scholarly journals MODL-28. IMMUNE PRIMING WITH INTERFERON-Γ COMBINED WITH EPIGENETIC MODULATION IN PEDIATRIC BRAIN TUMORS

2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii416-iii417
Author(s):  
Erin Crotty ◽  
Shelli Morris ◽  
Ken Brasel ◽  
Emily Girard ◽  
Alyssa Noll ◽  
...  
Keyword(s):  
T Cell ◽  
Brain Tumors ◽  
Pediatric Brain Tumors ◽  
Interferon Γ ◽  
Interferon Response ◽  
Class I Mhc ◽  
Mhc I ◽  
Immune Priming ◽  
Oncofetal Antigens ◽  
Pediatric Brain

Abstract Systemic interferon-γ (IFNγ) has been shown to induce major histocompatibility complex class I (MHC-I) and T cell infiltration in solid tumors in adult patients, demonstrating a potential strategy to abrogate tumor-intrinsic mechanisms of immune escape. Pediatric brain tumors (PBT) may be particularly sensitive to this approach but have a paucity of immunogenic tumor antigens for presentation on MHC-I. Decitabine and other DNA methyltransferase (DNMT) inhibitors promote expression of oncofetal antigens and endogenous immune responses through epigenetic alterations. We tested the convergence of these immune priming mechanisms using a novel combination of IFNγ and decitabine across a spectrum of PBT. Primary human cell lines (Med-411FH, PBT-05FH, GBM-511FH, CCHMC-GBM-1, CCHMC-GBM-4, ATRT-310FH) and murine transgenic models were treated with IFNγ alone or in combination with decitabine and evaluated expression of cell surface MHC-I and PD-L1, interferon response genes (ISGs), and oncofetal antigens. PBT showed exquisite sensitivity to IFNγ, increasing expression of MHC-1/PD-L1 along with ISGs (TAP1, MX1, IRF1). Decitabine enhanced IFNγ-induced gene expression of oncofetal antigens NY-ESO-1 and MAGE-A1. In a medulloblastoma flank tumor model, MHC-I was increased by 40-fold following intraperitoneal IFNγ treatment (p=0.01), with a 3-fold increase in PD-L1 (p=0.005) compared to untreated controls. Effect on CD8+ T cell killing and validation in humanized models is ongoing. Immune priming of PBT with IFNγ is feasible and results in more substantial MHC-I upregulation compared to hypomethylating agents alone. These results provide a strong rationale for priming prior to checkpoint inhibition as a compelling therapeutic strategy in immunologically-quiescent PBT.

scholarly journals EXTH-73. HETEROGENEITY IN CELL SURFACE ANTIGEN AND HLA CLASS I EXPRESSION IN PEDIATRIC BRAIN TUMORS AND ITS IMPACT ON T-CELL IMMUNOTHERAPY

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii103-ii103
Author(s):  
Haley Houke ◽  
Xiaoyan Zhu ◽  
Kimberly S Mercer ◽  
Jennifer L Stripay ◽  
Jason Chiang ◽  
...  
Keyword(s):  
T Cells ◽  
Brain Tumor ◽  
T Cell ◽  
Brain Tumors ◽  
Cell Surface ◽  
Hla Class I ◽  
Pediatric Brain Tumors ◽  
Class I ◽  
Car T ◽  
Pediatric Brain

Abstract Immunotherapy with tumor antigen-specific chimeric antigen receptor (CAR) and/or ab (T-cell receptor) TCR T-cells has the potential to improve clinical outcomes of patients with pediatric brain tumors. As a prerequisite for successful T-cell therapies, we must determine which cell surface antigens are expressed and targetable in these tumors, and if HLA Class I is present, which is necessary for ab TCR T-cell recognition. Therefore, in this study we systematically analyzed pediatric patient-derived orthotopic xenograft (PDOX) brain tumor samples for cell surface expression of five known CAR targets: IL13Ra2, HER2, EphA2, B7-H3, and GD2, as well as HLA Class I. We established and validated a flow cytometry-based method of profiling tumor-associated antigens. Fifty-three PDOX samples have been profiled to date, including medulloblastoma, high grade glioma (HGG), diffuse intrinsic pontine glioma (DIPG), atypical teratoid rhabdoid tumor (ATRT), and ependymoma, among others. Our results showed high variability within and between individual samples. B7-H3 was the most consistently expressed, seen in 98% of the samples tested. We validated these results by conventional immunohistochemistry staining for B7-H3 and found comparable RESULTS: HLA Class I was highly expressed on all HGG samples but was undetectable on 47.8% of other brain tumor samples. This suggests that down-regulation of HLA class I is one mechanism by which brain tumors evade conventional T-cells, and that HLA-independent CAR T-cells would be useful therapies. We also compared expression of antigens in fresh patient samples and corresponding PDOX tumors and saw that they were indeed similar. To our knowledge, this is the largest group of pediatric brain tumor PDOX samples methodically analyzed for potential CAR target antigens and HLA Class I. Taken together, our data demonstrate that elimination of tumors by CAR T-cell immunotherapies will require targeting multiple antigens, and our profiling method could inform how to circumvent antigen-negative relapse.

scholarly journals Cell surface antigen profiling of pediatric brain tumors: B7-H3 is consistently expressed and can be targeted via local or systemic CAR T-cell delivery

2020 ◽  
Author(s):  
Dalia Haydar ◽  
Haley Houke ◽  
Jason Chiang ◽  
Zhongzhen Yi ◽  
Zelda Odé ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Brain Tumors ◽  
Hla Class I ◽  
Pediatric Brain Tumors ◽  
Class I ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T ◽  
Pediatric Brain

Abstract Background Immunotherapy with CAR T-cells is actively being explored for pediatric brain tumors in preclinical models and early phase clinical studies. At present it is unclear which CAR target antigens are consistently expressed across different pediatric brain tumor types. In addition, the extent of HLA class-I expression is unknown, which is critical for tumor recognition by conventional αβTCR T-cells. Methods We profiled 49 low- and high-grade pediatric brain tumor patient-derived orthotopic xenografts (PDOX) by flow analysis for the expression of five CAR targets (B7-H3, GD2, IL13Rα2, EphA2, HER2), and HLA class-I. In addition, we generated B7-H3-CAR T-cells and evaluated their antitumor activity in vitro and in vivo. Results We established an expression hierarchy for the analyzed antigens (B7-H3 = GD2 >> IL13Rα2 > HER2 = EphA2) and demonstrated that antigen expression is heterogenous. All high-grade gliomas expressed HLA class-I, but only 57.1% of other tumor subtypes had detectable expression. We then selected B7-H3 as a target for CAR T-cell therapy. B7-H3-CAR T-cells recognized tumor cells in an antigen-dependent fashion. Local or systemic administration of B7-H3-CAR T-cells induced tumor regression in PDOX and immunocompetent murine glioma models resulting in a significant survival advantage. Conclusions Our study highlights the importance of studying target antigen and HLA class-I expression in PDOX samples for the future design of immunotherapies. In addition, our results support active preclinical and clinical exploration of B7-H3-targeted CAR T-cell therapies for a broad spectrum of pediatric brain tumors.

Immunophenotyping of pediatric brain tumors: correlating immune infiltrate with histology, mutational load, and survival and assessing clonal T cell response

2018 ◽  
Vol 137 (2) ◽  
pp. 269-278 ◽  
Author(s):  
Ashley S. Plant ◽  
Shohei Koyama ◽  
Claire Sinai ◽  
Isaac H. Solomon ◽  
Gabriel K. Griffin ◽  
...  
Keyword(s):  
T Cell ◽  
Brain Tumors ◽  
Cell Response ◽  
Pediatric Brain Tumors ◽  
T Cell Response ◽  
Mutational Load ◽  
Immune Infiltrate ◽  
Pediatric Brain

scholarly journals IMMU-04. IMMUNOPHENOTYPING OF PEDIATRIC BRAIN TUMORS: CORRELATING IMMUNE INFILTRATE WITH HISTOLOGY, MUTATIONAL LOAD, AND SURVIVAL AND ASSESSING CLONAL T CELL RESPONSE

2017 ◽  
Vol 19 (suppl_6) ◽  
pp. vi113-vi113
Author(s):  
Ashley Plant ◽  
Shohei Koyama ◽  
Claire Sinai ◽  
Isaac Solomon ◽  
Gabriel Griffin ◽  
...  
Keyword(s):  
T Cell ◽  
Brain Tumors ◽  
Cell Response ◽  
Pediatric Brain Tumors ◽  
T Cell Response ◽  
Mutational Load ◽  
Immune Infiltrate ◽  
Pediatric Brain

scholarly journals IMMU-14. IMPLICATIONS FOR T-CELL IMMUNOTHERAPY: CELL SURFACE ANTIGEN AND HLA class I EXPRESSION IN PEDIATRIC BRAIN TUMORS ARE HETEROGENOUS

2019 ◽  
Vol 21 (Supplement_2) ◽  
pp. ii96-ii96
Author(s):  
Haley Houke ◽  
Suzanne J Baker ◽  
Martine F Roussel ◽  
Stephen Gottschalk ◽  
Giedre Krenciute
Keyword(s):  
T Cell ◽  
Brain Tumors ◽  
Cell Surface ◽  
Surface Antigen ◽  
Hla Class I ◽  
Pediatric Brain Tumors ◽  
Cell Surface Antigen ◽  
Cell Immunotherapy ◽  
Pediatric Brain ◽  
T Cell Immunotherapy

scholarly journals IMMU-06. T-CELL IMMUNOTHERAPY FOR PEDIATRIC BRAIN TUMORS: DIVERSITY IN CELL SURFACE ANTIGEN AND HLA EXPRESSION NECESSITATES A MULTI-PRONGED APPROACH

2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii360-iii361
Author(s):  
Haley Houke ◽  
Xiaoyan Zhu ◽  
Kimberly S Mercer ◽  
Jennifer L Stripay ◽  
Jason Chiang ◽  
...  
Keyword(s):  
T Cell ◽  
Brain Tumors ◽  
Cell Surface ◽  
Hla Class I ◽  
Pediatric Brain Tumors ◽  
Class I ◽  
Fresh Tissue ◽  
Cell Immunotherapy ◽  
Pediatric Brain ◽  
T Cell Immunotherapy

Abstract Cell surface or intracellular antigens expressed in pediatric brain tumors are potential targets for chimeric antigen receptor (CAR) or ab (T-cell receptor) TCR T-cell immunotherapy. At present it remains unknown what cell surface antigens are suitable CAR targets for pediatric brain tumors; in addition, cell surface expression of HLA class I, a molecule critical for ab TCR T-cell recognition, has not been systemically studied in these tumors. Therefore, we set out to assess expression of five CAR targets (IL13Ra2, HER2, EphA2, B7-H3, GD2) and HLA class I. We established and validated a flow cytometry-based method to profile CAR targets and HLA class I expression from pediatric patient-derived xenograft (PDX) samples. To date, we profiled 53 PDX samples, including medulloblastoma, HGG, DIPG, ATRT, and ependymoma. We found that antigen expression has high intra- and inter-PDX sample variability with B7-H3 and IL13Ra2 being most consistently expressed. We confirmed these findings using conventional IHC for B7-H3 with PDX samples and patient tissue microarrays. HLA class I was present on the cell surface of HGGs and DIPGs, however significantly down-regulated in 26 out of 36 other brain tumor types. Finally, matched fresh tissue and PDX sample analysis revealed that cells derived from PDX models are indeed representative of fresh tissue. Our results indicate that more than one antigen needs to be targeted to achieve a more complete tumor clearance. In addition, variable expression of HLA class I suggests that pediatric brain tumors have developed immune evasion strategies to prevent recognition by conventional T cells.

scholarly journals New Era of Immunotherapy in Pediatric Brain Tumors: Chimeric Antigen Receptor T-Cell Therapy

2021 ◽  
Vol 22 (5) ◽  
pp. 2404
Author(s):  
Wan-Tai Wu ◽  
Wen-Ying Lin ◽  
Yi-Wei Chen ◽  
Chun-Fu Lin ◽  
Hsin-Hui Wang ◽  
...  
Keyword(s):  
T Cell ◽  
Brain Tumors ◽  
Cell Therapy ◽  
Pediatric Brain Tumors ◽  
T Cell Therapy ◽  
New Era ◽  
Car T Cell ◽  
Car T Cell Therapy ◽  
Car T ◽  
Pediatric Brain

Immunotherapy, including chimeric antigen receptor (CAR) T-cell therapy, immune checkpoint inhibitors, cancer vaccines, and dendritic cell therapy, has been incorporated as a fifth modality of modern cancer care, along with surgery, radiation, chemotherapy, and target therapy. Among them, CAR T-cell therapy emerges as one of the most promising treatments. In 2017, the first two CAR T-cell drugs, tisagenlecleucel and axicabtagene ciloleucel for B-cell acute lymphoblastic leukemia (ALL) and diffuse large B-cell lymphoma (DLBCL), respectively, were approved by the Food and Drug Administration (FDA). In addition to the successful applications to hematological malignancies, CAR T-cell therapy has been investigated to potentially treat solid tumors, including pediatric brain tumor, which serves as the leading cause of cancer-associated death for children and adolescents. However, the employment of CAR T-cell therapy in pediatric brain tumors still faces multiple challenges, such as CAR T-cell transportation and expansion through the blood–brain barrier, and identification of the specific target antigen on the tumor surface and immunosuppressive tumor microenvironment. Nevertheless, encouraging outcomes in both clinical and preclinical trials are coming to light. In this article, we outline the current propitious progress and discuss the obstacles needed to be overcome in order to unveil a new era of treatment in pediatric brain tumors.

scholarly journals IMMU-23. IMMUNOPHENOTYPING OF PEDIATRIC BRAIN TUMORS: CORRELATING IMMUNE INFILTRATE WITH HISTOLOGY, MUTATIONAL LOAD, AND SURVIVAL AND ASSESSING CLONAL T CELL RESPONSE

2017 ◽  
Vol 19 (suppl_4) ◽  
pp. iv32-iv32
Author(s):  
Ashley S. Plant ◽  
Shohei Koyama ◽  
Claire Sinai ◽  
Isaac Solomon ◽  
Gabriel Griffin ◽  
...  
Keyword(s):  
T Cell ◽  
Brain Tumors ◽  
Cell Response ◽  
Pediatric Brain Tumors ◽  
T Cell Response ◽  
Mutational Load ◽  
Immune Infiltrate ◽  
Pediatric Brain

scholarly journals IMMU-16. TARGETING GLYPICAN 2 (GPC2) ON PEDIATRIC MALIGNANT BRAIN TUMORS WITH MRNA CAR T CELLS

2021 ◽  
Vol 23 (Supplement_1) ◽  
pp. i30-i30
Author(s):  
Jessica Foster ◽  
Crystal Griffin ◽  
Allison Stern ◽  
Cameron Brimley ◽  
Samantha Buongervino ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Brain Tumors ◽  
Pediatric Brain Tumors ◽  
Embryonal Tumors ◽  
Car T Cells ◽  
Group 4 ◽  
Car T ◽  
Pediatric Brain

Abstract Glypican 2 (GPC2) is a cell-surface oncoprotein initially identified in neuroblastoma, retinoblastoma, and medulloblastoma as an ideal target for immunotherapy (Cancer Cell, 2017). Here we evaluated GPC2 expression across the spectrum of pediatric brain tumors using RNA sequencing from specimens in the Children’s Brain Tumor Network (CBTN). High GPC2 expression, defined as >10 FPKM, was found in 100% of embryonal tumors with multilayered rosettes (ETMRs) (n=6), 95% of medulloblastomas (n=122), 86% of other embryonal tumors (n=21), 50% of choroid plexus carcinomas (n=4), 42% of high grade gliomas (HGG) (n=117), and 37% of diffuse midline gliomas (DMG) (n=65). Within medulloblastoma subtypes, group 4 tumors had the highest expression, and within the HGG tumor cohort H3.3 G34 mutated gliomas had the highest GPC2 expression. High GPC2 protein expression was validated with medulloblastoma and HGG/DMG primary tumors and cell lines using IHC, Western blot, and flow cytometry. We next developed two potent CAR T cell constructs using the D3 specific scFv directed against GPC2 for testing in brain tumor models. GPC2-directed CAR T cells were tested in vitro against medulloblastoma and HGG cells lines, and in vivo using two patient-derived medulloblastoma xenograft models: Rcmb28 (group 3) and 7316-4509 (group 4). GPC2-directed mRNA CAR T cells induced significant GPC2-specific cell death in medulloblastoma and HGG cellular models with concomitant T cell degranulation compared to CD19-directed mRNA CAR T cells. In vivo, GPC2-directed mRNA CAR T cells delivered locoregionally induced significant tumor regression measured by bioluminescence after 4–6 intratumoral infusions of 4 x 106 CAR T cells (p<0.0001 for Rcmb28, p<0.05 for 7316-4509). No GPC2-directed CAR T cell related toxicity was observed. GPC2 is a highly differentially expressed cell surface protein on multiple malignant pediatric brain tumors that can be targeted safely with local delivery of mRNA CAR T cells.

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