ABSTRACT
Depending on the initiating stimulus, cancer cell death can be immunogenic or nonimmunogenic. Immunogenic cell death (ICD) involves changes in the composition of the cell surface as well as the release of soluble mediators, occurring in a defined temporal sequence. Such signals operate on a series of receptors expressed by dendritic cells to stimulate the presentation of tumor antigens to T cells. We postulate that ICD constitutes a prominent pathway for the activation of the immune system against cancer, which in turn determines the long-term success of anticancer therapies. Hence, suboptimal regimens (failing to induce ICD), selective alterations in cancer cells (preventing the emission of immunogenic signals during ICD), or defects in immune effectors (abolishing the perception of ICD by the immune system) can all contribute to therapeutic failure. We surmise that ICD and its subversion by pathogens also play major roles in antiviral immune responses.
Subject(s)
Immunity, Cellular , Neoplasms/immunology , Neoplasms/pathology , Animals , Cancer Vaccines/therapeutic use , Cell Death/immunology , Humans , Neoplasms/physiopathologyABSTRACT
Blood myeloid cells are known to be dysregulated in coronavirus disease 2019 (COVID-19), caused by SARS-CoV-2. It is unknown whether the innate myeloid response differs with disease severity and whether markers of innate immunity discriminate high-risk patients. Thus, we performed high-dimensional flow cytometry and single-cell RNA sequencing of COVID-19 patient peripheral blood cells and detected disappearance of non-classical CD14LowCD16High monocytes, accumulation of HLA-DRLow classical monocytes (Human Leukocyte Antigen - DR isotype), and release of massive amounts of calprotectin (S100A8/S100A9) in severe cases. Immature CD10LowCD101-CXCR4+/- neutrophils with an immunosuppressive profile accumulated in the blood and lungs, suggesting emergency myelopoiesis. Finally, we show that calprotectin plasma level and a routine flow cytometry assay detecting decreased frequencies of non-classical monocytes could discriminate patients who develop a severe form of COVID-19, suggesting a predictive value that deserves prospective evaluation.
Subject(s)
Coronavirus Infections , Coronavirus , Pandemics , Pneumonia, Viral , Betacoronavirus , COVID-19 , Flow Cytometry , Humans , Leukocyte L1 Antigen Complex , Monocytes , Myeloid Cells , Prospective Studies , SARS-CoV-2ABSTRACT
Dying mammalian cells emit numerous signals that interact with the host to dictate the immunological correlates of cellular stress and death. In the absence of reactive antigenic determinants (which is generally the case for healthy cells), such signals may drive inflammation but cannot engage adaptive immunity. Conversely, when cells exhibit sufficient antigenicity, as in the case of infected or malignant cells, their death can culminate with adaptive immune responses that are executed by cytotoxic T lymphocytes and elicit immunological memory. Suggesting a key role for immunogenic cell death (ICD) in immunosurveillance, both pathogens and cancer cells evolved strategies to prevent the recognition of cell death as immunogenic. Intriguingly, normal cells succumbing to conditions that promote the formation of post-translational neoantigens (for example, oxidative stress) can also drive at least some degree of antigen-specific immunity, pointing to a novel implication of ICD in the etiology of non-infectious, non-malignant disorders linked to autoreactivity.
Subject(s)
Neoplasms , Adaptive Immunity , Animals , Antigens , Cell Death , Immunogenic Cell Death , MammalsABSTRACT
Anticancer immune responses can be considered a desirable form of autoimmunity that may be profoundly shaped by the microbiome. Here, we discuss evidence for the microbiome's influence on anti-tumor immunosurveillance, including those that are indirect and can act at a distance, and we put forward hypotheses regarding mechanisms of how these effects are implemented. These may involve cross-reactivity between microbial and tumor antigens shaping T cell repertoires and/or microbial products stimulating pattern recognition receptors that influence the type and intensity of immune responses. Understanding how the microbiome impacts natural cancer immunosurveillance as well as treatment-induced immune responses will pave the way for more effective therapies and prophylactics.
Subject(s)
Biological Therapy , Microbiota , Neoplasms/immunology , Neoplasms/therapy , Animals , Dysbiosis , Humans , Hygiene Hypothesis , Monitoring, ImmunologicABSTRACT
Mononuclear phagocytes (MNPs) encompass dendritic cells, monocytes, and macrophages (MoMac), which exhibit antimicrobial, homeostatic, and immunoregulatory functions. We integrated 178,651 MNPs from 13 tissues across 41 datasets to generate a MNP single-cell RNA compendium (MNP-VERSE), a publicly available tool to map MNPs and define conserved gene signatures of MNP populations. Next, we generated a MoMac-focused compendium that revealed an array of specialized cell subsets widely distributed across multiple tissues. Specific pathological forms were expanded in cancer and inflammation. All neoplastic tissues contained conserved tumor-associated macrophage populations. In particular, we focused on IL4I1+CD274(PD-L1)+IDO1+ macrophages, which accumulated in the tumor periphery in a T cell-dependent manner via interferon-γ (IFN-γ) and CD40/CD40L-induced maturation from IFN-primed monocytes. IL4I1_Macs exhibited immunosuppressive characteristics through tryptophan degradation and promoted the entry of regulatory T cell into tumors. This integrated analysis provides a robust online-available platform for uniform annotation and dissection of specific macrophage functions in healthy and pathological states.
Subject(s)
Dendritic Cells/immunology , Gene Expression/immunology , Monocytes/immunology , Transcriptome/genetics , Tumor-Associated Macrophages/immunology , Arthritis, Rheumatoid/immunology , COVID-19/immunology , Gene Expression/genetics , Gene Expression Profiling , Humans , Interferon-gamma/immunology , L-Amino Acid Oxidase/metabolism , Liver Cirrhosis/immunology , Macrophages/immunology , Neoplasms/immunology , RNA, Small Cytoplasmic/genetics , Single-Cell Analysis , T-Lymphocytes, Regulatory/immunology , Transcriptome/immunologyABSTRACT
Quantitative and qualitative aspects of nutrition have a profound effect on leukocytes and thereby affect proinflammatory carcinogenic effects or anticancer immune responses. As a result, nutrition affects the incidence, natural progression and therapeutic response of malignant diseases, both in humans and in preclinical animal models. Here we discuss the molecular mechanisms through which alimentary cues modulate metabolic, microbial and neuroendocrine circuitries and thus affect the probability of developing premalignant lesions that progress to clinically manifested disease and the response to therapeutic intervention. We examine each of the connections that compose the triangle of nutrition, immunological and inflammatory reactions and cancer while focusing on the mechanistic aspects of these relationships.
Subject(s)
Inflammation/immunology , Metabolic Syndrome/immunology , Microbiota/immunology , Neoplasms/immunology , Obesity/immunology , Diet , Diet, Western , Humans , Overnutrition/immunology , Risk Factors , VitaminsABSTRACT
Avoiding destruction by immune cells is a hallmark of cancer, yet how tumors ultimately evade control by natural killer (NK) cells remains incompletely defined. Using global transcriptomic and flow-cytometry analyses and genetically engineered mouse models, we identified the cytokine-TGF-ß-signaling-dependent conversion of NK cells (CD49a-CD49b+Eomes+) into intermediate type 1 innate lymphoid cell (intILC1) (CD49a+CD49b+Eomes+) populations and ILC1 (CD49a+CD49b-Eomesint) populations in the tumor microenvironment. Strikingly, intILC1s and ILC1s were unable to control local tumor growth and metastasis, whereas NK cells favored tumor immunosurveillance. Experiments with an antibody that neutralizes the cytokine TNF suggested that escape from the innate immune system was partially mediated by TNF-producing ILC1s. Our findings provide new insight into the plasticity of group 1 ILCs in the tumor microenvironment and suggest that the TGF-ß-driven conversion of NK cells into ILC1s is a previously unknown mechanism by which tumors escape surveillance by the innate immune system.
Subject(s)
Cellular Reprogramming/immunology , Fibrosarcoma/immunology , Gastrointestinal Neoplasms/immunology , Gastrointestinal Stromal Tumors/immunology , Immunity, Innate/immunology , Killer Cells, Natural/immunology , Neoplasms, Experimental/immunology , Tumor Escape/immunology , Animals , Case-Control Studies , Cell Line, Tumor , Enzyme-Linked Immunosorbent Assay , Flow Cytometry , Gene Expression Profiling , Humans , Killer Cells, Natural/cytology , Lymphocytes/cytology , Lymphocytes/immunology , Mice , Sequence Analysis, RNA , Signal Transduction , Transforming Growth Factor beta/immunologyABSTRACT
Effective anticancer immunosurveillance after oncolytic viral infection is often hindered by the defective metabolic function of tumor-infiltrating lymphocytes (TILs). A recent paper by Rivadeneira et al. demonstrates that intratumoral delivery of leptin by a recombinant oncolytic vaccinia virus can metabolically enhance TIL effector and memory functions through improved mitochondrial oxidative phosphorylation, thereby enhancing therapeutic efficacy.
Subject(s)
Neoplasms , Oncolytic Viruses , Humans , Leptin , Lymphocytes, Tumor-Infiltrating , T-LymphocytesABSTRACT
Mutations affecting exon 9 of the CALR gene lead to the generation of a C-terminally modified calreticulin (CALR) protein that lacks the KDEL endoplasmic reticulum (ER) retention signal and consequently mislocalizes outside of the ER where it activates the thrombopoietin receptor in a cell-autonomous fashion, thus driving myeloproliferative diseases. Here, we used the retention using selective hooks (RUSH) assay to monitor the trafficking of CALR. We found that exon-9-mutated CALR was released from cells in response to the biotin-mediated detachment from its ER-localized hook, in vitro and in vivo. Cellular CALR release was confirmed in suitable mouse models bearing exon-9-mutated hematopoietic systems or tumors. Extracellular CALR mediated immunomodulatory effects and inhibited the phagocytosis of dying cancer cells by dendritic cells (DC), thereby suppressing antineoplastic immune responses elicited by chemotherapeutic agents or by PD-1 blockade. Altogether, our results demonstrate paracrine immunosuppressive effects for exon-9-mutated CALR.
Subject(s)
Calreticulin/genetics , Immune Tolerance/genetics , Mutation , Neoplasms/genetics , Neoplasms/immunology , Animals , Calreticulin/metabolism , Cell Line, Tumor , Humans , Mice , Mice, Inbred C57BL , PhagocytosisABSTRACT
The search for immunostimulatory drugs applicable to cancer immunotherapy may profit from target-agnostic methods in which agents are screened for their functional impact on immune cells cultured in vitro without any preconceived idea on their mode of action. We have built a synthetic mini-immune system in which stressed and dying cancer cells (derived from standardized cell lines) are confronted with dendritic cells (DCs, derived from immortalized precursors) and CD8+ T-cell hybridoma cells expressing a defined T-cell receptor. Using this system, we can identify three types of immunostimulatory drugs: (i) pharmacological agents that stimulate immunogenic cell death (ICD) of malignant cells; (ii) drugs that act on DCs to enhance their response to ICD; and (iii) drugs that act on T cells to increase their effector function. Here, we focus on strategies to develop drugs that enhance the perception of ICD by DCs and to which we refer as "ICD enhancers." We discuss examples of ICD enhancers, including ligands of pattern recognition receptors (exemplified by TLR3 ligands that correct the deficient function of DCs lacking FPR1) and immunometabolic modifiers (exemplified by hexokinase-2 inhibitors), as well as methods for target deconvolution applicable to the mechanistic characterization of ICD enhancers.
Subject(s)
CD8-Positive T-Lymphocytes , Immunogenic Cell Death , Humans , Immunotherapy , Dendritic Cells , PerceptionABSTRACT
Natural killer (NK) cells are innate lymphoid cells, and their presence within human tumors correlates with better prognosis. However, the mechanisms by which NK cells control tumors in vivo are unclear. Here, we used reflectance confocal microscopy (RCM) imaging in humans and in mice to visualize tumor architecture in vivo. We demonstrated that signaling via the NK cell receptor NKp46 (human) and Ncr1 (mouse) induced interferon-γ (IFN-γ) secretion from intratumoral NK cells. NKp46- and Ncr1-mediated IFN-γ production led to the increased expression of the extracellular matrix protein fibronectin 1 (FN1) in the tumors, which altered primary tumor architecture and resulted in decreased metastases formation. Injection of IFN-γ into tumor-bearing mice or transgenic overexpression of Ncr1 in NK cells in mice resulted in decreased metastasis formation. Thus, we have defined a mechanism of NK cell-mediated control of metastases in vivo that may help develop NK cell-dependent cancer therapies.
Subject(s)
Antigens, Ly/metabolism , Fibronectins/metabolism , Interferon-gamma/metabolism , Killer Cells, Natural/metabolism , Natural Cytotoxicity Triggering Receptor 1/metabolism , Neoplasms/metabolism , Animals , Blotting, Western , Female , Flow Cytometry , Fluorescent Antibody Technique , Gene Expression Regulation, Neoplastic/genetics , Humans , Male , Mice , Microscopy, Confocal , Neoplasm Metastasis/genetics , Neoplasms/pathology , Real-Time Polymerase Chain Reaction , Signal Transduction/geneticsABSTRACT
Dietary fibers, including chitin, have a major impact on gastrointestinal (GI) physiology and immunity. Two recent articles, by Parrish et al. and Kim et al., credit depletion of dietary fibers or supplementation with chitin, with negative and positive effects, respectively, on the immune system of the murine digestive tract. This has relevant implications for food allergies and systemic metabolism.
Subject(s)
Dietary Fiber , Verrucomicrobia , Humans , Animals , Mice , Verrucomicrobia/metabolism , Gastrointestinal Tract , Chitin/metabolismABSTRACT
A recent article by Kratofil et al. investigated the immune inflammatory response against Staphylococcus aureus-contaminated foreign bodies placed under mouse skin. In this model, neutrophils are indispensable for bacterial clearance, while monocyte-derived macrophages are required for optimal wound healing. Intriguingly, ghrelin produced by macrophages favors, and leptin produced by hypodermal adipocytes inhibits, an adequate foreign body response.
Subject(s)
Ghrelin , Staphylococcal Infections , Animals , Leptin , Mice , Neutrophils , Wound HealingABSTRACT
Inhibition of immune regulatory checkpoints, such as CTLA-4 and the PD-1-PD-L1 axis, is at the forefront of immunotherapy for cancers of various histological types. However, such immunotherapies fail to control neoplasia in a significant proportion of patients. Here, we review how a range of cancer-cell-autonomous cues, tumor-microenvironmental factors, and host-related influences might account for the heterogeneous responses and failures often encountered during therapies using immune-checkpoint blockade. Furthermore, we describe the emerging evidence of how the strong interrelationship between the immune system and the host microbiota can determine responses to cancer therapies, and we introduce a concept by which prior or concomitant modulation of the gut microbiome could optimize therapeutic outcomes upon immune-checkpoint blockade.
Subject(s)
Antibodies, Monoclonal/therapeutic use , Costimulatory and Inhibitory T-Cell Receptors/immunology , Drug Resistance, Neoplasm , Immunotherapy/methods , Neoplasms/therapy , Animals , Costimulatory and Inhibitory T-Cell Receptors/antagonists & inhibitors , Humans , Molecular Targeted Therapy , Neoplasms/immunology , Tumor Escape , Tumor MicroenvironmentABSTRACT
Checkpoint blockade immunotherapies can be extraordinarily effective, but might benefit only the minority of patients whose tumors are pre-infiltrated by T cells. Here, using lung adenocarcinoma mouse models, including genetic models, we show that autochthonous tumors that lacked T cell infiltration and resisted current treatment options could be successfully sensitized to host antitumor T cell immunity when appropriately selected immunogenic drugs (e.g., oxaliplatin combined with cyclophosphamide for treatment against tumors expressing oncogenic Kras and lacking Trp53) were used. The antitumor response was triggered by direct drug actions on tumor cells, relied on innate immune sensing through toll-like receptor 4 signaling, and ultimately depended on CD8(+) T cell antitumor immunity. Furthermore, instigating tumor infiltration by T cells sensitized tumors to checkpoint inhibition and controlled cancer durably. These findings indicate that the proportion of cancers responding to checkpoint therapy can be feasibly and substantially expanded by combining checkpoint blockade with immunogenic drugs.
Subject(s)
Adenocarcinoma/therapy , CD8-Positive T-Lymphocytes/drug effects , Immunotherapy/methods , Lung Neoplasms/therapy , Lymphocytes, Tumor-Infiltrating/drug effects , Adenocarcinoma/immunology , Animals , Cell Line, Tumor , Central Nervous System Sensitization/drug effects , Cyclophosphamide/administration & dosage , Disease Models, Animal , Drug Therapy/methods , Genes, cdc/drug effects , Humans , Immunity, Innate , Lung Neoplasms/immunology , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Mice, Knockout , Organoplatinum Compounds/administration & dosage , Oxaliplatin , Toll-Like Receptor 4/metabolismABSTRACT
The efficacy of the anti-cancer immunomodulatory agent cyclophosphamide (CTX) relies on intestinal bacteria. How and which relevant bacterial species are involved in tumor immunosurveillance, and their mechanism of action are unclear. Here, we identified two bacterial species, Enterococcus hirae and Barnesiella intestinihominis that are involved during CTX therapy. Whereas E. hirae translocated from the small intestine to secondary lymphoid organs and increased the intratumoral CD8/Treg ratio, B. intestinihominis accumulated in the colon and promoted the infiltration of IFN-γ-producing γδT cells in cancer lesions. The immune sensor, NOD2, limited CTX-induced cancer immunosurveillance and the bioactivity of these microbes. Finally, E. hirae and B. intestinihominis specific-memory Th1 cell immune responses selectively predicted longer progression-free survival in advanced lung and ovarian cancer patients treated with chemo-immunotherapy. Altogether, E. hirae and B. intestinihominis represent valuable "oncomicrobiotics" ameliorating the efficacy of the most common alkylating immunomodulatory compound.
Subject(s)
Cyclophosphamide/pharmacology , Enterococcus hirae/immunology , Immunologic Factors/immunology , Neoplasms/drug therapy , Neoplasms/immunology , Animals , Colon/immunology , Colon/microbiology , Immunologic Memory/immunology , Immunotherapy/methods , Interferon-gamma/immunology , Intestine, Small/immunology , Intestine, Small/microbiology , Mice , Mice, Inbred C57BL , Monitoring, Immunologic , Nod2 Signaling Adaptor Protein/immunology , Th1 Cells/immunologyABSTRACT
Dying cells release and expose at their surface molecules that signal to the immune system. We speculate that combinations of these molecules determine the route by which dying cells are engulfed and the nature of the immune response that their death elicits.
Subject(s)
Cell Death , Immunity , Inflammation/immunology , Animals , Autophagy , Cellular Senescence , Endoplasmic Reticulum/physiology , Humans , Inflammation/physiopathology , Stress, PhysiologicalABSTRACT
This article is part of the Dendritic Cell Guidelines article series, which provides a collection of state-of-the-art protocols for the preparation, phenotype analysis by flow cytometry, generation, fluorescence microscopy and functional characterization of mouse and human dendritic cells (DC) from lymphoid organs and various nonlymphoid tissues. DC are sentinels of the immune system present in almost every mammalian organ. Since they represent a rare cell population, DC need to be extracted from organs with protocols that are specifically developed for each tissue. This article provides detailed protocols for the preparation of single-cell suspensions from various mouse nonlymphoid tissues, including skin, intestine, lung, kidney, mammary glands, oral mucosa and transplantable tumors. Furthermore, our guidelines include comprehensive protocols for multiplex flow cytometry analysis of DC subsets and feature top tricks for their proper discrimination from other myeloid cells. With this collection, we provide guidelines for in-depth analysis of DC subsets that will advance our understanding of their respective roles in healthy and diseased tissues. While all protocols were written by experienced scientists who routinely use them in their work, this article was also peer-reviewed by leading experts and approved by all coauthors, making it an essential resource for basic and clinical DC immunologists.
Subject(s)
Dendritic Cells , Skin , Animals , Humans , Flow Cytometry , Myeloid Cells , Kidney , MammalsABSTRACT
In the complex interplay between malignant cells and their microenvironment, caspase-1 activation complexes (inflammasomes) have contrasting roles. Inflammasomes may operate at the cell-autonomous level to eliminate malignant precursors through programmed cell death or, conversely, may stimulate the production of trophic factors for cancer cells and their stroma. In inflammatory cells, caspase-1 activation can fuel a cycle that leads to sterile inflammation and carcinogenesis, whereas in antigen-presenting cells, inflammasomes can stimulate anticancer immune responses. The inhibition of inflammasomes or neutralization of their products, mainly interleukin 1ß (IL-1ß) and IL-18, has profound effects on carcinogenesis and tumor progression. Thus, inflammasomes are promising therapeutic targets in cancer-related clinical conditions. Here we discuss present and future indications for the clinical use of inflammasome inhibitors.