Brain stem gliomas and current landscape Wummer, Brandon; Woodworth, Delaney; Flores, Catherine
Journal of neuro-oncology,
2021/1, Letnik:
151, Številka:
1
Journal Article
Recenzirano
Purpose
CNS malignancies are currently the most common cause of disease related deaths in children. Although brainstem gliomas are invariably fatal cancers in children, clinical studies against this ...disease are limited. This review is to lead to a succinct collection of knowledge of known biological mechanisms of this disease and discuss available therapeutics.
Methods
A hallmark of brainstem gliomas are mutations in the histone H3.3 with the majority of cases expressing the mutation K27M on histone 3.3. Recent studies using whole genome sequencing have revealed other mutations associated with disease. Current standard clinical practice may merely involve radiation and/or chemotherapy with little hope for long term survival. Here we discuss the potential of new therapies.
Conclusion
Despite the lack of treatment options using frequently practiced clinical techniques, immunotherapeutic strategies have recently been developed to target brainstem gliomas. To target brainstem gliomas, investigators are evaluating the use of broad non-targeted therapy with immune checkpoint inhibitors. Alternatively, others have begun to explore adoptive T cell strategies against these fatal malignancies.
Adoptive T-cell immunotherapy (ACT) has emerged as a viable therapeutic for peripheral and central nervous system (CNS) tumors. In peripheral cancers, optimal efficacy of ACT is reliant on dendritic ...cells (DCs) in the tumor microenvironment. However, the CNS is largely devoid of resident migratory DCs to function as antigen-presenting cells during immunotherapy. Herein, we demonstrate that cellular interactions between adoptively transferred tumor-reactive T cells and bone marrow-derived hematopoietic stem and progenitor cells (HSPCs) lead to the generation of potent intratumoral DCs within the CNS compartment.
We evaluated HSPC differentiation during ACT
in glioma-bearing hosts and HSPC proliferation and differentiation
using a T-cell coculture system. We utilized FACS, ELISAs, and gene expression profiling to study the phenotype and function of HSPC-derived cells
and
To demonstrate the impact of HSPC differentiation and function on antitumor efficacy, we performed survival experiments.
Transfer of HSPCs with concomitant ACT led to the production of activated CD86
CD11c
MHCII
cells consistent with DC phenotype and function within the brain tumor microenvironment. These intratumoral DCs largely supplanted abundant host myeloid-derived suppressor cells. We determined that during ACT, HSPC-derived cells in gliomas rely on T-cell-released IFNγ to differentiate into DCs, activate T cells, and reject intracranial tumors.
Our data support the use of HSPCs as a novel cellular therapy. Although DC vaccines induce robust immune responses in the periphery, our data demonstrate that HSPC transfer uniquely generates intratumoral DCs that potentiate T-cell responses and promote glioma rejection
.
Introduction
Brain tumors remain especially challenging to treat due to the presence of the blood–brain barrier. The unique biophysical properties of nanomaterials enable access to the tumor ...environment with minimally invasive injection methods such as intranasal and systemic delivery.
Methods
In this review, we will discuss approaches taken in NP delivery to brain tumors in preclinical neuro-oncology studies and ongoing clinical studies.
Results
Despite recent development of many promising nanoparticle systems to modulate immunologic function in the preclinical realm, clinical work with nanoparticles in malignant brain tumors has largely focused on imaging, chemotherapy, thermotherapy and radiation.
Conclusion
Review of early preclinical studies and clinical trials provides foundational safety, feasibility and toxicology data that can usher a new wave of nanotherapeutics in application of immunotherapy and translational oncology for patients with brain tumors.
BackgroundGlioma-induced immune dysregulation of the hematopoietic system has been described in a limited number of studies. In this study, our group further demonstrates that gliomas interrupt the ...cellular differentiation programming and outcomes of hematopoietic stem and progenitor cells (HSPCs) in the bone marrow. HSPCs from glioma-bearing mice are reprogrammed and driven towards expansion of myeloid lineage precursors and myeloid-derived suppressor cells (MDSCs) in secondary lymphoid organs. However, we found this expansion is reversed by immunotherapy. Adoptive cellular therapy (ACT) has been demonstrably efficacious in multiple preclinical models of central nervous system (CNS) malignancies, and here we describe how glioma-induced dysfunction is reversed by this immunotherapeutic platform.MethodsThe impact of orthotopic KR158B-luc glioma on HSPCs was evaluated in an unbiased fashion using single cell RNAseq (scRNAseq) of lineage− cells and phenotypically using flow cytometry. Mature myeloid cell frequencies and function were also evaluated using flow cytometry. Finally, ACT containing total body irradiation, tumor RNA-pulsed dendritic cells, tumor-reactive T cells and HSPCs isolated from glioma-bearing or non-tumor-bearing mice were used to evaluate cell fate differentiation and survival.ResultsUsing scRNAseq, we observed an altered HSPC landscape in glioma-bearing versus non-tumor-bearing mice . In addition, an expansion of myeloid lineage subsets, including granulocyte macrophage precursors (GMPs) and MDSCs, were observed in glioma-bearing mice relative to non-tumor-bearing controls. Furthermore, MDSCs from glioma-bearing mice demonstrated increased suppressive capacity toward tumor-specific T cells as compared with MDSCs from non-tumor-bearing hosts. Interestingly, treatment with ACT overcame these suppressive properties. When HSPCs from glioma-bearing mice were transferred in the context of ACT, we observed significant survival benefit and long-term cures in orthotopic glioma models compared with mice treated with ACT using non-glioma-bearing HSPCs.
e14534
Background: Cancer immunotherapies have offered limited efficacy in treating mCRPC. A novel class of immunotherapy are BiTEs, which target both a specific cancer antigen and CD3 to enhance T ...cell anti-tumor activity. Although BiTEs are a promising avenue for cancer research, their safety profiles are not well-understood. Thus far, it is known that first-in-class blinatumomab is associated with AEs such as cytokine release syndrome, neurotoxicity, and febrile neutropenia. Given their mechanism of action and possible propensity to produce a general inflammatory environment, we aimed to explore the systemic and inflammatory AEs of BiTEs in mCRPC patients. Methods: A retrospective chart review was performed on an IRB-approved database. Inclusion criteria included a history of mCRPC and BiTE therapy. There were no exclusion criteria. Study objectives were to evaluate whether BiTE therapy led to de novo inflammatory AEs or exacerbation of pre-existing inflammatory disorders. AEs were defined/graded as immune system disorders per Common Terminology Criteria for Adverse Effects v5.0. Results: 24 mCRPC patients in our clinic received at least 1 dose of BiTE therapy. Mean (range) age was 67.3 (54-79) years. 5 (20.8%) had pre-existing inflammatory disorders. Mean (range) treatment course was 14 (0-44) weeks. 6 (25.0%) discontinued due to inflammatory AEs, 15 (62.5%) discontinued due to disease progression, 1 (4.2%) discontinued due to noncompliance, and 2 (8.4%) are currently on BiTE therapy. Notable de novo AEs included arthralgia (8.4%), thrombophlebitis (8.4%), myocarditis (4.2%), giant cell arteritis (4.2%), and pneumonitis (4.2%). Patients with pre-existing inflammatory conditions (5/5) were statistically more likely to develop inflammatory AEs after BiTE therapy initiation compared to those without (4/19) (p < 0.01). Of the 9 patients who developed inflammatory AEs, 6 (66.7%) developed inflammatory AEs after the first dose of BiTE therapy. After the first dose, mean C-reactive protein was significantly elevated in patients with pre-existing inflammatory conditions (10.0) compared to those without (1.6) (p = 0.041). Conclusions: Our analysis suggests that BiTE therapies are associated with inflammatory AEs other than cytokine release syndrome, neurotoxicity, and febrile neutropenia. In particular, some of our patients developed vasculitis, myocarditis, or pneumonitis. Furthermore, patients with pre-existing inflammatory conditions are at significantly greater risk of developing inflammatory AEs compared to patients without pre-existing inflammatory conditions. Thus, patients with pre-existing inflammatory conditions who are receiving BiTE therapy should be cautiously observed. Additional data from larger BiTE therapy clinical trials is needed to further support these findings.
OBJECTIVES/SPECIFIC AIMS: Despite aggressive chemotherapy, surgical resection, and radiation therapy, glioblastoma remains almost universally fatal. In a pilot, randomized, and blinded clinical ...trial, we recently demonstrated that administration of RNA-loaded DC vaccines was associated with significantly improved progression-free and overall survival in patients with glioblastoma (Mitchell
et al
.,
Nature
, 2015). Furthermore, clinical outcomes correlated with DC migration to vaccine-site draining lymph nodes measured by Indium-111 labeling of RNA-loaded DCs and SPECT/CT imaging. Although these studies demonstrated that tracking DC migration may be an important clinical biomarker for response to DC vaccination, the complexity and regulatory requirements associated with nuclear labelling to track DC migration limits widespread application of this technique. We have therefore developed RNA-loaded magnetic nanoparticles (RNA-NPs) to enhance DC migration to LNs and track that migration with a widely available imaging modality (i.e., MRI). METHODS/STUDY POPULATION: Cationic liposomes were loaded with iron oxide nanoparticles with or without cholesterol. The resulting nanoparticles were complexed with RNA and used to transfect DCs ex vivo. RNA-NP-loaded DsRed+ DCs were then injected intradermally into mice and tracked noninvasively with T2-weighted 11T MRI before excision and quantification with flow cytometry. RESULTS/ANTICIPATED RESULTS: In vitro experiments demonstrate that iron oxide loading does not reduce RNA-NP-mediated transfection of DCs. Additionally, replacement of cationic lipids with cholesterol increased RNA-NP transfection of the DC2.4 cell line and enhanced the T cell stimulatory capacity of treated bone marrow-derived dendritic cells (BMDCs). Compared to electroporation, RNA-NPs enhanced DC migration to lymph nodes and reduced T2 MRI intensity in DC-bearing lymph nodes. DISCUSSION/SIGNIFICANCE OF IMPACT: This data suggests that iron oxide-loaded RNA-NPs enable noninvasive cell tracking with MRI and enhance DC migration to lymph nodes. We have further shown that inclusion of cholesterol in RNA-NPs augments the stimulatory capacity of transfected DCs. Future work will consider effects of RNA-NPs on antitumor immune responses and the utility of MRI-detected DC migration as a biomarker of vaccine efficacy.
Cancer vaccines initiate antitumor responses in a subset of patients, but the lack of clinically meaningful biomarkers to predict treatment response limits their development. Here, we design ...multifunctional RNA-loaded magnetic liposomes to initiate potent antitumor immunity and function as an early biomarker of treatment response. These particles activate dendritic cells (DCs) more effectively than electroporation, leading to superior inhibition of tumor growth in treatment models. Inclusion of iron oxide enhances DC transfection and enables tracking of DC migration with magnetic resonance imaging (MRI). We show that T 2*-weighted MRI intensity in lymph nodes is a strong correlation of DC trafficking and is an early predictor of antitumor response. In preclinical tumor models, MRI-predicted “responders” identified 2 days after vaccination had significantly smaller tumors 2–5 weeks after treatment and lived 73% longer than MRI-predicted “nonresponders”. These studies therefore provide a simple, scalable nanoparticle formulation to generate robust antitumor immune responses and predict individual treatment outcome with MRI.
Abstract
RNA vaccines have shown great promise as activators of immune responses against viral pathogens but their efficacy in cancer is unclear. Here, we describe a versatile, personalized ...mRNA-nanoparticle (RNA-NP) platform that can be customized to produce powerful anti-tumor immune activation, reprogram the brain tumor microenvironment, and predict vaccine efficacy just two days after treatment. Lipid mixtures (i.e. DOTAP, Cholesterol) with or without iron oxide nanoparticle-cores were complexed with mRNA encoding tumor antigens. Intravenous administration of RNA-NPs induced robust activation of innate immune cells resulting in prolonged survival in murine models of subcutaneous and intracranial melanoma. Inclusion of cholesterol in the lipid backbone enabled delivery of nucleic acids across the blood brain barrier and into tumor-associated myeloid cells in intracranial GL261 and KR158b tumors. These cholesterol-bearing liposomes not only activated innate immune cells in the tumor microenvironment (i.e. increased expression of CD80 and MHCII), but also enabled further manipulation of this compartment. Use of RNA-NPs to deliver siRNA targeting PD-L1 resulted in significant reduction in PD-L1 expression among tumor associated myeloid cells, leading to 37% long term survivorship in combination with systemic checkpoint blockade in an otherwise fatal model of GL261. We have also shown that IONPs incorporated into the cores of these particles enable non-invasive tracking of dendritic cells by MRI, enabling creation of a theranostic approach to: 1) enhance immunologic effects; 2) facilitate translocation across the blood-brain barrier; and 3) enable non-invasive imaging to predict response to RNA-NPs.
Abstract
BACKGROUND
Mutated neoantigens have shown promise as targets for cancer immunotherapy but embryonal pediatric brain tumors with notoriously low mutational burden have more limited ...opportunities for neoantigen directed therapies. Evidence suggests that embryonal brain tumors such as medulloblastoma (MB) and brain stem gliomas (BSG) arise from the aberrant reactivation of fetal developmental programming. We explored the hypothesis that neonatal mouse cerebellum and brainstem express developmentally regulated proteins that could serve as potent tumor rejection antigens for a preclinical model of Group 3 MB (NSC) and H3.3K27M positive BSG (K2), respectively. We thus generated tumor-reactive T cells by using P5 cerebellum and P4 brain stem RNA as sources of antigens. P5-cerebellum-specific T cells (cDevAg-T cells) and P4-brain stem-specific T cells (bsDevAg-T cells) demonstrated effector function against respective MB and BSG tumor cells with exquisite specificity.
METHODS
RNA was isolated from P5 cerebellum and P4 brain stem and pulsed into bone marrow-derived dendritic cells. These were then used to in vitro activate splenocytes from previously immunized mice, generating either cDevAg-T cells or bsDevAg-T cells. In vitro functionality assays against tumor targets were conducted to determine reactivity and specificity. DevAg-T cells were used in adoptive cellular therapy in orthotopic models to determine therapeutic efficacy of DevAg-specific T cells in vivo. Results and
CONCLUSIONS
DevAg-T cells produce high levels of Th1-type cytokines that recognize distinct subtypes of MB and BSG, show no cross-reactivity with normal brain. Adoptive cellular therapy employing DevAg-specific T cells demonstrate a significant survival benefit in orthotopic models of established Group 3 NSC MB and H3.3K27M mutation positive BSG. Our studies demonstrate that RNA encoding non-mutated and organ-specific developmental antigens can serve as novel tumor rejection antigens for pediatric brain cancers.
Translation of nanoparticles (NPs) into human clinical trials for patients with refractory cancers has lagged due to unknown biologic reactivities of novel NP designs. To overcome these limitations, ...simple well-characterized mRNA lipid-NPs have been developed as cancer immunotherapeutic vaccines. While the preponderance of RNA lipid-NPs encoding for tumor-associated antigens or neoepitopes have been designed to target lymphoid organs, they remain encumbered by the profound intratumoral and systemic immunosuppression that may stymie an activated T cell response. Herein, we show that systemic localization of untargeted tumor RNA (derived from whole transcriptome) encapsulated in lipid-NPs, with excess positive charge, primes the peripheral and intratumoral milieu for response to immunotherapy. In immunologically resistant tumor models, these RNA-NPs activate the preponderance of systemic and intratumoral myeloid cells (characterized by coexpression of PD-L1 and CD86). Addition of immune checkpoint inhibitors (ICIs) (to animals primed with RNA-NPs) augments peripheral/intratumoral PD-1+CD8+ cells and mediates synergistic antitumor efficacy in settings where ICIs alone do not confer therapeutic benefit. These synergistic effects are mediated by type I interferon released from plasmacytoid dendritic cells (pDCs). In translational studies, personalized mRNA-NPs were safe and active in a client-owned canine with a spontaneous malignant glioma. In summary, we demonstrate widespread immune activation from tumor loaded RNA-NPs concomitant with inducible PD-L1 expression that can be therapeutically exploited. While immunotherapy remains effective for only a subset of cancer patients, combination therapy with systemic immunomodulating RNA-NPs may broaden its therapeutic potency.
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