IMMU-14. REVEALING THE MANY MYELOID STATES IN HUMAN BRAIN TUMORS AND WAYS TO PERTURB THEM

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi94-vi95
Author(s):  
Tyler Miller ◽  
Chadi El Farran ◽  
Julia Verga ◽  
Charles Couturier ◽  
Zeyu Chen ◽  
...  
Keyword(s):  
Brain Tumor ◽  
Tumor Microenvironment ◽  
Immune Cells ◽  
Ex Vivo ◽  
Myeloid Cells ◽  
Human Tumor ◽  
Myeloid Cell ◽  
Low Grade ◽  
Tumor Patients ◽  
The Many

Abstract Recent breakthroughs in immunotherapy have revolutionized treatment for many types of cancer, but unfortunately trials of these therapies have failed to provide meaningful life-prolonging benefit for brain tumor patients, potentially due to abundant immunosuppressive myeloid cells in the tumor. Our ultimate goal is to reprogram immunosuppressive tumor associated myeloid cells to an antitumor state to enable effective immunotherapy. Towards this goal, we have deeply characterized the immune microenvironment of more than 50 primary high and low grade gliomas using high-throughput single-cell RNA-sequencing to reveal recurrent myeloid cell states and immunosuppressive programs across IDH1 wild-type and mutant tumors. We have also established a brain tumor organoid model from primary patient tissue that maintains all of the tumor microenvironment, including myeloid and other immune cells. We utilize the this model to functionally test data-driven reprogramming strategies and understand how they impact the states of tumor and immune cells in the ex vivo human tumor microenvironment.

scholarly journals Pro-atherogenic diet accelerates tumor growth in mice through IL-1β and myeloid cell-derived VEGF-A

2020 ◽  
Author(s):  
Thi Tran ◽  
Bruno Esposito ◽  
Melanie Montabord ◽  
Jaouen Tran Rajau ◽  
Nadege Gruel ◽  
...  
Keyword(s):  
Tumor Microenvironment ◽  
Tumor Growth ◽  
Solid Tumors ◽  
Immune Cell ◽  
Myeloid Cells ◽  
Myeloid Cell ◽  
Atherogenic Diet ◽  
Low Grade ◽  
Dependent Manner ◽  
The Metabolic Syndrome

Abstract Aims: Myeloid inflammatory cells are recruited to the tumor microenvironment and subsequently educated in situ to acquire a pro-invasive, pro-angiogenic and immunosuppressive phenotype. Components of the metabolic syndrome are known to aggravate tumorigenesis in part through myeloid cell activation. We hypothesized that consumption of a high fat/high cholesterol pro-atherogenic diet and its associated low-grade inflammation would accelerate the initiation of solid tumors. Methods and results: Here, we show that two-week feeding of wildtype C57BL/6J mice with a pro-atherogenic diet increases the pool of circulating inflammatory Ly-6Chi monocytes available for initial melanoma development and amplifies the accumulation of myeloid cells within the tumor microenvironment, in an IL-1β-dependent manner. Under pro-atherogenic diet feeding, myeloid cells display heightened pro-angiogenic, pro-inflammatory and immunosuppressive activities. Within the first days after tumor implantation, myeloid cells become the main producer of VEGF-A in the tumor. Depletion of Ly-6Chi monocytes in mice fed with a pro-atherogenic diet limits immune cell infiltration in the tumor, and inhibits tumor growth. IL-1β deficiency or specific inhibition of VEGF-A in myeloid cells recapitulates the beneficial effect of Ly-6Chi monocyte depletion, suggesting their complementary roles in tumorigenesis in the context of mild hyperlipidemia. Conclusion: Our study shows that dyslipidemia provide high amounts of activated myeloid cells with pro-tumoral activity and shed light on cross-disease communication between cardiovascular pathologies and cancer. Translational Perspective: In this study we demonstrate that dyslipidemia accelerates the development of solid tumors through the increased infiltration of Ly6Chi monocytes that differentiate into pro-tumoral myeloid cells. These findings demonstrate that dyslipidemia can silently boost tumor development in normal-weight individuals through the action of IL-1β and VEGF-A. Our work sheds light on the potential benefit of targeting IL-1β and VEGF-A in cancer patients with moderate dyslipidemia.

scholarly journals IMMU-20. SINGLE-CELL RNASEQ OF TUMOR INFILTRATING IMMUNE CELLS FROM NEOADJUVANT ANTI-PD1 TREATED GBM PATIENTS REVEALS GLOBAL TRANSCRIPTIONAL CHANGES AND IMMUNOSUPPRESSIVE ADAPTIVE RESPONSES BY MYELOID CELLS

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii108-ii109
Author(s):  
Alexander Lee ◽  
Aaron Mochizuki ◽  
Frances Chow ◽  
Jeremy Reynoso ◽  
Joey Orpilla ◽  
...  
Keyword(s):  
T Cell ◽  
Tumor Microenvironment ◽  
Single Cell ◽  
T Cell Activation ◽  
Immune Cells ◽  
Trajectory Analysis ◽  
Myeloid Cells ◽  
Myeloid Cell ◽  
Lymphoid Cells ◽  
Transcriptional Changes

Abstract INTRODUCTION Neoadjuvant anti-PD1 therapy (neo-aPD1) was previously shown to significantly increase the survival of recurrent glioblastoma patients in a small randomized clinical trial. However, neo-aPD1 alone was not curative so defining the limitations of neo-aPD1 and discovering where other immunotherapies can be used alongside neo-aPD1 is needed. METHODS To understand how immune cells in the tumor microenvironment change with neo-aPD1, we used single-cell RNAsequencing to analyze cells from 27 glioma patients (n = 105,143 cells) of which 9 patients had received neo-aPD1 (n = 33,325 cells). Using unsupervised clustering and pseudotime trajectory analysis, we characterized the transcriptional changes within immune cells and how these populations changed with therapy. RESULTS We defined the immune landscape of the glioblastoma tumor microenvironment. Compared to no immunotherapy treatment, neo-aPD1 significantly increased the ratio of T cells to myelo-monocytic cells and led to significant increases in the effector and memory T cell populations but no significant changes in myeloid cell composition. Our differential gene expression analysis of the myeloid compartment showed significant increases in interferon-γ-responsive genes and down-regulation of genes associated with M2 macrophages and MDSCs, suggestive that neo-aPD1 influences the transcriptional profile of myeloid cells in the tumor microenvironment. Interestingly, our psuedotime trajectory analysis showed that neo-aPD1 was associated with cells expressing both lymphoid and myeloid-related genes, which we theorized to actually be lymphoid-myeloid cell doublets caused by increased interactions between myeloid and lymphoid cells. These doublets were highly enriched in MHC I and II, macrophage, T cell, and T cell activation and exhaustion genes indicating that neo-aPD1 may result in some adaptive immunosuppressive mechanism by increasing these interactions. This could explain why neo-aPD1 alone is not curative for glioblastoma patients. CONCLUSIONS In total, neoadjuvant anti-PD1 therapy enhances effector T cell activity, but may concomitantly induce adaptive resistance mediated by myeloid cells in glioblastoma.

scholarly journals Therapeutic Approaches Targeting the Natural Killer-Myeloid Cell Axis in the Tumor Microenvironment

2021 ◽  
Vol 12 ◽  
Author(s):  
Larissa S. Carnevalli ◽  
Hormas Ghadially ◽  
Simon T. Barry
Keyword(s):  
Tumor Microenvironment ◽  
Nk Cells ◽  
Natural Killer ◽  
T Cell Activation ◽  
Immune Cells ◽  
Myeloid Cells ◽  
Myeloid Cell ◽  
Positive Effects ◽  
Adaptive Immune ◽  
Adaptive Immune Cells

Immunotherapy has transformed cancer treatment by promoting durable clinical responses in a proportion of patients; however, treatment still fails in many patients. Innate immune cells play a key role in the response to immunotherapy. Crosstalk between innate and adaptive immune systems drives T-cell activation but also limits immunotherapy response, as myeloid cells are commonly associated with resistance. Hence, innate cells have both negative and positive effects within the tumor microenvironment (TME), and despite investment in early clinical trials targeting innate cells, they have seen limited success. Suppressive myeloid cells facilitate metastasis and immunotherapy resistance through TME remodeling and inhibition of adaptive immune cells. Natural killer (NK) cells, in contrast, secrete inflammatory cytokines and directly kill transformed cells, playing a key immunosurveillance role in early tumor development. Myeloid and NK cells show reciprocal crosstalk, influencing myeloid cell functional status or antigen presentation and NK effector function, respectively. Crosstalk between myeloid cells and the NK immune network in the TME is especially important in the context of therapeutic intervention. Here we discuss how myeloid and NK cell interactions shape anti-tumor responses by influencing an immunosuppressive TME and how this may influence outcomes of treatment strategies involving drugs that target myeloid and NK cells.

scholarly journals Simulating the human tumor microenvironment in colorectal cancer organoids in vitro and in vivo

2019 ◽  
Author(s):  
Mahesh Devarasetty ◽  
Anthony Dominijanni ◽  
Samuel Herberg ◽  
Ethan Shelkey ◽  
Aleksander Skardal ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Tumor Microenvironment ◽  
Cancer Progression ◽  
Ex Vivo ◽  
Human Tumor ◽  
Cancer Therapeutics ◽  
Low Grade ◽  
Ecm Architecture

AbstractThe tumor microenvironment (TME) plays a significant role in cancer growth and metastasis. Bioengineered models of the TME will advance our understanding of cancer progression and facilitate identification of novel anti-cancer therapeutics that target TME components such as extracellular matrix (ECM) and stromal cells. However, most current in vitro models fail to recapitulate the extensive features of the human tumor stroma, especially ECM architecture, and are not exposed to intact body physiology. On the other hand, in vivo animal models do not accurately capture human tumor architecture. Using the features of biopsied colorectal cancer (CRC) tissue as a guide, we address these deficiencies by creating human organoids containing a colonic stromal ECM layer and CRC spheroids. Organoids were studied in vitro and upon implantation in mice for 28 days. We show that the stromal ECM micro-architecture, generated in vitro, was maintained in vivo for at least 28 days. Furthermore, comparisons with biopsied CRC tumors revealed that organoids with orderly structured TMEs induce an epithelial phenotype in CRC cells, similar to low-grade tumors, compared to a mesenchymal phenotype observed in disordered TMEs, similar to high-grade tumors. Altogether, these results are the first demonstration of replicating the human tumor ECM architecture in biofabricated tumor organoids under ex vivo and in vivo conditions.

scholarly journals Single-cell RNA Sequencing Reveals Immunosuppressive Myeloid Cell Diversity and Restricted Cytotoxic Effector Cell Trafficking and Activation During Malignant Progression in Glioma

2021 ◽  
Author(s):  
Sakthi Rajendran ◽  
Clayton Peterson ◽  
Alessandro Canella ◽  
Yang Hu ◽  
Amy Gross ◽  
...  
Keyword(s):  
T Cells ◽  
Tumor Microenvironment ◽  
Single Cell ◽  
Immune Cell ◽  
Myeloid Cell ◽  
Malignant Progression ◽  
Low Grade ◽  
Cell Trafficking ◽  
High Grade ◽  
Single Cell Rna Sequencing

Low grade gliomas (LGG) account for about two-thirds of all glioma diagnoses in adolescents and young adults (AYA) and malignant progression of these patients leads to dismal outcomes. Recent studies have shown the importance of the dynamic tumor microenvironment in high-grade gliomas (HGG), yet its role is still poorly understood in low-grade glioma malignant progression. Here, we investigated the heterogeneity of the immune microenvironment using a platelet-derived growth factor (PDGF)-driven RCAS (replication-competent ASLV long terminal repeat with a splice acceptor) glioma model that recapitulates the malignant progression of low to high-grade glioma in humans and also provides a model system to characterize immune cell trafficking and evolution. To illuminate changes in the immune cell landscape during tumor progression, we performed single-cell RNA sequencing on immune cells isolated from animals bearing no tumor (NT), LGG and HGG, with a particular focus on the myeloid cell compartment, which is known to mediate glioma immunosuppression. LGGs demonstrated significantly increased infiltrating T cells, CD4 T cells, CD8 T cells, B cells, and natural killer cells in the tumor microenvironment, whereas HGGs significantly abrogated this infiltration. Our study identified two distinct macrophage clusters in the tumor microenvironment; one cluster appeared to be bone marrow-derived while another was defined by overexpression of Trem2, a marker of tumor associated macrophages. Our data demonstrates that these two distinct macrophage clusters show an immune-activated phenotype (Stat1, Tnf, Cxcl9 and Cxcl10) in LGG which evolves to an immunosuppressive state (Lgals3, Apoc1 and Id2) in HGG that restricts T cell recruitment and activation. We identified CD74 and macrophage migration inhibition factor (MIF) as potential targets for these distinct macrophage populations. Interestingly, these results were mirrored by our analysis of the TCGA dataset, which demonstrated a statistically significant association between CD74 overexpression and decreased overall survival in AYA patients with grade II gliomas. Targeting immunosuppressive myeloid cells and intra-tumoral macrophages within this therapeutic window may ameliorate mechanisms associated with immunosuppression before and during malignant progression.

scholarly journals IMMU-39. RNA LOADED LIPID-NANOPARTICLES FUNCTION AS CUSTOMIZABLE IMMUNOTHERAPEUTIC VEHICLES AGAINST MALIGNANT GLIOMAS

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi127-vi127
Author(s):  
Adam Grippin ◽  
Brandon Wummer ◽  
Hector Mendez-Gomez ◽  
Brian Stover ◽  
Jianping Huang ◽  
...  
Keyword(s):  
Brain Tumor ◽  
Tumor Microenvironment ◽  
Immune Cells ◽  
Lipid Nanoparticles ◽  
Lymphoid Organs ◽  
Innate Immune ◽  
T Cell Immunity ◽  
Innate Immune Cells ◽  
Cell Immunity ◽  
The Brain

Abstract BACKGROUND While dendritic cell (DC) vaccine therapy has shown considerable promise for glioblastoma (GBM) patients (Mitchell et al. Nature, 2015), their advancement into human clinical trials has been fraught with challenges in the development, manufacturing, and marketing of successful cancer immunotherapies. To circumvent the challenges associated with cell therapy, we have developed a new platform technology consisting of tumor derived mRNA complexed into lipid-nanoparticles (RNA-NPs) for systemic delivery to DCs in vivo and induction of antigen specific T cell immunity against GBM. OBJECTIVES/ METHODS We sought to assess if surface and charge modifications to our custom lipid-NP could facilitate its localization to lymphoid organs and the brain tumor microenvironment. RESULTS We demonstrate that intravenous administration of our unmodified custom RNA-NPs mediate systemic activation of DCs; these include activation of CD11c+ cells in the brains of animals with intact blood brain-barriers (BBBs). RNA-NPs mediate antigen specific T cell immunity and anti-tumor efficacy with increased tumor infiltrating lymphocytes against a NF-1/p53 mutant glioma that recapitulates features of human GBM in immunocompetent mice. Modification of surface charge could direct these RNA-NPs to lymphoid organs (e.g. spleen, lymph nodes) while modification of the lipid backbone (with cholesterol) enhances localization to innate immune cells in NF-1/p53 mutant and GL261 gliomas. We therefore assessed if this customizable lipid-NP could be leveraged for delivery of immune checkpoint inhibitors (ICIs) (i.e. PD-L1 siRNA) to the brain tumor microenvironment. Compared with scrambled siRNA-NPs in combination with ICIs, surface modified siRNA-NPs (antagonizing PD-L1) in combination with ICIs mediated significant antitumor efficacy with 37% long term survivors in an otherwise fatal brain tumor model. CONCLUSION We designed multifunctional RNA-NPs with a simple, scalable synthesis method that enables delivery of nucleic acids to innate immune cells in lymphoid organs and brain tumors.

scholarly journals TMIC-12. TUMOR-HOMING RNA-NANOPARTICLES REPROGRAM IMMUNE CELLS IN THE BRAIN TUMOR MICROENVIRONMENT

2018 ◽  
Vol 20 (suppl_6) ◽  
pp. vi258-vi258
Author(s):  
Adam Grippin ◽  
Hector Mendez-Gomez ◽  
Brandon Wummer ◽  
Tyler Wildes ◽  
Kyle Dyson ◽  
...  
Keyword(s):  
Brain Tumor ◽  
Tumor Microenvironment ◽  
Immune Cells ◽  
Tumor Homing ◽  
The Brain

Aptamers against mouse and human tumor-infiltrating myeloid cells as reagents for targeted chemotherapy

2020 ◽  
Vol 12 (548) ◽  
pp. eaav9760
Author(s):  
Adriana De La Fuente ◽  
Serena Zilio ◽  
Jimmy Caroli ◽  
Dimitri Van Simaeys ◽  
Emilia M. C. Mazza ◽  
...  
Keyword(s):  
Mouse Models ◽  
Anticancer Agents ◽  
Targeted Delivery ◽  
Tumor Regression ◽  
Ex Vivo ◽  
Myeloid Cells ◽  
Human Tumor ◽  
Rna Aptamers ◽  
Targeted Chemotherapy

Local delivery of anticancer agents has the potential to maximize treatment efficacy and minimize the acute and long-term systemic toxicities. Here, we used unsupervised systematic evolution of ligands by exponential enrichment to identify four RNA aptamers that specifically recognized mouse and human myeloid cells infiltrating tumors but not their peripheral or circulating counterparts in multiple mouse models and from patients with head and neck squamous cell carcinoma (HNSCC). The use of these aptamers conjugated to doxorubicin enhanced the accumulation and bystander release of the chemotherapeutic drug in both primary and metastatic tumor sites in breast and fibrosarcoma mouse models. In the 4T1 mammary carcinoma model, these doxorubicin-conjugated aptamers outperformed Doxil, the first clinically approved highly optimized nanoparticle for targeted chemotherapy, promoting tumor regression after just three administrations with no detected changes in weight loss or blood chemistry. These RNA aptamers recognized tumor infiltrating myeloid cells in a variety of mouse tumors in vivo and from human HNSCC ex vivo. This work suggests the use of RNA aptamers for the detection of myeloid-derived suppressor cells in humans and for a targeted delivery of chemotherapy to the tumor microenvironment in multiple malignancies.

scholarly journals Cerebrospinal Fluid MicroRNA Signatures as Diagnostic Biomarkers in Brain Tumors

Cancers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1546 ◽  
Author(s):  
Alena Kopkova ◽  
Jiri Sana ◽  
Tana Machackova ◽  
Marek Vecera ◽  
Lenka Radova ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Brain Tumor ◽  
Brain Tumors ◽  
Low Grade ◽  
Tumor Type ◽  
Tumor Patients ◽  
Primary Tumors ◽  
Mirna Profiling ◽  
Tumor Types ◽  
Cns Malignancies

Central nervous system (CNS) malignancies include primary tumors that originate within the CNS as well as secondary tumors that develop as a result of metastatic spread. Circulating microRNAs (miRNAs) were found in almost all human body fluids including cerebrospinal fluid (CSF), and they seem to be highly stable and resistant to even extreme conditions. The overall aim of our study was to identify specific CSF miRNA patterns that could differentiate among brain tumors. These new biomarkers could potentially aid borderline or uncertain imaging results onto diagnosis of CNS malignancies, avoiding most invasive procedures such as stereotactic biopsy or biopsy. In total, 175 brain tumor patients (glioblastomas, low-grade gliomas, meningiomas and brain metastases), and 40 non-tumor patients with hydrocephalus as controls were included in this prospective monocentric study. Firstly, we performed high-throughput miRNA profiling (Illumina small RNA sequencing) on a discovery cohort of 70 patients and 19 controls and identified specific miRNA signatures of all brain tumor types tested. Secondly, validation of 9 candidate miRNAs was carried out on an independent cohort of 105 brain tumor patients and 21 controls using qRT-PCR. Based on the successful results of validation and various combination patterns of only 5 miRNA levels (miR-30e, miR-140, let-7b, mR-10a and miR-21-3p) we proposed CSF-diagnostic scores for each tumor type which enabled to distinguish them from healthy donors and other tumor types tested. In addition to this primary diagnostic tool, we described the prognostic potential of the combination of miR-10b and miR-196b levels in CSF of glioblastoma patients. In conclusion, we performed the largest study so far focused on CSF miRNA profiling in patients with brain tumors, and we believe that this new class of biomarkers have a strong potential as a diagnostic and prognostic tool in these patients.

scholarly journals OR04-04 Identification of a Novel Transcriptional Regulator of Metabolic Disease in Circulating and Central Myeloid Cells

2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
David R Sweet ◽  
Neelakantan T Vasudevan ◽  
Liyan Fan ◽  
Chloe E Booth ◽  
Komal S Keerthy ◽  
...  
Keyword(s):  
Metabolic Disease ◽  
Immune Cells ◽  
Therapeutic Option ◽  
Myeloid Cells ◽  
Metabolic Stress ◽  
Myeloid Cell ◽  
Metabolic Phenotype ◽  
Adipose Tissue Macrophages ◽  
Improved Outcomes ◽  
Peripheral Immune Cells

Abstract Derangement in systemic metabolic homeostasis is tightly associated with widespread activation of resident and circulating immune cells, a phenomenon known as ‘metaflammation’. Numerous studies have explored the role of tissue resident and circulating macrophages in contributing to metaflammation, obesity, and their sequelae; however, there is a dearth of information regarding targetable transcriptional regulators of the genesis and persistence of metabolic disease. Here, we identify myeloid Krüppel-like factor 2 (KLF2) as a novel regulator of metabolic disease. Previous reports demonstrate that KLF2 serves as a critical regulator of myeloid cell quiescence and is downregulated in numerous acute and chronic inflammatory states. Specifically in the context of chronic metaflammation, we note that KLF2 expression is decreased in circulating immune cells of obese patients and in adipose tissue macrophages of high fat diet (HFD) fed mice, which is consistent with the hypothesis that KLF2 regulates metaflammation. To explore this further, we utilized mice with myeloid cell-specific deletion of KLF2 (K2KO) which exhibit accelerated obesity and insulin resistance. K2KO mice have widespread central (i.e. CNS) and peripheral metaflammation both in the basal and HFD-stimulated states. To discern whether the effect of myeloid deletion of KLF2 on metabolism is due to deletion in microglia in the feeding centers of the hypothalamus or in peripheral immune cells, bone marrow chimeras with head shielding were created. 50% reconstitution of circulating immune cells with K2KO cells in wildtype (WT) mice was sufficient to maintain the metabolic disease phenotype, while mice with K2KO microglia + WT circulating cells had only slightly improved outcomes compared to K2KO mice. Conversely, ablation of microglia in K2KO mice using PLX5622 formulated in HFD also successfully attenuated the aberrant feeding behavior, weight gain, and glucose dyshomeostasis seen in K2KO mice. Together, these data demonstrate a role for loss of KLF2 in hematopoietic and CNS resident cells in causing metabolic disease. Given that myeloid KLF2 expression decreases under metabolic stress in WT mice and humans, we sought to explore whether maintenance of KLF2 expression in these cells would be protective against diet-induced metabolic disease. Indeed, mice with myeloid-specific overexpression of KLF2 demonstrated a markedly improved metabolic phenotype when challenged with HFD, providing evidence that targeting KLF2 expression in myeloid cells may prove to be a therapeutic option against metaflammation.

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