| P541 | The immunosuppressive tumor microenvironment (TME) in Epstein-Barr virus (EBV)-positive and EBV-negative gastric cancers: implications for immunotherapy | Sepideh Besharati, MD; Tracee L. McMiller, MS; Mark Yarchoan; Qingfeng Zhu, PhD; Elizabeth L. Engle, MSc; Janis M. Taube, MD, MSC; Alan Berger; Robert A. Anders, MD, PhD; Suzanne L. Topalian, MD | Biomarkers; Checkpoint blockade; Coinhibition; Cytokine; Gene expression; Immune suppression; Monocyte/Macrophage; Tumor infiltrating lymphocytes (TILs); Tumor evasion; Tumor microenvironment |
| P542 | Exposure to anti-PD-1 causes Functional Differences in Tumor-Infiltrating Lymphocytes in Solid Tumors | Caitlin Creasy, MS; Cara Haymaker, PhD; Marie-Andrée Forget, Ph.D.; Gopal Singh, PhD; Coya Tapia, MD, PhD; Jeane M. Painter, PhD; Funda Meric-Bernstam, MD; Chantale Bernatchez; Aung Naing, MD, FACP | Clinical trial; Solid tumors; Tumor infiltrating lymphocytes (TILs) |
| P543 | Neoantigen heterogeneity as contributing factor for non-responders to neoantigen specific T-cell therapy in patients with metastatic gastrointestinal malignancies | Eric M. Groh, MD; Jared Gartner, MS; Todd D. Prickett, PhD; Yong Li, MS; Steven A. Rosenberg, MD, PhD; Paul F. Robbins, PhD | Adoptive immunotherapy; Neoantigens; Solid tumors; Tumor infiltrating lymphocytes (TILs) |
| P544 | Interferon-γ regulates the expression of PD-L1 and NKG2D ligand families in nasopharyngeal carcinoma | Lingling Guo; Yu Chen, MD, PhD; Lingling Guo; Chuanben Chen; | Biomarkers; Immune tolerance; NK/NK T cell; Tumor evasion; Tumor microenvironment |
| P545 | The tumor inflammasome functions as a rheostat for regulating the efficacy of anti-PD-1 antibody immunotherapy by driving the recruitment of myeloid-derived suppressor cells | Bala Thievanthiran, Ph.D.; Kathy Evans, B.S.; Nicholas DeVito, M.D.; Christine Xiao, BS; Yubin Kang, M.D.; David Hsu, M.D., Ph.D.; Alisha H. Holtzhausen, PhD; Brent A. Hanks, MD, PhD; | Checkpoint blockade; Chemokine; Granulocyte; Immune suppression; Myeloid cells; MDSC; Solid tumors; TLR; Tumor evasion; Tumor microenvironment |
| P546 | Targeted hypoxia reduction restores T cell infiltration and sensitivity to immunotherapy in prostate cancer | Priyamvada Jayaprakash, PhD; Midan Ai, PhD; Arthur Liu; Pratha Budhani, BS, MS; Todd Bartkowiak; Jie Sheng; Casey Ager, BS; Courtney Nicholas, PhD; Ashvin Jaiswal; Yanqiu Sun; Krishna Shah; Sadhana Balasubramanyam; Nan Li; Guocan Wang, PhD; Jing Ning; Anna Zal; Tomasz Zal, PhD; Michael A. Curran, PhD | Checkpoint blockade; Immune suppression; Myeloid cells; MDSC; Metabolism; T cell; Tumor infiltrating lymphocytes (TILs); Tumor evasion; Tumor microenvironment; Tumor stroma |
| P547 | Adoptive cell therapy and intratumoral nanoplexed poly I:C as an effective immunotherapy in interferon-signaling deficient melanoma | Anusha Kalbasi, MD; Kevin Hakimi, B.S.; Sarah Kremer; Christine Nguyen, B.S.; Davis Y. Torrejon, MD; Giulia Parisi; Pedro P. Lopez-Casas, PhD; Marisol Quintero, PhD, MBA; Antoni Ribas, MD, PhD | Adoptive immunotherapy; T cell; TLR; Tumor evasion |
| P548 | Association between corticosteroid use at time of immune checkpoint inhibitor (CPI) therapy initiation and CNS disease control/survival in patients with brain metastases (BM) | William J. Kelly, MD; Neil J. Shah; Michael T. Serzan, MD; Barbara T. Ma; Matthew Blackburn; Sebastian Ochoa; Alice R. Knoedler; Jeevan M. Puthiamadathil; Ariana Santopietro; Subha Madhavan; Anas Belouali; Shruti Rao; Kellie Gardner, NP; Suthee Rapisuwon, MD; Stephen Liu, MD; Deepa Subramaniam; Michael B. Atkins, MD; Geoffrey T. Gibney, MD; | Checkpoint blockade; Solid tumors |
| P549 | Cell proliferation defines an additional mechanism of immune escape in non-small cell lung cancer | Carl D. Morrison, MD, DVM; Sarabjot Pabla, MSc, PhD, BS; Mary Nesline, MS; Jeffrey Conroy, BS; Sean T. Glenn, PhD; Antonios Papanicolau-Sengos, MD; Paul DePietro, PhD; Jacob Hagen; Blake Burgher, BS, RN; Vincent Giamo, BS, MS; Jonathan Andreas, MS; Felicia L. Lenzo; Maochun Qin, MD, MS; Yirong Wang, M.S.; Devin Dressman, PhD; Konstantin Dragnev, MD; Laura J. Tafe; Tian Zhang, MD; Jeffrey M. Clarke, MD; Matthew Zibelman, MD; Luis de la Cruz-Merino; Alexander C. MacKinnon; Robin Jacob; Oliver Binns; Neel Shah; Mark Gardner; Grace K. Dy | Biomarkers; Solid tumors; Tumor microenvironment |
| P550 | Defeating checkpoint resistance: Highly specific inhibition of latent TGFβ1 activation renders resistant solid tumors vulnerable to PD-1 blockade | Thomas Schürpf; Constance J. Martin, PhD; Christopher Littlefield, MSc; Christopher Chapron, M.S.; Stefan Wawersik, PhD; Ashish Kalra, Ph.D.; Kevin Dagbay, PhD; Allison Simpson, BS; Francis Danehy, B.S.; Christopher Boston; Anastasia Nikiforov, MS; Susan Lin, BS; Justin Jackson, BS; Pichai Raman, PhD; Elizabeth Rainbolt, B.S.; Laurie Comfort, BS; David Harris; Madelyn Cecil-Taylor; Lorne Celentano; Danielle Meadows; gregory J. carven, PhD; Alan Buckler, Ph.D; Allan Capili, PhD; Abhishek Datta, PhD | Antibody; Checkpoint blockade; Immune suppression; Tumor infiltrating lymphocytes (TILs); Tumor microenvironment |
| P551 | Suppression of immune response by tumor cell-induced XIAP-NFκB signaling and targeting strategies to overcome immunotherapy resistance in breast cancer | Michael A. Morse; Scott J. Sauer, PhD; Myron Evans; Mohamed M. Ibrahim, MD; Xuhui Bao, MD; Pranalee Patel; Gayathri Devi, MSc., PhD; Gayathri Devi, MSc., PhD | Immune suppression; Tumor evasion |
| P552 | Analysis of TIL from human carcinoma combined with tissue imaging and in vitro models uncovers tumor-inflicted T cell deviations related to immune escape and strategies of intervention | Elfriede Noessner, PhD; Petra U. Prinz; Ilias Masouris; Anna Mendler; | Adoptive immunotherapy; Costimulation; Immune contexture; Monocyte/Macrophage; Solid tumors; T cell; Tumor evasion; Tumor microenvironment |
| P553 | Targeting mechanisms of immune suppression via CXCR2 inhibition to enhance checkpoint blockade | Elaine Pinheiro, PhD; Sarah Javaid, PhD; Ruban Mangadu; Marlene Hinton; Yun Wang; Sonia Feau; Amanda A. Watkins, PhD; Andrey Loboda, PhD; Xue Liang; Dario Gutierrez; Rebecca Ruck; Michael Rosenzweig, DVM, PhD; Vincent Giranda, MD, PhD; | Chemokine; Immune suppression; Myeloid cells; MDSC; Tumor infiltrating lymphocytes (TILs) |
| P554 | Role of immune escape for resistance to cancer (immuno) therapy and its strategies targeting these mechanisms | Barbara Seliger, MD, PhD; Juergen Bukur, PhD MD | Cytokine; Targeted therapy |
| P555 | A role for mutant p53 in mediating T cell immune evasion in pancreatic adenocarcinoma and other solid tumors | Deborah A. Silverman, BS; Supporting Author - Emily Ashkin; Simone Punt, PhD; Minying Zhang; Leila Williams, MSc; Anil Korkut; Jason Roszik, PhD; Anirban Maitra, MBBS; Patrick Hwu, MD; | Adoptive immunotherapy; Antigen presenting cells; Bioinformatics; Gene expression; Immune suppression; Solid tumors; T cell; Tumor infiltrating lymphocytes (TILs); Tumor evasion; Tumor microenvironment; Tumor stroma |
| P556 | STAT3-related cytokines drive IR-specific immune suppression of effector, memory and naïve, peripheral blood CD8+ T cells in cancer patients | Ashwin Somasundaram, MD; Dario A. Vignali, PhD; Anthony R. Cillo, PhD; James Herman; John M. Kirkwood, MD; Robert L. Ferris, MD, PhD; Tullia C. Bruno, PhD | Antibody; Biomarkers; Checkpoint blockade; Chemokine; Cytokine; Immune monitoring; Immune suppression; Immune tolerance; T cell; T cell lineages; Tumor evasion; Tumor microenvironment |
| P557 | Overcoming genetically-based resistance mechanisms to PD-1 blockade | Davis Y. Torrejon, MD; Gabriel Abril-Rodriguez, MS; Jennifer Tsoi; Ameya Champhekar; Giulia Parisi; Gardenia Cheung-Lau; Tom Wohlwender; Mykola Onyshchenko; Beata Berent-maoz; Catherine S. Grasso; Begoña Comin-Anduix, PhD; Siwen Hu-Lieskovan, MD, PhD; Antoni Ribas, MD, PhD; | Antigen presenting cells; Biomarkers; Checkpoint blockade; NK/NK T cell; T cell; T cell lineages; Tumor infiltrating lymphocytes (TILs); TLR; Tumor evasion; Tumor microenvironment |
| P558 | Secondary resistance to immunotherapy associated with β-catenin pathway activation or genetic loss of phosphatase and tensin homolog (PTEN) in metastatic melanoma | Jonathan A. Trujillo, MD, PhD; Jason J. Luke, MD, FACP; Stefani Spranger, PhD; Yuanyuan Zha, PhD; Karen Matijevich, RN, BSN; Thomas F. Gajewski, MD, PhD; | Checkpoint blockade; Immune monitoring; Solid tumors; Tumor evasion; Tumor microenvironment; Vaccine |
| P559 | Co-expression of TNF receptor 1 and 2 on human BRAF V600E+ melanomas is required for TNF-induced resistance to MAPK pathway inhibitors | Lazar Vujanovic, PhD; Cindy Sander, BS; Jian Shi, MD; John M. Kirkwood, MD; Lisa H. Butterfield, PhD | Chemotherapy; Cytokine; Immune contexture; Immune monitoring; Inflammation; Solid tumors; Tumor evasion; Tumor microenvironment |
| P560 | Resistance of CD44+ subpopulation to CTL though high production a protease inhibitor in colorectal cancer | Tomonori Yaguchi, MD, PhD; Tsubasa Miyauchi; Kenji Morii, MS; Yutaka Kawakami, MD PhD | Immune suppression; Tumor microenvironment |
| P561 | A new mechanism of ADCC resistance | David Zahavi, MS, BS; Dalal Aldeghaither; Louis M. Weiner, MD; Joseph Murray, MD, PhD; Elana Fertig; Garrett Graham; Yong-Wei Zhang; Allison O'Connell, MD/PhD Candidate; Junfeng Ma; Sandra Jablonski, PhD; | Antibody; NK/NK T cell; Targeted therapy; Tumor evasion |
| O39 | PAK4 inhibition reverses immune cell exclusion and overcomes resistance to checkpoint blockade therapy | Gabriel Abril-Rodriguez, MS; Antoni Ribas, MD, PhD; Davis Y. Torrejon, MD; Jesse Zaretsky; Theodore S. Nowicki, MD, PhD; Siwen Hu-Lieskovan, MD, PhD; Beata Berent-maoz; Begonya Comin-Anduix, PhD; Catherine S. Grasso; Antoni Ribas, MD, PhD; | Checkpoint blockade; Immune contexture; Tumor infiltrating lymphocytes (TILs); Tumor evasion |
| O40 | Anti-CTLA4 activation of intratumoral NK cells may contribute to intratumoral Treg depletion | Erica Stone, PhD; Erin M. O'Brien, MS; Emilio Sanseviero; Jenna Karras, PhD; Tamer Shabaneh; Bulent A. Aksoy, Ph.D.; Wei Xu; Xiaowei Xu; Giorgos Karakousis; Ravi K. Amaravadi, MD; Mark P. Rubinstein, PhD; Mary Jo Turk; Jeffrey Hammerbacher, BA; Lynn M. Schuchter, MD; Tara C. Mitchell; Qin Liu | Checkpoint blockade; NK/NK T cell; Regulatory T cell (Treg cell); T cell; T cell lineages; Tumor infiltrating lymphocytes (TILs); Tumor microenvironment |
| O41 | Tumor-derived GDF-15 which impairs LFA-1 dependent T cell recruitment represents a roadblock and a new target for cancer immunotherapy | Jörg Wischhusen, PhD; Markus MH. Haake, PhD | Antibody; Biomarkers; Checkpoint blockade; Coinhibition; Cytokine; Immune tolerance; Solid tumors; Tumor infiltrating lymphocytes (TILs); Tumor evasion; Tumor microenvironment |
