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The stromal compartment of the tumor microenvironment consists of a heterogeneous set of tissue-resident and tumor-infiltrating cells, which are profoundly moulded by cancer cells. An outstanding question is to what extent this heterogeneity is similar between cancers affecting different organs. Here, we profile 233,591 single cells from patients with lung, colorectal, ovary and breast cancer (n = 36) and construct a pan-cancer blueprint of stromal cell heterogeneity using different single-cell RNA and protein-based technologies. We identify 68 stromal cell populations, of which 46 are shared between cancer types and 22 are unique. We also characterise each population phenotypically by highlighting its marker genes, transcription factors, metabolic activities and tissue-specific expression differences. Resident cell types are characterised by substantial tissue specificity, while tumor-infiltrating cell types are largely shared across cancer types. Finally, by applying the blueprint to melanoma tumors treated with checkpoint immunotherapy and identifying a naïve CD4+ T-cell phenotype predictive of response to checkpoint immunotherapy, we illustrate how it can serve as a guide to interpret scRNA-seq data. In conclusion, by providing a comprehensive blueprint through an interactive web server, we generate the first panoramic view on the shared complexity of stromal cells in different cancers. ispartof: CELL RESEARCH vol:30 issue:9 pages:745-762 ispartof: location:England status: published

Caspase-1 activation in GSDMD-deficient cells induces a rapid form of caspase-3–dependent secondary necrosis that is licenced by caspase-1–induced Bid cleavage and the release of mitochondrial SMAC., Caspase-1 drives a lytic inflammatory cell death named pyroptosis by cleaving the pore-forming cell death executor gasdermin-D (GSDMD). Gsdmd deficiency, however, only delays cell lysis, indicating that caspase-1 controls alternative cell death pathways. Here, we show that in the absence of GSDMD, caspase-1 activates apoptotic initiator and executioner caspases and triggers a rapid progression into secondary necrosis. GSDMD-independent cell death required direct caspase-1–driven truncation of Bid and generation of caspase-3 p19/p12 by either caspase-8 or caspase-9. tBid-induced mitochondrial outer membrane permeabilization was also required to drive SMAC release and relieve inhibitor of apoptosis protein inhibition of caspase-3, thereby allowing caspase-3 auto-processing to the fully active p17/p12 form. Our data reveal that cell lysis in inflammasome-activated Gsdmd-deficient cells is caused by a synergistic effect of rapid caspase-1–driven activation of initiator caspases-8/-9 and Bid cleavage, resulting in an unusually fast activation of caspase-3 and immediate transition into secondary necrosis. This pathway might be advantageous for the host in counteracting pathogen-induced inhibition of GSDMD but also has implications for the use of GSDMD inhibitors in immune therapies for caspase-1–dependent inflammatory disease.

In the setting of the coronavirus disease 2019 (COVID-19) pandemic, only few data regarding lung pathology induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is available, especially without medical intervention interfering with the natural evolution of the disease. We present here the first case of forensic autopsy of a COVID-19 fatality occurring in a young woman, in the community. Diagnosis was made at necropsy and lung histology showed diffuse alveolar damage, edema, and interstitial pneumonia with a geographically heterogeneous pattern, mostly affecting the central part of the lungs. This death related to COVID-19 pathology highlights the heterogeneity and severity of central lung lesions after natural evolution of the disease.

Breast cancer has different molecular subtypes, which determine the prognosis and response to the treatment. CD133 is a marker for cancer stem cells in tumor microenvironment with diagnostic/therapeutic importance. The tumor associated macrophages (TAMs) interact with the cancer stem cells through the CXCR1 receptor. In this study, we wanted to investigate the expression of these markers in patients with different molecular subtypes, in order to detect pathophysio- logical mechanisms and new molecular targets for the prospective targeted therapies. In this study we hypothesized a difference in expression of these antigens among different subtypes. We investigated expression of antigens in breast cancer patients with luminal A (LA), luminal B (LB), HER2 overexpressing (HER2OE), triple negative (TN) subtypes (n=70) and control patients (n=10) without cancer diagnosis. We applied indirect immunohistochemistry and evaluated immunostaining. CD133 expression was at the periphery and CXCR1 expression was at the central area of the tumor. The cytoplasmic CXCR1, CD133 expressions and nuclear CD133 expression, which is prominent in the TN subtype, were observed in patients. There was a statistically significant difference between the groups for CD133 (p=0.004), CXCR1 (p=0.002) H-Score values and M2 macrophages/whole TAM ratios (p=0.022). Between the CD133 and CXCR1 H-scores, there was a weak positive correlation (r=0.249, p=0.035). This study showed the compartment specific expression of the CD133 and CXCR1 antigens in neoplastic cells. The use of CD133 as a stem cell marker may be limited to TN subtype, due to its heterogeneous expression

Tumor-associated macrophages (TAMs) can be educated within the tumor microenvironment to promote cancer development and progression. While TAM-targeted agents have largely focused on macrophage depletion as an anticancer strategy, it is becoming increasingly evident that TAM re-education may represent a more effective approach. In this perspective, we discuss different means to achieve TAM re-education, and review the beneficial effects of these strategies, particularly when combined with immune checkpoint inhibitors.

International audience; OBJECTIVE:The two related tumor necrosis factor members a proliferation-inducing ligand (APRIL) and B-cell activation factor (BAFF) are currently targeted in autoimmune diseases as B-cell regulators. In multiple sclerosis (MS), combined APRIL/BAFF blockade led to unexpected exacerbated inflammation in the central nervous system (CNS) of patients. Here, we investigate the role of the APRIL/BAFF axis in the CNS.METHODS:APRIL expression was analyzed in MS lesions by immunohistochemistry. The in vivo role of APRIL was assessed in the murine MS model, experimental autoimmune encephalitis (EAE). Functional in vitro studies were performed with human and mouse astrocytes.RESULTS:APRIL was expressed in lesions from EAE. In its absence, the disease was worst. Lesions from MS patients also showed APRIL expression upon infiltration of macrophages. Notably, all the APRIL secreted by these macrophages specifically targeted astrocytes. The upregulation of chondroitin sulfate proteoglycan, sometimes bearing chondroitin sulfate of type E sugar moieties, binding APRIL, in reactive astrocytes explained the latter selectivity. Astrocytes responded to APRIL by producing a sufficient amount of IL-10 to dampen antigen-specific T-cell proliferation and pathogenic cytokine secretion. Finally, an intraspinal delivery of recombinant APRIL before disease onset, shortly reduced EAE symptoms. Repeated intravenous injections of recombinant APRIL before and even at disease onset also had an effect.INTERPRETATION:Our data show that APRIL mediates an anti-inflammatory response from astrocytes in MS lesions. This protective activity is not shared with BAFF. ANN NEUROL 2019;85:406-420.© 2019 American Neurological Association.

SummaryExtensive transcriptional and ontogenetic diversity exists among normal tissue-resident macrophages, with unique transcriptional profiles endowing the cells with tissue-specific functions. However, it is unknown whether the origins of different macrophage populations affect their roles in malignancy. Given potential artifacts associated with irradiation-based lineage tracing, it remains unclear if bone-marrow-derived macrophages (BMDMs) are present in tumors of the brain, a tissue with no homeostatic involvement of BMDMs. Here, we employed multiple models of murine brain malignancy and genetic lineage tracing to demonstrate that BMDMs are abundant in primary and metastatic brain tumors. Our data indicate that distinct transcriptional networks in brain-resident microglia and recruited BMDMs are associated with tumor-mediated education yet are also influenced by chromatin landscapes established before tumor initiation. Furthermore, we demonstrate that microglia specifically repress Itga4 (CD49D), enabling its utility as a discriminatory marker between microglia and BMDMs in primary and metastatic disease in mouse and human.

OBJECTIVES: Macrophages play a central role in the cellular inflammatory response to myocardial infarction (MI) and predict subsequent clinical outcomes. We aimed to assess temporal changes in cellular inflammation and tissue oedema in patients with acute MI using ultrasmallsuperparamagnetic particles of iron oxide (USPIO)-enhanced MRI.METHODS: Thirty-one patients were recruited following acute MI and followed up for 3 months with repeated T2 and USPIO-enhanced T2*-mapping MRI. Regions of interest were categorised into infarct, peri-infarct and remote myocardial zones, and compared with control tissues.RESULTS: Following a single dose, USPIO enhancement was detected in the myocardium until 24 hours (pCONCLUSION: Myocardial macrophage activity can be detected using USPIO-enhanced MRI in the first 2 weeks following acute MI. This observed pattern of cellular inflammation is distinct, and provides complementary information to the more prolonged myocardial oedema detectable using T2 mapping. This imaging technique holds promise as a non-invasive method of assessing and monitoring myocardial cellular inflammation with potential application to diagnosis, risk stratification and assessment of novel anti-inflammatory therapeutic interventions.TRIAL REGISTRATION NUMBER: Trial registration number: 14663. Registered on UK Clinical Research Network (http://public.ukcrn.org.uk) and also ClinicalTrials.gov (https://clinicaltrials.gov/ct2/show/NCT02319278?term=DECIFER&rank=2).

AIMS: Atherosclerosis is the leading cause of death in Western societies and a chronic inflammatory disease. However, the key mediators linking recruitment of inflammatory cells to atherogenesis remain poorly defined. Poly(ADP-ribose) polymerase 1 (PARP1) is a nuclear enzyme, which plays a role in acute inflammatory diseases. METHODS AND RESULTS: In order to test the role of PARP in atherogenesis, we applied chronic pharmacological PARP inhibition or genetic PARP1 deletion in atherosclerosis-prone apolipoprotein E-deficient mice and measured plaque formation, adhesion molecules, and features of plaque vulnerability. After 12 weeks of high-cholesterol diet, plaque formation in male apolipoprotein E-deficient mice was decreased by chronic inhibition of enzymatic PARP activity or genetic deletion of PARP1 by 46 or 51%, respectively (P < 0.05, n >or= 9). PARP inhibition or PARP1 deletion reduced PARP activity and diminished expression of inducible nitric oxide synthase, vascular cell adhesion molecule-1, and P- and E-selectin. Furthermore, chronic PARP inhibition reduced plaque macrophage (CD68) and T-cell infiltration (CD3), increased fibrous cap thickness, and decreased necrotic core size and cell death (P < 0.05, n >or= 6). CONCLUSION: Our data provide pharmacological and genetic evidence that endogenous PARP1 is required for atherogenesis in vivo by increasing adhesion molecules with endothelial activation, enhancing inflammation, and inducing features of plaque vulnerability. Thus, inhibition of PARP1 may represent a promising therapeutic target in atherosclerosis.

The genetic and phenotypic diversity of cells within tumors is a major obstacle for cancer treatment. Because of the stochastic nature of genetic alterations, this intratumoral heterogeneity is often viewed as chaotic. Here we show that the altered metabolism of cancer cells creates predictable gradients of extracellular metabolites that orchestrate the phenotypic diversity of cells in the tumor microenvironment. Combining experiments and mathematical modeling, we show that metabolites consumed and secreted within the tumor microenvironment induce tumor-associated macrophages (TAMs) to differentiate into distinct subpopulations according to local levels of ischemia and their position relative to the vasculature. TAMs integrate levels of hypoxia and lactate into progressive activation of MAPK signaling that induce predictable spatial patterns of gene expression, such as stripes of macrophages expressing arginase 1 (ARG1) and mannose receptor, C type 1 (MRC1). These phenotypic changes are functionally relevant as ischemic macrophages triggered tube-like morphogenesis in neighboring endothelial cells that could restore blood perfusion in nutrient-deprived regions where angiogenic resources are most needed. We propose that gradients of extracellular metabolites act as tumor morphogens that impose order within the microenvironment, much like signaling molecules convey positional information to organize embryonic tissues. Unearthing embryology-like processes in tumors may allow us to control organ-like tumor features such as tissue repair and revascularization and treat intratumoral heterogeneity.

Purpose: To investigate the applicability of serine/arginine-rich protein kinase (SRPK)-specific inhibitor, SRPIN340, for attenuation of choroidal neovascularization (CNV) formation using a mouse model. Methods: Laser photocoagulation was performed to induce CNV in C57BL/6J mice, followed by intravitreal injection of SRPIN340 or vehicle. Seven days after the treatment, the CNV size was evaluated using a flatmount technique. Protein levels of vascular endothelial growth factor (VEGF) and inflammation-associated molecules, such as monocyte chemoattractant protein (MCP)-1 and intercellular adhesion molecule (ICAM)-1, in the retinal pigment epithelium-choroid complex were measured with enzyme-linked immunosorbent assay. Expression levels of total Vegf, exon 8a-containing Vegf isoforms, and F4/80 (a specific marker for macrophage) were assessed using real-time PCR. Results: SRPIN340 inhibited CNV formation in a dose-dependent manner. Compared with the vehicle, SRPIN340 significantly decreased the protein levels of VEGF, MCP-1, ICAM-1, and consequently inhibited macrophage infiltration. Furthermore, SRPIN340 suppressed the gene expression levels of total Vegf and exon 8a-containing Vegf isoforms. Conclusions: SRPIN340, a specific inhibitor of SRPK, suppressed Vegf expression and attenuated CNV formation. Our data suggest the possibility that SRPIN340 is applicable for neovascular age-related macular degeneration as a novel chemical therapeutics.

OBJECTIVE: Intimal hyperplasia and surface thrombogenicity are major factors in the high failure rate of synthetic small-diameter bypass grafts. Vascular endothelial growth factor is a potent stimulus for endothelial growth, and its provision in a fibrin matrix coating at the luminal graft surface may hold a key to spontaneous graft endothelialization and improved graft patency. METHODS: Pigs underwent bilateral carotid artery interposition of expanded polytetrafluoroethylene grafts either impregnated with fibrin (n = 11)--engineered to locally release vascular endothelial growth factor121 (vascular endothelial growth factor-fibrin; n = 11)--or left uncoated (n = 12). Graft patency was assessed by quantitative carotid angiography followed by graft histomorphometry at the 1-month experimental end point. RESULTS: Patency rates were not significantly different between study groups. Grafts coated with fibrin or vascular endothelial growth factor-fibrin exhibited significantly increased angiographic narrowing at the proximal anastomosis (for both P < .05 vs uncoated) and no difference at the distal anastomosis and the grafts' middle. Histological analysis showed 80% to 90% endothelial coverage and buildup of intima throughout the lengths of all grafts. Examination of the grafts' midportion revealed significantly enlarged neointimal layers of smooth muscle actin-positive cells in grafts coated with vascular endothelial growth factor-fibrin (242 +/- 47 microm2/micron) and fibrin (177 +/- 41 microm2/micron), compared with uncoated grafts (131 +/- 39 microm2/micron) (for both P < .05 vs uncoated). This thickening could not be explained by enhanced inflammation or vessel wall angiogenesis, which were minimal at the experimental end point. CONCLUSIONS: Fibrin and vascular endothelial growth factor produced effects deleterious to graft healing, by increasing the narrowing at proximal anastomosis and neointimal growth beyond that seen in uncoated grafts. It may reflect direct activation by exogenous vascular endothelial growth factor of vascular smooth muscle cells.

Dermatomyositis (DM) is a rare treatable muscle disorder with a reported favorable outcome in most patients. A localized skin/muscle involvement in a DM patient raises questions of definition and causes such as lymphoma, or relapse. We describe here a young treated DM patient who presented a focal biopsy-proven destructive myositis and dermatitis restricted to the left thigh 15 months after the onset of a treated dermatomyositis. There was evidence of subcutaneous lobular panniculitis, somewhat resembling cytophagic histocytic panniculitis associated with a focal inflammatory myopathy with abundant macrophages that destroyed the sartorius muscle. Mild signs of hemophagocytosis and T-CD3 lymphocytosis were present in the bone marrow, but no monoclonal T-lymphocyte expansion was observed, as searched by autoradiography of the totality of TcR Vgamma families. The patient improved with prednisone and azathioprine. We conclude that this focal complication suggests a continuum between dermatomyositis, CHP, and IMAM, the three syndromes where T-cell activation plays an important role.

Background—Fas (CD95/Apo-1) ligand (FasL)–induced apoptosis in Fas-bearing cells is critically involved in modulating immune reactions and tissue repair. Apoptosis has also been described after mechanical vascular injury such as percutaneous coronary intervention. However, the relevance of cell death in this context of vascular repair remains unknown.Methods and Results—To determine whether FasL-induced apoptosis is causally related to neointimal lesion formation, we subjected FasL-deficient (generalized lymphoproliferative disorder [gld], C57BL/6J) and corresponding wild-type (WT) mice to carotid balloon distension injury, which induces marked endothelial denudation and medial cell death. FasL expression in WT mice was induced in injured vessels compared with untreated arteries (Pgldmice decreased medial and intimal apoptosis (terminal deoxynucleotidyltransferase–mediated dUTP nick end labeling [TUNEL] index) at 1 hour and 7 days after balloon injury (Pgldmice showed no apoptosis and enhanced migration (PPPPgldmice (intima/media ratio, ×3.8 of WT;PConclusions—Our data identify proapoptotic and antiinflammatory effects of endogenous FasL as important factors in the process of neointimal lesion formation after balloon injury. Moreover, they suggest that activation of FasL may decrease neointimal thickening after percutaneous coronary intervention.

Myocardial reperfusion injury is mediated by several processes including increase of reactive oxygen species (ROS). The aim of the study is to identify potential sources of ROS contributing to myocardial ischemia reperfusion injury. For this purpose we investigated myocardial ischemia/reperfusion pathology in mice deficient in various NADPH oxidase isoforms (Nox1 Nox2 Nox4 as well as Nox1/2 double knockout). Following 30. min of ischemia and 24. h of reperfusion a significant decrease in the size of myocardial infarct was observed in Nox1 Nox2 and Nox1/Nox2 but not in Nox4 deficient mice. However no protection was observed in a model of chronic ischemia suggesting that NOX1 and NOX2 mediated oxidative damage occurs during reperfusion. Cardioprotective effect of Nox1 and Nox2 deficiencies was associated with decrease of neutrophil invasion but on the other hand an improved reperfusion injury was also observed in isolated perfused hearts (Langendorff model) suggesting that inflammatory cells were not the major source of oxidative damage. A decrease in global post reperfusion oxidative stress was clearly detected in Nox2 but not in Nox1 deficient hearts. Analysis of key signaling pathways during reperfusion suggests distinct cardioprotective patterns: increased phosphorylation was seen for Akt and Erk in Nox1 deficient mice and for Stat3 and Erk in Nox2 deficient mice. Consequently NOX1 and NOX2 represent interesting drug targets for controlling reperfusion damage associated with revascularization in coronary disease. © 2013 Elsevier Ltd.

Purpose: The aim of this study was to evaluate the effect of a new porcine biomaterial and collagen paste in 20 New Zealand rabbits. Materials and Methods: Forty implants using a porcine xenograft made up of 80% corticocancellous collagenated bone particles of ≤300 μm in size were placed in the proximal metaphyseal area of both tibiae. Four periods of time were formed: 1h, 5, 8, and 15 months. After implantation, an anteroposterior and lateral radiological study was carried out. Samples were sectioned at 5 μm and stained using hematoxylin-eosin, Masson's trichromic, and Gordon-Switt reticulin stains. Results: These results confirmed the biocompatibility of this porcine biomaterial-collagen paste; only a few, occasional macrophages and scattered lymphocytes were observed. No fibrosis was observed between the implants and the bone. Moreover, the material was osteoconductive acting as a “scaffold” for bone cells, and there was a progressive increase in bone growth in and around the implants. Conclusion: This new porcine biomaterial-collagen paste seemed to be biocompatible, bioresorbable, and osteoconductive.

Aluminium-based adjuvants have been used throughout the world since 1926, and their safety profile is such that they have long been the sole adjuvants registered for clinical use. Their safety has nevertheless been questioned in France over the last few years following the demonstration that aluminium could persist for prolonged periods at the injection site, within macrophages gathered around the muscular fibres and forming a microscopic histological lesion called "macrophagic myofasciitis (MMF)". This image has been observed in patients undergoing a deltoid muscular biopsy for diagnostic purposes of various symptoms essentially including muscular pain and fatigue, in association with a large panel of various symptoms and diseases, including those of an autoimmune nature. Studies of the clinical, biological and epidemiological characteristics undertaken to identify a possible association between the MMF histological image and a systematic disease have remained negative. As of today, available evidence indicates that although vaccine aluminium may persist at the site of injection for years ("vaccine tattoo"), this does not reflect the existence of a diffuse inflammatory muscular disease and is not associated with a specific clinical disease. The existence of sampling bias inherent to the complexity of the clinical and pathological diagnoses remains the most likely hypothesis.

Histiocytic cytophagic panniculitis presents with subcutaneous panniculitis. Histologically, it is characterized by phagocytosis of blood cells in the subcutaneous tissue and bone marrow. One patient with histiocytic cytophagic panniculitis is described in whom hemophagocytosis macrophages and histiocytes was observed histologically and was confirmed in vitro measuring phagocytosis by peripheral blood monocytes by means of chemiluminescence. In vitro measurements of phagocytosis corresponded well with the clinical course. Chemiluminescence for measuring phagocytosis in vitro may be suitable for analyzing disease activity and for testing therapeutic compounds in vitro.