bluuebunny/crossref_metadata_2025_split huggingface dataset:
IMMU-05. DISRUPTION OF THE CCR2 CHEMOKINE RECEPTOR PATHWAY OVERCOMES THERAPEUTIC RESISTANCE TO PD-1 BLOCKADE IN MALIGNANT GLIOMA
Authors: Flores-Toro Joseph , Luo Defang , Campbell James , Charo Israel , Singh Rajinder , Schall Thomas , Datta Meenal , Jain Rakesh , Mitchell Duane , Harrison Jeffrey 
Published: November 2019

Abstract

INTRODUCTION
Large scale clinical trials have failed to determine efficacy of adjuvant PD-1 blockade in recurrent glioblastoma (GBM). However, recent phase 2 clinical trial results demonstrating the potential of neo-adjuvant anti-PD-1 treatment have renewed enthusiasm for the use of immune checkpoint inhibitors (ICIs) in GBM. Additional benefit of ICIs in GBM will likely derive from development of novel therapies directed against immunosuppressive resistance mechanisms. Chemokine receptor 2 (CCR2) expressing tumor infiltrative immune suppressive myeloid cells represent a targetable axis within ICI resistant gliomas. We have established that CCR2 disruption unmasks an effect of anti-PD-1 therapy in ICI resistant murine glioma models. However, the mechanism(s) by which combined inhibition of PD-1 and CCR2 achieves efficacy is unknown.

OBJECTIVE
Determine the impact of combination anti-PD-1 and CCR2 antagonism on immune cells within anti-PD-1 resistant gliomas.

METHODS
Immune cell characteristics were determined in CCR2 antagonist (CCX872)/anti-PD-1 treated KR158 or 005 GSC glioma-bearing wild type or CCR2+/rfp/CX3CR1+/gfp reporter mice.

RESULTS
CCX872 increased median survival (32 vs. 50 days, P=.002) in KR158 tumor-bearing animals and in combination with anti-PD-1 significantly increased durable survival (P=.0005). In 005 GSC glioma-bearing mice, combination therapy also enhanced median survival (30 vs. 49 days, P=.005). CCX872 decreased CD45+/CD11bhi/Ly6Chi MDSCs (40%, P=.038) within gliomas, and increased these cells within bone marrow in both models (74%, P=.020). Three distinct intra-tumoral populations of CCR2+ and CX3CR1+ cells were identified in both glioma models including CCR2+/CX3CR1-/CD45hi/CD11blo, CCR2+/CX3CR1+/CD45hi/CD11bhi/Ly6Chi, and CX3CR1+/CD45lo/CD11bhi/F4/80+/MHCII+, with both CCR2+ populations being reduced by CCX872 treatment. Examination of tumor infiltrating lymphocytes revealed both increased presence and decreased exhaustion (PD-1+/Tim3+) of CD4+ (P=.029) and CD8+ (P=.011) T-cells following CCX872/anti-PD-1 treatment.

CONCLUSION
CCX872/anti-PD-1 combination therapy is effective in clinically relevant murine glioma models, providing a basis to progress this novel combinatorial treatment to human clinical trials.
IMMU-09. COMBINATION IMMUNE TREATMENT OF A HIGHLY AGGRESSIVE ORTHOTOPIC MURINE GLIOBLASTOMA WITH CHECKPOINT BLOCKADE AND MULTI-VALENT NEOANTIGEN VACCINATION
Authors: Liu Connor , Schaettler Maximilian , Bowman-Kirigin Jay , Kobayashi Dale , Miller Chris , Johanns Tanner , Dunn Gavin 
Published: November 2019

Abstract
Recent success using immunotherapies to treat a growing range of cancer types has reinvigorated efforts to identify effective immune-based treatments for glioblastoma (GBM). However, the limited clinical benefit observed in GBM patients treated with checkpoint blockade immunotherapy (CBI) has indicated a need for more rigorous approaches to augment host-immune recognition and killing of GBM. Of the myriad barriers to effective brain tumor immunotherapy, one potentially critical consideration is that a more systematic approach to tumor-specific antigen identification and targeting is necessary to potently stimulate and direct T cells to treat GBM. Therefore, in this study we set out to identify endogenous tumor neoantigens in the anti-PD-L1 resistant murine glioblastoma, CT2A, and assess the efficacy of neoantigen vaccination in combination with anti-PD-L1 treatment. In order to identify candidate CT2A neoantigens, we employed DNA whole exome sequencing, RNA sequencing, and in silico neoantigen prediction analyses. High-affinity H-2Kb and H-2Db candidate CT2A neoantigens were screened for immunogenicity by IFN-γ ELISPOT assays. Of the 30 top-ranking neoantigen candidates, 13 demonstrated immunogenic CD8+ T cell responses in the spleens of mice vaccinated with mutant peptides. Assessing for endogenous reactivity, we identified neoantigen specific CD8+ T cell responses in the intracranial TIL and draining lymph nodes to two H2-Kb restricted, Epb4H471L and Pomgnt1R497L, and one H2-Db restricted neoantigen, Plin2G332R. Survival studies showed that therapeutic neoantigen vaccination with Epb4H471L, Pomgnt1R497L, and Plin2G332R, in combination with anti-PD-L1 checkpoint blockade was superior to either neoantigen vaccination or anti-PD-L1 therapy alone. Thus, by applying a cancer immunogenomics approach to identify endogenous neoantigen reactivity in an aggressive and treatment resistant murine glioblastoma, we provide a preclinical framework to investigate the effects of multi-modality immunotherapeutic interventions in anti-glioma immunity.
IMMU-13. MECHANISMS OF IMMUNOLOGICAL ESCAPE DURING ADOPTIVE CELLULAR THERAPY IN HIGH GRADE GLIOMA
Authors: Wildes Tyler , Dyson Kyle , Francis Connor , Wummer Brandon , Yang Changlin , Yegorov Oleg , Shin David , Grippin Adam , Divita Bayli , Mitchell Duane , Flores Catherine 
Published: November 2019

Abstract

INTRODUCTION
Immunotherapy is remarkably effective, yet tumor escape is common. Herein, we investigated tumor escape after adoptive cellular therapy (ACT) in intractable glioma models. These studies revealed multiple mechanisms of escape including a shift in immunogenic tumor antigens, downregulation of MHC-I, and upregulation of checkpoint molecules. Despite these changes, we HYPOTHESIZED that a new population of escape variant-specific polyclonal T cells could be generated to target immune-escaped tumors through using tumor escape variant RNA.

METHODS
We studied KR158B-luc glioma-bearing mice during treatment with ACT with polyclonal tumor-specific T cells. We tested the immunogenicity of primary and escaped tumors using T cell restimulation assays. We used flow cytometry and RNA profiling of whole tumors to further define escape mechanisms. To treat immune-escaped tumors, we generated escape variant-specific T cells through the use of escape variant total tumor RNA and administered these cells as ACT.

RESULTS
Escape mechanisms included a shift in immunogenic tumor antigens, downregulation of major histocompatibility complex (MHC) class I by 50%, and upregulation of checkpoint molecules. This included activated T cells and NK cells from tumor-draining lymph nodes expressing 50% and 30% PD-1 after ACT. Importantly, polyclonal T cells specific for escape variants displayed greater recognition of escaped tumors than primary tumors. When administered as ACT, these T cells prolonged median survival of escape variant-bearing mice by 60% (24 to 33 days, p=.0003). The rational combination of ACT with PD-1 blockade prolonged median survival of escape variant glioma-bearing mice by 110% and was dependent upon NK cells and T cells as determined by cell depletion experiments. To prevent escape from primary tumors, we combined ACT with PD-1 blockade to yield 71% long-term cures in KR158B-luc-bearing mice.

CONCLUSIONS
These findings suggest that the immune landscape of brain tumors is markedly different post-immunotherapy yet can still be targeted with immunotherapy.
IMMU-23. TARGETING METASTATIC AND CNS TUMORS VIA MANNAN-BAM, TLR LIGANDS AND ANTI-CD40 ANTIBODY
Authors: Wang Herui , Medina Rogelio , Caisova Veronika , Uher Ondrej , Zenka Jan , Pacak Karel , Zhuang Zhengping 
Published: November 2019

Abstract
Immunotherapy based on activation of innate immunity has been tested in syngeneic mouse tumor models via intratumoral administration of the following components: phagocytosis-stimulating ligands (Mannan-BAM), toll-like receptor (TLR) agonists, and immunostimulant anti-CD40 antibody (abbreviated as MBTA). In this study, syngeneic colon carcinoma (CT26) and glioma (GL261) models were established to assess MBTA’s efficacy in generating immune responses against distal metastatic lesions and CNS tumors. Additionally, we investigated if therapeutic delivery of MBTA could be optimized beyond intratumoral delivery. In the colon carcinoma model, intratumoral injection of MBTA significantly reduced all metastatic CT26 tumor growth rate and induced complete remission (CR) in 33% (3/9) of treated animals. In the glioma model, subcutaneous injection of GL261 cells incubated with MBTA resulted in the complete regression of intracranial gliomas in 87.5% (7/8) of treated animals. Therapeutic effect of MBTA was abrogated in CD4+ and CD8+ lymphocyte depleted mice. Tumor infiltrating leukocyte analyses demonstrated significantly increased CD8+ cytotoxic T-lymphocytes (CTL) in metastatic tumors with higher percentages of TNFα and IFNγ positive cells. Further assessments with MHC I tetramers revealed significantly increased CT26-associated peptide (AH1) specific CTLs in the blood of MBTA treated animals. All animals that achieved complete remission in the colon carcinoma model resisted subsequent peripheral and intracranial challenges with CT26 cells, confirming the induction of immunological memory against CT26 tumors. Collectively, our investigation demonstrates that MBTA can effectively induce a tumor-specific adaptive immune response that can target tumors located in the periphery and within the CNS.
IMMU-26. RADIATION AND TEMOZOLOMIDE UP-REGULATES CD70 EXPRESSION AND ENHANCES CAR T- CELL RECOGNITION IN GBM
Authors: Na Meng , Jin Linchun , Tao Haipeng , Hou Alicia , Karachi Aida , Lin Zhiguo , Deleyrolle Loic , Sayour Elias , Mitchell Duane , Huang Jianping 
Published: November 2019

Abstract

BACKGROUND
Glioblastoma (GBM) is a recalcitrant brain cancer in the clinic. The therapeutic effect of using standard care (SC), such as surgery, radiation and/or temozolomide (TMZ) is dismal. CAR T-cell therapy has been increasingly recognized in the field as an innovative therapeutic approach for this malignancy. We identified CD70 as a glioma marker, and show that CD70CAR T cells recognize CD70+ GBMs and mediated regression of established tumors. Since recurrent GBMs that had been heavily treated by the SC treatments expressed a relatively higher level of CD70 than primary tumors, we thus hypothesize that these modalities may help to enhance the expression of CD70 and therapeutic effect of the CD70CAR T cell therapy in GBM.

OBJECTIVE
To determine if radiation or TMZ treatments could influence the CD70 expression of GBM, and the CD70CAR T-cell recognition.

METHODS
CD70 expression on GBM cell lines, including primary GBMs (CD70+ or CD70-) and U87 (CD70+), were assessed after treating with escalated doses of irradiation or TMZ. The protein and gene expression were determined by FACS or qRT-PCR analysis, respectively, at 4, 24, 48, and 120 hours post irradiation or TMZ treatment. Tumor recognition post-treatment was also carried out. Paired samples using an RNA-seq dataset from TCGA before and after tumor recurrence were evaluated for the CD70 expression.

RESULTS
CD70 expression was markedly increased by irradiation or TMZ treatment in a dose-dependent manner (beginning at 24 hours) in vitro in CD70+ GBMs, and a slight increased in the CD70— GBMs. The treatments enhance CD70CAR T cell recognition. Up-regulation of CD70 was found in the paired GBM patients.

CONCLUSION
This study demonstrates that the irradiation or TMZ treatment significantly up-regulates CD70 expression on GBMs and the CAR-T cell recognition, providing a rationale to combine CD70CAR-T cell therapy with SC for enhanced therapeutic efficacy in GBM.
IMMU-40. CANCER IMMUNOEDITING SHAPES THE IMMUNE ESCAPE SIGNATURE AND CLONAL ARCHITECTURE IN GLIOMAS
Authors: Lamszus Katrin , Mohme Malte , Maire Cecile , Riecken Kristoffer , Alawi Malik , Fehse Boris , Westphal Manfred 
Published: November 2019

Abstract
Immunotherapeutic strategies are increasingly important in neuro-oncology, and the elucidation of escape mechanisms which lead to treatment resistance is crucial. Understanding heterogeneous clonal dynamics and emergence of immune escape variants during cancer immunoediting can yield valuable insights into the adaptive processes governing treatment resistance. We applied a recently developed multicolor labeling strategy termed optical barcoding to compare in vivo clonality in an immunocompetent vs immunodeficient environment. Optically barcoded GL261 glioma cells were implanted in parallel into the brains of i) wildtype (wt) C57BL/6 mice, ii) immunodeficient Pfp-/- Rag2-/- mice or iii) PD1-/- mice and tumor growth was monitored. Ex vivo analysis of individual tumor clones revealed that tumors in immunocompetent mice had a profoundly different clonal architecture compared to immunodeficient mice. Whereas tumors in pfp-/- rag2-/- mice exhibited a highly polyclonal composition, immunoedited tumors in wt and PD1-/- mice showed reduced clonality with emergence of immune escape clones, independent of in vitro proliferation rates. Survival of wt mice was significantly longer than of Pfp-/- Rag2-/- mice and was even more prolonged in PD1-/- mice. Immunoediting in immunocompetent mice was further associated with striking differences in vascularity and invasiveness. Time-course microarray analyses, flow-cytometric phenotyping of tumor-infiltrating immune cells and immunostaining highlighted the role of PD-L1 and other immunosuppressive mediators as mechanisms to adapt to T-cell infiltration and IFN-ɣ production. Furthermore, RNAseq profiling of FACS-separated tumor cells, T cells and macrophages/microglia allowed the identification of IFN-ɣ-mediated T-cell-shaped gene expression signatures and of new pathways potentially involved in the immune escape of gliomas. To conclude, the process of cancer immunoediting during tumor evolution not only shapes gene expression profiles and growth patterns, but also has a profound impact on the intratumoral clonal heterogeneity in malignant gliomas.
IMMU-43. POLYAMINE METABOLISM REGULATES MYELOID IMMUNE SUPPRESSION IN GLIOBLASTOMA
Authors: Miska Jason , Lee Chang Catalina , Rashidi Aida , Han Yu , Lopez-Rosas Aurora , Lesniak Maciej S 
Published: November 2019

Abstract
Tumor-associated myeloid cells, which consist of tumor associated macrophages and myeloid-derived suppressor cells (MDSCs), make up a majority of cellular infiltrates in glioma. Glioma infiltrating MDSCs highly express arginase-1 (Arg-1), a catabolic enzyme thought to deplete arginine from the tumor microenvironment. Despite being a well-known marker of immunosuppressive cells, the metabolic reasons for this choice are not clear. Examination of MDSC phenotype in murine glioma models using: RNA-seq, bulk metabolomics, and Carbon-13 arginine flux revealed that two separate pathways of arginine catabolism converge on the generation of ornithine. Ornithine is the prerequisite substrate for the de-novo generation of polyamines, a group of nitrogen-rich metabolites with foundational importance to all mammalian, bacterial, and plant biology. Importantly, we found that the rate-limiting step of polyamine generation, ornithine decarboxylase 1 (ODC1), is dramatically upregulated by glioma infiltrating MDSCs, suggesting de-novo polyamine generation is important for MDSC function. Treatment with a specific inhibitor of de-novo polyamine synthesis, difluoromethylornithine (DMFO), inhibited the immunosuppressive function of in-vitro generated glioma associated MDSCs. However, DFMO only exerted effects before differentiation, as DFMO treatment post-generation did not change their suppressive functions. This suggests that the generation of the polyamine pool is critical to immune suppression by MDSCs. Interestingly the expression of the rate limiting step of polyamine degradation (SAT1) is inversely correlated with (ODC1) during MDSC differentiation, suggesting that utilization of this polyamine pool may be required for the suppressive functions of these cells. Inhibition of SAT1 after MDSC generation blunted MDSC mediated T-cell suppression. The results of this study show that the role of arginine metabolism in tumor infiltrating MDSCs is to generate pools of polyamines which maintain MDSC function in glioma. Therapeutic targeting of this pathway may be a novel and powerful tool to combat immunosuppression in glioma.
IMMU-45. CAR-T TREATMENT OF NOVEL MOUSE MODEL OF EGFRVIII+ GBM MIRRORS CLINICAL TRIAL OUTCOMES AND PROVIDES A SYNGENEIC PLATFORM FOR THE INVESTIGATION OF CAR-T MECHANISMS OF ACTION
Authors: Chuntova Polly , Yamamichi Akane , Naka Ryosuke , Hou Yafei , Okada Hideho 
Published: November 2019

Abstract
Despite the recent successes in cancer immunotherapy, brain tumors continue to present a significant challenge due to the unique relationship between the CNS and the immune system. Adoptive cell transfer of chimeric antigen receptor T-cells (CAR-T cells) targets tumor-associated and tumor-specific antigens. Multiple clinical trials testing CAR-T cells in the brain tumor setting have demonstrated the feasibility and safety, but also highlighted the limitations and continued need for treatment improvement. These challenges include recurrence of tumor cells that do not express the target antigens and induction of immuno-regulatory mechanisms, such as PD-L1 expression within the tumor. In this study, we used a murine GBM cell line (SB28), engineered to express the tumor-specific neoantigen human epidermal growth factor receptor variant III, to study the in vivo effects of EGFRvIII-CAR T-cells in a novel fully immunocompetent mouse model. SB28 cells have been shown to recapitulate key characteristics of human GBM, such as aggressive growth, low mutation burden, and resistance to immune checkpoint blockade therapy, and therefore, allow us to investigate many clinically relevant questions and variations in treatment protocol. Intravenous administration of CAR-transduced murine T-cells in EGFRvIII-expressing SB28 tumors showed survival benefit only when preceded by a lymphodepleting regimen. Despite prolonging survival, EGFRvIII-CAR-T cells were not curative, and the recurrent tumors displayed profound antigen loss, similar to post-treatment human tumor samples. Preliminary mechanistic studies revealed upregulation of IFNγ-inducible molecules, such as PD-L1 on tumor cells and tumor-infiltrating myeloid cells, as well as the emergence of a small, but discreet population of activated antigen presenting cells. Currently ongoing studies are aimed at delineating the exact molecular and cellular changes in the tumor microenvironment in response to the EGFRvIII-CAR T-cell treatment, in combination with clinically relevant therapies targeting the largely immunosuppressive tumor myeloid compartment
IMMU-50. SYSTEMIC ADOPTIVE TRANSFER IMMUNOTHERAPY WITH TCR-TRANSDUCED T-CELLS TARGETING NY-ESO-1 FOR MENINGIOMA
Authors: Sun Matthew , Orpilla Joey , Contreras Erick , Treger Janet , Molaie Donna , Tsang Jonathan , Antonios Joseph , Wang Anthony , Liau Linda , Prins Robert , Everson Richard 
Published: November 2019

Abstract

INTRODUCTION
The lack of immunotherapeutic antigen targets selectively expressed on meningiomas have historically hindered its immunotherapy development. However, recent literature showed that in meningiomas, NY-ESO-1 is the most frequently expressed Cancer-Testis(CT)-antigen, which is a group of proteins silent in somatic cells but reactivated in cancers. NY-ESO-1 also has higher expression in higher-grade meningiomas. Decitabine is known to upregulate CT-antigens and augment immunotherapy. To evaluate systemic adoptive transfer for meningiomas, we tested the efficacy of NY-ESO-1 T-cell-receptor(TCR)-transduced T-cells in vitro and in vivo, and the role of decitabine in meningioma immunotherapy.

METHODS
NY-ESO-1 TCR-Transduced T-cells were generated by double-transfection with supernatants from PG-13 retroviral packaging cell line encoding HLA-A*0201–restricted NY-ESO-1(157 – 165)-specific TCR. In vitro cytolysis was measured using the xCelligence Real-Time Cell Analyzer System. We utilized human meningioma cells SF1335(Grade I, HLA-A2.1 positive) and CH157(Grade III, HLA-A2.1 negative) in vitro and in vivo.

RESULTS
CH157 and SF1335 have high and low NY-ESO-1 expression, respectively. Decitabine upregulated NY-ESO-1 mRNA expression in SF1335 by 6-fold after 2 days and by 100-fold after 9 days, with similar effect on protein expression. Co-culturing CH157, CH157-HLA-A2.1(CH157 transduced with HLA-A2.1 vector), SF1335, and decitabine-pretreated-SF1335 cells individually with NY-ESO-1 TCR transduced T-cells at a ratio of 1:1 resulted in 0%, 65%, 20% and 40% cytolysis at 10hours, respectively. Systemic(intravenous) adoptive transfer of TCR-transduced T-cells significantly increased overall survival in NSG mice with intracranial xenografts of CH157-HLA-A2.1 (p=0.04) and SF1335(not treated with decitabine) (p=0.06).

CONCLUSIONS
NY-ESO-1 TCR-transduced T-cells induce NY-ESO-1 and HLA-A2.1-specific cytolysis in meningioma in vitro, and systemic adoptive transfer confers a statistically significant survival benefit in vivo for meningiomas with high NY-ESO-1 expression. Decitabine upregulates NY-ESO-1 expression and increases tumor cytolysis by TCR-transduced T-cells in meningiomas. Targeting NY-ESO-1 may be a clinically feasible immunotherapeutic strategy to treat aggressive meningiomas.
INNV-08. VALIDATION OF READIBAND™ ACTIGRAPH AND ASSOCIATED SLEEP/WAKE CLASSIFICATION ALGORITHMS IN PREDICTING CANCER-RELATED FATIGUE IN HIGH GRADE GLIOBLASTOMA
Authors: Tipps Megan , Hultman Meghan , Banerji Nilanjana , Jackson Kelsey , Liu Minda , Ellenberger Amy , Sanville Emily , Trusheim John 
Published: November 2019

Abstract

INTRODUCTION
Standard care for glioblastoma consists of maximal surgical resection followed by radiotherapy with concurrent and adjuvant temozolomide. Fatigue and sleep disturbances are among the most common side-effect reported by these patients. Monitoring long-term sleep patterns and fatigue levels in this population would allow for comparison between iatrogenic sleep disturbances, disease progression, treatment tolerance, and self-reported levels of fatigue. Wearable actigraph devices provide a potential alternative approach to polysomnography for long-term sleep monitoring. Here, we describe initial results from the implementation of the Readiband™ Sleep Tracker (Fatigue Science) for monitoring sleep patterns and fatigue in newly diagnosed glioblastoma patients.

PATIENTS AND METHODS
Patients with primary glioblastoma were prospectively enrolled and asked to wear the Readiband™ Sleep Tracker for a maximum of twelve months or until disease progression. Data regarding alertness levels and sleep patterns were collected from Fatigue Science. Patients were also asked to report fatigue levels and sleep quality via the Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F) and Pittsburg Sleep Quality Index (PSQI) questionnaires, respectively. Demographic, pathologic, and clinical information was abstracted from electronic medical records.

RESULTS
The Readiband™ data includes sleep/wake assessments, as well as sleep quality, sleep efficiency, and alertness scores. The overall sleep patterns reported by Readiband™ align with self-reported sleep times and sleep quantity. In addition, the SAFTE™ alertness scores show a positive correlation with FACIT-F (r=0.80) scores, and the sleep quality scores generated by Readiband™ show a negative correlation with PSQI (r=-0.83) scores.

CONCLUSION
The Readiband™ Sleep Tracker is a convenient and viable approach for monitoring sleep and fatigue in glioblastoma patients. Our preliminary findings suggest that actigraph measures can be used to monitor sleep quality and predict fatigue in this population. The study is ongoing to understand implications of sleep patterns on disease progression and treatment tolerance in primary glioblastoma.