Regulating T-cells and Their Response to Cancer最新文献

{"title":"Abstract A215: Thymocyte selection-associated HMG box protein TOX is a master regulator of tumor-specific T-cell dysfunction","authors":"A. Scott, Steven Camara, P. Lauer, A. Synder, D. Zamarin, T. Walther, Olivier Levy, M. Glickman, J. Kaye, M. Philip, A. Schietinger","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A215","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A215","url":null,"abstract":"Tumor-specific CD8 T-cells in cancers enter a state of dysfunction characterized by the expression of inhibitory receptors and failure to produce effector cytokines and cytotoxic molecules. Here we identify the nuclear factor, Thymocyte selection-associated HMG box protein, TOX, as a master regulator of tumor-specific T-cell dysfunction. TOX is uniquely expressed in dysfunctional CD8 T-cells from mouse and human tumors but absent in functional T-cells. TOX expression is driven by continuous TCR stimulation and NFAT activity. Forced expression of TOX in functional effector T-cells was sufficient to induce a transcriptional program of dysfunction through the concerted expression of genes encoding numerous inhibitory receptors and dysfunction-associated transcription factors. Notably, TOX-deficient tumor-infiltrating T-cells did not upregulate inhibitory receptors such as PD1, LAG3, CD38, or CD39 and maintained high TCF1 expression. Surprisingly, despite their normal, “non-exhausted” phenotype, TOX-deficient T-cells failed to make effector cytokines, suggesting that loss of effector function in tumor-specific T-cells is uncoupled from inhibitory receptor expression. Furthermore, TOX-deficient T-cells failed to persist in tumors, ultimately undergoing activation-induced cell death. We propose that the TOX-induced transcriptional program of hyporesponsiveness is a physiologic negative feedback mechanism that prevents overstimulation; thus TOX is absolutely required for T-cell survival in the setting of chronic antigen stimulation as in cancers. Citation Format: Andrew C. Scott, Steven Camara, Peter Lauer, Alexandra Synder, Dmitriy Zamarin, Tyler Walther, Olivier Levy, Michael Glickman, Jonathan Kaye, Mary Philip, Andrea Schietinger. Thymocyte selection-associated HMG box protein TOX is a master regulator of tumor-specific T-cell dysfunction [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 A215.","PeriodicalId":170885,"journal":{"name":"Regulating T-cells and Their Response to Cancer","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129530445","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 A185: Effective expansion of poly-functional tumor-reactive TILs from NSCLC correlates with an immune-engaged T-cell profile in tumor tissues","authors":"R. Groot, M. Loenen, A. Guislain, D. Amsen, J. Haanen, K. Monkhorst, K. Hartemink, M. Wolkers","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A185","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A185","url":null,"abstract":"Non-small cell lung cancer (NSCLC) is the second most frequently occurring type of cancer. Because of the high mortality rates with the current treatment regimens, novel therapeutic approaches are warranted. The high mutational rate of the tumors, and the high level of T-cell infiltrates should render NSCLC patients eligible for autologous T-cell therapy. Here we show that tumor-infiltrating lymphocytes (TILs) from treatment naive, stage I-IIIa NSCLC tumors can be effectively expanded and reprogrammed. With an optimized detection essay for tumor-reactive T-cells, we observed that 13/17 tested TIL products (76.5%) from primary NSCLC tumor tissues contained cytokine-producing CD4+ and/or CD8+ T-cells in response to primary tumor digest. Tumor responses ranged from 0.5%-30%, and correlated well with activation markers on CD4+ and CD8+ T-cells. Importantly, 29.4% of the TIL products contained poly-functional T-cells that produced TNF-alfa and/or IL-2 in addition to IFN-gamma, and poly-functional T-cells correlated with high levels of tumor reactivity. Furthermore, high percentages of CD103+CD69+CD8+ T-cells, PD-1+CD4+ T-cells and FoxP3+CD25+CD4+ T-cells in the tumors were good predictors for the generation of highly tumor-reactive TIL products. In conclusion, we show that most NSCLCs contain tumor-specific T-cells that can be efficiently expanded and become highly poly-functional, depending on the initial T-cell profile of TILs. Our findings show the feasibility of culturing tumor-reactive TILs from NSCLC and provide keys to individualize adoptive T-cell therapy. Therefore, autologous T-cell therapy should be reconsidered as treatment for NSCLC patients. Citation Format: Rosa De Groot, Marleen M. van Loenen, Aurelie Guislain, Derk Amsen, John B.A.G. Haanen, Kim Monkhorst, Koen J. Hartemink, Monika C. Wolkers. Effective expansion of poly-functional tumor-reactive TILs from NSCLC correlates with an immune-engaged T-cell profile in tumor tissues [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 A185.","PeriodicalId":170885,"journal":{"name":"Regulating T-cells and Their Response to Cancer","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117226704","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 A172: Cxcr6-deficiency impairs cancer vaccine efficacy and resident memory CD8+ T-cells recruitment in tumor","authors":"S. Karaki, C. Blanc, T. Tran, I. Galy-Fauroux, M. Anson, R. Golub, E. Tartour","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A172","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A172","url":null,"abstract":"Immunization route is directly correlated with cancer vaccine efficacy. Our team previously showed that mucosal (intranasal, i.n.) and systemic (intramuscular) vaccinations are both able to induce systemic specific CD8+ T-cells but only i.n. immunization allows an efficient control of mucosal tumor growth. Indeed, the i.n. vaccination favors the tumor infiltration of specific CD8+ T-cells and especially tissue-resident memory T-cells (Trm), which are crucial for a potent antitumor activity. Based on a transcriptomic analysis, we have identified a chemokine receptor, CXCR6, highly expressed by these specific Trm CD8+ T-cells, induced by the i.n. vaccination. To understand the role of CXCR6 in vaccination efficacy, we have set up a body of experiments using heterozygous Cxcr6gfp/+ mice, where GFP reflects CXCR6 expression and homozygous Cxcr6-deficient mice Cxcr6gfp/gfp.We have then confirmed CXCR6 expression on specific Trm CD8+ T-cells induced by i.n. vaccination in lung mucosa. Using an orthotopic head and neck tumor model, CXCR6 expression on tumor-infiltrating Trm induced by i.n. immunization has also been reported. In addition, we showed that Cxcr6-deficiency impairs mice survival in a prophylactic and therapeutic i.n. vaccination settings in various mucosal tumor models. In this Cxcr6-deficient mouse model, the loss of vaccine-induced protection against tumor graft correlates with a clear reduction of Trm infiltration in tumor. Finally, in a cohort of human lung cancer, we have observed endogenous CXCR6+ Trm infiltrating these tumors in situ. To conclude, we have identified CXCR6 as a required parameter to recruit the crucial anti-tumor Trm in mucosal tumor. Our results finally indicate that CXCR6 might be a new surrogate biomarker to evaluate antitumor vaccine efficacy. Citation Format: Soumaya Karaki, Charlotte Blanc, Thi Tran, Isabelle Galy-Fauroux, Marie Anson, Rachel Golub, Eric Tartour. Cxcr6-deficiency impairs cancer vaccine efficacy and resident memory CD8+ T-cells recruitment in tumor [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 A172.","PeriodicalId":170885,"journal":{"name":"Regulating T-cells and Their Response to Cancer","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128179075","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 A213: Exploit the zebrafish to study lymphocyte infiltration in MYCN-amplified neuroblastoma","authors":"Xiaodan Qin, Andrew Lam, H. Feng","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A213","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A213","url":null,"abstract":"Neuroblastoma is one of the most common pediatric solid tumors that derives from sympathetic nerve ganglia. Children with MYCN-amplified tumors have a very poor prognosis. MYCN amplification is associated with impaired inflammatory profiles and reduced numbers of tumor-infiltrating cytotoxic T-lymphocytes (CTL). However, it remains elusive how MYCN blocks the trafficking of T-cells to tumors and protects tumor cells escaping from CTL-mediated cytotoxicity. Elucidation of the mechanism by which MYCN suppresses immune surveillance in the neuroblastoma microenvironment could lead to improved treatment outcomes through immunotherapy. We generated a zebrafish model, in which lymphocytes and tumor cells were differentially labeled with red and green fluorochromes. We monitored these fish for trafficking of mCherry-labeled lymphocytes to EGFP-positive MYCN-overexpressing premalignant neural crests on 5, 14, and 21 days post fertilization (dpf). We found that MYCN-overexpressing premalignant neural crests could attract lymphocytes in living fish. To observe lymphocyte infiltration in different stages of tumor development, we will perform cryosection and quantify lymphocyte infiltration in each stage of tumor development. While this zebrafish model is useful in studying the behaviors of immune cells at different stages of tumor development, it can be further exploited to understand how MYCN regulates immune escape and how immune cell infiltration can be enhanced in MYCN-amplified neuroblastoma to suppress tumor onset and progression. This knowledge is critical for development of more efficient immunotherapies in treating children with neuroblastoma. Citation Format: Xiaodan Qin, Andrew Lam, Hui Feng. Exploit the zebrafish to study lymphocyte infiltration in MYCN-amplified neuroblastoma [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 A213.","PeriodicalId":170885,"journal":{"name":"Regulating T-cells and Their Response to Cancer","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129025629","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 A188: T-cell priming with Deep IL-15 improves preclinical safety compared to systemic IL-15, and increases in vivo persistence and activity","authors":"E. Geretti, P. Bardwell, X. Liang, Santina Caruso, De-Kuan Chang, J. Lyons, Austin W Boesch, Aaron Handler, C. Tassa, S. Bilic, Janice Lancita, Becker Hawes, J. Fitzgerald, T. Andresen","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A188","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A188","url":null,"abstract":"Introduction: Interleukin-15 (IL-15), provides strong activation of both CD8+ T-cells and NK cells, without regulatory T-cells activation, making it an attractive immune modulator in cancer therapy. Systemic delivery of IL-15 to patients has revealed dose-limited toxicities resulting primarily in expansion of NK cells. Preclinical data suggest that IL-15 immunotoxicity is mediated by hyperproliferation and activation of NK cells (Guo Y, J Immunol 2015). In this study, we investigate safety and efficacy of T-cells loaded with Deep IL-15 (Deep IL-15 Primed T-cells), in a syngeneic mouse model. Deep IL-15 is a multimer of chemically crosslinked IL-15/IL-15 Rα/Fc heterodimers (IL15-Fc) that is designed for T-cell loading prior to adoptive cell transfer with the aim of improving the therapeutic window by autocrine signaling to the primed cells without causing the immunotoxicologic effects normally associated with IL-15. Deep IL-15 is loaded on the T-cells and, upon crosslinker cleavage, releases IL15-Fc to stimulate the primed cells. This novel T-cell-based therapeutic approach enables autocrine T-cell activation and expansion, and limits systemic exposure to IL15-Fc, thus reducing associated toxicities. Methods: Deep IL-15 was synthesized by incubation of IL15-Fc with a crosslinking reagent. PMEL CD8+ T (PMEL) cells were isolated from B6.Cg-Thy1a/Cy Tg(TcraTcrb)8Rest/J mice. PMEL cells carry a transgenic T-cell receptor specific for gp100, a protein expressed by B16-F10 melanoma cells. PMEL cells were activated, expanded, and loaded with Deep IL-15 to generate Deep IL-15 Primed PMEL (Deep-15 PMEL) cells. Deep-15 PMEL cells were transferred into naive or B16-F10 tumor-bearing mice (10 x 106; 15 ug Deep IL-15/106 cells), and the toxicity of Deep-15 PMEL was compared with PMEL (10 x 106) co-injected with soluble IL15-Fc at the maximum tolerated dose of 10 μg/mouse (PMEL + IL15-Fc). Readouts included IL15-Fc systemic exposure (ELISA), cytokine release (Luminex), and changes in endogenous T-cells (complete blood counts, CBC; flow cytometry). In addition, the biodistribution and the antitumor activity of Deep-15 PMEL was evaluated in B16-F10 tumor-bearing mice. Results: Deep-15 PMEL cells, carrying 15-fold more IL15-Fc than PMEL + IL15-Fc, resulted in >300-fold lower systemic exposure to IL15-Fc and 30-fold lower circulating IFN-γ. Deep-15 PMEL did not affect CBCs and did not expand endogenous CD8+ nor NK cells. Conversely, IL15-Fc induced significant changes in CBCs and promoted expansion of both transferred and endogenous CD8+ (6.7-fold) and NK (18.2-fold) cells. Similar results were observed in both naive and tumor-bearing mice. Deep-15 PMEL improved persistence of transferred cells across multiple tissues (15-44-fold rel. to PMEL co-injected with IL15-Fc; day 16): blood, spleen, lymph nodes (tumor draining and non-draining) and tumor. The tumor presence affected the biodistribution of Deep-15 PMEL cells, resulting in lower (0.5-fold) accumulation of ce","PeriodicalId":170885,"journal":{"name":"Regulating T-cells and Their Response to Cancer","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122141599","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 A202: Lysophosphatidic acid impedes the effector function of CD8+ T-cells through LPA5R","authors":"D. Mathew, Pamela Strauch, R. Pelanda, R. Torres","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A202","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A202","url":null,"abstract":"Immunotherapies have demonstrated the utility of targeting the immune system for the eradication of tumors, yet a majority of patients remain refractory to such treatments. Therefore, further advances in our understanding of T-cell activation and inhibitory signals are required to find alternative combinational strategies to treat cancers. Lysophosphatidic acid (LPA) is a bioactive lipid that has been characterized to promote tumor growth via distinct mechanisms and thus displays multiple “hallmarks” of tumorgenesis, including enhancing tumor-promoting inflammation, metastasis, and angiogenesis. Despite LPA receptors (LPARs) being expressed on all immune cells, the impact of LPA on immune cells remains unclear. Work from our lab has previously shown that LPA signals via LPAR5 expressed by CD8+ T-cells to suppress TCR-mediated intracellular calcium mobilization. Thus, we propose that aberrant expression of LPA by diverse tumors serves also to dampen adaptive immune responses, thereby creating an immune suppressive tumor microenvironment. Here, we demonstrate that CD8+ T-cells express three of the six known LPA receptors, and that LPA signaling through LPA5R on CD8+ T-cells has not only a profound inhibition of Ca2+ release after TCR stimulation, but also impedes ERK and Nur77 TCR induced signaling pathway. Importantly we now demonstrate that LPA signaling also decreases the cytolytic function of CD8+ T-cells by inhibiting granule exocytosis. Both adoptive transfer of Lpar5-/- CD8+ T-cells and implantation of tumors into Lpar5-/- hosts leads to greater control of tumor growth, underscoring an immunosuppressive signal mediated by LPA through LPA5R on CD8+ T-cells. Finally, human CD8+ T-cells also express the same LPARs as in the mouse and similarly fail to efficiently release Ca2+ upon TCR stimulation in the presence of LPA. Pharmaceutical inhibition of the human LPA5 receptor restores Ca2+ flux, suggesting a similar mechanism seen in mice. Thus, our data illuminate a novel lipid-receptor interaction that suppresses CD8+ T-cell function in both human and murine cells. Citation Format: Divij Mathew, Pamela Strauch, Roberta Pelanda, Raul Torres. Lysophosphatidic acid impedes the effector function of CD8+ T-cells through LPA5R [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 A202.","PeriodicalId":170885,"journal":{"name":"Regulating T-cells and Their Response to Cancer","volume":"110 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131351336","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 A210: Tumor-associated ADAM10 and ADAM17 produce soluble PD-L1 (sPD-L1, sB7-H1) and affect downstream tumor immunity – A resistance mechanism to PD-1 checkpoint blockade in melanoma","authors":"J. Orme, Khalid A Jazieh, S. Harrington, M. Ball, T. Azam, Xin Liu, Tiancheng Xie, A. Mansfield, R. Dronca, Haidong Dong","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A210","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A210","url":null,"abstract":"Background: Tumor surface PD-L1 (B7-H1) signals through T-cell surface receptor PD-1 to suppress antitumor immunity. PD-1 inhibitors like pembrolizumab block this pathway to prevent tumor escape from immunosurveillance. These PD-1 checkpoint inhibitors achieve objective response in 20-30% of patients with melanoma (1-3). As the majority of these patients are resistant to this treatment, there is a critical need to combat PD-1 checkpoint inhibitor resistance in melanoma. What is the mechanism of PD-1 checkpoint inhibitor resistance in melanoma? Our group has reported that soluble PD-L1 (sPD-L1, sB7-H1) is elevated in the serum of patients with PD-1 inhibitor-resistant melanoma and non-small cell lung cancer (NSCLC) (4). We have also shown that soluble PD-L1 is produced by cleavage from other tumor types and leads to apoptosis in CD8+ T-cells (5). The aim of this study is to confirm the source of sPD-L1 in human melanoma and its relation to outcomes. Methods: B7H1-expressing transgenic melanoma cells (Mel-B7H1) were treated with an array of protease inhibitors over 24 hours. Cells were then pelleted and supernatants were analyzed by ELISA for sPD-L1 (sB7-H1) production. Tumor serum samples were also analyzed by ELISA for sPD-L1 production.Tumor pathology slides from patients with melanoma (serum donors from the above study) were stained by immunohistochemistry with antibodies against proteases ADAM10 or ADAM17. Slides were visualized by microscopy for the presence of these antigens. Activated human CD8+ T-cells were cultured with recombinant human B7-H1 (PD-L1) protein, sPD-L1-rich, or sPD-L1-depleted supernatants from a tumor cell line in the presence of placebo or PD-1 checkpoint inhibitor antibodies. Cell survival was measured at 48 hours by flow cytometry.Results: ADAM10 inhibitor GI254023X, ADAM17 inhibitor TAPI-0, and broad metalloprotease inhibitor TAPI-2 inhibited Mel-B7H1 production of sB7H1 (p Citation Format: Jacob J. Orme, Khalid Jazieh, Susan Harrington, Matthew Ball, Tariq U. Azam, Xin (Cindy) Liu, Tiancheng Xie, Aaron Mansfield, Roxana S. Dronca, Haidong Dong. Tumor-associated ADAM10 and ADAM17 produce soluble PD-L1 (sPD-L1, sB7-H1) and affect downstream tumor immunity – A resistance mechanism to PD-1 checkpoint blockade in melanoma [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 A210.","PeriodicalId":170885,"journal":{"name":"Regulating T-cells and Their Response to Cancer","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128301090","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 A171: A fully human tissue-based ex vivo cell migration analysis model to study T-cell infiltration and distribution in colorectal cancer liver metastases","authors":"Anna Berthel, M. Suarez-Carmona, Jakob Nikolas Kather, Rodrigo Rojas-Moraleda, Pornpimol Chaorentong, N. Valous, F. Klupp, Martin Schneider, A. Ulrich, M. Buechler, I. Zoernig, D. Jaeger, N. Halama","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A171","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A171","url":null,"abstract":"T-cell exclusion by tumors is one of the major obstacles for cancer immunotherapies. In colorectal cancer liver metastasis (CRC-LM) patients, effector T-cells are mainly found in the invasive margin and not in the tumor epithelium. Such T-cell exclusion might hinder an effective antitumor immune response and could account for therapy failures with immune checkpoint inhibitors, which is observed in the majority of CRC-LM patients. As T-cell infiltration and distribution are difficult to detect in patients, little is known about detailed immunotherapy effects on tumor-infiltrating lymphocytes (TIL). Therefore, we established a fully human tissue-based ex vivo cell migration analysis model to monitor T-cell infiltration and positioning in the authentic tumor microenvironment of CRC-LM patients. In brief, we isolated T-cells from fresh resected CRC-LM patient tissue samples, labeled the cells with a fluorescent dye and returned the labeled T-cells to the tissues, which were cultured for a certain time period. Besides autologous T-cells, several tissue samples were treated with non-autologous labeled T-cells isolated from a healthy donor. After tissue processing, immunostaining and cell quantification, we observed that remigration of the labeled autologous and donor T-cells into the tissues was significantly associated with numbers of endogenous TIL. The labeled autologous and donor T-cells showed a similar distribution pattern to endogenous TIL with highest densities in the invasive margin of patient tissues. No relevant changes in tumor cell numbers or apoptosis protein concentrations could be observed by both treatments. Furthermore, quantification of the chemokines CXCL9, CXCL10 and CCL5 showed significant associations with labeled autologous and donor T-cell infiltration. Interestingly, treatment with a PD1 inhibitor did not support infiltration of exogenous or endogenous T-cells into the tumor epithelium. Our findings highlight that infiltrating T-cells in CRC-LM are always positioned into the invasive margin independently of the T-cell´s origin. Especially microenvironmental factors such as CXCL9, CXCL10 and CCL5 seem to be involved in this process, preventing T-cell contact with the tumor epithelium, which could also not be abrogated by immune checkpoint inhibition. The similar infiltration and distribution pattern of T-cells in the ex vivo and in vivo settings highlights the functionality and reliability of the human tissue-based cell migration analysis model, emphasizing its use for studying therapy effects on TIL in CRC-LM patient tissues. Citation Format: Anna Berthel, Meggy Suarez-Carmona, Jakob N. Kather, Rodrigo Rojas-Moraleda, Pornpimol Chaorentong, Nektarios A. Valous, Fee Klupp, Martin Schneider, Alexis Ulrich, Markus Buechler, Inka Zoernig, Dirk Jaeger, Niels Halama. A fully human tissue-based ex vivo cell migration analysis model to study T-cell infiltration and distribution in colorectal cancer liver metastases [abstract]. In: Pro","PeriodicalId":170885,"journal":{"name":"Regulating T-cells and Their Response to Cancer","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129803343","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 A199: TNFR2-targeted elimination of Tregs and tumor-residing T-cells in a murine colon cancer model","authors":"R. LaMontagne","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A199","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A199","url":null,"abstract":"Introduction: Tumor necrosis factor receptor 2 (TNFR2, or TNFRSF1B) is a lymphoid marker of the most potent regulatory T-cell (Treg) subtype and a commonly expressed oncogene in human tumors. TNFR2 Tregs are also enriched in the tumor microenvironment. TNFR2 antagonistic antibodies have been developed to inhibit NFkB-driven growth through the TNFR2 receptor, showing both Treg and tumor inhibition with specificity for the tumor microenvironment (Sci Signaling 2017). A mouse surrogate, TY101, has been developed to assess efficacy in murine models of colon cancer. Methods: We designed monoclonal antibodies to target the TNFR2 oncogene and directly kill tumor cells in syngeneic murine models of colon cancer: CT26 and MC28. All studies were conducted by an independent third party (Champions Oncology). The primary endpoint was a reduction in tumor size. Results: In MC38 mice, the TNFR2 antagonist combined with anti-PD1 immunotherapy was more effective than placebo or immunotherapy alone in reducing mean tumor volume (P=0.004). In CT26 mice, the TNFR2 antagonist as a monotherapy was more effective compared to placebo or combination therapy with anti-PD1 (p Citation Format: Russell LaMontagne. TNFR2-targeted elimination of Tregs and tumor-residing T-cells in a murine colon cancer model [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 A199.","PeriodicalId":170885,"journal":{"name":"Regulating T-cells and Their Response to Cancer","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114427352","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 A226: Cell-free membrane reconstitution system for cis and trans interaction of T-cell co-receptors and ligands","authors":"Yunlong Zhao, E. Hui","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A226","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A226","url":null,"abstract":"Immunotherapy, which harnesses the immune system to combat cancers, is a paradigm-shifting approach in oncology. One important branch of immunotherapy is to use drugs to perturb molecular interactions at the T-cell–antigen presenting cell (APC) interface. In particular, antibodies that block the T-cell coinhibitory receptor PD-1 or its ligand PD-L1 have produced unprecedented clinical activities against a subset of human cancers in a fraction of patients. Extending immunotherapy to a larger patient population requires a better understanding of the interaction network at the T-cell-APC interface. Typically, it is believed that ligands from APCs bind to receptors on T-cells (in trans) to trigger intracellular signaling. A largely overlooked fact is that many receptors often co-exist with ligands on T-cells and APCs, including PD-1/PD-L1 and CD28/B7.1. Using novel reconstitution approaches, we recently discovered that co-expressed PD- 1 and PD-L1 bind to each other in cis and this cis interaction competes with their trans interaction to inhibit PD-1 signaling. We hypothesize that cis interaction occurs with many other ligand-receptor pairs and may regulate other aspects of tumor immunity by perturbing their trans interactions. We are currently using our robust reconstitution systems to ask whether other immunoreceptors and ligands interact in cis and how the putative cis interaction affect their trans interactions. Specifically, to detect cis interaction, we co-attach the ligand and receptor to liposomes, and probe their cis interaction using a fluorescence resonance energy transfer (FRET) readout. To detect trans interaction, we have developed a liposome-lipid bilayer conjugation assay, in which binding between ligand- labeled liposomes and receptor-labeled supported lipid bilayer (SLB) is used as an index for trans interaction. To determine whether cis interaction inhibits trans interaction, we ask in the liposome-bilayer system if addition of receptor on liposomes decreases liposome-SLB conjugation. Our preliminary data revealed that CD28 only binds B7.1 in trans, but not in cis. In contrast, PD-1 binds with PD-L1 both in cis and trans, and the two modes of interaction compete with each other. Further experiments in cells confirmed our finding in vitro, demonstrating the utility of our cell-free reconstitution systems in detecting cis and trans interaction of T-cell co-receptors. Insights from this study will help us clarify the ligand-receptor interaction network at the immunological synapse. Citation Format: Yunlong Zhao, Enfu Hui. Cell-free membrane reconstitution system for cis and trans interaction of T-cell co-receptors and ligands [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 A226.","PeriodicalId":170885,"journal":{"name":"Regulating T-cells and Their Response to Cancer","volume":"88 4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126105729","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}