Immune Macrophages Research Articles

Liposome-encapsulated curcumin attenuates HMGB1-mediated hepatic inflammation and fibrosis in a murine model of Wilson's disease.

Wilson's disease (WD) is an inherited disorder of copper metabolism with predominant hepatic manifestations. Left untreated, it can be fatal. Current therapies focus on treating copper overload rather than targeting the pathophysiology of copper-induced liver injuries. We sought to investigate whether liposome-encapsulated curcumin (LEC) could attenuate the underlying pathophysiology of WD in a mouse model of WD. Subcutaneous administration in a WD mouse model with ATP7B knockout (Atp7b-/-) resulted in robust delivery of LEC to the liver as determined by in-vitro and in-vivo imaging. Treatment with LEC attenuated hepatic injuries, restored lipid metabolism and decreased hepatic inflammation and fibrosis, and thus hepatosplenomegaly in Atp7b-/- mice. Mechanistically, LEC decreased hepatic immune cell and macrophage infiltration and attenuated the hepatic up-regulation of p65 by preventing cellular translocation of high-mobility group box-1 (HMGB-1). Moreover, decreased translocation of HMGB1 was associated with reduced splenic CD11b+/CD43+/Ly6CHi inflammatory monocyte expansion and circulating level of proinflammatory cytokines. Nevertheless there was no change in expression of oxidative stress-related genes or significant copper chelation effect of LEC in Atp7b-/- mice. Our results indicate that treatment with subcutaneous LEC can attenuate copper-induced liver injury in an animal model of WD via suppression of HMGB1-mediated hepatic and systemic inflammation. These findings provide important proof-of-principle data to develop LEC as a novel therapy for WD as well as other inflammatory liver diseases.

Inflammatory Signatures of Maternal Obesity as Risk Factors for Neurodevelopmental Disorders: Role of Maternal Microbiota and Nutritional Intervention Strategies.

Obesity is a main risk factor for the onset and the precipitation of many non-communicable diseases. This condition, which is associated with low-grade chronic systemic inflammation, is of main concern during pregnancy leading to very serious consequences for the new generations. In addition to the prominent role played by the adipose tissue, dysbiosis of the maternal gut may also sustain the obesity-related inflammatory milieu contributing to create an overall suboptimal intrauterine environment. Such a condition here generically defined as “inflamed womb” may hold long-term detrimental effects on fetal brain development, increasing the vulnerability to mental disorders. In this review, we will examine the hypothesis that maternal obesity-related gut dysbiosis and the associated inflammation might specifically target fetal brain microglia, the resident brain immune macrophages, altering neurodevelopmental trajectories in a sex-dependent fashion. We will also review some of the most promising nutritional strategies capable to prevent or counteract the effects of maternal obesity through the modulation of inflammation and oxidative stress or by targeting the maternal microbiota.

Pathogenic role of monocytes/macrophages in large vessel vasculitis.

Vasculitis is an autoimmune vascular inflammation with an unknown etiology and causes vessel wall destruction. Depending on the size of the blood vessels, it is classified as large, medium, and small vessel vasculitis. A wide variety of immune cells are involved in the pathogenesis of vasculitis. Among these immune cells, monocytes and macrophages are functionally characterized by their capacity for phagocytosis, antigen presentation, and cytokine/chemokine production. After a long debate, recent technological advances have revealed the cellular origin of tissue macrophages in the vessel wall. Tissue macrophages are mainly derived from embryonic progenitor cells under homeostatic conditions, whereas bone marrow-derived circulating monocytes are recruited under inflammatory conditions, and then differentiate into macrophages in the arterial wall. Such macrophages infiltrate into an otherwise immunoprotected vascular site, digest tissue matrix with abundant proteolytic enzymes, and further recruit inflammatory cells through cytokine/chemokine production. In this way, macrophages amplify the inflammatory cascade and eventually cause tissue destruction. Recent studies have also demonstrated that monocytes/macrophages can be divided into several subpopulations based on the cell surface markers and gene expression. In this review, the subpopulations of circulating monocytes and the ontogeny of tissue macrophages in the artery are discussed. We also update the immunopathology of large vessel vasculitis, with a special focus on giant cell arteritis, and outline how monocytes/macrophages participate in the disease process of vascular inflammation. Finally, we discuss limitations of the current research and provide future research perspectives, particularly in humans. Through these processes, we explore the possibility of therapeutic strategies targeting monocytes/macrophages in vasculitis.

Gut Barrier Damage and Gut Translocation of Pathogen Molecules in Lupus, an Impact of Innate Immunity (Macrophages and Neutrophils) in Autoimmune Disease.

The gut barrier is a single cell layer that separates gut micro-organisms from the host, and gut permeability defects result in the translocation of microbial molecules from the gut into the blood. Despite the silent clinical manifestation, gut translocation of microbial molecules can induce systemic inflammation that might be an endogenous exacerbating factor of systemic lupus erythematosus. In contrast, circulatory immune-complex deposition and the effect of medications on the gut, an organ with an extremely large surface area, of patients with active lupus might cause gut translocation of microbial molecules, which worsens lupus severity. Likewise, the imbalance of gut microbiota may initiate lupus and/or interfere with gut integrity which results in microbial translocation and lupus exacerbation. Moreover, immune hyper-responsiveness of innate immune cells (macrophages and neutrophils) is demonstrated in a lupus model from the loss of inhibitory Fc gamma receptor IIb (FcgRIIb), which induces prominent responses through the cross-link between activating-FcgRs and innate immune receptors. The immune hyper-responsiveness can cause cell death, especially apoptosis and neutrophil extracellular traps (NETosis), which possibly exacerbates lupus, partly through the enhanced exposure of the self-antigens. Leaky gut monitoring and treatments (such as probiotics) might be beneficial in lupus. Here, we discuss the current information on leaky gut in lupus.

Gene expression and involvement of signaling pathways during host-pathogen interplay in Orientia tsutsugamushi infection.

Scrub typhus is a neglected tropical disease that affects one-third of the world’s population. The disease is caused by Orientia tsutsugamushi (OT), an obligate intracellular Gram-negative bacterium. OT efficiently escapes from the endosomal pathway after entering the host cell and replicates inside cytosol. OT infection promotes cellular autophagy, the autonomous defense mechanism unlike other bacteria. This study has discussed the bacterial invasion process through the extracellular matrix and the immune response activated by the bacterium within the hosts. Furthermore, we have emphasized the importance of extracellular matrix and their cross-talk with the immune cells, such as, macrophages, neutrophils, and dendritic cells followed by their inflammatory response. We have also put an insight into the host factors associated with signaling pathways during scrub typhus disease with a special focus on the OT-induced stress response, autophagy, apoptosis, and innate immunity. Multiple cytokines and chemokines play a significant role in activating different immune-related signaling pathways. Due to the presence of high antigenic diversity among strains, the signaling pathways during the host–pathogen interplay of OT with its host is very complicated. Thus, it hinders to mitigate the severity of the pandemic occurred by the respective pathogen. Our investigation will provide a useful guide to better understand the virulence and physiology of this intracellular pathogen which will lead towards a better therapeutic diagnosis and vaccine development.

Simulated hypoxia modulates P2X7 receptor function in mice peritoneal macrophages

The inflammatory focus is similar to the tumor microenvironment, which contains a complex milieu with immune cells and macrophages. The accumulation of cells promotes local pH and O2 tension decline (hypoxia). Local O2 tension decline activates hypoxia-inducible factor α and β (HIF-1α and HIF-1β adenosine triphosphate (ATP) release. ATP activates the P2X7 receptor and modulates ischemic/hypoxic conditions. Similarly, α1α may regulate P2X7 receptor expression in the hypoxic microenvironment. Therefore, we investigated P2X7 receptor function under simulated hypoxic conditions by pretreating peritoneal macrophages with mitochondrial electron transport chain complex inhibitors (simulated hypoxia). Treatment with mitochondrial electron transport chain complex inhibitors until three hours of exposure did not cause LDH release. Additionally, mitochondrial electron transport chain complex inhibitors increased ATP-induced P2X7 receptor function without being able to directly activate this receptor. Other P2 receptor subtypes do not appear to participate in this mechanism. Simulated hypoxia augmented HIF-1α levels and suppressed HIF-1α and P2X7 receptor antagonists. Similarly, simulated hypoxia increased ATP-induced dye uptake and inhibited HIF-1α antagonists. Another factor activated in simulated hypoxic conditions was the intracellular P2X7 receptor regulator PIP2. Treatment with HIF-1α agonists increased PIP2 levels and reversed the effects of HIF-1α and P2X7 receptor antagonists. Additionally, the improved ATP-induced dye uptake caused by the simulated hypoxia stimulus was inhibited by P2X7 receptor and PIP2 antagonists. Therefore, simulated hypoxia may augment P2X7 receptor activity for a pathway dependent on HIF-1α and PIP2 activation.

SYK Is Associated With Malignant Phenotype and Immune Checkpoints in Diffuse Glioma.

Background: Diffuse glioma, the most common intracranial malignant tumor, is characterized by immunosuppression. The prognostic significance and potential therapeutic value of SYK remain obscure. Here, we explored the performance of SYK in predicting patient outcomes and as a therapeutic target. Methods: The mRNA expression and clinical data for pancancer and normal tissues and more than 2,000 glioma samples were collected from public databases. The expression level of SYK was evaluated by qPCR and IHC. The prognostic value of SYK was assessed using the Kaplan–Meier curves and univariate and multivariate Cox regression analyses. A sequence of immune and stromal infiltration analyses was calculated based on the ESTIMATE algorithm, ssGSEA algorithm, TIMER, and single-cell analysis. The SYK-related subtypes were identified via a Consensus Cluster Plus analysis. Results: SYK was significantly differentially expressed in multiple tumors and normal tissues. Importantly, high-expression SYK was enriched in malignant phenotypes of diffuse gliomas, which was further validated by qPCR and IHC. Survival analysis uncovered that SYK was an independently unfavorable prognostic marker in diffuse glioma. Functional enrichment analysis and immune and stromal infiltration analyses showed that SYK was involved in shaping the immunosuppressive microenvironment of diffuse glioma. Additionally, SYK expression was closely associated with some immune checkpoint molecules and M2 macrophage infiltration, which was validated by IHC and single-cell analysis. Diffuse glioma with Sub1 exhibited a worse prognosis, immunosuppressive microenvironment, and higher expression of immune checkpoint genes. Conclusion: SYK is involved in shaping the immunosuppressive microenvironment and served as a promising prognosis biomarker and immunotherapeutic target for diffuse glioma.

The Dual Role of Innate Immune Response in Acetaminophen-Induced Liver Injury.

Simple SummaryAn injury to the liver caused by a drug or its metabolites is referred to as drug-induced liver injury (DILI). The clinical manifestations of DILI are varied, and it may even result in acute liver failure under certain circumstances. Based on findings in the United States and China, Acetyl-para-aminophenol (APAP) may not be the most prevalent cause of DILI, but it is the leading cause of acute liver failure. The study of immune responses in APAP-induced liver injury (AILI) has been making significant progress in recent years. It should be noted, however, that different studies have reported differing results regarding the role played by immune cells in AILI, with some studies indicating they are proinflammatory, while others have showed no effect, or even pro-repair effects. Therefore, we here discuss the mechanisms of the dual role of immune cells in AILI.Acetyl-para-aminophenol (APAP), a commonly used antipyretic analgesic, is becoming increasingly toxic to the liver, resulting in a high rate of acute hepatic failure in Europe and the United States. Excessive APAP metabolism in the liver develops an APAP–protein adduct, which causes oxidative stress, MPTP opening, and hepatic necrosis. HMGB-1, HSP, nDNA, mtDNA, uric acid, and ATP are DMAPs released during hepatic necrosis. DMAPs attach to TLR4-expressing immune cells such KCs, macrophages, and NK cells, activating them and causing them to secrete cytokines. Immune cells and their secreted cytokines have been demonstrated to have a dual function in acetaminophen-induced liver injury (AILI), with a role in either proinflammation or pro-regeneration, resulting in contradicting findings and some research confusion. Neutrophils, KCs, MoMFs, NK/NKT cells, γδT cells, DCs, and inflammasomes have pivotal roles in AILI. In this review, we summarize the dual role of innate immune cells involved in AILI and illustrate how these cells initiate innate immune responses that lead to persistent inflammation and liver damage. We also discuss the contradictory findings in the literature and possible protocols for better understanding the molecular regulatory mechanisms of AILI.

The effect of expressive writing on wound healing: Immunohistochemistry analysis of skin tissue two weeks after punch biopsy wounding

ObjectiveTo investigate the effects of expressive writing and its timing (pre or post wounding) on re-epithelialisation and leucocyte subsets within healing tissue. We previously showed expressive writing pre-wounding improved re-epithelialisation. Here we investigate cellular processes in the wound. MethodsIn a 2(writing content) x 2(writing timing) randomized trial, 122 participants were randomized to perform either expressive or control writing, before or after a 4 mm punch biopsy wound. On day 14 post-wounding, participants had a 5 mm punch biopsy of the initial wound. Seven of 16 primary registered outcomes were analysed, including re-epithelialisation from two photographs of the 4 mm biopsy (previously reported). This paper reports immunohistochemistry analysis of five primary outcomes - Langerhans cells, immune cell activation (HLA and CD3+), and macrophages (CD68 and MPO) - in the 5 mm biopsies in a random sample of 96 participants. ResultsParticipants who performed either writing task pre-wounding had greater Langerhans cell infiltration, than those who wrote post-wounding (F(1,85) = 7.86, p = .006, ηp2 = 0.08). Those who performed expressive writing also had greater Langerhans cell infiltration than those who performed control writing (F(1,85) = 4.00, p = .049, ηp2 = 0.04). There were no significant group or interaction effects on immune cell activation or macrophages. Healed wounds on day 10 had lower levels of macrophages (z = −1.96, p = .050), and CD3+ cells (z = −1.99, p = .046) than non-healed wounds. ConclusionLangerhans cells in the healing skin are affected by the timing and topic of writing. More research is needed to further explore timing and corroborate these results. Clinical Trials RegistrationRegistered at https://www.anzctr.org.au/ (Trial ID: ACTRN12614000971639).

Innate Immunity Crosstalk with Helicobacter pylori: Pattern Recognition Receptors and Cellular Responses

Helicobacter pylori is one of the most successful gastric pathogens that has co-existed with human for centuries. H. pylori is recognized by the host immune system through human pattern recognition receptors (PRRs), such as toll-like receptors (TLRs), C-type lectin like receptors (CLRs), NOD-like receptors (NLRs), and RIG-I-like receptors (RLRs), which activate downstream signaling pathways. Following bacterial recognition, the first responders of the innate immune system, including neutrophils, macrophages, and dendritic cells, eradicate the bacteria through phagocytic and inflammatory reaction. This review provides current understanding of the interaction between the innate arm of host immunity and H. pylori, by summarizing H. pylori recognition by PRRs, and the subsequent signaling pathway activation in host innate immune cells.

Macrophage-derived MLKL in alcohol-associated liver disease: Regulation of phagocytosis.

Mixed lineage kinase domain-like pseudokinase (MLKL), a key terminal effector of necroptosis, also plays a role in intracellular vesicle trafficking that is critical for regulating liver inflammation and injury in alcohol-associated liver disease (ALD). Although receptor interacting protein kinase 3 (Rip3)-/- mice are completely protected from ethanol-induced liver injury, Mlkl-/- mice are only partially protected. Therefore, we hypothesized that cell-specific functions of MLKL may contribute to ethanol-induced injury. Bone marrow transplants between Mlkl-/- mice and littermates were conducted to distinguish the role of myeloid versus nonmyeloid Mlkl in the Gao-binge model of ALD. Ethanol-induced hepatic injury, steatosis, and inflammation were exacerbated in Mlkl-/- →wild-type (WT) mice, whereas Mlkl deficiency in nonmyeloid cells (WT→ Mlkl-/- ) had no effect on Gao-binge ethanol-induced injury. Importantly, Mlkl deficiency in myeloid cells exacerbated ethanol-mediated bacterial burden and accumulation of immune cells in livers. Mechanistically, challenging macrophages with lipopolysaccharide (LPS) induced signal transducer and activator of transcription 1-mediated expression and phosphorylation of MLKL, as well as translocation and oligomerization of MLKL to intracellular compartments, including phagosomes and lysosomes but not plasma membrane. Importantly, pharmacological or genetic inhibition of MLKL suppressed the phagocytic capability of primary mouse Kupffer cells (KCs) at baseline and in response to LPS with/without ethanol as well as peripheral monocytes isolated from both healthy controls and patients with alcohol-associated hepatitis. Further, in vivo studies revealed that KCs of Mlkl-/- mice phagocytosed fewer bioparticles than KCs of WT mice. Together, these data indicate that myeloid MLKL restricts ethanol-induced liver inflammation and injury by regulating hepatic immune cell homeostasis and macrophage phagocytosis.

Oncogenetic Function and Prognostic Value of DNA Topoisomerase II Alpha in Human Malignances: A Pan-Cancer Analysis.

Increasing studies have revealed significant associations between TOP2A with oncogenesis and prognosis of human cancers; however, pan-cancer analysis has not been reported. Here, we explored the potential carcinogenic function and the association with clinical outcomes of TOP2A in 33 different human cancers. The results showed that TOP2A was amplified in 31 investigated cancers; TOP2A expression was significantly associated with metastasis of six different cancers and significantly associated with the survival of patients in ten different cancers; TOP2A-encoded protein was obviously upregulated in five available cancers; phosphorylated TOP2A protein at S1106 was significantly upregulated in all six available cancers. Moreover, TOP2A expression was found to be associated with the cancer-associated immune cell infiltration, including fibroblasts, Tregs, and macrophages. In addition, the Kyoto encyclopedia of genes and genomes (KEGG) pathway and Gene Ontology (GO) enrichment analyses revealed a most significant association between TOP2A with the Wnt signaling pathway and DNA conformation change. This work provides a comprehensive knowledge of TOP2A in different cancers, including carcinogenic function, prognostic values for metastasis, and clinical outcomes.

Immune system and sarcopenia: Presented relationship and future perspective.

Sarcopenia, a geriatric syndrome that is characterized by a progressive and generalized skeletal muscle disorder, can be associated with many comorbidities, including obesity, diabetes, and fracture. Currently, the importance and urgency of sarcopenia have gained more consensus. Discovering the mechanisms of sarcopenia has been more and more important. It has been previously suggested that immune system during ageing plays an important role in the progression of sarcopenia. Immune ageing, which is often highlighted in elder individuals, may be an important contributor in sarcopenia. Immune ageing can occur in different aspects. The alteration in immune organs can affect both the innate immunity and adaptive immunity, affecting the whole condition of the body through circulation. Several kinds of immune cells, including lymphocytes, macrophages, neutrophils and other immune cells, together alters the situation of muscle fiber, causing muscle weakness, loss of muscle strength and muscle mass. Synergistic and cumulative effect of cytokines, such as TNF-α and IFN-γ, interrelates with obesity and diabetes, impairing the condition of skeletal muscle tissue and leading to deterioration of sarcopenia. Studying the relationship of sarcopenia and immune system offers great potential in future studies. Thoroughly studying these mechanisms can help to better determine an ideal scheme and better management of sarcopenia and its associated comorbidities, which tends to offer deeper insight and guidance in treating sarcopenia through alterations of food intake, exercise and medical intervention.

P-595 Heterogeneity of preovulatory follicle cell types between normo- and hyporesponders

Abstract Study question Is there a difference in the proportions of preovulatory follicle cell types between normo- and hyporesponders? Summary answer Human preovulatory follicles consist of 14 distinct cell types, 3 of them are significantly different between normo- and hyporesponder patients. What is known already Human ovarian follicles are a diverse dynamic environment for oocytes to mature and ovulate. Follicles consist of multiple cell types in layers and altogether they are responsible for a repertoire of biological processes. Dysregulations in follicular cells could result in hyporesponsiveness to ovarian stimulation. Hyporesponse might lead to the failure of IVF, due to a low number of retrieved oocytes. Its pathophysiological mechanisms have not been fully elucidated so far. This condition affects up to 25% of patients and investigating their follicular cell populations in detail is highly informative for increasing their prognosis for the live birth outcome. Study design, size, duration Study groups consisted of IVF patients with normoresponse (n = 10) and hyporesponse (n = 9) to rFSH stimulation according to antagonist protocol undergoing in vitro fertilization treatment at Nova Vita Clinic, Estonia. Hyporesponse to treatment was diagnosed if ≥ 200 IU of rFSH was administered to retrieve an oocyte. All study participants were ≤40 years of age with matched BMI and normal ovarian reserve. Women with polycystic ovary morphology and ovarian abnormalities observed by ultrasound examination were excluded. Participants/materials, setting, methods Oocyte pick-up was performed for patients after 36 hours of hCG trigger. Cumulus-oocyte complex was removed from the follicular fluid for IVF and the remaining cells were collected by centrifugation and treated with hyaluronidase and DNase. Genome-wide single-cell RNA-seq was performed for >6000 individual cells of 3 normoresponder patients each. RNA-seq was performed for pooled follicular cells of each participant. CIBERTSORTx software was used to deconvolute the proportion of cell types from bulk RNA-seq data. Main results and the role of chance By analyzing a total number of 24 213 single cells from preovulatory follicles, we identified 4 immune cell lineages (CD45+), including neutrophils, T cells, M1 and M2 macrophages along with 10 non-immune cell lineages (CD45-): epithelial cells and theca cells, cumulus cells and 7 subtypes of granulosa cells with different functional transcriptomic profiles (p < 0.05). We identified granulosa cell subclusters that were highly active in progesterone or estrogen production, extracellular matrix remodeling, ovulational process, cell migration, and apoptosis. Comparing the proportion of cell populations between normo- and hyporesponders from deconvoluted RNA-seq data (adjusted to age), we identified that 3 cell clusters varied with statistical significance (p < 0.05). These detected clusters with different proportions between the studied patient groups suggest their role in contributing to hyporesponse in a preovulatory follicle regarding patients undergoing IVF treatment. Limitations, reasons for caution The small sample size limits the study. Wider implications of the findings Our work advances understanding the heterogeneity of cell types in human preovulatory follicles. The differences in the proportions of cell types of preovulatory follicles of hyporesponders could provide valuable insight for assisting IVF treatment by introducing potential therapeutic targets to improve their live birth outcome. Trial registration number not applicable

Babesia microti Infection Inhibits Melanoma Growth by Activating Macrophages in Mice.

Babesia microti is an obligate intraerythrocytic protozoan transmitted by an Ixodes tick. Infections caused by protozoa, including Plasmodium yoelii and Toxoplasma gondii, are shown to inhibit tumor development by activating immune responses. Th1 immune response and macrophages not only are essential key factors in Babesia infection control but also play an important role in regulating tumor development. In this study, we investigated the effects of B. microti infection on melanoma in tumor-bearing mice. The results showed that B. microti infection could inhibit the growth of melanoma, significantly enlarge the spleen size (p ≤ 0.0001), and increase the survival period (over 7 days) of tumor-bearing mice. Mouse spleen immune cell analysis revealed that B. microti-infected tumor-bearing mice could increase the number of macrophages and CD4+ T cells, as well as the proportion of CD4+ T cells and M1 macrophages in the tumor. Immunohistochemical assays showed that B. microti infection could inhibit tumor angiogenesis (p ≤ 0.0032). Meanwhile, both B. microti-infected erythrocytes and culture supernatant were observed to significantly (p ≤ 0.0021) induce the mRNA expression of iNOS, IL-6, and TNF-α in macrophages. Moreover, B. microti culture supernatant could also repolarize IL-4-induced M2 macrophages to the M1 type. Overall, B. microti exerted antitumor effects by stimulating the immune system of tumor-bearing mice and inducing the polarization of immunosuppressive M2 macrophages to pro-inflammatory M1 macrophages.

Excess Heme Promotes the Migration and Infiltration of Macrophages in Endometrial Hyperplasia Complicated with Abnormal Uterine Bleeding.

In patients, endometrial hyperplasia (EH) is often accompanied by abnormal uterine bleeding (AUB), which is prone to release large amounts of heme. However, the role of excess heme in the migration and infiltration of immune cells in EH complicated by AUB remains unknown. In this study, 45 patients with AUB were divided into three groups: a proliferative phase group (n = 15), a secretory phase group (n = 15) and EH (n = 15). We observed that immune cell subpopulations were significantly different among the three groups, as demonstrated by flow cytometry analysis. Of note, there was a higher infiltration of total immune cells and macrophages in the endometrium of patients with EH. Heme up-regulated the expression of heme oxygenase-1 (HO-1) and nuclear factor erythroid-2-related factor 2 (Nrf2) in endometrial epithelial cells (EECs) in vitro, as well as chemokine (e.g., CCL2, CCL3, CCL5, CXCL8) levels. Additionally, stimulation with heme led to the increased recruitment of THP-1 cells in an indirect EEC-THP-1 co-culture unit. These data suggest that sustained and excessive heme in patients with AUB may recruit macrophages by increasing the levels of several chemokines, contributing to the accumulation and infiltration of macrophages in the endometrium of EH patients, and the key molecules of heme metabolism, HO-1 and Nrf2, are also involved in this regulatory process.

Role of Inflammasomes in Keloids and Hypertrophic Scars-Lessons Learned from Chronic Diabetic Wounds and Skin Fibrosis.

Keloids and hypertrophic scars are pathological cutaneous scars. They arise from excessive wound healing, which induces chronic dermal inflammation and results in overwhelming fibroblast production of extracellular matrix. Their etiology is unclear. Inflammasomes are multiprotein complexes that are important in proinflammatory innate-immune system responses. We asked whether inflammasomes participate in pathological scarring by examining the literature on scarring, diabetic wounds (also characterized by chronic inflammation), and systemic sclerosis (also marked by fibrosis). Pathological scars are predominantly populated by anti-inflammatory M2 macrophages and recent literature hints that this could be driven by non-canonical inflammasome signaling. Diabetic-wound healing associates with inflammasome activation in immune (macrophages) and non-immune (keratinocytes) cells. Fibrotic conditions associate with inflammasome activation and inflammasome-induced transition of epithelial cells/endothelial cells/macrophages into myofibroblasts that deposit excessive extracellular matrix. Studies suggest that mechanical stimuli activate inflammasomes via the cytoskeleton and that mechanotransduction-inflammasome crosstalk is involved in fibrosis. Further research should examine (i) the roles that various inflammasome types in macrophages, (myo)fibroblasts, and other cell types play in keloid development and (ii) how mechanical stimuli interact with inflammasomes and thereby drive scar growth. Such research is likely to significantly advance our understanding of pathological scarring and aid the development of new therapeutic strategies.

Associating transcriptomics data with inflammatory markers to understand tumour microenvironment in hepatocellular carcinoma.

Liver cancer is the fourth leading cause of cancer-related death globally which is estimated to reach more than 1 million deaths a year by 2030. Among liver cancer types, hepatocellular carcinoma (HCC) accounts for approximately 90% of the cases and is known to have a tumour promoting inflammation regardless of its underlying aetiology. However, current promising treatment approaches, such as immunotherapy, are partially effective for most of the patients due to the immunosuppressive nature of the tumour microenvironment (TME). Therefore, there is an urgent need to fully understand TME in HCC and discover new immune markers to eliminate resistance to immunotherapy. We analyse three microarray datasets, using unsupervised and supervised methods, in an effort to discover signature genes. First, univariate, and multivariate, feature selection methods, such as the Boruta algorithm, are applied. Subsequently, an optimisation procedure, which utilises random forest algorithm with three dataset pairs combinations, is performed. The resulting optimal gene sets are then combined and further subjected to network analysis and pathway enrichment analysis so as to obtain information related to their biological relevance. The microarray datasets were analysed via the MCP-counter, CIBERSORT, TIMER, EPIC, and quanTIseq deconvolution methods and an estimation of cell type abundances for each dataset sample were identified. The differences in the cell type abundances, between the adjacent and tumour sample groups, were then assessed using a Wilcoxon Rank Sum test (p-value < 0.05). The optimal gene signature sets, derived from each of the data pairs combination, achieved AUC values ranging from 0.959 to 0.988 in external validation sets using Random Forest model. CLEC1B and PTTG1 genes are retrieved across each optimal set. Among the signature genes, PTTG1, AURKA, and UBE2C genes are found to be involved in the regulation of mitotic sister chromatid separation and anaphase-promoting complex (APC) dependent catabolic process (adjusted p-value < 0.001). Additionally, the application of deconvolution algorithms revealed significant changes in cell type abundances of Regulatory T (Treg) cells, M0 and M1 macrophages, and T CD8+ cells between adjacent and tumour samples. We identified ECM1 gene as a potential immune-related marker acting through immune cell migration and macrophage polarisation. Our results indicate that macrophages, such as M0 macrophage and M1 macrophage cells, undergo significant changes in HCC TME. Moreover, our immune deconvolution approach revealed significant infiltration of Treg cells and M0 macrophages, and a significant decrease in T CD8+ cells and M1 macrophages in tumour samples.

Abstract 2540: A multi-dimensional analysis of human gliomas at the single cell level identifies immune suppressive macrophage molecular signatures and a novel immunotherapy target for GBM

Abstract Glioblastoma (GBM) is the most prevalent primary brain malignancy in adults. The current standard of care includes maximal surgical resection followed by radio- and chemotherapy with temozolomide. Yet &amp;lt;5% of GBM patients survive more than five years. This indicates a desperate need for more effective treatments, such as immunotherapy for GBM patients. Unfortunately, most immunotherapy trials, including vaccines, adoptive cellular therapy, CAR-T cells, and checkpoint blockade, showed only modest benefits in GBM patients. A major barrier to immunotherapy efficacy is GBM’s immunosuppressive microenvironment composed of few tumor infiltrating lymphocytes (TILs; &amp;lt;5%) but abundant myeloid cells, making it an immune cold tumor. By contrast, immune hot tumors, characterized by abundant tumoricidal effector T cells necessary to mount a meaningful attack, have consistently responded better to immunotherapy. Hence, a better definition of the heterogeneous cell types in the GBM microenvironment and their function is urgently needed. Fortunately, single cell transcriptomics approaches provide comprehensive and high-resolution cellular and molecular understanding to resolve this heterogeneity. Here we report an integrated, multiregional and -dimensional single cell transcriptomic analysis of 201,986 human glioma and immune cells derived from 44 tissue fragments from 18 human glioma patients. In doing so, we map GBM cellular heterotypia and spatial, molecular, and functional heterogeneity of glioma associated immune cells. We report extensive spatial and molecular heterogeneity of glioma cells, microglia, macrophages, and T cells within the same tumor samples in low grade gliomas, primary GBMs, and recurrent GBMs. Importantly, our analysis of 83,479 glioma infiltrating myeloid cells identifies 9 molecularly distinct myeloid subtypes: 4 microglial, 4 bone marrow derived macrophage and dendritic cells subtypes. Importantly, in multiple independent glioma patient cohorts, 5 of these myeloid cell subtype gene signatures were independent predictors of patient survival. We also provide evidence that cell:cell communication between glioma and immune cells is more robust than glioma:Tcells, indicating that myeloid cells form a communication hub in vivo. Additionally, we identified S100A4 as highly expressed in immunosuppressive macrophages and T cells, and provide in vitro and in vivo evidence that S100a4 plays a critical role in promoting immunosuppressive phenotypes in glioma associated leukocytes. This study not only provides the first comprehensive single cell atlas of GBM to include both glioma and immune cells from same samples but also demonstrates its utility in elucidating cell:cell communication among different cell types in vivo and discovering new therapeutic targets for this poorly immunogenic cancer. Citation Format: Nourhan Abdelfattah, Parveen Kumar, Caiyi Wang, Jia-Shiun Leu, William W. Flynn, Ruli Gao, David S. Baskin, Kumar Pichumani, Omkar B. Ijare, Stephanie Wood, Suzanne Powell, David Haviland, Frederick F. Lang, Sujit Prabhu, Kristin Huntoon, Brittany C. Parker Kerrigan, Wen Jiang Jiang, Betty Y. Kim, Joshy George, Kyuson Yun. A multi-dimensional analysis of human gliomas at the single cell level identifies immune suppressive macrophage molecular signatures and a novel immunotherapy target for GBM [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2540.

Abstract 5273: The peripheral proinflammatory responses in COVID-19: Clinical spectrum and outcome in patients with and without cancer

Abstract Background: A meta-analysis of COVID-19 shows that the pooled prevalence of cancer is 1.4%. Febrile illness during COVID-19 is caused by cytokine release syndrome energized by innate inflammatory immune cells, neutrophils, monocytes, and macrophages. Cancer has a worse clinical outcome with COVID-19 due to a potential contribution of the disordered inflammatory microenvironment and immune system. This study aimed to determine the impact of peripheral inflammatory responses on clinical outcome and severity of COVID-19 patients with and without cancer and compare their clinical spectra. Methodology: This IRB-approved, retrospective chart review performed at PNOC included patients 18 years or older with PCR-confirmed COVID-19 from April 2020 to April 2021. Histopathology-confirmed cases identified excluded cranial metastases, pregnancy, or ICU-ineligible due to advanced malignancy or missing data. We collected the first clinical encounter data following a positive COVID-19 test, including CDC-defined COVID-19 symptoms, co-morbidities, cancer status, and treatment—clinical outcomes and death from any cause within30 days of COVID-19 diagnosis. We determined peripheral blood inflammatory cells of neutrophils, lymphocytes, monocytes, platelets and the ratios between lymphocytes and the other three. According to INH guidelines, we ranked clinical severity as presymptomatic, mild, moderate, severe, or critical. Results: Of 3745 people with PCR-confirmed COVID-19, 65 (1.7%) had cancer. We randomly selected 130 non-cancer subjects, homogeneously distributed across each month. The median age was 59 years. Of all, 52.3% were women, 43% were diabetic, 45% were hypertensive, and 35% had the cardiopulmonary disease. Dyspnea occurs in 30.8% of those with cancer but in 59.2% of those without cancer (P &amp;lt; .001). High neutrophil was significantly associated with severity (P = .038), but there was no significant difference between cancer and non-cancer groups. High lymphocytes, MPV, and Neutrophil/Lymphocyte ratio were associated with symptoms but not outcome or severity. Death from any cause was more in the group with cancer 23.1% vs. 6.9%, P= .001. Only 2% of study participants with cancer continued chemotherapy after the diagnosis of COVID-19 was confirmed. Conclusion: Mortality significantly remains higher when cancer is comorbid with COVID-19, as seen in international groups. Further studies are needed to confirm whether cancer immunomodulation is a factor. Peripheral inflammatory response modestly predicts a worse outcome, particularly with elevated neutrophils, known for its proinflammatory rule by polarization and neutrophil extracellular trap (NET) formation with platelet activation. There was a modest increase in symptoms severity in non-cancer COVID19 but more mortality in cancer comorbid COVID-19 Citation Format: Amer N. Radwi, Zahra H. Alshardi, Rakan H. Alelyani, Raha M. Garout, Lojain N. Alruwaili, Muhammad T. Bakhsh. The peripheral proinflammatory responses in COVID-19: Clinical spectrum and outcome in patients with and without cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5273.