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

{"title":"Abstract A121: Single-cell transcriptomic analyses reveal heterogeneity of vascular endothelial cells in cancer models","authors":"Yu Zhu, Nicole Salazar, Kevin F. Brulois, E. Butcher","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A121","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A121","url":null,"abstract":"The immune system has demonstrated promising potential as a therapeutic target in the treatment of certain cancer types, yet in many tumors the efficacy of immunotherapies is still extremely poor. One major obstacle is the limited access of immune cells to the tumor tissue. The tumor vasculature plays critical roles in regulating the recruitment of anti-tumor immune cells and the delivery of immunotherapies to the tumor sites. These immune processes require functional specialization of endothelial cells (ECs). However, there is a major gap in our understanding of the diversity, molecular specialization, and developmental relationships of tumor-associated EC subsets. To understand the heterogeneity of tumor-associated endothelium, we performed single-cell RNA sequencing (scRNAseq) analyses on ECs isolated from mouse cancer models. scRNAseq identified several subsets of endothelium in the tumor tissue, including ECs that compose the artery, capillary, and post-capillary venules. Interestingly, within the capillary endothelial compartment, we identified an EC subset that resembles tip cells in sprouting angiogenesis and demonstrates molecular signature of stem or progenitor cells. These putative progenitor cells are dramatically expanded in tumors compared to normal tissues, and comprise both quiescent and proliferative populations. The quiescent ECs express high levels of genes coding for antiapoptotic proteins, extracellular matrix molecules, immune checkpoint molecules, monocyte/macrophage recruiting cytokines, and stem cell signaling components, such as Notch4. On the other hand, the proliferative tip-like ECs express genes coding for cyclins and cyclin-dependent kinases, DNA damage repair molecules, necroptosis machinery, and epigenetic regulators. Taken together, these data define the heterogeneity of tumor-associated endothelial cells, and reveal a putative progenitor population that gives rise to the tumor vasculature and could be targeted to improve the efficacy of immunotherapies. Citation Format: Yu Zhu, Nicole Salazar, Kevin Brulois, Eugene Butcher. Single-cell transcriptomic analyses reveal heterogeneity of vascular endothelial cells in cancer models [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 A121.","PeriodicalId":22141,"journal":{"name":"Tackling the Tumor Microenvironment: Beyond T-cells","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86922529","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 A098: SLC12A2 as a novel “brake” on immunogenic apoptotic cell clearance","authors":"Justin S. A. Perry, Sho Morioka, C. B. Medina, Michael H. Raymond, K. Ravichandran","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A098","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A098","url":null,"abstract":"Phagocytes face a key challenge during efferocytosis – they must engulf an apoptotic cell, often similar in size, while maintaining their own cell integrity, shape, and volume. Yet little is known about phagocyte volume homeostasis during apoptotic cell clearance. To this end, we performed an unbiased transcriptomics screen designed to reveal alterations of phagocyte gene expression after engulfment of apoptotic Jurkat lymphoma cells and identified several transcriptional programs distinctly modified in engulfing phagocytes. We identified a program involving cell volume regulation and potassium/chloride flux, the latter of which is thought to underlie immunogenic responses. Disruption of one member of this cell volume program, SLC12A2, resulted in “overeating” of apoptotic JurkaT-cells by individual phagocytes and a significant increase in cell size. Importantly, we demonstrate that SLC12A2-deficient phagocytes actively engulfing apoptotic JurkaT-cells led to a downregulation of the hallmark antiinflammatory efferocytosis program and robust upregulation of a proinflammatory program. In particular, we observed robust upregulation of immunogenic programs, including a type I interferon signature, in SLC12A2-deficient engulfing phagocytes that were not observed in phagocytes over-expressing the phosphatidylserine receptor TIM4, Mechanistically, we found that the chloride-sensing kinase WNK1 and downstream kinases OSR1 and SPAK function to regulate chloride flux into engulfing phagocytes via SLC12A2, and that this pathway regulates the apoptotic JurkaT-cell “overeating” observed in SLC12A2-deficient phagocytes. Collectively, these data elucidate a novel mechanism by which phagocytes protect themselves from potentially dangerous apoptotic cell-derived inflammatory ligands and suggest that SLC12A2 serves to actively suppress immunogenic responses by phagocytes and limits the rate of corpse uptake during efferocytosis. Citation Format: Justin Shaun Arnold Perry, Sho Morioka, Christopher Medina, Michael Raymond, Kodi Ravichandran. SLC12A2 as a novel “brake” on immunogenic apoptotic cell clearance [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 A098.","PeriodicalId":22141,"journal":{"name":"Tackling the Tumor Microenvironment: Beyond T-cells","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79906281","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 A075: A protective role for group 3 innate lymphoid cells in colitis-associated colorectal cancer","authors":"J. Goc, N. Bessman, S. Sahota, F. Laure, G. Putzel, D. Withers, J. Arthur, Manish A. Shah, Gregory F. Sonnenberg","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A075","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A075","url":null,"abstract":"Chronic inflammation is recognized as a causative factor in the development of cancer and recent paradigms suggest that microbe-driven chronic inflammation is causally associated with the development and progression of cancer in the colon. Further, recent studies in mice have implicated innate lymphoid cells (ILC) as a key cell population that regulates intestinal inflammation. Group 3 innate lymphoid cells (ILC3) are essential regulators of immunity, inflammation and tissue homeostasis in the intestine, yet their role in cancer remains poorly defined. Here, we identify that ILC3 are associated with both human and mouse colon tumors. Tumor-associated ILC3 are selectively localized within lymphoid aggregates and exhibit a unique phenotypic profile as compared with nonmalignant tissue. Critically, mice with a selective deletion of ILC3-specific MHCII exhibit a striking increased susceptibility to intestinal tissue damage and develop highly invasive and flat colorectal tumors. These data demonstrate a protective role for antigen-presenting ILC3 in the context of cancer development and progression in the intestine, and suggest that further interrogation may lead to the development of novel immunotherapeutic strategies in colon cancer. Citation Format: Jeremy Goc, Nick Bessman, Sheena Sahota, Flamar Anne Laure, Gregory Putzel, David Withers, Janelle Arthur, Manish Shah, Gregory Sonnenberg. A protective role for group 3 innate lymphoid cells in colitis-associated colorectal 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 A075.","PeriodicalId":22141,"journal":{"name":"Tackling the Tumor Microenvironment: Beyond T-cells","volume":"90 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89630847","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":"19 1","pages":""},"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":"10 1","pages":""},"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":"34 1","pages":""},"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":"32 1","pages":""},"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":"37 1","pages":""},"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":"165 1","pages":""},"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":"5 1","pages":""},"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}