scholarly journals The Immune Endocannabinoid System of the Tumor Microenvironment

2020 ◽  
Vol 21 (23) ◽  
pp. 8929
Author(s):  
Melanie Kienzl ◽  
Julia Kargl ◽  
Rudolf Schicho

Leukocytes are part of the tumor microenvironment (TME) and are critical determinants of tumor progression. Because of the immunoregulatory properties of cannabinoids, the endocannabinoid system (ECS) may have an important role in shaping the TME. Members of the ECS, an entity that consists of cannabinoid receptors, endocannabinoids and their synthesizing/degrading enzymes, have been associated with both tumor growth and rejection. Immune cells express cannabinoid receptors and produce endocannabinoids, thereby forming an “immune endocannabinoid system”. Although in vitro effects of exogenous cannabinoids on immune cells are well described, the role of the ECS in the TME, and hence in tumor development and immunotherapy, is still elusive. This review/opinion discusses the possibility that the “immune endocannabinoid system” can fundamentally influence tumor progression. The widespread influence of cannabinoids on immune cell functions makes the members of the ECS an interesting target that could support immunotherapy.

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii63-ii63
Author(s):  
Lakshmi Bollu ◽  
Derek Wainwright ◽  
Lijie Zhai ◽  
Erik Ladomersky ◽  
Kristen Lauing ◽  
...  

Abstract INTRODUCTION Indoleamine 2,3-dioxygenase 1 (IDO; IDO1) is a rate-limiting enzyme that metabolizes the essential amino acid tryptophan into kynurenine. Recent work by our group has revealed that IDO promotes tumor development and suppresses immune cell functions independent of its enzyme activity. Moreover, pharmacologic IDO enzyme inhibitors that currently serve as the only class of drugs available for targeting immunosuppressive IDO activity, fail to improve the survival of patients with GBM. Here, we developed IDO-Proteolysis Targeting Chimeras (IDO-PROTACs). PROTACs bind to a specific protein and recruit an E3 ubiquitin ligase that enhance proteasome-mediated degradation of the target protein. METHODS A library of ≥100 IDO-PROTACs were developed by joining BMS986205 (IDO binder) with a linker group to various E3-ligase ligands. Western blot analysis of PROTAC-induced IDO degradation was tested in vitro among multiple human and mouse GBM cell lines including U87, GBM6, GBM43 and GL261 along a time course ranging between 1–96 hours of treatment and at varying concentrations. The mechanism of IDO protein degradation was investigated using pharmacologic ligands that inhibit or compete with the proteasome-mediated protein degradation pathway. RESULTS Primary screening identified several IDO-PROTACs with IDO protein degradation potential. Secondary screening showed that our lead compound has a DC50 value of ~0.5µM with an ability to degrade IDO in all GBM cells analyzed, and an initial activity within 12 hours of treatment that extended for up to 96 hours. Mutating the CRBN-binding ligand, pretreatment with the ubiquitin proteasome system inhibitors MG132 or MLN4924 or using unmodified parental compound all inhibited IDO protein degradation. CONCLUSIONS This study developed an initial IDO-PROTAC technology that upon further optimization, can neutralize both IDO enzyme and non-enzyme immunosuppressive effects. When combined with other forms of immunotherapy, IDO-PROTACs have the potential to substantially enhance immunotherapeutic efficacy in patients with GBM.


Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1020
Author(s):  
Stefan Grote ◽  
Guillermo Ureña-Bailén ◽  
Kenneth Chun-Ho Chan ◽  
Caroline Baden ◽  
Markus Mezger ◽  
...  

Background: Melanoma is the most lethal of all skin-related cancers with incidences continuously rising. Novel therapeutic approaches are urgently needed, especially for the treatment of metastasizing or therapy-resistant melanoma. CAR-modified immune cells have shown excellent results in treating hematological malignancies and might represent a new treatment strategy for refractory melanoma. However, solid tumors pose some obstacles for cellular immunotherapy, including the identification of tumor-specific target antigens, insufficient homing and infiltration of immune cells as well as immune cell dysfunction in the immunosuppressive tumor microenvironment (TME). Methods: In order to investigate whether CAR NK cell-based immunotherapy can overcome the obstacles posed by the TME in melanoma, we generated CAR NK-92 cells targeting CD276 (B7-H3) which is abundantly expressed in solid tumors, including melanoma, and tested their effectivity in vitro in the presence of low pH, hypoxia and other known factors of the TME influencing anti-tumor responses. Moreover, the CRISPR/Cas9-induced disruption of the inhibitory receptor NKG2A was assessed for its potential enhancement of NK-92-mediated anti-tumor activity. Results: CD276-CAR NK-92 cells induced specific cytolysis of melanoma cell lines while being able to overcome a variety of the immunosuppressive effects normally exerted by the TME. NKG2A knock-out did not further improve CAR NK-92 cell-mediated cytotoxicity. Conclusions: The strong cytotoxic effect of a CD276-specific CAR in combination with an “off-the-shelf” NK-92 cell line not being impaired by some of the most prominent negative factors of the TME make CD276-CAR NK-92 cells a promising cellular product for the treatment of melanoma and beyond.


Author(s):  
Irene Romayor ◽  
Joana Márquez ◽  
Aitor Benedicto ◽  
Alba Herrero ◽  
Beatriz Arteta ◽  
...  

Colorectal cancer (CRC) colonization of the liver and its further metastatic growth are the result of complex interaction between the tumor cell, the collagenous extracellular matrix (ECM) and the hepatic sinusoidal cells (SCs). Discoidin domain receptor 1 (DDR1) is a tyrosine kinase receptor activated by collagen and a bad prognosis factor in cancer. DDR1 signaling regulates key cell functions for tumor development, such as proliferation, migration, invasion and metalloproteinases (MMPs) secretion. However, the mechanisms underlying the implication of DDR1 in the conformation of the metastatic niche in the liver remain poorly known. In this study, we used an experimental model of liver metastasis from CRC to investigate the role of DDR1 in the context of the pro-metastatic crosstalk between tumor cells and the hepatic stroma. Bioinformatics and immunohistochemical analysis revealed that DDR1 was highly expressed in tumor tissues from patients with primary CRC and hepatic CRC metastasis. Besides, DDR1 overexpression was associated with poor outcome. In vitro, SCs-derived soluble factors promoted DDR1 phosphorylation and MMP2 production by CRC cells. In vivo, tumor DDR1 participated in hepatic ECM remodeling by modulating the expression of collagen and MMP2, and stimulated the recruitment of stromal cells into the tumor microenvironment. In addition, tumor DDR1 favored SCs ability to modify the ECM organization by controlling the expression of collagen and MMPs. Altogether, our results show that tumor DDR1 plays an important role in the desmoplastic response of hepatic tumor microenvironment during CRC invasion and growth.


2020 ◽  
Vol 8 (1) ◽  
pp. e000529 ◽  
Author(s):  
Yongling Ning ◽  
Jun Ding ◽  
Xiao Sun ◽  
Yewen Xie ◽  
Mingming Su ◽  
...  

BackgroundThe tumor microenvironment (TME) contains a variety of immune cells, which play critical roles during the multistep development of tumors. Histone deacetylase 9 (HDAC9) has been reported to have either proinflammatory or anti-inflammatory effects, depending on the immune environment. In this study, we investigated whether HDAC9 in the tumor stroma regulated inflammation and antitumor immunity.MethodsHdac9 knockout mice were generated to analyze the HDAC9-associated inflammation and tumor progression. Immune cells and cytokines in TME or draining lymph nodes were quantified by flow cytometry and quantitative reverse transcription-PCR. The antigen presentation and CD8+ T cell priming by tumor-infiltrating dendritic cells (DCs) were evaluated in vitro and in vivo. HDAC9-associated inflammation was investigated in a mouse model with dextran sulfate sodium–induced colitis. Correlation of HDAC9 with CD8+ expression was assessed in tissue sections from patients with non-small cell lung cancer.ResultsHDAC9 deficiency promoted tumor progression by decreasing the CD8+ DC infiltration of the TME. Compared with wild-type mice, the tumor-infiltrating DCs of Hdac9-/- mice displayed impaired cross-presentation of tumor antigens and cross-priming of CD8+ T cells. Moreover, HDAC9 expression was significantly positively correlated with CD8+ cell counts in human lung cancer stroma samples.ConclusionsHDAC9 deficiency decreased inflammation and promoted tumor progression by decreasing CD8+ DC infiltration of the TME. HDAC9 expression in the tumor stroma may represent a promising biomarker to predict the therapeutic responses of patients receiving CD8+ T cell-dependent immune treatment regimens.


2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Juliana Hofstatter Azambuja ◽  
Nils Ludwig ◽  
Saigopalakrishna Yerneni ◽  
Aparna Rao ◽  
Elizandra Braganhol ◽  
...  

Abstract Background Glioblastoma is one of the most immunosuppressive human tumors. Emerging data suggest that glioblastoma-derived exosomes (GBex) reprogram the tumor microenvironment into a tumor-promoting milieu by mechanisms that not yet understood. Methods Exosomes were isolated from supernatants of glioblastoma cell lines by size exclusion chromatography. The GBex endosomal origin, size, protein cargos, and ex vivo effects on immune cell functions were determined. GBex were injected intravenously into mice to evaluate their ability to in vivo modulate normal immune cell subsets. Results GBex carried immunosuppressive proteins, including FasL, TRAIL, CTLA-4, CD39, and CD73, but contained few immunostimulatory proteins. GBex co-incubated with primary human immune cells induced simultaneous activation of multiple molecular pathways. In CD8+ T cells, GBex suppressed TNF-α and INF-γ release and mediated apoptosis. GBex suppressed natural killer (NK) and CD4+ T-cell activation. GBex activated the NF-κB pathway in macrophages and promoted their differentiation into M2 cells. Inhibition of the NF-κB pathway in macrophages reversed the GBex-mediated effects. GBex-driven reprogramming of macrophages involved the release of soluble factors that promoted tumor proliferation in vitro. In mice injected with GBex, the frequency of splenic CD8+ T cells, NK cells, and M1-like macrophages was reduced, while that of naïve and M2-like macrophages increased (P < .05). Conclusions GBex reprogrammed functions of all types of immune cells in vitro and altered their frequency in vivo. By creating and sustaining a highly immunosuppressive environment, GBex play a key role in promoting tumor progression.


Cancers ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 127
Author(s):  
Federico Virga ◽  
Lorena Quirico ◽  
Stefania Cucinelli ◽  
Massimiliano Mazzone ◽  
Daniela Taverna ◽  
...  

The metabolism of cancer cells is generally very different from what is found in normal counterparts. However, in a tumor mass, the continuous crosstalk and competition for nutrients and oxygen among different cells lead to metabolic alterations, not only in cancer cells, but also in the different stromal and immune cells of the tumor microenvironment (TME), which are highly relevant for tumor progression. MicroRNAs (miRs) are small non-coding RNAs that silence their mRNA targets post-transcriptionally and are involved in numerous physiological cell functions as well as in the adaptation to stress situations. Importantly, miRs can also be released via extracellular vesicles (EVs) and, consequently, take part in the bidirectional communication between tumor and surrounding cells under stress conditions. Certain miRs are abundantly expressed in stromal and immune cells where they can regulate various metabolic pathways by directly suppressing enzymes or transporters as well as by controlling important regulators (such as transcription factors) of metabolic processes. In this review, we discuss how miRs can induce metabolic reprogramming in stromal (fibroblasts and adipocytes) and immune (macrophages and T cells) cells and, in turn, how the biology of the different cells present in the TME is able to change. Finally, we debate the rebound of miR-dependent metabolic alterations on tumor progression and their implications for cancer management.


2020 ◽  
Vol 12 (10) ◽  
pp. 250-262
Author(s):  
Sheena C Kerr ◽  
Molly M Morgan ◽  
Amani A Gillette ◽  
Megan K Livingston ◽  
Karina M Lugo-Cintron ◽  
...  

Abstract The prostate tumor microenvironment (TME) is strongly immunosuppressive; it is largely driven by alteration in cell phenotypes (i.e. tumor-associated macrophages and exhausted cytotoxic T cells) that result in pro-tumorigenic conditions and tumor growth. A greater understanding into how these altered immune cell phenotypes are developed and could potentially be reversed would provide important insights into improved treatment efficacy for prostate cancer. Here, we report a microfluidic model of the prostate TME that mimics prostate ducts across various stages of prostate cancer progression, with associated stroma and immune cells. Using this platform, we exposed immune cells to a benign prostate TME or a metastatic prostate TME and investigated their metabolism, gene and cytokine expression. Immune cells exposed to the metastatic TME showed metabolic differences with a higher redox ratio indicating a switch to a more glycolytic metabolic profile. These cells also increased expression of pro-tumor response cytokines that have been shown to increase cell migration and angiogenesis such as Interleukin-1 (IL-1) a and Granulocyte-macrophage colony-stimulating factor (GM-CSF). Lastly, we observed decreased TLR, STAT signaling and TRAIL expression, suggesting that phenotypes derived from exposure to the metastatic TME could have an impaired anti-tumor response. This platform could provide a valuable tool for studying immune cell phenotypes in in vitro tumor microenvironments.


2020 ◽  
Vol 21 (15) ◽  
pp. 5521
Author(s):  
Karim Pérez-Romero ◽  
Ramón M. Rodríguez ◽  
Amedeo Amedei ◽  
Gwendolyn Barceló-Coblijn ◽  
Daniel H. Lopez

Integration of the tumor microenvironment as a fundamental part of the tumorigenic process has undoubtedly revolutionized our understanding of cancer biology. Increasing evidence indicates that neoplastic cells establish a dependency relationship with normal resident cells in the affected tissue and, furthermore, develop the ability to recruit new accessory cells that aid tumor development. In addition to normal stromal and tumor cells, this tumor ecosystem includes an infiltrated immune component that establishes complex interactions that have a critical effect during the natural history of the tumor. The process by which immune cells modulate tumor progression is known as immunoediting, a dynamic process that creates a selective pressure that finally leads to the generation of immune-resistant cells and the inability of the immune system to eradicate the tumor. In this context, the cellular and functional characterization of the immune compartment within the tumor microenvironment will help to understand tumor progression and, ultimately, will serve to create novel prognostic tools and improve patient stratification for cancer treatment. Here we review the impact of the immune system on tumor development, focusing particularly on its clinical implications and the current technologies used to analyze immune cell diversity within the tumor.


2019 ◽  
Vol 20 (17) ◽  
pp. 4320 ◽  
Author(s):  
Buoncervello ◽  
Gabriele ◽  
Toschi

The tumor microenvironment (TME) is a complex entity where host immune and non-immune cells establish a dynamic crosstalk with cancer cells. Through cell-cell interactions, which are mediated by key signals, such as the PD-1/PD-L1 axis, as well as the release of soluble mediators, this articulated process defines the nature of TME determining tumor development, prognosis, and response to therapy. Specifically, tumors are characterized by cellular plasticity that allows for the microenvironment to polarize towards inflammation or immunosuppression. Thus, the dynamic crosstalk among cancer, stromal, and immune components crucially favors the dominance of one of the Janus-faced contexture of TME crucial to the outcome of tumor development and therapeutic response. However, mostly, TME is dominated by an immunosuppressive landscape that blocks antitumor immunity and sustain tumor progression. Hence, in most cases, the immunosuppressive components of TME are highly competent in suppressing tumor-specific CD8+ T lymphocytes, the effectors of cancer destruction. In this complex context, immunotherapy aims to arm the hidden Janus face of TME disclosing and potentiating antitumor immune signals. Herein, we discuss recent knowledge on the immunosuppressive crosstalk within TME, and share perspectives on how immunotherapeutic approaches may exploit tumor immune signals to generate antitumor immunity.


2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A528-A528
Author(s):  
Lin Ma ◽  
Jian-Hua Mao ◽  
Mary Helen Barcellos-Hoff ◽  
Jade Moore

BackgroundCheckpoint inhibitors can induce robust and durable responses in a subset of patients. Extending this benefit to more patients could be facilitated by better understanding of how interacts with immune cells with the tumor microenvironment, which is a critical barrier to control both local and systemic disease. The composition and pattern of the immune infiltrate associates with the likelihood of response to immunotherapy. Inflamed tumors that exhibit a brisk immune cell infiltrate are responsive, while those in which immune cells are completely or partially excluded are not. Transforming growth factor β (TGFβ) is immunosuppressive and associated with the immune excluded phenotype.MethodsUsing an immune competent mammary tumor derived transplant (mTDT) model recently developed in our lab, exhibits inflamed, excluded or deserts immune infiltrate phenotypes based on localization of CD8 lymphocytes. Using whole transcriptome deep sequencing, cytof, and PET-CT imaging, we evaluated the tumor, microenvironment, and immune pathway activation among immune infiltrate phenotypes.ResultsThree distinct inflamed tumors phenotypes were identified: ‘classically’ inflamed characterized by pathway evidence of increased CD8+ T cells and decreased PD-L1 expression, inflamed tumors with pathways indicative of neovascularization and STAT3 signaling and reduced T cell mobilization, and an inflamed tumor with increased immunosuppressive myeloid phenotypes. Excluded tumors were characterized by TGFβ gene expression and pro-inflammatory cytokine signaling (e.g. TNFα, IL1β), associated with decreased leukocytes homing and increased immune cell death of cells. We visualized and quantified TGFβ activity using PET-CT imaging of 89Zr-fresolimumab, a TGFβ neutralizing antibody. TGFβ activity was significantly increased in excluded tumors compared to inflamed or desert tumors, which was supported by quantitative pathology (Perkin Elmer) of its canonical signaling target, phosphorylated SMAD2 (pSMAD2). pSMAD2 was positively correlated with PD-L1 expression in the stroma of excluded tumors. In contrast, in inflamed tumors, TGFβ activity positively correlated with increased F4/80 positive macrophages and negatively correlated with expression of PD-L1. CyTOF analysis of tumor and spleen immune phenotypes revealed increased trafficking of myeloid cells in mice bearing inflamed tumors compared to excluded and deserts.ConclusionsThe immunocompetent mTDT provides a model that bridges the gap between the immune landscape and tumor microenvironment. Integration of these high-dimensional data with further studies of response to immunotherapies will help to identify tumor features that favor response to treatment or the means to convert those that are unresponsive.


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