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Pazdrak B, Sonnemann HM, Bentebibel SE, Nassif BM, Lizee G, Diab A. Abstract 5079: Intratumoral CD40 agonist enhances the antitumor effect of anti-PD1 immunotherapy by activation of antigen-presenting cells and selective expansion of effector CD8+ T cells. Cancer Res 2023. [DOI: 10.1158/1538-7445.am2023-5079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2023]
Abstract
Abstract
Agonistic CD40 antibodies have shown promise when used in combination with checkpoint inhibitors in clinical trials for the treatment of malignancies. However, the mechanisms driving antitumor immune responses in patients are not well understood. The aim of this study was to use a preclinical melanoma model to evaluate the impact of intratumoral anti-CD40 administration on treatment efficacy and the tumor immune landscape in the context of systemic anti-PD1 therapy. Mice bearing 8-day established B16 melanoma tumors were injected with CD40 agonist intratumorally, either alone or in combination with anti-PD1 Ab, every 3 days for a total 4 doses. All mice treated with the combination therapy exhibited tumor growth arrest while progressive tumor growth was observed in control mice and mice treated with anti-PD1 alone. At day 15, tumor weights were 7- and 3-fold reduced in mice treated with the combination therapy as compared to control IgG or PD1 monotherapy, respectively. CyTOF analysis showed a 4-fold increase in the frequency of tumor-infiltrating immune cells in mice treated with either CD40 agonist alone or the combination therapy. Interestingly, CD40 agonistic Ab selectively expanded CD8+ T cells and the combination therapy exhibited a more pronounced effect compared to treatment with anti-PD1 Ab alone. Moreover, CD39+ CD8 T cells, representing tumor antigen-specific cytotoxic T cells, were 14- and 3-fold higher in tumors from mice treated with the combination therapy as compared to control or PD1-treated mice, respectively. This effect correlated with increases in the frequency of antigen-presenting cells, including cDC1 (6-fold) and B cells expressing CD40 (3-fold) in response to the combination therapy. In addition, the combination therapy significantly decreased myeloid cell population resulting in an 8-fold reduction in the ratio of myeloid cells to T cells. Amongst myeloid cells, the density of the monocytic population was diminished, with a selective 10-fold reduction of CD206+ M2-macrophages in tumors from mice treated with both Abs. Our findings provide evidence that combining systemic anti-PD1 therapy with intratumoral CD40 agonist enhanced antitumor immune responses by selectively expanding tumor antigen-specific effector CD8+ T cells, which was associated with increased infiltration of antigen-presenting cells and attenuation of immunosuppressive myeloid cells.
Citation Format: Barbara Pazdrak, Heather M. Sonnemann, Salah-Eddine Bentebibel, Barbara M. Nassif, Greg Lizee, Adi Diab. Intratumoral CD40 agonist enhances the antitumor effect of anti-PD1 immunotherapy by activation of antigen-presenting cells and selective expansion of effector CD8+ T cells. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5079.
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Affiliation(s)
| | | | | | | | - Greg Lizee
- 1UT MD Anderson Cancer Center, Houston, TX
| | - Adi Diab
- 1UT MD Anderson Cancer Center, Houston, TX
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Sonnemann HM, Pazdrak B, Antunes DA, Roszik J, Lizée G. Vestigial-like 1 (VGLL1): An ancient co-transcriptional activator linking wing, placenta, and tumor development. Biochim Biophys Acta Rev Cancer 2023; 1878:188892. [PMID: 37004960 DOI: 10.1016/j.bbcan.2023.188892] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Accepted: 03/27/2023] [Indexed: 04/03/2023]
Abstract
Vestigial-like 1 (VGLL1) is a recently discovered driver of proliferation and invasion that is expressed in many aggressive human malignancies and is strongly associated with poor prognosis. The VGLL1 gene encodes for a co-transcriptional activator that shows intriguing structural similarity to key activators in the hippo pathway, providing important clues to its functional role. VGLL1 binds to TEADs in an analogous fashion to YAP1 but appears to activate a distinct set of downstream gene targets. In mammals, VGLL1 expression is found almost exclusively in placental trophoblasts, cells that share many hallmarks of cancer. Due to its role as a driver of tumor progression, VGLL1 has become a target of interest for potential anticancer therapies. In this review, we discuss VGLL1 from an evolutionary perspective, contrast its role in placental and tumor development, summarize the current knowledge of how signaling pathways can modulate VGLL1 function, and discuss potential approaches for targeting VGLL1 therapeutically.
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Jackson KR, Antunes DA, Talukder AH, Maleki AR, Amagai K, Salmon A, Katailiha AS, Chiu Y, Fasoulis R, Rigo MM, Abella JR, Melendez BD, Li F, Sun Y, Sonnemann HM, Belousov V, Frenkel F, Justesen S, Makaju A, Liu Y, Horn D, Lopez-Ferrer D, Huhmer AF, Hwu P, Roszik J, Hawke D, Kavraki LE, Lizée G. Charge-based interactions through peptide position 4 drive diversity of antigen presentation by human leukocyte antigen class I molecules. PNAS Nexus 2022; 1:pgac124. [PMID: 36003074 PMCID: PMC9391200 DOI: 10.1093/pnasnexus/pgac124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 07/20/2022] [Indexed: 06/15/2023]
Abstract
Human leukocyte antigen class I (HLA-I) molecules bind and present peptides at the cell surface to facilitate the induction of appropriate CD8+ T cell-mediated immune responses to pathogen- and self-derived proteins. The HLA-I peptide-binding cleft contains dominant anchor sites in the B and F pockets that interact primarily with amino acids at peptide position 2 and the C-terminus, respectively. Nonpocket peptide-HLA interactions also contribute to peptide binding and stability, but these secondary interactions are thought to be unique to individual HLA allotypes or to specific peptide antigens. Here, we show that two positively charged residues located near the top of peptide-binding cleft facilitate interactions with negatively charged residues at position 4 of presented peptides, which occur at elevated frequencies across most HLA-I allotypes. Loss of these interactions was shown to impair HLA-I/peptide binding and complex stability, as demonstrated by both in vitro and in silico experiments. Furthermore, mutation of these Arginine-65 (R65) and/or Lysine-66 (K66) residues in HLA-A*02:01 and A*24:02 significantly reduced HLA-I cell surface expression while also reducing the diversity of the presented peptide repertoire by up to 5-fold. The impact of the R65 mutation demonstrates that nonpocket HLA-I/peptide interactions can constitute anchor motifs that exert an unexpectedly broad influence on HLA-I-mediated antigen presentation. These findings provide fundamental insights into peptide antigen binding that could broadly inform epitope discovery in the context of viral vaccine development and cancer immunotherapy.
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Affiliation(s)
- Kyle R Jackson
- University of Texas MD Anderson Cancer Center, UTHealth Graduate School of Biomedical Sciences, Houston, TX, USA
- Department of Melanoma, UT MD Anderson Cancer Center, Houston, TX, USA
| | - Dinler A Antunes
- Department of Biology and Biochemistry, University of Houston, Houston, TX, USA
- Department of Computer Science, Rice University, Houston, TX, USA
| | - Amjad H Talukder
- Department of Melanoma, UT MD Anderson Cancer Center, Houston, TX, USA
| | - Ariana R Maleki
- Department of Melanoma, UT MD Anderson Cancer Center, Houston, TX, USA
| | - Kano Amagai
- Department of Melanoma, UT MD Anderson Cancer Center, Houston, TX, USA
| | - Avery Salmon
- University of Texas MD Anderson Cancer Center, UTHealth Graduate School of Biomedical Sciences, Houston, TX, USA
- Department of Immunology, UT MD Anderson Cancer Center, Houston, TX, USA
| | - Arjun S Katailiha
- Department of Melanoma, UT MD Anderson Cancer Center, Houston, TX, USA
| | - Yulun Chiu
- Department of Melanoma, UT MD Anderson Cancer Center, Houston, TX, USA
| | - Romanos Fasoulis
- Department of Computer Science, Rice University, Houston, TX, USA
| | | | - Jayvee R Abella
- Department of Computer Science, Rice University, Houston, TX, USA
| | - Brenda D Melendez
- University of Texas MD Anderson Cancer Center, UTHealth Graduate School of Biomedical Sciences, Houston, TX, USA
- Department of Melanoma, UT MD Anderson Cancer Center, Houston, TX, USA
| | - Fenge Li
- Department of Melanoma, UT MD Anderson Cancer Center, Houston, TX, USA
| | - Yimo Sun
- University of Texas MD Anderson Cancer Center, UTHealth Graduate School of Biomedical Sciences, Houston, TX, USA
- Department of Melanoma, UT MD Anderson Cancer Center, Houston, TX, USA
| | - Heather M Sonnemann
- University of Texas MD Anderson Cancer Center, UTHealth Graduate School of Biomedical Sciences, Houston, TX, USA
- Department of Melanoma, UT MD Anderson Cancer Center, Houston, TX, USA
| | | | | | | | | | - Yang Liu
- ThermoFisher Scientific, San Jose, CA, USA
| | - David Horn
- ThermoFisher Scientific, San Jose, CA, USA
| | | | | | - Patrick Hwu
- Department of Melanoma, UT MD Anderson Cancer Center, Houston, TX, USA
| | - Jason Roszik
- Department of Melanoma, UT MD Anderson Cancer Center, Houston, TX, USA
| | - David Hawke
- Department of Systems Biology, UT MD Anderson Cancer Center, Houston, TX, USA
| | - Lydia E Kavraki
- Department of Computer Science, Rice University, Houston, TX, USA
| | - Gregory Lizée
- Department of Melanoma, UT MD Anderson Cancer Center, Houston, TX, USA
- Department of Immunology, UT MD Anderson Cancer Center, Houston, TX, USA
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Ratnam NM, Sonnemann HM, Frederico SC, Chen H, Hutchinson MKND, Dowdy T, Reid CM, Jung J, Zhang W, Song H, Zhang M, Davis D, Larion M, Giles AJ, Gilbert MR. Reversing Epigenetic Gene Silencing to Overcome Immune Evasion in CNS Malignancies. Front Oncol 2021; 11:719091. [PMID: 34336705 PMCID: PMC8320893 DOI: 10.3389/fonc.2021.719091] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 06/29/2021] [Indexed: 11/24/2022] Open
Abstract
Glioblastoma (GBM) is an aggressive brain malignancy with a dismal prognosis. With emerging evidence to disprove brain-immune privilege, there has been much interest in examining immunotherapy strategies to treat central nervous system (CNS) cancers. Unfortunately, the limited success of clinical studies investigating immunotherapy regimens, has led to questions about the suitability of immunotherapy for these cancers. Inadequate inherent populations of tumor infiltrating lymphocytes (TILs) and limited trafficking of systemic, circulating T cells into the CNS likely contribute to the poor response to immunotherapy. This paucity of TILs is in concert with the finding of epigenetic silencing of genes that promote immune cell movement (chemotaxis) to the tumor. In this study we evaluated the ability of GSK126, a blood-brain barrier (BBB) permeable small molecule inhibitor of EZH2, to reverse GBM immune evasion by epigenetic suppression of T cell chemotaxis. We also evaluated the in vivo efficacy of this drug in combination with anti-PD-1 treatment on tumor growth, survival and T cell infiltration in syngeneic mouse models. GSK126 reversed H3K27me3 in murine and human GBM cell lines. When combined with anti-PD-1 treatment, a significant increase in activated T cell infiltration into the tumor was observed. This resulted in decreased tumor growth and enhanced survival both in sub-cutaneous and intracranial tumors of immunocompetent, syngeneic murine models of GBM. Additionally, a significant increase in CXCR3+ T cells was also seen in the draining lymph nodes, suggesting their readiness to migrate to the tumor. Closer examination of the mechanism of action of GSK126 revealed its ability to promote the expression of IFN-γ driven chemokines CXCL9 and CXCL10 from the tumor cells, that work to traffic T cells without directly affecting T maturation and/or proliferation. The loss of survival benefit either with single agent or combination in immunocompromised SCID mice, suggest that the therapeutic efficacy of GSK126 in GBM is primarily driven by lymphocytes. Taken together, our data suggests that in glioblastoma, epigenetic modulation using GSK126 could improve current immunotherapy strategies by reversing the epigenetic changes that enable immune cell evasion leading to enhanced immune cell trafficking to the tumor.
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Affiliation(s)
- Nivedita M Ratnam
- Neuro-Oncology Branch, National Cancer Institute, Bethesda, MD, United States
| | - Heather M Sonnemann
- Neuro-Oncology Branch, National Cancer Institute, Bethesda, MD, United States
| | - Stephen C Frederico
- Neuro-Oncology Branch, National Cancer Institute, Bethesda, MD, United States
| | - Huanwen Chen
- Neuro-Oncology Branch, National Cancer Institute, Bethesda, MD, United States
| | | | - Tyrone Dowdy
- Neuro-Oncology Branch, National Cancer Institute, Bethesda, MD, United States
| | - Caitlin M Reid
- Neuro-Oncology Branch, National Cancer Institute, Bethesda, MD, United States
| | - Jinkyu Jung
- Neuro-Oncology Branch, National Cancer Institute, Bethesda, MD, United States
| | - Wei Zhang
- Neuro-Oncology Branch, National Cancer Institute, Bethesda, MD, United States
| | - Hua Song
- Neuro-Oncology Branch, National Cancer Institute, Bethesda, MD, United States
| | - Meili Zhang
- Neuro-Oncology Branch, National Cancer Institute, Bethesda, MD, United States
| | - Dionne Davis
- Neuro-Oncology Branch, National Cancer Institute, Bethesda, MD, United States
| | - Mioara Larion
- Neuro-Oncology Branch, National Cancer Institute, Bethesda, MD, United States
| | - Amber J Giles
- Neuro-Oncology Branch, National Cancer Institute, Bethesda, MD, United States
| | - Mark R Gilbert
- Neuro-Oncology Branch, National Cancer Institute, Bethesda, MD, United States
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Li F, Deng L, Jackson KR, Talukder AH, Katailiha AS, Bradley SD, Zou Q, Chen C, Huo C, Chiu Y, Stair M, Feng W, Bagaev A, Kotlov N, Svekolkin V, Ataullakhanov R, Miheecheva N, Frenkel F, Wang Y, Zhang M, Hawke D, Han L, Zhou S, Zhang Y, Wang Z, Decker WK, Sonnemann HM, Roszik J, Forget MA, Davies MA, Bernatchez C, Yee C, Bassett R, Hwu P, Du X, Lizee G. Neoantigen vaccination induces clinical and immunologic responses in non-small cell lung cancer patients harboring EGFR mutations. J Immunother Cancer 2021; 9:jitc-2021-002531. [PMID: 34244308 PMCID: PMC8268925 DOI: 10.1136/jitc-2021-002531] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/07/2021] [Indexed: 12/22/2022] Open
Abstract
Background Neoantigen (NeoAg) peptides displayed at the tumor cell surface by human leukocyte antigen molecules show exquisite tumor specificity and can elicit T cell mediated tumor rejection. However, few NeoAgs are predicted to be shared between patients, and none to date have demonstrated therapeutic value in the context of vaccination. Methods We report here a phase I trial of personalized NeoAg peptide vaccination (PPV) of 24 stage III/IV non-small cell lung cancer (NSCLC) patients who had previously progressed following multiple conventional therapies, including surgery, radiation, chemotherapy, and tyrosine kinase inhibitors (TKIs). Primary endpoints of the trial evaluated feasibility, tolerability, and safety of the personalized vaccination approach, and secondary trial endpoints assessed tumor-specific immune reactivity and clinical responses. Of the 16 patients with epidermal growth factor receptor (EGFR) mutations, nine continued TKI therapy concurrent with PPV and seven patients received PPV alone. Results Out of 29 patients enrolled in the trial, 24 were immunized with personalized NeoAg peptides. Aside from transient rash, fatigue and/or fever observed in three patients, no other treatment-related adverse events were observed. Median progression-free survival and overall survival of the 24 vaccinated patients were 6.0 and 8.9 months, respectively. Within 3–4 months following initiation of PPV, seven RECIST-based objective clinical responses including one complete response were observed. Notably, all seven clinical responders had EGFR-mutated tumors, including four patients that had continued TKI therapy concurrently with PPV. Immune monitoring showed that five of the seven responding patients demonstrated vaccine-induced T cell responses against EGFR NeoAg peptides. Furthermore, two highly shared EGFR mutations (L858R and T790M) were shown to be immunogenic in four of the responding patients, all of whom demonstrated increases in peripheral blood neoantigen-specific CD8+ T cell frequencies during the course of PPV. Conclusions These results show that personalized NeoAg vaccination is feasible and safe for advanced-stage NSCLC patients. The clinical and immune responses observed following PPV suggest that EGFR mutations constitute shared, immunogenic neoantigens with promising immunotherapeutic potential for large subsets of NSCLC patients. Furthermore, PPV with concurrent EGFR inhibitor therapy was well tolerated and may have contributed to the induction of PPV-induced T cell responses.
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Affiliation(s)
- Fenge Li
- Department of Melanoma, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Ligang Deng
- Tianjin HengJia Biotechnology Development Co Ltd, Tianjin, China
| | - Kyle R Jackson
- Department of Melanoma, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Amjad H Talukder
- Department of Melanoma, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Arjun S Katailiha
- Department of Melanoma, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Sherille D Bradley
- Department of Melanoma, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Qingwei Zou
- Tianjin HengJia Biotechnology Development Co Ltd, Tianjin, China
| | - Caixia Chen
- Tianjin HengJia Biotechnology Development Co Ltd, Tianjin, China
| | - Chong Huo
- Tianjin HengJia Biotechnology Development Co Ltd, Tianjin, China
| | - Yulun Chiu
- Department of Melanoma, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Matthew Stair
- Mary Bird Perkins Cancer Center, Baton Rouge, Louisiana, USA
| | - Weihong Feng
- Department of Oncology, Tianjin Beichen Hospital, Tianjin, China
| | | | | | | | | | | | | | - Yaling Wang
- Tianjin HengJia Biotechnology Development Co Ltd, Tianjin, China
| | - Minying Zhang
- Department of Melanoma, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - David Hawke
- Department of Systems Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Ling Han
- Department of Oncology, Tianjin Beichen Hospital, Tianjin, China
| | - Shuo Zhou
- Provincial Clinical College, Fujian Medical University, Fujian, China
| | - Yan Zhang
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, China
| | - Zhenglu Wang
- Biological Sample Resource Sharing Center, Tianjin First Central Hospital, Tianjin, China
| | - William K Decker
- Department of Immunology, Baylor College of Medicine, Houston, Texas, USA
| | - Heather M Sonnemann
- Department of Melanoma, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Jason Roszik
- Department of Melanoma, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Marie-Andree Forget
- Department of Melanoma, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Michael A Davies
- Department of Melanoma, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Chantale Bernatchez
- Department of Melanoma, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Cassian Yee
- Department of Melanoma, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA.,Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Roland Bassett
- Department of Immunology, The University of Texas M.D. Anderson Cancer Center, Houston, Texas, USA
| | - Patrick Hwu
- Department of Melanoma, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Xueming Du
- Department of Oncology, Tianjin Beichen Hospital, Tianjin, China
| | - Gregory Lizee
- Department of Melanoma, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA .,Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
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6
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Bradley SD, Talukder AH, Lai I, Davis R, Alvarez H, Tiriac H, Zhang M, Chiu Y, Melendez B, Jackson KR, Katailiha A, Sonnemann HM, Li F, Kang Y, Qiao N, Pan BF, Lorenzi PL, Hurd M, Mittendorf EA, Peterson CB, Javle M, Bristow C, Kim M, Tuveson DA, Hawke D, Kopetz S, Wolff RA, Hwu P, Maitra A, Roszik J, Yee C, Lizée G. Vestigial-like 1 is a shared targetable cancer-placenta antigen expressed by pancreatic and basal-like breast cancers. Nat Commun 2020; 11:5332. [PMID: 33087697 PMCID: PMC7577998 DOI: 10.1038/s41467-020-19141-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Accepted: 09/24/2020] [Indexed: 12/13/2022] Open
Abstract
Cytotoxic T lymphocyte (CTL)-based cancer immunotherapies have shown great promise for inducing clinical regressions by targeting tumor-associated antigens (TAA). To expand the TAA landscape of pancreatic ductal adenocarcinoma (PDAC), we performed tandem mass spectrometry analysis of HLA class I-bound peptides from 35 PDAC patient tumors. This identified a shared HLA-A*0101 restricted peptide derived from co-transcriptional activator Vestigial-like 1 (VGLL1) as a putative TAA demonstrating overexpression in multiple tumor types and low or absent expression in essential normal tissues. Here we show that VGLL1-specific CTLs expanded from the blood of a PDAC patient could recognize and kill in an antigen-specific manner a majority of HLA-A*0101 allogeneic tumor cell lines derived not only from PDAC, but also bladder, ovarian, gastric, lung, and basal-like breast cancers. Gene expression profiling reveals VGLL1 as a member of a unique group of cancer-placenta antigens (CPA) that may constitute immunotherapeutic targets for patients with multiple cancer types.
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MESH Headings
- Antigens, Neoplasm/genetics
- Antigens, Neoplasm/immunology
- Biomarkers, Tumor/genetics
- Biomarkers, Tumor/immunology
- Breast Neoplasms/genetics
- Breast Neoplasms/immunology
- Carcinoma, Pancreatic Ductal/genetics
- Carcinoma, Pancreatic Ductal/immunology
- Carcinoma, Pancreatic Ductal/therapy
- Cell Line, Tumor
- Cytotoxicity, Immunologic
- DNA-Binding Proteins/genetics
- DNA-Binding Proteins/immunology
- Female
- Gene Expression Profiling
- HLA-A1 Antigen/immunology
- Humans
- Immunotherapy, Adoptive
- Pancreatic Neoplasms/genetics
- Pancreatic Neoplasms/immunology
- Pancreatic Neoplasms/therapy
- Placenta/immunology
- Pregnancy
- Prognosis
- T-Lymphocytes, Cytotoxic/immunology
- Transcription Factors/genetics
- Transcription Factors/immunology
- Pancreatic Neoplasms
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Affiliation(s)
- Sherille D Bradley
- Department of Melanoma Medical Oncology, UT MD Anderson Cancer Center, Houston, TX, USA
| | - Amjad H Talukder
- Department of Melanoma Medical Oncology, UT MD Anderson Cancer Center, Houston, TX, USA
| | - Ivy Lai
- Department of Melanoma Medical Oncology, UT MD Anderson Cancer Center, Houston, TX, USA
| | - Rebecca Davis
- Department of Melanoma Medical Oncology, UT MD Anderson Cancer Center, Houston, TX, USA
| | - Hector Alvarez
- Department of Hematopathology, UT MD Anderson Cancer Center, Houston, TX, USA
| | - Herve Tiriac
- Cold Spring Harbor Laboratory Cancer Center, Cold Spring Harbor, NY, USA
| | - Minying Zhang
- Department of Melanoma Medical Oncology, UT MD Anderson Cancer Center, Houston, TX, USA
| | - Yulun Chiu
- Department of Melanoma Medical Oncology, UT MD Anderson Cancer Center, Houston, TX, USA
| | - Brenda Melendez
- Department of Melanoma Medical Oncology, UT MD Anderson Cancer Center, Houston, TX, USA
| | - Kyle R Jackson
- Department of Melanoma Medical Oncology, UT MD Anderson Cancer Center, Houston, TX, USA
| | - Arjun Katailiha
- Department of Melanoma Medical Oncology, UT MD Anderson Cancer Center, Houston, TX, USA
| | - Heather M Sonnemann
- Department of Melanoma Medical Oncology, UT MD Anderson Cancer Center, Houston, TX, USA
| | - Fenge Li
- Department of Melanoma Medical Oncology, UT MD Anderson Cancer Center, Houston, TX, USA
| | - Yaan Kang
- Department of Surgical Oncology, UT MD Anderson Cancer Center, Houston, TX, USA
| | - Na Qiao
- Department of Breast Surgery Research, UT MD Anderson Cancer Center, Houston, TX, USA
| | - Bih-Fang Pan
- Department of Systems Biology, UT MD Anderson Cancer Center, Houston, TX, USA
| | - Philip L Lorenzi
- Department of Bioinformatics and Computational Biology, UT MD Anderson Cancer Center, Houston, TX, USA
| | - Mark Hurd
- Ahmed Center for Pancreatic Cancer Research, UT MD Anderson Cancer Center, Houston, TX, USA
| | | | | | - Milind Javle
- Department of Gastrointestinal Medical Oncology, UT MD Anderson Cancer Center, Houston, TX, USA
| | - Christopher Bristow
- Center for Co-clinical Trials, UT MD Anderson Cancer Center, Houston, TX, USA
| | - Michael Kim
- Department of Surgical Oncology, UT MD Anderson Cancer Center, Houston, TX, USA
| | - David A Tuveson
- Cold Spring Harbor Laboratory Cancer Center, Cold Spring Harbor, NY, USA
| | - David Hawke
- Department of Systems Biology, UT MD Anderson Cancer Center, Houston, TX, USA
| | - Scott Kopetz
- Department of Gastrointestinal Medical Oncology, UT MD Anderson Cancer Center, Houston, TX, USA
| | - Robert A Wolff
- Department of Gastrointestinal Medical Oncology, UT MD Anderson Cancer Center, Houston, TX, USA
| | - Patrick Hwu
- Department of Melanoma Medical Oncology, UT MD Anderson Cancer Center, Houston, TX, USA
| | - Anirban Maitra
- Department of Pathology, UT MD Anderson Cancer Center, Houston, TX, USA
| | - Jason Roszik
- Department of Melanoma Medical Oncology, UT MD Anderson Cancer Center, Houston, TX, USA
| | - Cassian Yee
- Department of Melanoma Medical Oncology, UT MD Anderson Cancer Center, Houston, TX, USA.
- Department of Immunology, UT MD Anderson Cancer Center, Houston, TX, USA.
| | - Gregory Lizée
- Department of Melanoma Medical Oncology, UT MD Anderson Cancer Center, Houston, TX, USA.
- Department of Immunology, UT MD Anderson Cancer Center, Houston, TX, USA.
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7
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Ratnam NM, Sonnemann HM, Gilbert MR, Giles AJ. Abstract B5: Reversing epigenetic gene silencing to overcome immune evasion in CNS malignancies. Cancer Immunol Res 2020. [DOI: 10.1158/2326-6074.tumimm19-b5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Glioblastoma (GBM) is a lethal brain malignancy, and standard of care only offers a modest survival benefit. Emerging evidence of immune surveillance in the brain has prompted investigation of immunotherapy as a potential treatment strategy. However, preliminary studies have demonstrated impaired immune cell trafficking to the tumor, making GBMs immunologically “cold.” One mechanism of immune evasion by the tumor is to epigenetically silence the expression of chemoattractant cytokines. Previous studies in ovarian and prostate cancer have successfully established the ability of GSK126, a small-molecule inhibitor of histone methyl transferase EZH2, to promote tumor T-cell infiltration and subsequent antitumor response. Mechanistically, GSK126 was shown to promote expression of interferon gamma (IFN gamma)-induced chemokines CXCL9 and CXCL10. In the present study we evaluated the therapeutic efficacy of GSK126 in preclinical models of GBM. Our studies determined that treatment of murine and human glioblastoma cell lines with GSK126 increased IFN gamma-mediated gene expression of CXCL9 and CXCL10. Transwell migration assays performed using human T cells demonstrated increased T-cell migration when exposed to conditioned medium from tumor cells treated with GSK126 and IFN gamma. In vivo, efficacy of GSK126 was tested in combination with anti-PD-1 antibody in C57Bl/6 immunocompetent mice subcutaneously implanted with the syngeneic glioma cell line CT2A. Mice treated with the combination of GSK126 and anti-PD-1 antibody showed a significant decrease in tumor volume and improved overall survival. Tumors treated with combination therapy showed increased infiltration of CD8+ IFN gamma expressing T cells and increased CXCR3+ migratory T cells in the tumor-draining lymph node. Interestingly, treatment of mice with intracranial CT2A tumors with GSK126 alone resulted in small tumors with better prognosis. Treatment-related survival benefit was lost in immune-compromised mice, suggesting that efficacy depended upon drug-related increased lymphocyte trafficking and subsequent T cell-mediated antitumor response. Analysis of post-treatment tumor by LC-MS confirmed that GSK126 crosses the blood-brain barrier. Taken together, our data suggest a potential synergistic therapeutic role for GSK126 in glioblastoma by enhancing current immunotherapy regimens with reversing the epigenetic changes that enable immune cell evasion with resultant increases in immune cell trafficking to the tumor.
Citation Format: Nivedita M. Ratnam, Heather M. Sonnemann, Mark R. Gilbert, Amber J. Giles. Reversing epigenetic gene silencing to overcome immune evasion in CNS malignancies [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2019 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(3 Suppl):Abstract nr B5.
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Ratnam NM, Sonnemann HM, Gilbert MR, Giles AJ. Abstract 1188: Reversing epigenetic gene silencing to overcome immune evasion in CNS malignancies. Cancer Res 2019. [DOI: 10.1158/1538-7445.am2019-1188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Glioblastoma remains a lethal brain cancer, and current treatment provides only modest survival benefit. Immunotherapy is currently being investigated as a potential treatment for this disease, but immune cell trafficking to tumor is hampered. Glioblastoma are immunologically “cold”, lacking infiltrating lymphocytes. Tumors epigenetically silence the expression of chemokines that attract lymphocytes to evade immune attack. Previous studies in ovarian cancer demonstrated that the histone methyltransferase inhibitor, GSK126, increased T cell infiltration into the tumor, promoting immune-mediated tumor suppression. Lymphocyte infiltration was driven by elevated expression of interferon gamma (IFNγ)-induced chemokines CXCL9 and CXCL10. In the current study, we evaluate the ability of GSK126 to similarly reverse the silencing of CXCL9 and CXCL10 and thereby improve immunotherapy outcome for glioblastoma. We first determined that treatment of murine and human glioblastoma cell lines with GSK126 increased IFNγ-mediated gene expression of CXCL9 and CXCL10 by qPCR and protein by ELISA. Subsequently, transwell migration assays performed using human and murine T cells demonstrated increased T cell migration when exposed to conditioned medium from tumor cells treated with GSK126 and IFNγ. In addition, T cells exposed to GSK126 and IFNγ up regulated CXCR3, the receptor for CXCL9 and CXCL10 and further increased their expression of IFNγ. The in vivo efficacy of GSK126 was tested in combination with anti-PD-1 antibody in C57Bl/6 mice subcutaneously implanted with the syngeneic glioma cell line CT2A. Mice treated with a combination of GSK126 and anti-PD-1 antibody showed a significant decrease in tumor volume with treatment, providing an overall survival benefit compared the anti-PD-1 or GSK126 alone. Taken together, our data suggests a therapeutic role for GSK126 in glioblastoma that could enhance current immunotherapy regimens by reversing the epigenetic changes that enable immune cell evasion and encourage immune cell trafficking to the tumor.
Citation Format: Nivedita M. Ratnam, Heather M. Sonnemann, Mark R. Gilbert, Amber J. Giles. Reversing epigenetic gene silencing to overcome immune evasion in CNS malignancies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1188.
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Giles AJ, Hutchinson MKND, Sonnemann HM, Jung J, Fecci PE, Ratnam NM, Zhang W, Song H, Bailey R, Davis D, Reid CM, Park DM, Gilbert MR. Dexamethasone-induced immunosuppression: mechanisms and implications for immunotherapy. J Immunother Cancer 2018; 6:51. [PMID: 29891009 PMCID: PMC5996496 DOI: 10.1186/s40425-018-0371-5] [Citation(s) in RCA: 261] [Impact Index Per Article: 43.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 05/30/2018] [Indexed: 12/18/2022] Open
Abstract
Background Corticosteroids are routinely utilized to alleviate edema in patients with intracranial lesions and are first-line agents to combat immune-related adverse events (irAEs) that arise with immune checkpoint blockade treatment. However, it is not known if or when corticosteroids can be administered without abrogating the efforts of immunotherapy. The purpose of this study was to evaluate the impact of dexamethasone on lymphocyte activation and proliferation during checkpoint blockade to provide guidance for corticosteroid use while immunotherapy is being implemented as a cancer treatment. Methods Lymphocyte proliferation, differentiation, and cytokine production were evaluated during dexamethasone exposure. Human T cells were stimulated through CD3 ligation and co-stimulated either directly by CD28 ligation or by providing CD80, a shared ligand for CD28 and CTLA-4. CTLA-4 signaling was inhibited by antibody blockade using ipilimumab which has been approved for the treatment of several solid tumors. The in vivo effects of dexamethasone during checkpoint blockade were evaluated using the GL261 syngeneic mouse intracranial model, and immune populations were profiled by flow cytometry. Results Dexamethasone upregulated CTLA-4 mRNA and protein in CD4 and CD8 T cells and blocked CD28-mediated cell cycle entry and differentiation. Naïve T cells were most sensitive, leading to a decrease of the development of more differentiated subsets. Resistance to dexamethasone was conferred by blocking CTLA-4 or providing strong CD28 co-stimulation prior to dexamethasone exposure. CTLA-4 blockade increased IFNγ expression, but not IL-2, in stimulated human peripheral blood T cells exposed to dexamethasone. Finally, we found that CTLA-4 blockade partially rescued T cell numbers in mice bearing intracranial gliomas. CTLA-4 blockade was associated with increased IFNγ-producing tumor-infiltrating T cells and extended survival of dexamethasone-treated mice. Conclusions Dexamethasone-mediated T cell suppression diminishes naïve T cell proliferation and differentiation by attenuating the CD28 co-stimulatory pathway. However, CTLA-4, but not PD-1 blockade can partially prevent some of the inhibitory effects of dexamethasone on the immune response. Electronic supplementary material The online version of this article (10.1186/s40425-018-0371-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Amber J Giles
- Neuro-Oncology Branch, CCR, NCI, National Institutes of Health, 37 Convent Dr. Bldg. 37, Rm. 1142B, Bethesda, MD, 20892, USA.
| | - Marsha-Kay N D Hutchinson
- Neuro-Oncology Branch, CCR, NCI, National Institutes of Health, 37 Convent Dr. Bldg. 37, Rm. 1142B, Bethesda, MD, 20892, USA
| | - Heather M Sonnemann
- Neuro-Oncology Branch, CCR, NCI, National Institutes of Health, 37 Convent Dr. Bldg. 37, Rm. 1142B, Bethesda, MD, 20892, USA
| | - Jinkyu Jung
- Neuro-Oncology Branch, CCR, NCI, National Institutes of Health, 37 Convent Dr. Bldg. 37, Rm. 1142B, Bethesda, MD, 20892, USA
| | - Peter E Fecci
- Department of Neurosurgery, Duke University Medical Center, Durham, NC, USA
| | - Nivedita M Ratnam
- Neuro-Oncology Branch, CCR, NCI, National Institutes of Health, 37 Convent Dr. Bldg. 37, Rm. 1142B, Bethesda, MD, 20892, USA
| | - Wei Zhang
- Neuro-Oncology Branch, CCR, NCI, National Institutes of Health, 37 Convent Dr. Bldg. 37, Rm. 1142B, Bethesda, MD, 20892, USA
| | - Hua Song
- Neuro-Oncology Branch, CCR, NCI, National Institutes of Health, 37 Convent Dr. Bldg. 37, Rm. 1142B, Bethesda, MD, 20892, USA
| | - Rolanda Bailey
- Neuro-Oncology Branch, CCR, NCI, National Institutes of Health, 37 Convent Dr. Bldg. 37, Rm. 1142B, Bethesda, MD, 20892, USA
| | - Dionne Davis
- Neuro-Oncology Branch, CCR, NCI, National Institutes of Health, 37 Convent Dr. Bldg. 37, Rm. 1142B, Bethesda, MD, 20892, USA
| | - Caitlin M Reid
- Neuro-Oncology Branch, CCR, NCI, National Institutes of Health, 37 Convent Dr. Bldg. 37, Rm. 1142B, Bethesda, MD, 20892, USA
| | - Deric M Park
- Neuro-Oncology Branch, CCR, NCI, National Institutes of Health, 37 Convent Dr. Bldg. 37, Rm. 1142B, Bethesda, MD, 20892, USA
| | - Mark R Gilbert
- Neuro-Oncology Branch, CCR, NCI, National Institutes of Health, 37 Convent Dr. Bldg. 37, Rm. 1142B, Bethesda, MD, 20892, USA
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Seldomridge AN, Jung J, Sonnemann HM, Giles A, Meetze K, Gilbert MR, Palena CM, Park DM. Abstract 1533: Transcriptional inhibition of brachyury in chordoma is associated with adoption of quiescent phenotype. Cancer Res 2017. [DOI: 10.1158/1538-7445.am2017-1533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
BACKGROUND: Brachyury is a mesoderm specification transcription factor involved in notochord development and overexpressed in a variety of cancers, including chordoma. High levels of brachyury protein expression in cancers is associated with a poor prognosis in part due to its role in mediating epithelial-mesenchymal transition (EMT). TG02 is a multikinase inhibitor that targets transcriptional regulation of cyclin-dependent kinases (CDKs). Because chordoma is characterized by a relative paucity of genomic mutations and largely driven by the super-enhancer activity of brachyury expression, we investigated the downstream effect of a transcriptional inhibitor, TG02, in chordomas.
METHODS: Established chordoma cell lines, UCH-1 and UM-Chor1, were exposed to increasing concentrations of TG02 to determine effect on brachyury protein expression. qPCR was used to analyze brachyury mRNA expression as well as the mesenchymal proteins, vimentin and fibronectin, typically associated with brachyury expression in tumor cells. Cell migration was
evaluated using wound healing assay. CellTiterGlo Luminescence Assay was used to quantify cell viability.
RESULTS: TG02 down-regulated protein expression of brachyury in a dose-dependent manner. Attenuation of brachyury expression was seen within 4 hours and persisted for 5 days upon single exposure to a clinically relevant concentration of TG02. Brachyury downregulation did not affect cell count or viability, and was associated with a quiescent phenotype, including impaired migration. Expression of vimentin and fibronectin, both associated with EMT, was also suppressed within 4 hours of TG02 treatment and persisted for 24 hours.
CONCLUSIONS: Inhibition of brachyury expression and its downstream signaling is associated with quiescent behavior of chordoma cells. Pharmacologically induced transcriptional targeting of brachyury using TG02, a potent CDK9 inhibitor, represents a potential therapeutic strategy.
Citation Format: Ashlee N. Seldomridge, Jinkyu Jung, Heather M. Sonnemann, Amber Giles, Kristan Meetze, Mark R. Gilbert, Claudia M. Palena, Deric M. Park. Transcriptional inhibition of brachyury in chordoma is associated with adoption of quiescent phenotype [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1533. doi:10.1158/1538-7445.AM2017-1533
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Affiliation(s)
| | - Jinkyu Jung
- 1Neuro-Oncology Branch, CCR, National Cancer Institute, NIH, Bethesda, MD
| | | | - Amber Giles
- 1Neuro-Oncology Branch, CCR, National Cancer Institute, NIH, Bethesda, MD
| | | | - Mark R. Gilbert
- 1Neuro-Oncology Branch, CCR, National Cancer Institute, NIH, Bethesda, MD
| | - Claudia M. Palena
- 3Laboratory of Tumor Immunology and Biology, CCR, National Cancer Institute, NIH, Bethesda, MD
| | - Deric M. Park
- 1Neuro-Oncology Branch, CCR, National Cancer Institute, NIH, Bethesda, MD
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Sonnemann HM, Giles AJ, Reid CM, Hutchinson MKN, Park DM, Gilbert MR. Abstract 3998: Alerting the immune system by removing epigenetic silencing of Th1 chemokines. Cancer Res 2017. [DOI: 10.1158/1538-7445.am2017-3998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
BACKGROUND: Solid tumors employ multiple mechanisms to evade an immune response. However, the potential to enhance the immune response to cancer has been proven in several malignancie and is under investigation in many others, including primary CNS tumors. Brain tumors in particular lack robust T-cell infiltration. Recent studies have found that certain tumors can be induced to express T-cell attracting chemokines, CXCL9 and CXCL10, by interferon gamma (IFNg). This response is further amplified using methyltransferase inhibitors (Peng, et al. Nature 2015. Vol 527: 249-253.), resulting in increased Tcell trafficking to tumors both in vitro and in vivo. We hypothesized that T-cell trafficking to brain tumors could likewise be enhanced with DNA and histone methyltransferase inhibitors to induce CXCL9 and CXCL10 transcription.
METHODS: Assays were performed on 7 human glioma brain tumor cell lines. CXCL9 and CXCL10 expression were measured by real-time PCR. Two commercially available methyltransferase inhibitors, 5-AZA-dC and GSK126, were utilized to demethylate DNA and histone H3 (K9 and K27), respectively. Histone methylation status was examined using Western blot. T-cell migration was measured using transwell migration assays.
RESULTS: IFNg increased CXCL9 and CXCL10 transcription in brain tumor lines. GSK126 and 5-AZA-dC enhanced expression of CXCL9 and CXCL10 compared to IFNg alone. Migration assays confirmed T-cell trafficking towards chemokines produced by tumor cells in response to methyltransferase inhibitors.
CONCLUSIONS: These studies demonstrate that brain tumors express T-cell attracting chemokines CXCL9 and CXCL10 in response to IFNg. Further, GSK126 and the combination of GSK126 and 5-AZA-dC enhanced expression of CXCL9 and CXCL10 transcription by real-time PCR and T-cell trafficking by migration assay. Together, these data provide a potential means to increase T-cell trafficking into tumors and potentially enhances the efficacy of immune therapies for brain tumors.
Citation Format: Heather M. Sonnemann, Amber J. Giles, Caitlin M. Reid, Marsha-Kay N. Hutchinson, Deric M. Park, Mark R. Gilbert. Alerting the immune system by removing epigenetic silencing of Th1 chemokines [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3998. doi:10.1158/1538-7445.AM2017-3998
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Hutchinson MKN, Giles AJ, Sonnemann HM, Reid CM, Park DM, Gilbert M. Abstract 569: Dexamethasone inhibits T-cell proliferation through a CTLA-4 mediated pathway. Cancer Res 2017. [DOI: 10.1158/1538-7445.am2017-569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
BACKGROUND: The use of corticosteroids for therapeutic benefit has to be weighed against the risks of adverse consequences associated with these drugs. Brain tumor patients in particular, are routinely prescribed dexamethasone (a glucocorticoid) to reduce edema associated with their lesion. Checkpoint blockade, a type of immune therapy, is currently being investigated as a potential treatment for brain tumors. However, glucocorticoid signaling has been shown to attenuate the immune response through several mechanisms including the repression of transcription of genes controlling pro-inflammatory cytokines and chemokines.
HYPOTHESIS: Here, we propose that dexamethasone’s ability to upregulate inhibitory T-cell molecules such as CTLA-4 and PD-1 might be an additional immunosuppressive mechanism.
METHODS: Healthy donor T cells were tested for response to dexamethasone. T cell proliferation, cell cycle analysis, apoptosis, and protein expression were assessed with flow cytometry. Protein expression was also measured with Western blots. Transcriptional changes were assessed with qPCR. A monoclonal antibody, ipilimumab, was used to block CTLA-4 binding.
RESULTS: Unexpectedly, dexamethasone did not elicit a direct lymphotoxic effect on T cells as measured by absolute cell number. However, we found that dexamethasone significantly reduced T cell entry into the cell cycle, but did not impact cells already undergoing mitosis. Checkpoint molecules CTLA-4 and PD-1 were increased with dexamethasone treatment when cells are stimulated. Blockade of CTLA-4 with Ipilimumab resulted in a substantial reversal of cell cycle entry inhibition that was induced by dexamethasone.
CONCLUSIONS: These results suggest that dexamethasone impairs T cell expansion by inhibiting cell cycle entry. Upregulated CTLA-4 expression contributes to cell cycle entry blockade which is reversed by inhibiting CTLA-4 with ipilimumab. These findings indicate that administration of ipilimumab before dexamethasone diminishes the negative proliferative effect on anti-tumor T cells suggesting that when needed, corticosteroids can be used after immune checkpoint blockade has been established.
Citation Format: Marsha-Kay N. Hutchinson, Amber J. Giles, Heather M. Sonnemann, Caitlin M. Reid, Deric M. Park, Mark Gilbert. Dexamethasone inhibits T-cell proliferation through a CTLA-4 mediated pathway [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 569. doi:10.1158/1538-7445.AM2017-569
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