ABSTRACT
CD8+ TĀ cell responses are critical for anti-tumor immunity. While extensively profiled in the tumor microenvironment, recent studies in mice identified responses in lymph nodes (LNs) as essential; however, the role of LNs in human cancer patients remains unknown. We examined CD8+ TĀ cells in human head and neck squamous cell carcinomas, regional LNs, and blood using mass cytometry, single-cell genomics, and multiplexed ion beam imaging. We identified progenitor exhausted CD8+ TĀ cells (Tpex) that were abundant in uninvolved LN and clonally related to terminally exhausted cells in the tumor. After anti-PD-L1 immunotherapy, Tpex in uninvolved LNs reduced in frequency but localized near dendritic cells and proliferating intermediate-exhausted CD8+ TĀ cells (Tex-int), consistent with activation and differentiation. LN responses coincided with increased circulating Tex-int. In metastatic LNs, these response hallmarks were impaired, with immunosuppressive cellular niches. Our results identify important roles for LNs in anti-tumor immune responses in humans.
Subject(s)
CD8-Positive T-Lymphocytes , Neoplasms , Humans , Animals , Mice , Lymph Nodes , Neoplasms/therapy , Neoplasms/pathology , Immunotherapy/methods , Tumor MicroenvironmentABSTRACT
Cancers display significant heterogeneity with respect to tissue of origin, driver mutations, and other features of the surrounding tissue. It is likely that individual tumors engage common patterns of the immune system-here "archetypes"-creating prototypical non-destructive tumor immune microenvironments (TMEs) and modulating tumor-targeting. To discover the dominant immune system archetypes, the University of California, San Francisco (UCSF) Immunoprofiler Initiative (IPI) processed 364 individual tumors across 12 cancer types using standardized protocols. Computational clustering of flow cytometry and transcriptomic data obtained from cell sub-compartments uncovered dominant patterns of immune composition across cancers. These archetypes were profound insofar as they also differentiated tumors based upon unique immune and tumor gene-expression patterns. They also partitioned well-established classifications of tumor biology. The IPI resource provides a template for understanding cancer immunity as a collection of dominant patterns of immune organization and provides a rational path forward to learn how to modulate these to improve therapy.
Subject(s)
Censuses , Neoplasms/genetics , Neoplasms/immunology , Transcriptome/genetics , Tumor Microenvironment/immunology , Biomarkers, Tumor , Cluster Analysis , Cohort Studies , Computational Biology/methods , Flow Cytometry/methods , Gene Expression Regulation, Neoplastic , Humans , Neoplasms/classification , Neoplasms/pathology , RNA-Seq/methods , San Francisco , UniversitiesABSTRACT
Differentiation of proinflammatory CD4+ conventional TĀ cells (Tconv) is critical for productive antitumor responses yet their elicitation remains poorly understood. We comprehensively characterized myeloid cells in tumor draining lymph nodes (tdLN) of mice and identified two subsets of conventional type-2 dendritic cells (cDC2) that traffic from tumor to tdLN and present tumor-derived antigens to CD4+ Tconv, but then fail to support antitumor CD4+ Tconv differentiation. Regulatory TĀ cell (Treg) depletion enhanced their capacity to elicit strong CD4+ Tconv responses and ensuing antitumor protection. Analogous cDC2 populations were identified in patients, and as in mice, their abundance relative to Treg predicts protective ICOS+ PD-1lo CD4+ Tconv phenotypes and survival. Further, in melanoma patients with lowĀ Treg abundance, intratumoral cDC2 density aloneĀ correlates with abundant CD4+ Tconv and with responsiveness to anti-PD-1 therapy. Together, this highlights a pathway that restrains cDC2 and whose reversal enhances CD4+ Tconv abundance and controls tumor growth.
Subject(s)
CD4-Positive T-Lymphocytes/immunology , Dendritic Cells/immunology , Animals , Antigens, Neoplasm/immunology , CD4-Positive T-Lymphocytes/cytology , CD4-Positive T-Lymphocytes/metabolism , Cell Differentiation , Cell Line, Tumor , Cytokines/metabolism , Dendritic Cells/cytology , Dendritic Cells/metabolism , Diphtheria Toxin/immunology , Forkhead Transcription Factors/metabolism , Humans , Lectins, C-Type/genetics , Lectins, C-Type/metabolism , Lymph Nodes/immunology , Lymph Nodes/metabolism , Lymphocyte Activation , Melanoma, Experimental/immunology , Melanoma, Experimental/pathology , Mice , Mice, Inbred C57BL , Mice, Knockout , Receptors, Chemokine/metabolism , T-Lymphocytes, Regulatory/immunology , Tumor MicroenvironmentABSTRACT
Chronic inflammation and tissue fibrosis are common responses that worsen organ function, yet the molecular mechanisms governing their cross-talk are poorly understood. In diseased organs, stress-induced gene expression changes fuel maladaptive cell state transitions1 and pathological interaction between cellular compartments. Although chronic fibroblast activation worsens dysfunction in the lungs, liver, kidneys and heart, and exacerbates many cancers2, the stress-sensing mechanisms initiating transcriptional activation of fibroblasts are poorly understood. Here we show that conditional deletion of the transcriptional co-activator Brd4 in infiltrating Cx3cr1+ macrophages ameliorates heart failure in mice and significantly reduces fibroblast activation. Analysis of single-cell chromatin accessibility and BRD4 occupancy in vivo in Cx3cr1+ cells identified a large enhancer proximal to interleukin-1Ć (IL-1Ć, encoded by Il1b), and a series of CRISPR-based deletions revealed the precise stress-dependent regulatory element that controls Il1b expression. Secreted IL-1Ć activated a fibroblast RELA-dependent (also known as p65) enhancer near the transcription factor MEOX1, resulting in a profibrotic response in human cardiac fibroblasts. In vivo, antibody-mediated IL-1Ć neutralization improved cardiac function and tissue fibrosis in heart failure. Systemic IL-1Ć inhibition or targeted Il1b deletion in Cx3cr1+ cells prevented stress-induced Meox1 expression and fibroblast activation. The elucidation of BRD4-dependent cross-talk between a specific immune cell subset and fibroblasts through IL-1Ć reveals how inflammation drives profibrotic cell states and supports strategies that modulate this process in heart disease and other chronic inflammatory disorders featuring tissue remodelling.
ABSTRACT
Although infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has pleiotropic and systemic effects in some individuals1-3, many others experience milder symptoms. Here, to gain a more comprehensive understanding of the distinction between severe and mild phenotypes in the pathology of coronavirus disease 2019 (COVID-19) and its origins, we performed a whole-blood-preserving single-cell analysis protocol to integrate contributions from all major immune cell types of the blood-including neutrophils, monocytes, platelets, lymphocytes and the contents of the serum. Patients with mild COVID-19 exhibit a coordinated pattern of expression of interferon-stimulated genes (ISGs)3 across every cell population, whereas these ISG-expressing cells are systemically absent in patients with severe disease. Paradoxically, individuals with severe COVID-19 produce very high titres of anti-SARS-CoV-2 antibodies and have a lower viral load compared to individuals with mild disease. Examination of the serum from patients with severe COVID-19 shows that these patients uniquely produce antibodies that functionally block the production of the ISG-expressing cells associated with mild disease, by activating conserved signalling circuits that dampen cellular responses to interferons. Overzealous antibody responses pit the immune system against itself in many patients with COVID-19, and perhaps also in individuals with other viral infections. Our findings reveal potential targets for immunotherapies in patients with severe COVID-19 to re-engage viral defence.
Subject(s)
Antibodies, Viral/immunology , COVID-19/immunology , COVID-19/physiopathology , Interferons/antagonists & inhibitors , Interferons/immunology , SARS-CoV-2/immunology , SARS-CoV-2/pathogenicity , Antibodies, Viral/blood , Antibody Formation , Base Sequence , COVID-19/blood , COVID-19/virology , Female , Humans , Immunoglobulin G/immunology , Interferons/metabolism , Male , Neutrophils/immunology , Neutrophils/pathology , Protein Domains , Receptor, Interferon alpha-beta/antagonists & inhibitors , Receptor, Interferon alpha-beta/immunology , Receptor, Interferon alpha-beta/metabolism , Receptors, IgG/immunology , Single-Cell Analysis , Viral Load/immunologyABSTRACT
Responsiveness to immune checkpoint blockade (ICB) therapy in cancer is currently predicted by disparate individual measures - with varying degrees of accuracy - including tumor mutation burden, tumor-infiltrating T cell densities, dendritic cell frequencies, and the expression of checkpoint ligands. We propose that many of these individual parameters are linked, forming two distinct 'reactive' immune archetypes - collections of cells and gene expression - in ICB-responsive patients. We hypothesize that these are 'seeds' of antitumor immunity and are supported by specific elements of the tumor microenvironment (TME) and by actions of the microbiome. Although removing 'immunosuppressive' factors in the TME is important, understanding and parsing reactive immunity is crucial for optimal prognosis and for engaging this biology with candidate therapies to increase tumor cure rates.
Subject(s)
Neoplasms , Tumor Microenvironment , Biomarkers, Tumor/metabolism , Humans , Neoplasms/therapy , Prognosis , T-LymphocytesABSTRACT
BACKGROUND: Endometriosis is a chronic, estrogen-dependent disorder where inflammation contributes to disease-associated symptoms of pelvic pain and infertility. Immune dysfunction includes insufficient immune lesion clearance, a pro-inflammatory endometrial environment, and systemic inflammation. Comprehensive understanding of endometriosis immune pathophysiology in different hormonal milieu and disease severity has been hampered by limited direct characterization of immune populations in endometrium, blood, and lesions. Simultaneous deep phenotyping at single-cell resolution of complex tissues has transformed our understanding of the immune system and its role in many diseases. Herein, we report mass cytometry and high dimensional analyses to study immune cell phenotypes, abundance, activation states, and functions in endometrium and blood of women with and without endometriosis in different cycle phases and disease stages. METHODS: A case-control study was designed. Endometrial biopsies and blood (n = 60 total) were obtained from women with (n = 20, n = 17, respectively) and without (n = 14, n = 9) endometriosis in the proliferative and secretory cycle phases of the menstrual cycle. Two mass cytometry panels were designed: one broad panel and one specific for mononuclear phagocytic cells (MPC), and all samples were multiplexed to characterize both endometrium and blood immune composition at unprecedented resolution. We combined supervised and unsupervised analyses to finely define the immune cell subsets with an emphasis on MPC. Then, association between cell types, protein expression, disease status, and cycle phase were performed. RESULTS: The broad panel highlighted a significant modification of MPC in endometriosis; thus, they were studied in detail with an MPC-focused panel. Endometrial CD91+ macrophages overexpressed SIRPα (phagocytosis inhibitor) and CD64 (associated with inflammation) in endometriosis, and they were more abundant in mild versus severe disease. In blood, classical and intermediate monocytes were less abundant in endometriosis, whereas plasmacytoid dendritic cells and non-classical monocytes were more abundant. Non-classical monocytes were higher in severe versus mild disease. CONCLUSIONS: A greater inflammatory phenotype and decreased phagocytic capacity of endometrial macrophages in endometriosis are consistent with defective clearance of endometrial cells shed during menses and in tissue homeostasis, with implications in endometriosis pathogenesis and pathophysiology. Different proportions of monocytes and plasmacytoid dendritic cells in blood from endometriosis suggest systemically aberrant functionality of the myeloid system opening new venues for the study of biomarkers and therapies for endometriosis.
Subject(s)
Endometriosis , Case-Control Studies , Endometriosis/metabolism , Endometrium/metabolism , Endometrium/pathology , Female , Humans , Immunophenotyping , Inflammation/metabolismABSTRACT
Background: Transforming growth factor beta (TGFĆ) is well-recognized as an immunosuppressive player in the tumor microenvironment but also has a significant impact on cancer cell phenotypes. Loss of TGFĆ signaling impairs DNA repair competency, which is described by a transcriptomic score, ĆAlt. Cancers with high ĆAlt have more genomic damage and are more responsive to genotoxic therapy. The growing appreciation that cancer DNA repair deficits are important determinants of immune response prompted us to investigate the association of ĆAlt with response to immune checkpoint blockade (ICB). We predicted that high ĆAlt tumors would be infiltrated with lymphocytes because of DNA damage burden and hence responsive to ICB. Methods: We analyzed public transcriptomic data from clinical trials and preclinical models using transcriptomic signatures of TGFĆ targets, DNA repair genes, tumor educated immune cells and interferon. A high ĆAlt, immune poor mammary tumor derived transplant model resistant to programmed death ligand 1 (PD-L1) antibodies was studied using multispectral flow cytometry to interrogate the immune system. Results: Metastatic bladder patients in IMvigor 210 who responded to ICB had significantly increased ĆAlt scores and experienced significantly longer overall survival compared to those with low ĆAlt scores (hazard ratio 0.62, P=0.011) . Unexpectedly, 75% of high ĆAlt cancers were immune poor as defined by low expression of tumor educated immune cell and interferon signatures. The association of high ĆAlt with immune poor cancer was also evident in TCGA and preclinical cancer models. We used a high ĆAlt, immune poor cancer to test therapeutic strategies to overcome its inherent anti-PD-L1 resistance. Combination treatment with radiation and TGFĆ inhibition were necessary for lymphocytic infiltration and activated NK cells were required for ICB response. Bioinformatic analysis identified high ĆAlt, immune poor B16 and CT26 preclinical models and paired biopsies of cancer patients that also demonstrated NK cell activation upon response to ICB. Conclusions: Our studies support ĆAlt as a biomarker that predicts response to ICB albeit in immune poor cancers, which has implications for the development of therapeutic strategies to increase the number of cancer patients who will benefit from immunotherapy.
ABSTRACT
The bone marrow is the main site of blood cell production in adults, however, rare pools of hematopoietic stem and progenitor cells with self-renewal and differentiation potential have been found in extramedullary organs. The lung is primarily known for its role in gas exchange but has recently been described as a site of blood production in mice. Here, we show that functional hematopoietic precursors reside in the extravascular spaces of the human lung, at a frequency similar to the bone marrow, and are capable of proliferation and engraftment. The organ-specific gene signature of pulmonary and medullary CD34+ hematopoietic progenitors indicates greater baseline activation of immune, megakaryocyte/platelet and erythroid-related pathways in lung progenitors. Spatial transcriptomics mapped blood progenitors in the lung to a vascular-rich alveolar interstitium niche. These results identify the lung as a pool for uniquely programmed blood stem and progenitor cells with the potential to support hematopoiesis in humans.
ABSTRACT
OBJECTIVE: To investigate if a positive result on ReceptivaDx for evaluation of B-cell lymphoma 6 (BCL6), a proposed marker of progesterone resistance associated with impaired uterine receptivity, correlates with a suboptimal profile of receptivity-associated markers in the window of implantation using the endometrial receptivity array and single-nucleus transcriptomic analysis DESIGN: Retrospective clinical cohort study; pilot study of single-nucleus RNA sequencing of prospectively collected window of implantation endometrium undergoing ReceptivaDx BCL6 evaluation SETTING: Academic center SUBJECTS: Patients with infertility who underwent endometrial biopsy for concurrent endometrial receptivity array analysis (ERAĀ®; Igenomix) and BCL6 immunostaining (ReceptivaDx™; Cicero Diagnostics, Inc.) EXPOSURE: Positive BCL6 result on ReceptivaDx™ (histologic score 'HSCORE' >1.4) MAIN OUTCOME MEASURES: Pre-receptive ERA result; relative expression levels of endometrial receptivity-associated epithelial genes by single-nucleus sequencing RESULTS: One hundred and seventy-two patients with concurrent ERA and ReceptivaDx evaluation were included in the analysis: 40 were BCL6-positive and 132 were BCL6-negative. One patient (2.5%) in the BCL6-positive group had a pre-receptive ERA result, compared to 29 patients (22.0%) in the BCL6-negative group (p<0.01). BCL6 positivity was associated with decreased odds of a pre-receptive ERA result (OR 0.09 95%CI [0.01-0.69], p=0.02). Single-nucleus transcriptomic analysis of 5,718 epithelial cell nuclei from four individuals showed significant cell type-specific transcriptomic changes associated with a positive ReceptivaDx BCL6 result in both natural cycle (NC) and programmed cycle (PC) endometrium: there were 2,801 significantly differentially expressed genes (DEGs) comparing NC BCL6-positive to -negative, and 1,062 DEGs comparing PC BCL6-positive to -negative. Of the 34 receptivity-associated epithelial markers evaluated, 16 were significantly upregulated in NC BCL6-positive versus -negative endometrium epithelial nuclei. In PC epithelial nuclei, 12 of the 34 receptivity-associated genes were significantly upregulated, while only 1 was significantly downregulated in BCL6-positive versus -negative endometrium. CONCLUSIONS: A positive ReceptivaDx BCL6 result does not correlate with a pre-receptive ERA. Epithelial cells from BCL6-positive endometrium did not show significantly decreased expression in most of the receptivity markers evaluated. These findings demonstrate discordance between the interpretation of "endometrial receptivity" by ReceptivaDx and ERA, and highlight the need for further validation of endometrial evaluation methods in fertility treatment.
ABSTRACT
Tumor progression is accompanied by fibrosis, a condition of excessive extracellular matrix accumulation, which is associated with diminished antitumor immune infiltration. Here we demonstrate that tumor-associated macrophages (TAMs) respond to the stiffened fibrotic tumor microenvironment (TME) by initiating a collagen biosynthesis program directed by transforming growth factor-Ć. A collateral effect of this programming is an untenable metabolic milieu for productive CD8+ T cell antitumor responses, as collagen-synthesizing macrophages consume environmental arginine, synthesize proline and secrete ornithine that compromises CD8+ T cell function in female breast cancer. Thus, a stiff and fibrotic TME may impede antitumor immunity not only by direct physical exclusion of CD8+ T cells but also through secondary effects of a mechano-metabolic programming of TAMs, which creates an inhospitable metabolic milieu for CD8+ T cells to respond to anticancer immunotherapies.
Subject(s)
Breast Neoplasms , CD8-Positive T-Lymphocytes , Collagen , Tumor Microenvironment , Tumor-Associated Macrophages , Tumor Microenvironment/immunology , CD8-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/metabolism , Female , Breast Neoplasms/immunology , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Collagen/metabolism , Animals , Tumor-Associated Macrophages/immunology , Tumor-Associated Macrophages/metabolism , Humans , Mice , Transforming Growth Factor beta/metabolism , Macrophages/immunology , Macrophages/metabolism , Metabolic ReprogrammingABSTRACT
BACKGROUND: Colitis caused by checkpoint inhibitors (CPI) is frequent and is treated with empiric steroids, but CPI colitis mechanisms in steroid-experienced or refractory disease are unclear. METHODS: Using colon biopsies and blood from predominantly steroid-experienced CPI colitis patients, we performed multiplexed single-cell transcriptomics and proteomics to nominate contributing populations. RESULTS: CPI colitis biopsies showed enrichment of CD4+resident memory (RM) T cells in addition to CD8+ RM and cytotoxic CD8+ T cells. Matching T cell receptor (TCR) clonotypes suggested that both RMs are progenitors that yield cytotoxic effectors. Activated, CD38+ HLA-DR+ CD4+ RM and cytotoxic CD8+ T cells were enriched in steroid-experienced and a validation data set of steroid-naĆÆve CPI colitis, underscoring their pathogenic potential across steroid exposure. Distinct from ulcerative colitis, CPI colitis exhibited perturbed stromal metabolism (NAD+, tryptophan) impacting epithelial survival and inflammation. Endothelial cells in CPI colitis after anti-TNF and anti-cytotoxic T-lymphocyte-associated antigen 4 (anti-CTLA-4) upregulated the integrin α4Ć7 ligand molecular vascular addressin cell adhesion molecule 1 (MAdCAM-1), which may preferentially respond to vedolizumab (anti-α4Ć7). CONCLUSIONS: These findings nominate CD4+ RM and MAdCAM-1+ endothelial cells for targeting in specific subsets of CPI colitis patients.
Subject(s)
CD8-Positive T-Lymphocytes , Colitis , Humans , Endothelial Cells , Tumor Necrosis Factor Inhibitors , Colitis/chemically induced , Colitis/drug therapy , CD4-Positive T-Lymphocytes , Steroids/pharmacology , Steroids/therapeutic use , Stromal CellsABSTRACT
Ulcerative colitis (UC) is driven by immune and stromal subsets, culminating in epithelial injury. Vedolizumab (VDZ) is an anti-integrin antibody that is effective for treating UC. VDZ is known to inhibit lymphocyte trafficking to the intestine, but its broader effects on other cell subsets are less defined. To identify the inflammatory cells that contribute to colitis and are affected by VDZ, we performed single-cell transcriptomic and proteomic analyses of peripheral blood and colonic biopsies in healthy controls and patients with UC on VDZ or other therapies. Here we show that VDZ treatment is associated with alterations in circulating and tissue mononuclear phagocyte (MNP) subsets, along with modest shifts in lymphocytes. Spatial multi-omics of formalin-fixed biopsies demonstrates trends towards increased abundance and proximity of MNP and fibroblast subsets in active colitis. Spatial transcriptomics of archived specimens pre-treatment identifies epithelial-, MNP-, and fibroblast-enriched genes related to VDZ responsiveness, highlighting important roles for these subsets in UC.
ABSTRACT
Ulcerative colitis (UC) is driven by immune and stromal subsets, culminating in epithelial injury. Vedolizumab (VDZ) is an anti-integrin antibody that is effective for treating UC. VDZ is known to inhibit lymphocyte trafficking to the intestine, but its broader effects on other cell subsets are less defined. To identify the inflammatory cells that contribute to colitis and are affected by VDZ, we perform single-cell transcriptomic and proteomic analyses of peripheral blood and colonic biopsies in healthy controls and patients with UC on VDZ or other therapies. Here we show that VDZ treatment is associated with alterations in circulating and tissue mononuclear phagocyte (MNP) subsets, along with modest shifts in lymphocytes. Spatial multi-omics of formalin-fixed biopsies demonstrates trends towards increased abundance and proximity of MNP and fibroblast subsets in active colitis. Spatial transcriptomics of archived specimens pre-treatment identifies epithelial-, MNP-, and fibroblast-enriched genes related to VDZ responsiveness, highlighting important roles for these subsets in UC.
Subject(s)
Colitis, Ulcerative , Humans , Colitis, Ulcerative/drug therapy , Colitis, Ulcerative/genetics , Integrins/genetics , Multiomics , Proteomics , Gastrointestinal Agents/therapeutic use , Treatment Outcome , Retrospective StudiesABSTRACT
Germinal matrix hemorrhage (GMH) is a devastating neurodevelopmental condition affecting preterm infants, but why blood vessels in this brain region are vulnerable to rupture remains unknown. Here we show that microglia in prenatal mouse and human brain interact with nascent vasculature in an age-dependent manner and that ablation of these cells in mice reduces angiogenesis in the ganglionic eminences, which correspond to the human germinal matrix. Consistent with these findings, single-cell transcriptomics and flow cytometry show that distinct subsets of CD45+ cells from control preterm infants employ diverse signaling mechanisms to promote vascular network formation. In contrast, CD45+ cells from infants with GMH harbor activated neutrophils and monocytes that produce proinflammatory factors, including azurocidin 1, elastase and CXCL16, to disrupt vascular integrity and cause hemorrhage in ganglionic eminences. These results underscore the brain's innate immune cells in region-specific angiogenesis and how aberrant activation of these immune cells promotes GMH in preterm infants.
ABSTRACT
Tumours are surrounded by a host immune system that can suppress or promote tumour growth. The tumour microenvironment (TME) has often been framed as a singular entity, suggesting a single type of immune state that is defective and in need of therapeutic intervention. By contrast, the past few years have highlighted a plurality of immune states that can surround tumours. In this Perspective, we suggest that different TMEs have 'archetypal' qualities across all cancers - characteristic and repeating collections of cells and gene-expression profiles at the level of the bulk tumour. We discuss many studies that together support a view that tumours typically draw from a finite number (around 12) of 'dominant' immune archetypes. In considering the likely evolutionary origin and roles of these archetypes, their associated TMEs can be predicted to have specific vulnerabilities that can be leveraged as targets for cancer treatment with expected and addressable adverse effects for patients.
Subject(s)
Neoplasms , Humans , Neoplasms/therapy , Neoplasms/drug therapy , Tumor MicroenvironmentABSTRACT
Tumor-associated macrophages (TAMs) are frequently and simplistically categorized as immunosuppressive, and one molecule prominently used to highlight their so-called 'M2' state is the surface protein CD206. However, direct evidence of the impact of macrophages remains impaired by the lack of sufficiently penetrant and specific tools to manipulate them in vivo. We thus made a novel conditional CD206 knock-in mouse to specifically visualize and/or deplete these TAMs. Early depletion of CD206+ macrophages and monocytes (here, 'MonoMacs') strikingly led to an indirect loss of a key anti-tumor network of NK cells, conventional type I dendritic cells (cDC1) and CD8 T cells. Among myeloid cells, we found that the CD206+ TAMs are the primary producers of CXCL9, the well-established chemoattractant for CXCR3-expressing NK and CD8 T cells. In contrast, a population of stress-responsive TAMs ("Hypoxic" or Spp1+) and immature monocytes, which remain following depletion, expressed vastly diminished levels of CXCL9. We confirmed that the missing NK and CD8 T cells are the primary producers of the cDC1-attracting chemokine Xcl1 and cDC1 growth factor Flt3l. Consistent with the loss of this critical network, CD206+ TAM depletion decreased tumor control in mice. Likewise, in humans, the CD206+ MonoMac signature correlated robustly with stimulatory cDC1 signature genes. Together, these findings negate the classification of CD206+ macrophages as immunosuppressive and instead illuminate the role of this majority of TAMs in organizing a critical tumor-reactive archetype of immunity.
ABSTRACT
Tissue repair responses in metazoans are highly coordinated by different cell types over space and time. However, comprehensive single-cell-based characterization covering this coordination is lacking. Here, we captured transcriptional states of single cells over space and time during skin wound closure, revealing choreographed gene-expression profiles. We identified shared space-time patterns of cellular and gene program enrichment, which we call multicellular "movements" spanning multiple cell types. We validated some of the discovered space-time movements using large-volume imaging of cleared wounds and demonstrated the value of this analysis to predict "sender" and "receiver" gene programs in macrophages and fibroblasts. Finally, we tested the hypothesis that tumors are like "wounds that never heal" and found conserved wound healing movements in mouse melanoma and colorectal tumor models, as well as human tumor samples, revealing fundamental multicellular units of tissue biology for integrative studies.
Subject(s)
Neoplasms , Wound Healing , Mice , Animals , Humans , Wound Healing/genetics , Skin/pathology , Neoplasms/pathology , Macrophages/metabolism , Fibroblasts/physiology , Stromal CellsABSTRACT
α-Fetoprotein (AFP) is expressed by stem-like and poor outcome hepatocellular cancer tumors and is a clinical tumor biomarker. AFP has been demonstrated to inhibit dendritic cell (DC) differentiation and maturation and to block oxidative phosphorylation. To identify the critical metabolic pathways leading to human DC functional suppression, here, we used two recently described single-cell profiling methods, scMEP (single-cell metabolic profiling) and SCENITH (single-cell energetic metabolism by profiling translation inhibition). Glycolytic capacity and glucose dependence of DCs were significantly increased by tumor-derived, but not normal cord blood-derived, AFP, leading to increased glucose uptake and lactate secretion. Key molecules in the electron transport chain in particular were regulated by tumor-derived AFP. These metabolic changes occurred at mRNA and protein levels, with negative impact on DC stimulatory capacity. Tumor-derived AFP bound significantly more polyunsaturated fatty acids (PUFA) than cord blood-derived AFP. PUFAs bound to AFP increased metabolic skewing and promoted DC functional suppression. PUFAs inhibited DC differentiation in vitro, and ω-6 PUFAs conferred potent immunoregulation when bound to tumor-derived AFP. Together, these findings provide mechanistic insights into how AFP antagonizes the innate immune response to limit antitumor immunity. SIGNIFICANCE: α-Fetoprotein (AFP) is a secreted tumor protein and biomarker with impact on immunity. Fatty acid-bound AFP promotes immune suppression by skewing human dendritic cell metabolism toward glycolysis and reduced immune stimulation.