Maintenance of Immune Balance: Effects of Targeted and Immune Therapies最新文献

{"title":"Abstract IA22: Autoimmune rheumatic diseases and cancer","authors":"L. Casciola‐Rosen, Ami A. Shah, A. Rosen","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-IA22","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-IA22","url":null,"abstract":"Some rheumatic disease autoantibodies are powerful markers of subgroups of patients who have distinct disease phenotypes and trajectories. Of particular interest are markers of several disease subgroups in whom cancer and rheumatic disease onset are clustered together in time. For example, a subgroup of scleroderma patients have coincident onset of cancer and scleroderma. This is observed in scleroderma patients with autoantibodies against RNA polymerase-3 (POLR3), and more recently with autoantibodies recognizing the minor spliceosome. In autoimmune myopathies, temporal clustering of diagnosis of cancer and myositis is associated with autoantibodies to NXP2 and components of the TIF1 complex. Interestingly, although the incidence of cancer is higher in patients with these autoantibodies, most patients with these autoantibodies do not manifest cancer, even with extended periods of follow-up. These observations provide an important opportunity to investigate the potential mechanisms which operate at the cancer-immune interface during development of rheumatic diseases. In cancers from anti-POLR3-positive scleroderma patients with a short scleroderma-cancer interval, we found genetic alterations of the POLR3A locus in six of eight patients with antibodies to POLR3 but not in eight patients without these antibodies. 3 antibody-positive patients had somatic mutations in POLR3A; 5 patients had loss of heterozygosity at the POLR3A locus. Analyses of peripheral blood lymphocytes and serum suggested that POLR3A mutations sparked cellular immunity and cross-reactive humoral immune responses. In a larger scleroderma cohort (>2300 patients), the incidence of cancer in various autoantibody subgroups was compared to data from the Surveillance, Epidemiology and End Results (SEER) Program. An increase in cancer incidence in scleroderma patients with POLR3 autoantibodies was observed compared to the general population; strikingly, patients with anti-centromere autoantibodies had a lower cancer incidence than observed in the general population. The finding that distinct serologic subgroups have different cancer risks suggests that cancer immunity may be a common principle across the scleroderma spectrum, with cancer emergence influenced by the effectiveness of the different immune responses. For example, in scleroderma patients with anti-centromere antibodies, cancer emergence may be inhibited, while inhibition of cancer emergence may only be partial for anti-POLR3. Prior studies in small cohorts of breast cancer patients have demonstrated that anti-centromere antibodies may be present, and may associate with improved disease-free and overall survival. Additionally, recent data also suggest that anti-DNA antibodies can have direct anti-cancer effects in cells with DNA repair defects, possibly explaining the decreased risk of breast and other cancers observed among patients with SLE.Taken together, these data suggest that at least some patients with autoimmune rheu","PeriodicalId":18169,"journal":{"name":"Maintenance of Immune Balance: Effects of Targeted and Immune Therapies","volume":"26 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83425402","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 A122: Self-recognition of Alu duplex RNAs is the basis for MDA5-mediated interferonopathies","authors":"Sadeem Ahmad, X. Mu, S. Hur","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A122","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A122","url":null,"abstract":"Melanoma Differentiation Associated Gene-5 (MDA5) is an innate immune receptor that binds to viral double-stranded RNAs (dsRNAs) and initiates type I and III interferon signaling cascade thereby playing a key role in antiviral immune response. Recently, a number of mutations that lead to aberrant activation of MDA5 have been implicated in various autoinflammatory disorders including Aicardi-Goutieres syndrome. The mechanistic basis of this constitutive MDA5 activation, however, has remained elusive. An understanding of the subtle balance of self vs. non-self discrimination by MDA5 is important, especially in the context of recent reports demonstrating the targeted activation of MDA5 as a potential therapeutic strategy against diverse carcinoma. Our work revealed a hitherto unknown role played by the RNA-rich cellular environment in preventing aberrant MDA5 activation by imposing cooperative filament assembly on dsRNAs as a functional requirement for signal activation. We further employed a novel RNase protection-RNAseq approach to show that the disease-causing gain-of-function (GOF) mutants of MDA5 can form signaling-competent filaments on endogenous RNA populations comprising mainly Alu RNA duplexes. Strikingly, under physiologic conditions, the wild type MDA5 is not activated by Alu RNAs because of its sensitivity to structural irregularities such as bulges and mismatches commonly occurring in Alu:Alu hybrids. The GOF mutants, on the other hand, show reduced sensitivity to disruptions in duplex RNA structures as revealed by our in-depth biochemical probing. Overall, the work reveals the underlying mechanism behind MDA5-mediated inflammatory disorders. Moreover, it highlights the unique role played by Alu RNAs as an evolutionary tether on MDA5, keeping its affinity towards “self” ligands under check during the course of evolution. Citation Format: Sadeem Ahmad, Xin Mu, Sun Hur. Self-recognition of Alu duplex RNAs is the basis for MDA5-mediated interferonopathies [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 A122.","PeriodicalId":18169,"journal":{"name":"Maintenance of Immune Balance: Effects of Targeted and Immune Therapies","volume":"57 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83243288","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 A138: CD39 increase on cytotoxic T-cell induced by myeloid-derived suppressor cell correlated with poor prognosis in patients with non-small cell lung cancer","authors":"J. Koh, K. Lee, Bo-Ryun Kim, Mi Soon Kim, H. Cho, Jong-Mu Sun, J. Ahn, Keunchil Park, M. Ahn","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A138","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A138","url":null,"abstract":"Background: The factors in tumor microenvironment hinder T-cell activities against tumor cells. The major immunosuppressive cells in tumor sites are myeloid-derived suppressor cell (MDSC), tumor-associated macrophage (TAM), and regulatory T (Treg) cell, and the effector molecules released by those immunosuppressive cells also regulate T-cell activities. Therefore, in this study we examined the pattern of immunosuppressive cells in patients with non-small cell lung cancer. Then, we tested T-cell activities to verify whether the suppressive immune cell populations can influence T-cell activity by monitoring T-cell exhaustion markers. Since CD39 and CD73 expression on cytotoxic T-cell are known to be T-cell exhaustion markers, we analyzed CD39 and CD73 on CD8+ T-cells. Method: Baseline and one week after anti-PD-1 immunotherapy (pembrolizumab and nivolumab) blood samples (n=81) were collected (stage III and IV). For the correlation of suppressive immune cells with disease progression, baseline blood samples from the patients (n=59, stage I~IV) and healthy donors (n=21) were collected. Granulocytic-MDSC, Monocytic-MDSC, TAM, Treg, and CD39+ and CD73+ cytotoxic T-cell population from patients’ PBMC (n=81 and n=59) were analyzed by FACS Verse. For the suppressive assay, isolated T-cells were activated with anti-CD3 and anti-CD28 and then MDSC was co-cultured with T-cells for a week followed by Ki-67, CD39 and CD73 analysis by FACS Verse. Results: G-MDSC (p-value=0.0023), M-MDSC (p-value=0.0032), TAM ((p","PeriodicalId":18169,"journal":{"name":"Maintenance of Immune Balance: Effects of Targeted and Immune Therapies","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80840402","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 A131: Targeting B7-H3 (CD276) in neuroblastoma: In vitro evaluation of Fc-optimized antibodies and immunocytokines","authors":"F. Heubach, P. Schlegel, L. Zekri, Timo Manz, S. Schleicher, A. Rabsteyn, G. Jung, H. Bühring, S. Gillies, R. Handgretinger, P. Lang","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A131","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A131","url":null,"abstract":"Introduction: Targeting disialoganglioside GD2 with monoclonal antibodies (mAbs) significantly improves survival in high-risk neuroblastoma (NB) patients after autologous or allogeneic SCT. However, GD2 expression is heterogeneous and the recently approved anti-GD2 mAb CH14.18 causes severe adverse effects, e.g., neuropathy and neuropathic pain due to neurotoxicity. Additional or alternative target antigens might improve therapy. B7-H3 belongs to the B7-CD28 family and is thought to function as an immune checkpoint by regulating T and NK cell response. B7-H3 is highly overexpressed on many solid tumors, correlating with poor prognosis and outcome. However, on healthy tissue its protein expression is very limited, thus making B7-H3 an interesting target for cancer immunotherapy. Therefore, we evaluated the use of B7-H3 as an alternative to GD2 and investigated different anti-B7-H3 mAb constructs and mAb-cytokine fusions (immunocytokines) for their ability to elicit antibody-dependenT-cellular cytotoxicity (ADCC). Methods: Derived from a parent anti-B7-H3 clone (HEK5-1B3), five additional mAb constructs were engineered: (1) chimeric with human IL-2 fusion (cHEK5-IL2), (2) chimeric and Fc-optimized (SDIE) w/o fusion (cHEK5opt), (3) cHEK5opt fused with human IL-2 (cHEK5opt-IL2), (4) cHEK5opt fused with human IL-15 (cHEK5opt-IL15), and (5) cHEK5-IL2 produced in rat myeloma YB2/0 to create an optimized low-fucose version (cHEX5LF-IL2). All IL-2 fusions were to the C-terminus of the light chain. The abilities of all six anti-B7-H3 mAb constructs and the GD2-specific mAb CH14.18 to mediate ADCC were compared in vitro in cytotoxicity assays using calcein release assays and the RTCA xCELLigence system. TargeT-cells: NB cell lines expressing high levels of B7-H3 but variable levels of GD2 (LAN-1, Kelly, SH-SY5Y). Effector cells: Human expanded NK cells (eNKs), expanded γ/δ T-cells and patient PBMCs after allogeneic SCT. Results: Except the parent clone, all anti-B7-H3 mAb constructs were able to elicit ADCC. TargeT-cell lysis of LAN-1 (high expression of both GD2 and B7-H3) mediated by the optimized anti-B7-H3 immunocytokines was comparable or even better than that mediated by CH14.18 (effectors: eNKs; calculated after 36 hrs.; in ascending order): Targets + effectors w/o mAb (24 %), parent pHEK5 (29 %), cHEK5opt (44 %), cHEK5-IL2 (76 %), cHEK5opt-IL15 (85 %), CH14.18 (90 %) and cHEK5opt-IL2 (97 %). Recently, we produced the low-fucose immunocytokine cHEX5LF-IL2. In a direct comparison with all other mAb constructs the cHEX5LF-IL2 immunocytokine mediated best targeT-cell lysis against SH-SY5Y (effectors: eNKs; calculated after 48 hrs.; in ascending order): Targets + effectors w/o mAb (31 %), CH14.18 (42 %), parent pHEK5 (46 %), cHEK5-IL2 (80 %), cHEK5opt (85 %), cHEK5opt-IL2 (93 %), cHEK5opt-IL15 (96 %) and low-fucose cHEX5LF-IL2 (100 %). Using expanded γ/δ T-cells of healthy donors we were able to confirm cHEX5LF-IL2 to be the most effective anti-B7-H3 mAb","PeriodicalId":18169,"journal":{"name":"Maintenance of Immune Balance: Effects of Targeted and Immune Therapies","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77274161","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 A132: Identification of pyroptosis inhibitors that target a reactive cysteine in gasdermin D","authors":"J. Hu, Xing Liu, Jingxia Zhao, S. Xia, J. Ruan, Xuemei Luo, Justin Kim, J. Lieberman, Hao Wu","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A132","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A132","url":null,"abstract":"Inflammasomes are multiprotein signaling scaffolds that assemble in response to invasive pathogens and sterile danger signals to activate inflammatory caspases (1/4/5/11), which trigger inflammatory death (pyroptosis) and processing and release of proinflammatory cytokines. Inflammasome activation contributes to many human diseases, including inflammatory bowel disease, gout, type II diabetes, cardiovascular disease, Alzheimer’s disease, and sepsis, the often fatal response to systemic infection. The recent identification of the pore-forming protein gasdermin D (GSDMD) as the final pyroptosis executioner downstream of inflammasome activation presents an attractive drug target for these diseases. Here we show that C-23 and C-27 potently inhibit GSDMD pore formation in liposomes and inflammasome-mediated pyroptosis and IL-1β secretion in human and mouse cells. Moreover, C-23, administered at a clinically well-tolerated dose, inhibits LPS-induced septic death and IL-1β secretion in mice. Both compounds covalently modify a conserved Cys (Cys191 in human and Cys192 in mouse GSDMD) that is critical for pore formation. Inflammatory caspases employ Cys active sites, and many previously identified inhibitors of inflammatory mediators, including those against NLRP3 and NF-κB, covalently modify reactive cysteine residues. Since NLRP3 and noncanonical inflammasome activation are amplified by cellular oxidative stress, these redox-sensitive reactive cysteine residues may regulate inflammation endogenously, and compounds that covalently modify reactive cysteines may inhibit inflammation by acting at multiple steps. Indeed, both C-23 and C-27 also directly inhibit inflammatory caspases and pleiotropically suppress multiple processes in inflammation triggered by both canonical and noncanonical inflammasomes, including priming, puncta formation and caspase activation. Hence, cysteine-reactive compounds, despite their lack of specificity, may be attractive agents for reducing inflammation. Citation Format: Jun Hu, Xing Liu, Jingxia Zhao, Shiyu Xia, Jianbin Ruan, Xuemei Luo, Justin Kim, Judy Lieberman, Hao Wu. Identification of pyroptosis inhibitors that target a reactive cysteine in gasdermin D [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 A132.","PeriodicalId":18169,"journal":{"name":"Maintenance of Immune Balance: Effects of Targeted and Immune Therapies","volume":"205 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77481833","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 A147: AO-176, a next-generation anti-CD47 antibody, induces immunogenic cell death","authors":"D. Pereira, Benjamin J. Capoccia, R. Hiebsch, Michael J. Donio, Alun J. Carter, Robyn J. Puro, W. C. Wilson, P. Manning, R. Carr","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A147","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A147","url":null,"abstract":"Recent success in cancer immunotherapy has targeted immune checkpoints such as PD-1, PDL-1, and CTLA-4 to enhance the cytotoxic activity of the adaptive T-cell immune response. While the clinical response to these therapies has been dramatic for some, many others have shown partial or even no response highlighting the need for alternative or synergistic approaches that activate innate immunity. Disruption of the interaction between SIRP alpha and CD47, an innate checkpoint inhibitor, using anti-CD47 antibodies, for example, is known to enhance innate immunity by increasing the phagocytosis of tumor cells by macrophages and dendritic cells (DCs) leading to processing and presentation of tumor antigens. Recently, we described AO-176, a next generation anti-CD47 antibody that blocks the CD47/SIRP alpha interaction, induces phagocytosis and causes a direct tumor cell-autonomous death while negligibly binding RBCs. Herein, we characterize the ability of our CD47 antibodies such as AO-176 to induce immunogenic cell death (ICD) and damage-associated molecular patterns (DAMPs) in tumor cells and to potentiate chemotherapy-induced ICD/DAMPs. ICD is a process whereby an agent induces cell surface exposure and release of DAMPs from dying cells which stimulates DCs and adaptive immune responses. Tumor cells were treated in vitro with our CD47 antibodies either alone or in combination with chemotherapeutics followed by assessment of ICD/DAMPs using flow cytometry and biochemical assays. RNAseq was also performed on cells undergoing CD47 antibody mediated ICD/DAMP induction to better understand how CD47 inhibition may regulate ICD. AO-176 and other CD47 antibodies, developed by Arch Oncology, caused mitochondrial stress and loss of outer-membrane integrity, typically observed prior to cells undergoing apoptosis. In addition, CD47 antibody treatment induced a significant ER stress response at the genetic level resulting in the surface exposure of ER chaperone proteins calreticulin, Hsp90, and PDIA3. Concomitantly, our CD47 antibodies increased autophagy and JAK/STAT signaling, which resulted in both ATP and HMGB1 release, respectively. Finally, we demonstrated that in combination, our antibodies potentiated the effects of ICD/DAMP-inducing chemotherapy (e.g., doxorubicin). Here, we describe the unique ability of a specific subset of next generation CD47 antibodies, such as AO-176 to induce ICD/DAMPs. RNAseq analysis of treated cells also revealed alteration of several pathways, including those where DAMPs play a role. In summary, next-generation CD47 antibodies such as AO-176 may provide a novel approach to enhancing the current landscape of checkpoint immunotherapy by enhancing both the innate and adaptive immune responses against tumors. Citation Format: Daniel S. Pereira, Benjamin J. Capoccia, Ronald R. Hiebsch, Michael J. Donio, Alun J. Carter, Robyn J. Puro, W. Casey Wilson, Pamela T. Manning, Robert W. Carr. AO-176, a next-generation anti-CD47 antibody, i","PeriodicalId":18169,"journal":{"name":"Maintenance of Immune Balance: Effects of Targeted and Immune Therapies","volume":"47 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78982856","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 A153: Targeting DNA damage response upregulates PD-L1 level and promotes antitumor immunity in small-cell lung cancer","authors":"T. Sen, B. L. Rodriguez, Limo Chen, N. Morikawa, J. Fujimoto, L. Diao, Youhong Fan, Jing Wang, B. Glisson, I. Wistuba, J. Sage, J. Heymach, D. Gibbons, L. Byers","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A153","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A153","url":null,"abstract":"Purpose of the Study: Despite recent advances in the use of immunotherapy, only a minority of small cell lung cancer (SCLC) patients respond to immune checkpoint blockade (ICB) with programmed cell death protein 1 (PD-1) or programmed death ligand 1 (PD-L1) antibodies as monotherapy or combination. Therefore, there is a critical need to develop strategies to enhance the efficacy of ICB in SCLC, an otherwise immunosuppressed disease with dismal 5-year survival rate of 30 years. We have previously shown that prexasertib and olaparib treatment enhanced the protein (but not mRNA) and surface expression of PD-L1 in SCLC cell lines and tumor models. Here we elucidate the previously unexplored mechanism of how DNA damage response targeting enhances antitumor immunity in SCLC. Methods: SCLC cell lines and immune competent murine models were treated with inhibitors targeting DNA damage repair (DDR) proteins, checkpoint kinase 1 (CHK1) (by prexasertib), poly (ADP-ribose) polymerase (PARP) (by olaparib) either as single agents or in combination with anti-PD-L1. End point analyses were done by Western blot, real-time RT-PCR, multicolor flow cytometry and reverse phase protein array (RPPA). Result: We observed increased PD-L1 glycosylation post-prexasertib and olaparib treatment. Prexasertib and/or olaparib +/- anti-PD-L1 combination activates mTOR and inactivates GSK3β pathway thus providing mechanistic insight into DDR-targeting mediated PD-L1 glycosylation and stabilization. We treated tumor-bearing immune-competent B6129F1 mice with either IgG (control), prexasertib (10mg/kg, 2/7), anti-PD-L1 (300ug, 1/7) or combination (n=10/group). At Day 21, anti-PD-L1 did not cause tumor regression and prexasertib treatment delayed tumor growth [T/C=0.31(p Citation Format: Triparna Sen, Bertha Leticia Rodriguez, Limo Chen, Naoto Morikawa, Junya Fujimoto, Lixia Diao, Youhong Fan, Jing Wang, Bonnie S. Glisson, Ignasio Wistuba, Julien Sage, John V. Heymach, Don L. Gibbons, Lauren A. Byers. Targeting DNA damage response upregulates PD-L1 level and promotes antitumor immunity in small-cell lung 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 A153.","PeriodicalId":18169,"journal":{"name":"Maintenance of Immune Balance: Effects of Targeted and Immune Therapies","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":"80817722","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 A143: Glutaminyl cyclase is an enzymatic modifier of the CD47- SIRPα axis and target for immunotherapy","authors":"Meike E. W. Logtenberg","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A143","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A143","url":null,"abstract":"Cancer cells are able to evade immune surveillance through the expression of inhibitory ligands that bind their cognate receptors on immune effector cells. CD47 serves as a “don9t eat me” signal for myeloid cells by binding to the inhibitory receptor signal-regulatory protein alpha (SIRPα). Prior work has provided strong evidence that antibody-based targeting of the CD47 axis can promote tumor control by both innate and adaptive immune cells, and clinical development of CD47 antagonists is ongoing. Using a haploid genetic screen, we identify glutaminyl-peptide cyclotransferase-like (QPCTL) as a regulator of the CD47-SIRPα checkpoint that is critical for pyroglutamate formation on CD47 at the SIRPα binding site. Both genetic and pharmacologic interference with QPCTL activity decrease SIRPα binding to CD47 and enhances antibody-dependenT-cellular phagocytosis and cellular cytotoxicity of tumor cells mediated by macrophages and neutrophils, respectively. Furthermore, interference with QPCTL expression leads to a major increase in tumor cell killing and neutrophil influx by tumor-opsonizing antibodies in vivo. These data provide an avenue for small-molecule inhibition of the CD47 pathway to augment antibody therapy of cancer. Citation Format: Meike Emma Willemijn Logtenberg. Glutaminyl cyclase is an enzymatic modifier of the CD47- SIRPα axis and target 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 A143.","PeriodicalId":18169,"journal":{"name":"Maintenance of Immune Balance: Effects of Targeted and Immune Therapies","volume":"5 Suppl 1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82297324","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 A128: Tumor endothelial cells say IDO to CD40-stimulating immunotherapy","authors":"A. Dimberg, Alexandros Karampatzakis, S. Tuit, Mohanraj Ramachandran, G. Fotaki, L. Hooren, Hua Huang, R. Lugano, Kaunisto Aura, P. Ellmark, S. Mangsbo, J. Schultze, M. Essand, Maria Georganaki","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A128","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A128","url":null,"abstract":"CD40, a tumor necrosis factor receptor superfamily member, is a promising immune-boosting target in cancer immunotherapy due to its role in promoting antitumor responses of immune cells. CD40 is also expressed on endothelial cells but the response of the tumor-associated vasculature to CD40-stimulating immunotherapy has not been studied. Herein, we have performed RNA-sequencing analysis of murine tumor endothelial cells (TECs) isolated from B16.F10 melanoma and MB49 bladder cancer treated with agonistic CD40 monoclonal antibody (mAb) or isotype control. Gene set and gene ontology enrichment analyses of the differentially expressed genes revealed that CD40 mAb treatment induces interferon-γ (IFNγ) signaling in the tumor microenvironment associated with up-regulation of immunosuppressive genes in TECs, including the enzyme indoleamine 2, 3-dioxygenase 1 (IDO1). Importantly, IDO1 was preferentially expressed in endothelial cells in the tumor and was positively correlated to infiltration of T-cells in the tumor microenvironment. In vitro, endothelial cells up-regulated IDO1 in response to T-cell-derived IFNγ, but not in response to CD40-stimulation. Collectively, our data suggest that IDO1 up-regulation in TECs occurs as a response to T-cell activation. Combining CD40 mAb therapy with the IDO1 inhibitor epacadostat delayed tumor growth and increased survival of B16.F10 tumor-bearing mice, which was associated with increased activation of cytotoxic T-cells. Hereby, we have uncovered a novel immunosuppressive feedback mechanism, in which the tumor vasculature limits the response to cancer immunotherapy by up-regulating IDO1. Citation Format: Anna Dimberg, Alexandros Karampatzakis, Sander Tuit, Mohanraj Ramachandran, Grammatiki Fotaki, Luuk van Hooren, Hua Huang, Roberta Lugano, Kaunisto Aura, Peter Ellmark, Sara M Mangsbo, Joachim L. Schultze, Magnus Essand, Maria Georganaki. Tumor endothelial cells say IDO to CD40-stimulating 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 A128.","PeriodicalId":18169,"journal":{"name":"Maintenance of Immune Balance: Effects of Targeted and Immune Therapies","volume":"74 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80618071","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 A150: Enhancing abscopal responses to radiation therapy by manipulating autophagy","authors":"M. Rybstein, T. Yamazaki, Aitziber Buqué Martinez, L. Galluzzi","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A150","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A150","url":null,"abstract":"Background: Macroautophagy (autophagy) is an evolutionary conserved cellular mechanism culminating with the lysosomal degradation of dispensable, damaged or potentially toxic cytoplasmic structures (e.g., permeabilized mitochondria). Autophagy helps cancer cells to adapt to harsh environmental conditions and to resist therapy. However, autophagy is also key for multiple steps of the anticancer immune response. Thus, whether autophagy should be inhibited or activated in the context of cancer therapy remains debated (Rybstein et al., Nat Cell Biol 2018). Since autophagy has been shown to play a key role in removal of cytosolic DNA, which is one mechanism leading to type I interferon (IFN) secretion, and since type I IFN is required for systemic immune responses activated by radiation therapy (RT), we asked the question as to whether selectively inhibiting autophagy in cancer cells may boost the ability of RT to initiate anticancer immunity. Methods/Tools: CRISPR/Cas9 technology was used to render mouse mammary carcinoma TSA and EO771 cells autophagy-deficient and chemical inhibitors of autophagy were also employed. Autophagy-competent versus –deficient systems were characterized for autophagy proficiency (by immunoblotting), growth (in vitro and in vivo), resistance to cell death induced by starvation, chemotherapy and RT (by multicolor flow cytometry and clonogenic assays) and production of type I IFN (by PCR and ELISA). Abscopal responses have been assessed in vivo. Results: In line with previous observations, autophagy inhibition reduced the growth of mouse mammary carcinoma cells, in vitro and in vivo, limited their clonogenic potential (at baseline) and increased their sensitivity to multiple stressors. Moreover, pharmacologic and genetic autophagy inhibition increased the capacity of mouse mammary carcinoma cells to secrete type I IFN in response to radiation. Finally, immunocompetent mice bearing syngeneic autophagy-deficient mouse mammary carcinoma cells mounted improved abscopal responses to RT (in the context of CTLA4 blockade) as compared to immunocompetent mice bearing syngeneic autophagy-competent cells, as determined by growth inhibition of a distant, non-irradiated, autophagy-competent lesion. Perspectives: We will test the innovative hypothesis that selective autophagy inhibition in cancer cells may synergize with autophagy activation at the whole-body level (by nutrient restriction or physical exercise), hence enabling superior therapeutic responses to radiation. Citation Format: Marissa Rybstein, Takahiro Yamazaki, Aitziber Buque Martinez, Lorenzo Galluzzi. Enhancing abscopal responses to radiation therapy by manipulating autophagy [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 A150.","PeriodicalId":18169,"journal":{"name":"Maintenance of Immune Balance: Effects of Targeted and Immune Therapies","volume":"57 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87627004","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}