Targeting Metabolic Pathways of Myeloid Cells Improves Cancer Immunotherapy

Tumor-infiltrating myeloid cells are a prominent pro-tumorigenic immune cell population that limit host anti-tumor immunity and present a significant obstacle for many cancer immunotherapies. Targeting the mechanisms regulating myeloid cell function within the tumor microenvironment may overcome immunotherapy resistance in some cancers. Recent discoveries in the emerging field of immunometabolism reveal that the metabolic profiles of intratumoral myeloid cells are rewired to adapt to the nutrition-limited tumor microenvironment, and this shapes their pro-tumor phenotypes. Interestingly, metabolic modulation can shift these myeloid cells toward the immune-stimulating anti-tumor phenotype. In this review, we will highlight the roles of specific metabolic pathways in the activation and function of myeloid cells, and discuss the therapeutic value of metabolically reprogramming myeloid cells to augment and improve outcomes with cancer immunotherapy.

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Immunosuppressive Roles of Galectin-1 in the Tumor Microenvironment

Biomolecules ◽

10.3390/biom11101398 ◽

2021 ◽

Vol 11 (10) ◽

pp. 1398

Author(s):

Yanyu Huang ◽

Hsiao-Chi Wang ◽

Junwei Zhao ◽

Ming-Heng Wu ◽

Tsung-Chieh Shih

Keyword(s):

Tumor Microenvironment ◽

Cell Function ◽

Immune Cell ◽

Immune Escape ◽

Immune Surveillance ◽

Human Tumor ◽

Immune Cell Function ◽

Tumor Immune Escape ◽

Cancer Tumor ◽

And Function

Evasion of immune surveillance is an accepted hallmark of tumor progression. The production of immune suppressive mediators by tumor cells is one of the major mechanisms of tumor immune escape. Galectin-1 (Gal-1), a pivotal immunosuppressive molecule, is expressed by many types of cancer. Tumor-secreted Gal-1 can bind to glycosylated receptors on immune cells and trigger the suppression of immune cell function in the tumor microenvironment, contributing to the immune evasion of tumors. The aim of this review is to summarize the current literature on the expression and function of Gal-1 in the human tumor microenvironment, as well as therapeutics targeting Gal-1.

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

10.21203/rs.3.rs-86825/v1 ◽

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.

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Myeloid Cell CK2 Regulates Inflammation and Resistance to Bacterial Infection

Frontiers in Immunology ◽

10.3389/fimmu.2020.590266 ◽

2020 ◽

Vol 11 ◽

Author(s):

Sandy R. Larson ◽

Nikki Bortell ◽

Alysha Illies ◽

William J. Crisler ◽

Jennifer L. Matsuda ◽

...

Keyword(s):

Essential Role ◽

Cell Function ◽

Immune Cell ◽

Myeloid Cells ◽

Myeloid Cell ◽

Innate Immune Responses ◽

In Trans ◽

Catalytic Ck2α Subunit ◽

Organismal Development ◽

Kinase Ck2

Kinase activity plays an essential role in the regulation of immune cell defenses against pathogens. The protein kinase CK2 (formerly casein kinase II) is an evolutionarily conserved kinase with hundreds of identified substrates. CK2 is ubiquitously expressed in somatic and immune cells, but the roles of CK2 in regulation of immune cell function remain largely elusive. This reflects the essential role of CK2 in organismal development and limited prior work with conditional CK2 mutant murine models. Here, we generated mice with a conditional (floxed) allele of Csnk2a, which encodes the catalytic CK2α subunit of CK2. When crossed to Lyz2-cre mice, excision of Csnk2a sequence impaired CK2α expression in myeloid cells but failed to detectably alter myeloid cell development. By contrast, deficiency for CK2α increased inflammatory myeloid cell recruitment, activation, and resistance following systemic Listeria monocytogenes (Lm) infection. Results from mixed chimera experiments indicated that CK2α deficiency in only a subset of myeloid cells was not sufficient to reduce bacterial burdens. Nor did cell-intrinsic deficiency for CK2α suffice to alter accumulation or activation of monocytes and neutrophils in infected tissues. These data suggest that CK2α expression by Lyz2-expressing cells promotes inflammatory and anti-bacterial responses through effects in trans. Our results highlight previously undescribed suppressive effects of CK2 activity on inflammatory myeloid cell responses and illustrate that cell-extrinsic effects of CK2 can shape inflammatory and protective innate immune responses.

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Cytokines Orchestrating the Natural Killer-Myeloid Cell Crosstalk in the Tumor Microenvironment: Implications for Natural Killer Cell-Based Cancer Immunotherapy

Frontiers in Immunology ◽

10.3389/fimmu.2020.621225 ◽

2021 ◽

Vol 11 ◽

Cited By ~ 1

Author(s):

Silvia Gaggero ◽

Kristina Witt ◽

Mattias Carlsten ◽

Suman Mitra

Keyword(s):

Tumor Microenvironment ◽

Nk Cells ◽

Natural Killer ◽

Cell Function ◽

Nk Cell ◽

Killer Cell ◽

Myeloid Cells ◽

Myeloid Cell ◽

Full Potential ◽

Cell Crosstalk

Natural killer (NK) cells are endowed with germline-encoded receptors that enable them to detect and kill malignant cells without prior priming. Over the years, overwhelming evidence has identified an essential role for NK cells in tumor immune surveillance. More recently, clinical trials have also highlighted their potential in therapeutic settings. Yet, data show that NK cells can be dysregulated within the tumor microenvironment (TME), rendering them ineffective in eradicating the cancer cells. This has been attributed to immune suppressive factors, including the tumor cells per se, stromal cells, regulatory T cells, and soluble factors such as reactive oxygen species and cytokines. However, the TME also hosts myeloid cells such as dendritic cells, macrophages, neutrophils, and myeloid-derived suppressor cells that influence NK cell function. Although the NK-myeloid cell crosstalk can promote anti-tumor responses, myeloid cells in the TME often dysregulate NK cells via direct cell-to-cell interactions down-regulating key NK cell receptors, depletion of nutrients and growth factors required for NK cell growth, and secretion of metabolites, chemokines and cytokines that ultimately alter NK cell trafficking, survival, and cytotoxicity. Here, we review the complex functions of myeloid-derived cytokines in both supporting and suppressing NK cells in the TME and how NK cell-derived cytokines can influence myeloid subsets. We discuss challenges related to these interactions in unleashing the full potential of endogenous and adoptively infused NK cells. Finally, we present strategies aiming at improving NK cell-based cancer immunotherapies via pathways that are involved in the NK-myeloid cell crosstalk in the TME.

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How Changes in the Nutritional Landscape Shape Gut Immunometabolism

Nutrients ◽

10.3390/nu13030823 ◽

2021 ◽

Vol 13 (3) ◽

pp. 823

Author(s):

Jian Tan ◽

Duan Ni ◽

Rosilene V. Ribeiro ◽

Gabriela V. Pinget ◽

Laurence Macia

Keyword(s):

Immune Cells ◽

Metabolic Pathways ◽

Immune Cell ◽

Food Additives ◽

Cell Activity ◽

Inflammatory Cells ◽

Therapeutic Approaches ◽

Food Antigens ◽

And Function ◽

Micro Organisms

Cell survival, proliferation and function are energy-demanding processes, fuelled by different metabolic pathways. Immune cells like any other cells will adapt their energy production to their function with specific metabolic pathways characteristic of resting, inflammatory or anti-inflammatory cells. This concept of immunometabolism is revolutionising the field of immunology, opening the gates for novel therapeutic approaches aimed at altering immune responses through immune metabolic manipulations. The first part of this review will give an extensive overview on the metabolic pathways used by immune cells. Diet is a major source of energy, providing substrates to fuel these different metabolic pathways. Protein, lipid and carbohydrate composition as well as food additives can thus shape the immune response particularly in the gut, the first immune point of contact with food antigens and gastrointestinal tract pathogens. How diet composition might affect gut immunometabolism and its impact on diseases will also be discussed. Finally, the food ingested by the host is also a source of energy for the micro-organisms inhabiting the gut lumen particularly in the colon. The by-products released through the processing of specific nutrients by gut bacteria also influence immune cell activity and differentiation. How bacterial metabolites influence gut immunometabolism will be covered in the third part of this review. This notion of immunometabolism and immune function is recent and a deeper understanding of how lifestyle might influence gut immunometabolism is key to prevent or treat diseases.

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Targeting HIF-1 alpha transcriptional activity drives cytotoxic immune effector cells into melanoma and improves combination immunotherapy

Oncogene ◽

10.1038/s41388-021-01846-x ◽

2021 ◽

Author(s):

Audrey Lequeux ◽

Muhammad Zaeem Noman ◽

Malina Xiao ◽

Kris Van Moer ◽

Meriem Hasmim ◽

...

Keyword(s):

Tumor Microenvironment ◽

Cancer Immunotherapy ◽

Transcriptional Activity ◽

Immune Cell ◽

Tumor Resistance ◽

Combination Strategy ◽

Immune Effector ◽

Effector Cells ◽

Melanoma Patients ◽

The Impact

AbstractHypoxia is a key factor responsible for the failure of therapeutic response in most solid tumors and promotes the acquisition of tumor resistance to various antitumor immune effectors. Reshaping the hypoxic immune suppressive tumor microenvironment to improve cancer immunotherapy is still a relevant challenge. We investigated the impact of inhibiting HIF-1α transcriptional activity on cytotoxic immune cell infiltration into B16-F10 melanoma. We showed that tumors expressing a deleted form of HIF-1α displayed increased levels of NK and CD8+ effector T cells in the tumor microenvironment, which was associated with high levels of CCL2 and CCL5 chemokines. We showed that combining acriflavine, reported as a pharmacological agent preventing HIF-1α/HIF-1β dimerization, dramatically improved the benefit of cancer immunotherapy based on TRP-2 peptide vaccination and anti-PD-1 blocking antibody. In melanoma patients, we revealed that tumors exhibiting high CCL5 are less hypoxic, and displayed high NK, CD3+, CD4+ and CD8+ T cell markers than those having low CCL5. In addition, melanoma patients with high CCL5 in their tumors survive better than those having low CCL5. This study provides the pre-clinical proof of concept for a novel triple combination strategy including blocking HIF-1α transcription activity along vaccination and PD-1 blocking immunotherapy.

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Cellular and metabolic mechanisms of nutrient actions in immune function

Nutrition and Diabetes ◽

10.1038/s41387-021-00162-3 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Philip Newsholme

Keyword(s):

Amino Acids ◽

Fatty Acids ◽

Vitamin D ◽

Immune System ◽

Cell Function ◽

Immune Cell ◽

Cell Structure ◽

Nutritional Intervention ◽

Immune Cell Function ◽

And Function

AbstractVarious nutrients can change cell structure, cellular metabolism, and cell function which is particularly important for cells of the immune system as nutrient availability is associated with the activation and function of diverse immune subsets. The most important nutrients for immune cell function and fate appear to be glucose, amino acids, fatty acids, and vitamin D. This perspective will describe recently published information describing the mechanism of action of prominent nutritional intervention agents where evidence exists as to their action and potency.

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When Cells Suffocate: Autophagy in Cancer and Immune Cells under Low Oxygen

International Journal of Cell Biology ◽

10.1155/2011/470597 ◽

2011 ◽

Vol 2011 ◽

pp. 1-13 ◽

Cited By ~ 16

Author(s):

Katrin Schlie ◽

Jaeline E. Spowart ◽

Luke R. K. Hughson ◽

Katelin N. Townsend ◽

Julian J. Lum

Keyword(s):

Tumor Microenvironment ◽

Cancer Cells ◽

Immune Cells ◽

Immune Cell ◽

Treatment Strategies ◽

Patient Treatment ◽

Low Oxygen ◽

Tumor Environment ◽

And Function ◽

The Impact

Hypoxia is a signature feature of growing tumors. This cellular state creates an inhospitable condition that impedes the growth and function of all cells within the immediate and surrounding tumor microenvironment. To adapt to hypoxia, cells activate autophagy and undergo a metabolic shift increasing the cellular dependency on anaerobic metabolism. Autophagy upregulation in cancer cells liberates nutrients, decreases the buildup of reactive oxygen species, and aids in the clearance of misfolded proteins. Together, these features impart a survival advantage for cancer cells in the tumor microenvironment. This observation has led to intense research efforts focused on developing autophagy-modulating drugs for cancer patient treatment. However, other cells that infiltrate the tumor environment such as immune cells also encounter hypoxia likely resulting in hypoxia-induced autophagy. In light of the fact that autophagy is crucial for immune cell proliferation as well as their effector functions such as antigen presentation and T cell-mediated killing of tumor cells, anticancer treatment strategies based on autophagy modulation will need to consider the impact of autophagy on the immune system.

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Clinical Significance of PDCD4 in Melanoma by Subcellular Expression and in Tumor-Associated Immune Cells

Cancers ◽

10.3390/cancers13051049 ◽

2021 ◽

Vol 13 (5) ◽

pp. 1049

Author(s):

Thuy T. Tran ◽

Chetan K. Rane ◽

Christopher R. Zito ◽

Sarah A. Weiss ◽

Shlomit Jessel ◽

...

Keyword(s):

Tumor Microenvironment ◽

Brain Metastasis ◽

Immune Cell ◽

Tissue Microarrays ◽

Pleckstrin Homology Domain ◽

Neoplastic Progression ◽

Melanoma Brain Metastasis ◽

Pdcd4 Expression ◽

Programmed Cell Death 4 ◽

And Function

Little is known about the subcellular localization and function of programmed cell death 4 (PDCD4) in melanoma. Our past studies suggest PDCD4 interacts with Pleckstrin Homology Domain Containing A5 (PLEKHA5) to influence melanoma brain metastasis outcomes, as high intracranial PDCD4 expression leads to improved survival. We aimed to define the subcellular distribution of PDCD4 in melanoma and in the tumor microenvironment during neoplastic progression and its impact on clinical outcomes. We analyzed multiple tissue microarrays with well-annotated clinicopathological variables using quantitative immunofluorescence and evaluated single-cell RNA-sequencing on a brain metastasis sample to characterize PDCD4+ immune cell subsets. We demonstrate differences in PDCD4 expression during neoplastic progression, with high tumor and stromal PDCD4 levels associated with improved survival in primary melanomas and in intracranial metastases, but not in extracranial metastatic disease. While the expression of PDCD4 is well-documented on CD8+ T cells and natural killer cells, we show that it is also found on B cells and mast cells. PDCD4 expression in the tumor microenvironment is associated with increased immune cell infiltration. Further studies are needed to define the interaction of PDCD4 and PLEKHA5 and to evaluate the utility of this pathway as a therapeutic target in melanoma brain metastasis.

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

10.1101/2021.09.24.461735 ◽

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.

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