the TME from these tumors using novel technologies such as RNAseq and multiplex immunohistochemistry. Strikingly, the TMEs from the same organs in different patients have similar immune gene expression profiles and in contrast, TMEs from the same patient differ greatly in different organs. Together, our research demonstrates an organ-specific difference between TMEs that leads to different responses to therapies. We anticipate that further study of how cancer cells sculpt the TME at different sites will greatly enhance our understanding of the TME and provide promising targets to enhance current immunotherapies, especially for patients who do not respond to existing therapies. Reference: 1. Devaud C., et al. Molecular Therapy 2014;22:18-27. Citation Format: Clare Y. Slaney, Amanda J. Oliver, Michael H. Kershaw. Targeting the tumor microenvironment to enhance immunotherapy against 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 A048.","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":"75701050","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 A090: The Duffy Antigen Receptor for Chemokines (DARC) influences levels of tumor-associated leukocytes in the breast tumor microenvironment","authors":"Rachel N. Martini, Brittany D. Jenkins, C. Yates, L. Newman, M. Davis","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A090","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A090","url":null,"abstract":"The regulation of immune cell infiltration into the tumor microenvironment can influence disease prognosis. The specific populations that are present can inform potential treatment options. This work investigates immune cell regulation in the breast cancer tumor microenvironment, specifically how an atypical chemokine receptor, known as the Duffy Antigen Receptor for Chemokines (DARC/ACKR1) can influence levels of leukocyte populations in the breast tumor environment. DARC is a nonsignaling receptor able to bind both the CC and CXC classes of chemokines, and mainly functions to modulate levels of chemokines in circulation, and aid in chemokine transport in tissues. In this regard, DARC expression may determine the profile of immune response.To investigate DARC expression and its effects on tumor-associated leukocyte (TAL) populations, we obtained RNA-seq data from The Cancer Genome Atlas (TCGA) Breast Cancer cohort. We proceeded through our analysis with those samples denoted as primary tumor samples (n=400). To estimate the relative abundance of TAL populations, we used the CIBERSORT online platform, which estimates fractions of 22 different TAL populations based on gene expression data. After completing the CIBERSORT analysis, we proceeded with only those samples that had a significant CIBERSORT output (n=167). In our analysis, we found that the total abundance of all TALs was significantly higher in tumors that have high DARC expression (p Citation Format: Rachel Martini, Brittany D. Jenkins, Clayton Yates, Lisa Newman, Melissa Davis. The Duffy Antigen Receptor for Chemokines (DARC) influences levels of tumor-associated leukocytes in the breast 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 A090.","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":"82296398","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 A072: Calreticulin exposures by malignant blasts correlate with robust anticancer immunity and improved clinical outcome in AML patients","authors":"J. Fucikova","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A072","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A072","url":null,"abstract":"Cancer cell death can be perceived as immunogenic by the host only when malignant cells emit immunostimulatory signals (so-called “damage-associated molecular patterns,” DAMPs), as they die in the context of failing adaptive responses to stress. Accumulating preclinical and clinical evidence indicates that the capacity of immunogenic cell death to (re-)activate an anticancer immune response is key to the success of various chemo- and radiotherapeutic regimens. Malignant blasts from patients with acute myeloid leukemia (AML) exposed multiple DAMPs, including calreticulin (CRT), heat-shock protein 70 (HSP70), and HSP90 on their plasma membrane irrespective of treatment. In these patients, high levels of surface-exposed (ecto)-CRT correlated with an increased proportion of natural killer cells and effector memory CD4+ and CD8+ T-cells in the periphery. Moreover, CRT exposure on the plasma membrane of malignant blasts positively correlated with the frequency of circulating T-cells specific for leukemia-associated antigens, indicating that ecto-CRT favors the initiation of anticancer immunity in patients with AML. Finally, although the levels of ecto-HSP70, ecto-HSP90, and ecto-CRT were all associated with improved relapse-free survival, only CRT exposure significantly correlated with superior overall survival. Thus, CRT exposure represents a novel powerful prognostic biomarker for patients with AML, reflecting the activation of a clinically relevant AML-specific immune response. Citation Format: Jitka Fucikova. Calreticulin exposures by malignant blasts correlate with robust anticancer immunity and improved clinical outcome in AML 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 A072.","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":"73107856","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 A079: Secreted IL-12p70 from long-term activated dendritic cells is lost concomitant with their apoptosis and release of IL-10","authors":"M. Hansen, L. Carstensen, A. Obers, I. Svane","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A079","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A079","url":null,"abstract":"The intimate balance between peripheral tolerance and adaptive immunity has profound implications in several disease settings. Interleukin-12 (IL-12) plays a major role in immunity to intracellular pathogens and cancer by controlling IFNγ-dependent adaptive immunity. The transient production of the bioactive IL-12p70 heterodimer and the concurrent expression of interleukin-10 (IL-10) serves as a myeloid checkpoint to avoid immunopathology. Here, long-term exposure to inflammatory stimuli was evaluated on monocyte-derived dendritic cells (DCs) activated with lipopolysaccharide (LPS) and gamma interferon (IFNγ). The secretion of IFNγ from co-cultures with allogeneic T-cells present in peripheral blood mononuclear cells from healthy volunteers served as a measure of T-cell activation.The secretion of IFNγ from co-cultures was progressively lost as exposure of DCs to inflammatory stimuli was extended from one up to four days prior to co-culture or following IL-12p70 antibody-mediated blockade. Most pronounced was the 12-fold reduction (N = 9 donor pairs) seen with four-day activated DCs. Furthermore, at four days of activation, a significant fraction of DCs underwent apoptosis concomitant with their increased release of IL-10 and a striking 10-fold drop in levels of IL-12p70 as compared with DCs activated one, two or three days. Furthermore, after four days of activation, DC-derived IL-12p70 was inversely correlated with IL-10 and with IFNγ derived from co-cultures. It is currently an open question whether IL-12p70 naturally degrades after four days of activation or whether apoptotic DCs actively stimulate the degradation of IL-12p70. Citation Format: Morten Hansen, Laura Stentoft Carstensen, Andreas Obers, Inge Marie Stentoft Svane. Secreted IL-12p70 from long-term activated dendritic cells is lost concomitant with their apoptosis and release of IL-10 [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 A079.","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":"75474703","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 PR03: Immune-based classification of soft-tissue sarcoma is associated with clinical outcome and unveils tertiary lymphoid structures as surrogate biomarker for the clinic","authors":"Weikang Chen, F. Petitprez, Cheng-Ming Sun, L. Lacroix, A. Reyniès, A. Italiano, M. Toulmonde, C. Lucchesi, Y. Laizet, C. Sautès-Fridman, W. Fridman","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-PR03","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-PR03","url":null,"abstract":"Soft tissue sarcoma (STS) are rare mesenchymal-originated tumors with more than 50 different histologies identified. Not every histology in STS responds to immunotherapy and immunologic predictive markers are lacking. The purpose of this study is to establish an immune classification of STS by analysis of the transcriptome. This was performed by using a deconvolution method that allowed us to quantify 8 immune populations and endothelial cells. As a secondary objective, we searched for a surrogate biomarker that could be assessable in the clinic. We analyzed transcriptomic data of four publicly available datasets, accounting for 608 complex genomic STS, including leiomyosarcoma (LMS, 35.4%), dedifferentiated liposarcoma (DDLPS, 33.9%) and undifferentiated pleomorphic sarcoma (UPS, 30.8%). By using the MCP-Counter deconvolution method, we characterized the tumor microenvironment (TME) of these tumors and established a robust immune classification that is consistent through various cohorts. We classified the patients into 5 Sarcoma Immune Classes (SIC), labeled as A1, A2, B, C1 and C2. The A1 and A2 groups are associated with very low to low immune infiltrates. Conversely, SIC C1 and C2 tumors are characterized by strong to very strong expression of signatures associated to all immune cells. SIC B tumors are characterized by a high expression of endothelial cell signature, an intermediate presence of neutrophils, and a rather low infiltration by other immune cell types. Regarding functional orientation of the TME, gene signatures associated with immune cells chemotaxis activation and survival, expression of major histocompatibility complex class I, and regulatory T-cells are highly expressed in SIC C1 and C2, modestly expressed in B and A2, and very lowly expressed in A1. Interestingly, immune checkpoint genes exhibited strong expression differences between SICs. SIC C2 had a strong expression of PD-1, PD-L2, CTLA-4 and TIM-3 genes. We also found that the lymphoid structure-associated B cell chemoattractant chemokine CXCL13 is remarkably highly expressed in C2 class. CXCL13 is associated with the presence of tertiary lymphoid structures (TLS). Although all histologies are distributed in each SIC group, LMS are more commonly found in the immune low SIC A1 and A2 groups, and we also extended our analysis to other histologies such as synovial sarcoma or gastrointestinal stromal tumors. Our classification is associated with clinical outcome, and SIC group C (C1/C2) has the longest overall survival, as compared to SIC A group (A1/A2) (p = 0.015). We then validated SIC classification using STS FFPE samples (n=32). SIC classification by RNA expression was correlated with quantitative immunohistochemistry (IHC) of CD3 (T-cells), DC-Lamp (activated dendritic cells), CD20 (B cells), CD8 (CD8+ T-cells), and CD34 (endothelial cells). Densities of CD3 (p=0.0033), CD8 (p=0.004) and CD20 (p=0.00043) were significantly higher in SIC C tumors. Tumor SIC B groups ha","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":"79775193","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 A070: Virotherapy eradicates established melanoma by reprogramming the tumor microenvironment and engaging the adaptive immunity","authors":"L. Flatz, S. Ring, D. Bomze, L. Onder, Jovana Cupovic, S. Schmidt, K. Orlinger, A. Bešše, L. Besse, C. Driessen, Hung-Wei Cheng, A. Lercher, D. Speiser, T. Bald, A. Bergthaler, B. Ludewig","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A070","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A070","url":null,"abstract":"Immunotherapy revolutionized the treatment of cancer patients. However, the lack of tumor specific T-cells and the immunosuppressive tumor microenvironment remain the major obstacles in curing treatment-resistant tumors. Here, we show that a novel, propagating noncytopathic virotherapy expressing the tumor-associated antigen TRP2 can eradicate established tumors. Interestingly, this was dependent on the route of treatment. Systemic administration of gene-based virotherapy induced a high number of tumor-infiltrating TRP2 specific CD8+ T-cells but was not able to cure established tumors. Moreover, localized tumor therapy in the periphery cured also distant metastasis in the lung, indicating that the locally induced immune response generates a systemic antitumor effect. Localized virotherapy predominantly infects tumor cells and tumor-associated fibroblasts, resulting in a proinflammatory reprogramming of the tumor microenvironment. Our data reveal that this immune activation is dependent on type I IFN signaling on the host but not on the tumor cell. These results have important clinical implications: i) our data explain why T-cell transfer or T-cell vaccines alone do not cure established tumors; ii) intratumoral gene-based cancer vaccination is superior to systemic treatment; and iii) a successful local antitumor response is associated with an efficient systemic antitumor response. Directly cancer targeting noncytopathic gene-based vaccines may be a promising approach by simultaneously supercharging the suppressive tumor microenvironment and inducing an adaptive immune response against selected tumor antigens. Citation Format: Lukas Flatz, Sandra Ring, David Bomze, Lucas Onder, Jovana Cupovic, Sarah Schmidt, Klaus Orlinger, Andrej Besse, Lenka Besse, Christoph Driessen, Hung-Wei Cheng, Alexander Lercher, Daniel Speiser, Tobias Bald, Andreas Bergthaler, Burkhard Ludewig. Virotherapy eradicates established melanoma by reprogramming the tumor microenvironment and engaging the adaptive immunity [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 A070.","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":"73967812","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 A083: Inflammasome-independent IL-1β release by myeloid cells promotes vessel destabilization and immune suppression in the tumor microenvironment","authors":"M. Kiss, L. Walle, Helena Van Damme, Aleksandar Murgaski, Evangelia Bolli, J. Keirsse, Maria Solange Martins, Y. Elkrim, A. Fossoul, J. Serneels, M. Mazzone, M. Lamkanfi, J. A. Ginderachter, Damya Laoui","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A083","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A083","url":null,"abstract":"Background: Chronic inflammation in the tumor microenvironment (TME) sustained by immune cells has a crucial role both in tumor initiation and progression. One of the central cytokines of inflammation, IL-1β, is produced as a biologically inactive precursor that requires proteolytic processing by caspase-1. Activation of caspase-1 is triggered by the formation of inflammasomes, multiprotein complexes that detect microbial and endogenous danger signals primarily via NOD-like receptors, such as NLRP3 and NLRC4. Biologically active IL-1β is believed to be released through membrane pores formed by gasdermin D during a lytic form of cell death called pyroptosis. Although IL-1β-mediated inflammation has been shown to have a detrimental role in tumor progression, the signaling pathway controlling IL-1β release in the TME and the exact effect of the cytokine on antitumor T-cell responses have not been fully elucidated. A better understanding of how IL-1β release is controlled in tumors will also pave the way towards the therapeutic utilization of small-molecule inhibitors available to target NOD-like receptors and caspase-1. Methods: First, we characterized the impact of IL-1β in the TME by assessing the immune cell composition and vasculature of Lewis lung carcinomas (LLC) and E0771 breast carcinomas in IL-1β-deficient mice using flow cytometry and histologic analysis. Next, we used mice deficient in different inflammasome components, including NLRP3, NLRC4 and caspase-1, to investigate the involvement of these proteins in controlling IL-1β release in LLC and E0771 tumors. Using immunoblots and small-molecule inhibitors, we further characterized the activation of alternative enzymatic pathways and their involvement in IL-1β release by tumor-associated myeloid cells. Finally, we examined the role of pyroptosis and necroptosis in IL-1β release using gasdermin D- and MLKL-deficient mice, respectively. Release of IL-1β was assessed using ELISA and immunoblots. Results: We found that IL-1β secretion was restricted to myeloid cells and promoted tumor progression in mouse models of lung and breast carcinoma. IL-1β deletion abrogated the tumor-induced mobilization of immunosuppressive neutrophils and normalized the tumor vasculature, thereby alleviating hypoxia. Consequently, proliferation of effector T-cells in the TME was enhanced, leading to higher CD4+ and CD8+ T-cell abundance in the absence of IL-1β. We observed that, although the NLRP3 inflammasome was active in tumor-infiltrating myeloid cells, NLRP3 and caspase-1 were not essential for the proteolytic maturation of pro-IL-1β and secretion of biologically active IL-1β in the TME. Inhibition or genetic deletion of caspase-8 reduced inflammasome-independent IL-1β release, indicating that caspase-8 provides an alternative pathway for proteolytic activation and secretion of IL-1β in tumor-infiltrating myeloid cells. Moreover, IL-1β release by tumor-infiltrating myeloid cells was independent of lytic cell de","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":"75095153","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 A062: TIM-3 plays distinct roles in different immune cells to regulate antitumor immune responses","authors":"J. Dai, J. Pei, M. Mohrs, G. Thurston, E. Ioffe","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A062","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A062","url":null,"abstract":"T-cell immunoglobulin and mucin-domain containing-3 (TIM-3) was originally identified as an inhibitory receptor that is expressed on Th1 T-cells to dampen T-cell immunity upon interaction with several putative ligands. The inhibitory role of TIM-3 is supported by multiple preclinical disease models, such as viral and bacterial infections, experimental autoimmune encephalitis, and allograft rejection. Recent evidence suggests that induction of TIM-3 expression on T-cells may promote resistance to cancer immunotherapy, including in response to treatment with PD-1/PD-L1 inhibitors. Thus, TIM-3 represents a putative novel immuno-oncology target. Here we report that in naive mice TIM-3 is absent on T-cells, but is constitutively expressed on myeloid cells, including dendritic cells and macrophages. In tumor-bearing mice, TIM-3 expression is highly enriched on PD-1 positive CD4 and CD8 T-cells in the tumor microenvironment, but not on T-cells in draining lymph nodes or peripheral blood. Prophylactic or therapeutic treatment with anti-PD-1 blocking antibody delays tumor growth in wild-type mice. However, unexpectedly, TIM-3 genetic deficiency reduced overall survival of tumor-bearing mice treated with anti-PD-1 compared to wild-type control mice. Using a series of in vitro functional cell-based assays, we found that blocking TIM-3 function by either genetic knock-out or an inhibitory Ab increased proliferation of, and IFN-γ production by, effector CD8 T-cells following direct antigen stimulation. By contrast, TIM-3 gene knockout in bone marrow-derived macrophages did not impact responses to stimulation with Toll-like receptor ligands, and TIM-3 blockade reduced phagocytosis of apoptotic tumor cells by a macrophage cell line. Taken together, our results suggest TIM-3 may play opposite roles in T-cells and macrophages (inhibitory vs activating, respectively), and highlight the pleiotropic roles of TIM-3 in different immune cells in tumor immunology. Citation Format: Jie Dai, Jerry Pei, Markus Mohrs, Gavin Thurston, Ella Ioffe. TIM-3 plays distinct roles in different immune cells to regulate antitumor immune responses [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 A062.","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":"76927384","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 A116: Lipid control of DNA-stimulated innate immunity","authors":"Xiaojun Tan, Conggang Zhang, Zhijian J. Chen","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A116","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A116","url":null,"abstract":"Type I interferon (IFN) plays essential roles in both spontaneous and iatrogenic tumor immunogenicity. Tumor-derived DNA is recognized by 2’,3’-cyclic GMP-AMP (cGAMP) synthase (cGAS) that is important in tumor immunogenicity. Upon DNA binding, cGAS produces the endogenous second messenger cGAMP that binds to and activates stimulator of IFN genes (STING), a signaling adaptor. cGAMP binding triggers STING trafficking from the endoplasmic reticulum (ER) to perinuclear compartments, with simultaneous activation of serine/threonine-protein kinase TBK1 that in turn phosphorylates the transcription factor IRF3, leading to upregulation of type I interferons. However, where and how TBK1 is activated by STING upon cGAMP stimulation is unclear. Our study focuses on the regulation of cGAMP-stimulated STING trafficking and activation by lipid messengers with essential roles in subcellular protein/membrane trafficking and signaling. Through in vitro signaling reconstitution, we identified a cellular lipid as an essential factor of STING signaling. We found both STING and TBK1 were lipid effectors. Lipid binding not only promotes STING trafficking but also stimulates TBK1 activation. These results reveal a new component of the STING-TBK1 complex that controls cytosolic DNA-stimulated innate immune signaling. Citation Format: Xiaojun Tan, Conggang Zhang, Zhijian J. Chen. Lipid control of DNA-stimulated innate immunity [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 A116.","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":"83591098","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}