Macrophage Subtypes Research Articles

Acute alcohol treatment alters macrophage heterogeneity by interfering with the polarization process

Abstract Alcohol abuse disorder increases the risk of a series of diseases. However, there is limited evidence to indicate how acute alcohol exposure alters immune and inflammatory responses. Macrophages are phagocytic cells with diverse functions. The heterogeneity of macrophages leads to a challenge of clear and precise identification of the functional status and mechanism by which acute alcohol alters macrophage function. To address this issue, we first establish an optimized eleven-parameter flow cytometry panel based on RAW 264.7 cells for identifying macrophage subtypes (Naïve, M1, M2a, and M2c). Then three sets of experiments have been conducted: 1) polarization stimuli were applied first, then alcohol was added to the cultures, 2) alcohol was added to the cells first then polarization stimuli, 3) alcohol and polarization stimuli were added simultaneously. A total of 32 cytokines and chemokines involved in inflammation and immunity were measured. Based on these results, we developed a mathematical expression of the M1-M2 continuum with the principal component analysis that can quantify the degree to which all the markers are consistent with an M1 phenotype or one of the M2 phenotypes, which provides a concise indicator to evaluate macrophage status. Results were consistent with previous studies in our lab using mouse peritoneal macrophages in vitro, and the results indicate that the effects of acute alcohol exposure differ depending on macrophage polarization status, and this may explain some of the effects of alcohol on macrophages that we and others have reported in vivo in a mouse model for binge drinking. The authors were supported by funding from an NIH Center of Biomedical Research Excellence (P20 GM103646-09). The authors were supported by funding from an NIH Center of Biomedical Research Excellence (P20 GM103646-09).

Metabololipidomic and proteomic profiling reveals aberrant macrophage activation and interrelated immunomodulatory mediator release during aging.

Macrophages adapt distinct pro-inflammatory (M1-like) and pro-resolving (M2-like) phenotypes with specific tasks in the immune response and tissue homeostasis. Altered macrophage responses with age are causative for unresolved inflammation, so-called inflammaging, and lead to higher infection susceptibility with unfavorable progression. Here, we reveal molecular determinants of age-related changes in phenotypic functions of murine peritoneal macrophages (PM) by employing comprehensive mass spectrometry-based proteomics (4746 protein groups) and metabololipidomics (>40 lipid mediators). Divergent expression of various macrophage-specific marker proteins and signaling pathways indicates aberrant PM phenotypes in old mice which detrimentally impact their capabilities to release immunomodulatory chemokines and cytokines. We show that aging strikingly compromises the polarization process of macrophages to adapt either pro-inflammatory or pro-resolving phenotypes, thereby yielding aberrant and afunctional macrophage subtypes that cannot be readily assigned to either a typical M1 or M2 phenotype. In particular, the phenotypic adaptation of the bacteria-challenged metabololipidome in macrophages related to inflammation is severely limited by age, which persists across ex vivo polarization towards M1 and M2a macrophages. Our results establish distinct age-associated PM phenotypes outside of the simplified M1 and M2 dichotomy and challenge the dogma of increased pro-inflammatory macrophage pre-activation due to aging by revealing maladaptive functions throughout all phases of inflammation, including resolution.

Single Cell Transcriptomics of Myeloid Cells in Black Americans with Multiple Sclerosis (P2-3.009)

<h3>Objective:</h3> Identify myeloid cell subsets from peripheral blood and monocyte-derived macrophages associated with MS in Black Americans. <h3>Background:</h3> Prior work in a cohort of patients composed primarily of underrepresented minority populations suggested an association between MS susceptibility and differential DNA methylation of genes that regulate cellular differentiation, proliferation, and invasion. <h3>Design/Methods:</h3> Peripheral blood mononuclear cells (PBMC) were obtained from Black American patients with MS and controls with non-inflammatory neurologic conditions under an IRB-approved protocol (UIC Neuroimmunology Biobank). Single cell libraries for RNAseq were constructed from PBMC (n=9) and monocyte-derived macrophages (MDM, n=6) using the Chromium Next GEM Single Cell 3′ Kit v3.1 and Chromium Next GEM Chip G (10x Genomics). Libraries were sequenced on an Illumina NovaSeq 6000. Expression data was analyzed in R software using the Seurat package (Butler et al., 2018). The SingleR and celldex packages (Aran et al., 2019) were used for identification of human peripheral immune cell types. <h3>Results:</h3> Peripheral blood monocytes from MS patients demonstrated an increase in relative numbers of transitional macrophages. These cells included those from classical CD163+ and non-classical CD16+ monocyte populations. Transcriptomic analysis showed an increase in the expression of a lncRNA (long non-coding RNA), KCNQ1OT1, in these cells. Analysis of MDM revealed expansion of a subset of C1Q1+ macrophages in MS. These cells express high levels of a pattern recognition receptor, FCN1 (ficolin 1). Global transcriptomic analysis revealed increased expression of SNHG5, a small nucleolar RNA host gene, in MS in all macrophage subtypes. <h3>Conclusions:</h3> These results suggest an association between expansion of specific monocyte-macrophage populations in our patient cohort. Increased expression of KCNQ1OT1 in transitional macrophages and SNHG5 in MDM is also consistent with our prior study of epigenetic biomarkers because these non-coding RNA’s are associated with cellular differentiation and proliferation in neoplastic diseases. <b>Disclosure:</b> Mr. Bingen has nothing to disclose. The institution of Dr. Clark has received research support from National Science Foundation. Ms. Wright has nothing to disclose. Fangxiu Xu has nothing to disclose. The institution of Dr. Carrithers has received research support from Biogen.

Increasing SUR1-related pathway activity with increasing injury severity in immune and neurovascular cells after murine TBI (P8-1.006)

<h3>Objective:</h3> To evaluate cell-specific changes in sulfonylurea-receptor-1 (SUR1)-transient receptor melastatin-4 (TRPM4) related pathway gene expression activity and biological processes by single-cell RNA sequencing (scRNA-Seq) across increasing severity of murine traumatic brain injury (TBI). <h3>Background:</h3> SUR1-TRPM4 inhibition is being evaluated in a phase-II TBI trial, however genes upstream/downstream of this channel may also be impacted differentially across cell types at the injury site. We hypothesized that SUR1-TRPM4 pathway gene expression and biological processes vary with severity, particularly in immune-cells subtypes. <h3>Design/Methods:</h3> Murine TBI models of increasing severity included naïve, mild-repetitive-TBI (mrTBI), Controlled-Cortical Impact (CCI). Dissociated single-cell suspensions from peri-injured tissue 24h post-TBI underwent scRNA-Seq (10X-Genomics, Illumina), pre-processing (CellRanger) and quality-control (Seurat). A network of 202 SUR1-related genes was developed and used to evaluate SUR1-pathway activity (AUCell). Gene expression, biological pathways, gene-ontology network, cell-communication and pseudotime analyses were assessed (R-packages). <h3>Results:</h3> 79,764 cells were sequenced (naïve=26,851, mrTBI=27,380, CCI=25,533), consisting of 11 cell-types and several subtypes. SUR1-pathway activity was absent in naïve myeloid cells, mildly increased in some cells after mrTBI, and markedly increased after CCI particularly in monocyte, microglia, macrophage and neutrophil subtypes. In B- and T-cells, SUR1-pathway activity was only noted after CCI. Increased SUR1-pathway activity was seen in several astrocyte- and endothelial-subtypes (limited to CCI). Only one neuronal subtype demonstrated increased SUR1-pathway activity after CCI. In immune cells S100a8, S100a9, Cxcl2, and Il1b displayed the highest correlation to SUR1-pathway activity. In astrocytes this was AQP4. Pseudotime analysis identified lineages specific for higher SUR1-pathway activity in several cell types. Biological processes associated with SUR1-pathway activity (chemotaxis, differentiation, apoptosis) were highly variable between cell types. <h3>Conclusions:</h3> SUR1-pathway activity and associated biological processes varied greatly with TBI severity (maximal in severe TBI), and cell type. These differences should be leveraged to develop cell-specific biomarkers and targeted pathway modulation/treatment. <b>Disclosure:</b> Mr. Sneiderman has nothing to disclose. Dr. Xiong has nothing to disclose. Dr. Rajasundaram has nothing to disclose. Dr. Simon has nothing to disclose. Dr. Catapano has nothing to disclose. Mrs. Mihaljevic has nothing to disclose. Dr. Shahjouei has nothing to disclose. Dr. Raikwar has nothing to disclose. Dr. Rani has nothing to disclose. Miss Trivedi has nothing to disclose. Mr. Rulney has nothing to disclose. Dr. Winkler has nothing to disclose. Ms. Miller has nothing to disclose. Mr. Lim has nothing to disclose. Ms. Feldman has nothing to disclose. Vincent Vagni has nothing to disclose. The institution of Dr. Kohanbash has received research support from NIH. Patrick M. Kochanek, MD, MCCM has received personal compensation in the range of $10,000-$49,999 for serving as an Expert Witness for Johns Hopkins Health System. The institution of Patrick M. Kochanek, MD, MCCM has received research support from Chuck Noll Foundation. The institution of Patrick M. Kochanek, MD, MCCM has received research support from NIH. Patrick M. Kochanek, MD, MCCM has received publishing royalties from a publication relating to health care. Dr. Jha has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Biogen. An immediate family member of Dr. Jha has received personal compensation in the range of $5,000-$9,999 for serving as an Expert Witness for Legal fees. The institution of Dr. Jha has received research support from NIH/NINDS, Chuck Noll Foundation, University of Pittsburgh, Barrow Neurological Foundation.

Dissecting the single-cell transcriptome network of macrophage and identifies a signature to predict prognosis in lung adenocarcinoma.

The tumor immune microenvironment (TME) plays a vital role in tumorigenesis, progression, and treatment. Macrophages, as an important component of the tumor microenvironment, play an essential role in antitumor immunity and TME remodeling. In this study, we aimed to explore the different functions of different origins macrophages in TME and their value as potential predictive markers of prognosis and treatment. We performed single-cell analysis using 21 lung adenocarcinoma (LUAD), 12 normal, and four peripheral blood samples from our data and public databases. A prognostic prediction model was then constructed using 502 TCGA patients and explored the potential factors affecting prognosis. The model was validated using data from 4 different GEO datasets with 544 patients after integration. According to the source of macrophages, we classified macrophages into alveolar macrophages (AMs) and interstitial macrophages (IMs). AMs mainly infiltrated in normal lung tissue and expressed proliferative, antigen-presenting, scavenger receptors genes, while IMs occupied the majority in TME and expressed anti-inflammatory, lipid metabolism-related genes. Trajectory analysis revealed that AMs rely on self-renew, whereas IMs originated from monocytes in the blood. Cell-to-cell communication showed that AMs interacted mainly with T cells through the MHC I/II signaling pathway, while IMs mostly interacted with tumor-associated fibrocytes and tumor cells. We then constructed a risk model based on macrophage infiltration and showed an excellent predictive power. We further revealed the possible reasons for its potential prognosis prediction by differential genes, immune cell infiltration, and mutational differences. In conclusion, we investigated the composition, expression differences, and phenotypic changes of macrophages from different origins in lung adenocarcinoma. In addition, we developed a prognostic prediction model based on different macrophage subtype infiltration, which can be used as a valid prognostic biomarker. New insights were provided into the role of macrophages in the prognosis and potential treatment of LUAD patients.

Epigenomic regulation of macrophage polarization: Where do the nuclear receptors belong?

Our laboratory has a long-standing research interest in understanding how lipid-activated transcription factors, nuclear hormone receptors, contribute to dendritic cell and macrophage gene expression regulation, subtype specification, and responses to a changing extra and intracellular milieu. This journey in the last more than two decades took us from identifying target genes for various RXR heterodimers to systematically mapping nuclear receptor-mediated pathways in dendritic cells to identifying hierarchies of transcription factors in alternative polarization in macrophages to broaden the role of nuclear receptors beyond strictly ligand-regulated gene expression. We detail here the milestones of the road traveled and draw conclusions regarding the unexpectedly broad role of nuclear hormone receptors as epigenomic components of dendritic cell and macrophage gene regulation as we are getting ready for the next challenges.

Adipose tissue macrophages as potential targets for obesity and metabolic diseases.

Macrophage infiltration into adipose tissue is a key pathological factor inducing adipose tissue dysfunction and contributing to obesity-induced inflammation and metabolic disorders. In this review, we aim to present the most recent research on macrophage heterogeneity in adipose tissue, with a focus on the molecular targets applied to macrophages as potential therapeutics for metabolic diseases. We begin by discussing the recruitment of macrophages and their roles in adipose tissue. While resident adipose tissue macrophages display an anti-inflammatory phenotype and promote the development of metabolically favorable beige adipose tissue, an increase in pro-inflammatory macrophages in adipose tissue has negative effects on adipose tissue function, including inhibition of adipogenesis, promotion of inflammation, insulin resistance, and fibrosis. Then, we presented the identities of the newly discovered adipose tissue macrophage subtypes (e.g. metabolically activated macrophages, CD9+ macrophages, lipid-associated macrophages, DARC+ macrophages, and MFehi macrophages), the majority of which are located in crown-like structures within adipose tissue during obesity. Finally, we discussed macrophage-targeting strategies to ameliorate obesity-related inflammation and metabolic abnormalities, with a focus on transcriptional factors such as PPARγ, KLF4, NFATc3, and HoxA5, which promote macrophage anti-inflammatory M2 polarization, as well as TLR4/NF-κB-mediated inflammatory pathways that activate pro-inflammatory M1 macrophages. In addition, a number of intracellular metabolic pathways closely associated with glucose metabolism, oxidative stress, nutrient sensing, and circadian clock regulation were examined. Understanding the complexities of macrophage plasticity and functionality may open up new avenues for the development of macrophage-based treatments for obesity and other metabolic diseases.

Analyses of the Cellular Interactions between the Ossification of Collagen-Based Barrier Membranes and the Underlying Bone Defects.

Barrier membranes are an essential tool in guided bone Regeneration (GBR), which have been widely presumed to have a bioactive effect that is beyond their occluding and space maintenance functionalities. A standardized calvaria implantation model was applied for 2, 8, and 16 weeks on Wistar rats to test the interactions between the barrier membrane and the underlying bone defects which were filled with bovine bone substitute materials (BSM). In an effort to understand the barrier membrane's bioactivity, deeper histochemical analyses, as well as the immunohistochemical detection of macrophage subtypes (M1/M2) and vascular endothelial cells, were conducted and combined with histomorphometric and statistical approaches. The native collagen-based membrane was found to have ossified due to its potentially osteoconductive and osteogenic properties, forming a "bony shield" overlying the bone defects. Histomorphometrical evaluation revealed the resorption of the membranes and their substitution with bone matrix. The numbers of both M1- and M2-macrophages were significantly higher within the membrane compartments compared to the underlying bone defects. Thereby, M2-macrophages significantly dominated the tissue reaction within the membrane compartments. Statistically, a correlation between M2-macropahges and bone regeneration was only found at 2 weeks post implantationem, while the pro-inflammatory limb of the immune response correlated with the two processes at 8 weeks. Altogether, this study elaborates on the increasingly described correlations between barrier membranes and the underlying bone regeneration, which sheds a light on the understanding of the immunomodulatory features of biomaterials.

Abstract 5871: Pan-cancer myeloid cell analysis at the single cell level reveals the influence of distinct organ sites in myeloid cell phenotypes and support targeting S100A4 to reverse immune suppression

Abstract With abundant pro-tumorigenic myeloid cells and few tumoricidal tumor-infiltrating lymphocytes (&amp;lt;5%), GBM is representative of “immune cold” tumors. As such, many different types of immunotherapies have failed to show significant benefits for most glioma patients. Hence, a better understanding of drivers of the immune suppressive microenvironment in GBM and other immune cold tumors is urgently needed to guide future immunotherapy development and application. We recently analyzed 201,986 human glioma and immune cells from 44 tissue fragments from 18 human glioma patients, and present a comprehensive and high-resolution cellular, molecular, and spatial heterogeneity atlas of human glioma. We report an extensive spatial and molecular heterogeneity of glioma and immune cells within the same patient. In addition, we discovered that cell:cell communication between glioma:myeloid cells is considerably more robust than glioma:T-cells, indicating that myeloid cells form a communication hub in vivo. To gain a deeper understanding of these important immune cells, we analyzed 83,479 glioma-infiltrating myeloid cells and identified 9 molecularly distinct myeloid subtypes: 3 microglia subtypes, 3 bone marrow-derived macrophage (BMDM) subtypes, MDSCs, neutrophils, and dendritic cells. Notably, we found that five of these myeloid cell subtype gene signatures are significant predictors of glioma patient survival, independent of glioma cell mutational profiles or gene expression patterns. Leveraging our dataset, we also identified a novel immunotherapy target that is highly expressed in immune-suppressive macrophages and T cells but not in anti-tumor leukocytes: S100A4. We provide both in vitro and in vivo evidence that S100a4 deletion in stromal cells is sufficient to reprogram the immune microenvironment and significantly extend the survival of two independent glioma models. To broaden the potential impact of targeting S100A4 as a selective modulator of immune suppressive leukocytes, we compared the molecular signatures of glioma-associated myeloid cells to those from 12 other cancer types and peripheral blood myeloid cells. We found that S100A4 expression pattern is highly consistent among all tumor types, where its expression is highest in the monocytes and MDSCs and low in most DCs and tissue-resident macrophages. Our preliminary analysis also shows that myeloid cells in gliomas are molecularly distinct from corresponding cell types in other cancers, strongly indicating the role brain microenvironment in influencing the infiltrating BMDM maturation and polarization. Citation Format: Nourhan Abdelfattah, Parveen Kumar, Caiyi Wang, Jia-Shiun Leu, David Baskin, William Flynn, Ruli Gao, Kumar Pichumani, Omkar Ijare, Stephanie Wood, Suzanne Powell, David Haviland, Brittany Parker Kerrigan, Frederick Lang, Sujit Prabhu, Kristin Huntoon, Wen Jiang, Betty Kim, Joshy George, Kyuson Yun. Pan-cancer myeloid cell analysis at the single cell level reveals the influence of distinct organ sites in myeloid cell phenotypes and support targeting S100A4 to reverse immune suppression. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5871.

MP03-02 ASSESSMENT OF MATRIX METALLOPROTEINASE-9 AND TISSUE INHIBITOR OF METALLOPROTEINASE-1 VIA M2 MACROPHAGE-SEEDED COLLAGEN MESH FOR TREATMENT OF STRESS URINARY INCONTENCE

You have accessJournal of UrologyCME1 Apr 2023MP03-02 ASSESSMENT OF MATRIX METALLOPROTEINASE-9 AND TISSUE INHIBITOR OF METALLOPROTEINASE-1 VIA M2 MACROPHAGE-SEEDED COLLAGEN MESH FOR TREATMENT OF STRESS URINARY INCONTENCE Ilaha Isali, Phillip McClellan, Thomas R. Wong, James M. Anderson, Ozan Akkus, and Adonis Hijaz Ilaha IsaliIlaha Isali More articles by this author , Phillip McClellanPhillip McClellan More articles by this author , Thomas R. WongThomas R. Wong More articles by this author , James M. AndersonJames M. Anderson More articles by this author , Ozan AkkusOzan Akkus More articles by this author , and Adonis HijazAdonis Hijaz More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003214.02AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Over the past decade, there have been several innovations with respect to macrophage-based therapies and biomaterials. Patients suffering from stress urinary incontinence (SUI) exhibit a significant increase in matrix metalloproteinase-9 (MMP-9) and a significant decrease in tissue inhibitor of metalloproteinase-1 (TIMP-1) expression. These findings are consistent with elevated rates of collagen breakdown and may play a critical role in the onset and development of SUI. Our recent study demonstrated improved biomechanical and histological outcomes following incorporation of M2 macrophages into a collagen mesh developed for tissue repair and offers future strategies focused on connective tissue regeneration. This study aims to assess the regulation of MMP-9 and TIMP-1 by M2 macrophages in terms of regenerating connective tissue in a rat model. METHODS: Macrophages were harvested from rat bone marrow, and macrophage subtypes were identified by flow cytometry. Electrochemically aligned collagen threads were filament wound to produce small collagen meshes and seeded with macrophages and cultured for up to 3 days. Macrophage subtype-seeded meshes were implanted subcutaneously in rats and harvested at 3 weeks and 3 months, respectively. Explanted meshes were analyzed using histology and immunohistochemistry. Specimens stained separately for MMP-9 and TIMP-1, and quantified to determine overall presence of MMP-9 and TIMP-1 in the harvested tissues. RESULTS: Immunohistochemical staining demonstrated a reduction of MMP-9 with addition of M2 macrophages, whereas the M1-seeded group continued to exhibit elevated MMP-9 after 3 months. TIMP-1 presence was elevated with the addition of M2 macrophages, whereas the M1-seeded group showed low TIMP-1 after 3 months (Figure 1). CONCLUSIONS: Delivery of M2 macrophages via collagen mesh can reduce MMP-9 while increasing TIMP-1, which may limit collagen breakdown associated with the development of SUI. This study shows the potential for improved restoration of extracellular matrix following the incorporation of M2 macrophages into a genipin-crosslinked collagen mesh for tissue repair and remodeling. Source of Funding: NIH grant: R21HD095439 © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e21 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Ilaha Isali More articles by this author Phillip McClellan More articles by this author Thomas R. Wong More articles by this author James M. Anderson More articles by this author Ozan Akkus More articles by this author Adonis Hijaz More articles by this author Expand All Advertisement PDF downloadLoading ...

Ebola virus–like particles reprogram cellular metabolism

Ebola virus can trigger a release of pro-inflammatory cytokines with subsequent vascular leakage and impairment of clotting finally leading to multiorgan failure and shock after entering and infecting patients. Ebola virus is known to directly target endothelial cells and macrophages, even without infecting them, through direct interactions with viral proteins. These interactions affect cellular mechanics and immune processes, which are tightly linked to other key cellular functions such as metabolism. However, research regarding metabolic activity of these cells upon viral exposure remains limited, hampering our understanding of its pathophysiology and progression. Therefore, in the present study, an untargeted cellular metabolomic approach was performed to investigate the metabolic alterations of primary human endothelial cells and M1 and M2 macrophages upon exposure to Ebola virus–like particles (VLP). The results show that Ebola VLP led to metabolic changes among endothelial, M1, and M2 cells. Differential metabolite abundance and perturbed signaling pathway analysis further identified specific metabolic features, mainly in fatty acid-, steroid-, and amino acid–related metabolism pathways for all the three cell types, in a host cell specific manner. Taken together, this work characterized for the first time the metabolic alternations of endothelial cells and two primary human macrophage subtypes after Ebola VLP exposure, and identified the potential metabolites and pathways differentially affected, highlighting the important role of those host cells in disease development and progression.Key messages• Ebola VLP can lead to metabolic alternations in endothelial cells and M1 and M2 macrophages.• Differential abundance of metabolites, mainly including fatty acids and sterol lipids, was observed after Ebola VLP exposure.• Multiple fatty acid-, steroid-, and amino acid–related metabolism pathways were observed perturbed.

Characterization of immature ovarian teratomas through single-cell transcriptome.

Immature ovarian teratomas are a type of malignant germ cell tumor composed of complicated cell types and are characterized by pathological features of immature neuroectodermal tubules/rosettes. However, there is a lack of understanding of patient-derived immature ovarian teratomas (PDT) at the single cell level. Moreover, whether stem cell lines derived from immature teratomas (CDT) can be used as models for research on PDT remains to be elucidated. Single-cell RNA sequencing (scRNA-seq) and subsequent bioinformatic analysis was performed on three patient-derived immature ovarian teratomas (PDT) samples to reveal the heterogeneity, evolution trajectory, and cell communication within the tumor microenvironment of PDT. Validations were conducted in additional seven samples through multiplex immunofluorescence. A total of qualified 22,153 cells were obtained and divided into 28 clusters, which can match to the scRNA-seq annotation of CDT as well as human fetal Cell Atlas, but with higher heterogeneity and more prolific cell-cell crosstalk. Radial glia cells (tagged by SOX2) and immature neuron (tagged by DCX) exhibited mutually exclusive expression and differentiated along distinct evolutionary trajectory from cycling neural progenitors. Proportions of these neuroectodermal cell subtypes may play important roles in PDT through contributing to the internal heterogeneity of PDTs. Moreover, the immune cells in PDTs were infiltrated rather than teratoma-derived, with more abundant macrophage in immature neuron than those in radial glia cells, and the infiltrated macrophage subtypes (i.e., M1 and M2) were significantly correlated to clinical grade. Overall, suppressed evolution process and transcriptome regulation in neuroectodermal cells, reduced cell-cell crosstalk, higher M1/M2 proportion ratio, and enhanced T cell effects in tumor microenvironment are enriched in patients with favorable prognosis. This study provides a comprehensive profile of PDT at the single cell level, shedding light on the heterogeneity and evolution of neuroectodermal cells within PDTs and the role of immune cells within the tumor microenvironment. Also, our findings highlight the potential usage of CDTs as a model for research on PDT.

Expanded characterization of in vitro polarized M0, M1, and M2 human monocyte-derived macrophages: Bioenergetic and secreted mediator profiles.

Respiratory macrophage subpopulations exhibit unique phenotypes depending on their location within the respiratory tract, posing a challenge to in vitro macrophage model systems. Soluble mediator secretion, surface marker expression, gene signatures, and phagocytosis are among the characteristics that are typically independently measured to phenotype these cells. Bioenergetics is emerging as a key central regulator of macrophage function and phenotype but is often not included in the characterization of human monocyte-derived macrophage (hMDM) models. The objective of this study was to expand the phenotype characterization of naïve hMDMs, and their M1 and M2 subsets by measuring cellular bioenergetic outcomes and including an expanded cytokine profile. Known markers of M0, M1 and M2 phenotypes were also measured and integrated into the phenotype characterization. Peripheral blood monocytes from healthy volunteers were differentiated into hMDM and polarized with either IFN-γ + LPS (M1) or IL-4 (M2). As expected, our M0, M1, and M2 hMDMs exhibited cell surface marker, phagocytosis, and gene expression profiles indicative of their different phenotypes. M2 hMDMs however were uniquely characterized and different from M1 hMDMs by being preferentially dependent on oxidativte phosphorylation for their ATP generation and by secreting a distinct cluster of soluble mediators (MCP4, MDC, and TARC). In contrast, M1 hMDMs secreted prototypic pro-inflammatory cytokines (MCP1, eotaxin, eotaxin-3, IL12p70, IL-1α, IL15, TNF-β, IL-6, TNF-α, IL12p40, IL-13, and IL-2), but demonstrated a relatively constitutively heightened bioenergetic state, and relied on glycolysis for ATP generation. These data are similar to the bioenergetic profiles we previously observed in vivo in sputum (M1) and BAL (M2)-derived macrophages in healthy volunteers, supporting the notion that polarized hMDMs can provide an acceptable in vitro model to study specific human respiratory macrophage subtypes.

The role of macrophages in the tumor microenvironment and tumor metabolism.

The complexity and plasticity of the tumor microenvironment (TME) make it difficult to fully understand the intratumoral regulation of different cell types and their activities. Macrophages play a crucial role in the signaling dynamics of the TME. Among the different subtypes of macrophages, tumor-associated macrophages (TAMs) are often associated with poor prognosis, although some subtypes of TAMs can at the same time improve treatment responsiveness and lead to favorable clinical outcomes. TAMs are key regulators of cancer cell proliferation, metastasis, angiogenesis, extracellular matrix remodeling, tumor metabolism, and importantly immunosuppression in the TME by modulating various chemokines, cytokines, and growth factors. TAMs have been identified as a key contributor to resistance to chemotherapy and cancer immunotherapy. In this review article, we aim to discuss the mechanisms by which TAMs regulate innate and adaptive immune signaling in the TME and summarize recent preclinical research on the development of therapeutics targeting TAMs and tumor metabolism.

Gene expression variability across cells and species shapes the relationship between renal resident macrophages and infiltrated macrophages

BackgroundTwo main subclasses of macrophages are found in almost all solid tissues: embryo-derived resident tissue macrophages and bone marrow-derived infiltrated macrophages. These macrophage subtypes show transcriptional and functional divergence, and the programs that have shaped the evolution of renal macrophages and related signaling pathways remain poorly understood. To clarify these processes, we performed data analysis based on single-cell transcriptional profiling of renal tissue-resident and infiltrated macrophages in human, mouse and rat.ResultsIn this study, we (i) characterized the transcriptional divergence among species and (ii) illustrated variability in expression among cells of each subtype and (iii) compared the gene regulation network and (iv) ligand-receptor pairs in human and mouse. Using single-cell transcriptomics, we mapped the promoter architecture during homeostasis.ConclusionsTranscriptionally divergent genes, such as the differentially TF-encoding genes expressed in resident and infiltrated macrophages across the three species, vary among cells and include distinct promoter structures. The gene regulatory network in infiltrated macrophages shows comparatively better species-wide consistency than resident macrophages. The conserved transcriptional gene regulatory network in infiltrated macrophages among species is uniquely enriched in pathways related to kinases, and TFs associated with largely conserved regulons among species are uniquely enriched in kinase-related pathways.

Single nuclei transcriptomics delineates complex immune and kidney cell interactions contributing to kidney allograft fibrosis

Chronic allograft dysfunction (CAD), characterized histologically by interstitial fibrosis and tubular atrophy, is the major cause of kidney allograft loss. Here, using single nuclei RNA sequencing and transcriptome analysis, we identified the origin, functional heterogeneity, and regulation of fibrosis-forming cells in kidney allografts with CAD. A robust technique was used to isolate individual nuclei from kidney allograft biopsies and successfully profiled 23,980 nuclei from five kidney transplant recipients with CAD and 17,913 nuclei from three patients with normal allograft function. Our analysis revealed two distinct states of fibrosis in CAD; low and high extracellular matrix (ECM) with distinct kidney cell subclusters, immune cell types, and transcriptional profiles. Imaging mass cytometry analysis confirmed increased ECM deposition at the protein level. Proximal tubular cells transitioned to an injured mixed tubular (MT1) phenotype comprised of activated fibroblasts and myofibroblast markers, generated provisional ECM which recruited inflammatory cells, and served as the main driver of fibrosis. MT1 cells in the high ECM state achieved replicative repair evidenced by dedifferentiation and nephrogenic transcriptional signatures. MT1 in the low ECM state showed decreased apoptosis, decreased cycling tubular cells, and severe metabolic dysfunction, limiting the potential for repair. Activated B, T and plasma cells were increased in the high ECM state, while macrophage subtypes were increased in the low ECM state. Intercellular communication between kidney parenchymal cells and donor-derived macrophages, detected several years post-transplantation, played a key role in injury propagation. Thus, our study identified novel molecular targets for interventions aimed to ameliorate or prevent allograft fibrogenesis in kidney transplant recipients.

Spatial Distribution of Macrophage Subtypes Among Rejection Subtypes in Renal Transplant Biopsies by Dual Immunohistochemistry.

We performed dual immunohistochemistry for CD163/CD34 and CD68/CD34 in 108 renal transplant indication biopsies to investigate the presence and distribution of macrophages in various renal compartments. All Banff scores and diagnoses were revised according to the Banff 2019 classification. CD163 and CD68 positive cell counts (CD163pos and CD68pos) were evaluated in the interstitium, glomerular mesangium, and, within glomerular and peritubular capillaries. The diagnosis was antibody-mediated rejection (ABMR) in 38 (35.2%), T-cell mediated rejection (TCMR) in 24 (22.2%), mixed rejection in 30 (27.8%), and no rejection in 16 (14.8%). Banff lesion scores t , i , and ti were correlated with both CD163 and CD68 interstitial inflammation scores ( r > 0.30; P < 0.05). Glomerular total CD163pos was correlated to Banff lesion scores g and cg ( r > 0.30; P < 0.05). Glomerular total, mesangial, and intracapillary CD68pos were correlated with g ( r > 0.30; P < 0.05). Both glomerular total and peritubular capillary CD68pos were correlated with peritubular capillaritis ( r > 0.30; P < 0.05). Glomerular CD163pos were significantly higher in ABMR compared with no rejection, in mixed rejection compared with no rejection and TCMR. CD163pos in peritubular capillaries was significantly higher in mixed rejection compared with no rejection. Glomerular CD68pos was significantly higher in ABMR compared with no rejection. CD68pos per peritubular capillary was higher in mixed rejection, ABMR, and TCMR compared with no rejection. In conclusion, compared with CD68 positive macrophages, localization of CD163 positive macrophages in various renal compartments seems to be different among rejection subtypes and their glomerular infiltration seems to be more specific for the presence of ABMR component.

The role of macrophages in non-small cell lung cancer and advancements in 3D co-cultures.

Lung cancer (LC) is the leading cause of cancer-related deaths worldwide. Traditional therapeutic approaches such as chemotherapy or radiotherapy have provided only a marginal improvement in the treatment of lung carcinomas. Inhibitors targeting specific genetic aberrations present in non-small cell lung cancer (NSCLC), the most common subtype (85%), have improved the prognostic outlook, but due to the complexity of the LC mutational spectrum, only a fraction of patients benefit from these targeted molecular therapies. More recently, the realization that the immune infiltrate surrounding solid tumors can foster tumor-promoting inflammation has led to the development and implementation of anticancer immunotherapies in the clinic. In NSCLC, one of the most abundant leukocyte infiltrates is macrophages. These highly plastic phagocytes, which are part of the cellular repertoire of the innate immunity, can have a pivotal role in early NSCLC establishment, malignant progression, and tumor invasion. Emerging macrophage-targeting therapies have been focused on the re-differentiation of the macrophages toward an antitumorigenic phenotype, depletion of tumor-promoting macrophage subtypes, or combination therapies combining traditional cytotoxic treatments with immunotherapeutic agents. The most extensively used models employed for the exploration of NSCLC biology and therapy have been 2D cell lines and murine models. However, studying cancer immunology requires appropriately complex models. 3D platforms, including organoid models, are quickly advancing powerful tools to study immune cell-epithelial cell interactions within the tumor microenvironment. Co-cultures of immune cells along with NSCLC organoids allow for an in vitro observation of the tumor microenvironment dynamics closely resembling in vivo settings. Ultimately, the implementation of 3D organoid technology into tumor microenvironment-modeling platforms might facilitate the exploration of macrophage-targeted therapies in NSCLC immunotherapeutic research, thus establishing a new frontier in NSCLC treatment.

Reconstruction of the tumor spatial microenvironment along the malignant-boundary-nonmalignant axis

Although advances in spatial transcriptomics (ST) enlarge to unveil spatial landscape of tissues, it remains challenging to delineate pathology-relevant and cellular localizations, and interactions exclusive to a spatial niche (e.g., tumor boundary). Here, we develop Cottrazm, integrating ST with hematoxylin and eosin histological image, and single-cell transcriptomics to delineate the tumor boundary connecting malignant and non-malignant cell spots in tumor tissues, deconvolute cell-type composition at spatial location, and reconstruct cell type-specific gene expression profiles at sub-spot level. We validate the performance of Cottrazm along the malignant-boundary-nonmalignant spatial axis. We identify specific macrophage and fibroblast subtypes localized around tumor boundary that interacted with tumor cells to generate a structural boundary, which limits T cell infiltration and promotes immune exclusion in tumor microenvironment. In this work, Cottrazm provides an integrated tool framework to dissect the tumor spatial microenvironment and facilitates the discovery of functional biological insights, thereby identifying therapeutic targets in oncologic ST datasets.

Role of macrophage polarisation in skin wound healing.

Skin wound healing is a complex pathophysiological change that is driven by macrophages and their secreted related factors. Depending on the stimuli, macrophages can be polarised into two subtypes of macrophages with completely different phenotypes and functions, namely M1 and M2. The aim of this study was to explore the role of M1 and M2 macrophages in skin healing in order to develop new drugs for the treatment of refractory wounds. Primary bone marrow-derived macrophages (BMDMs) were isolated from rats and expanded in vitro using macrophage colony stimulating factor. In addition, the BMDMs were polarised into the M1 and M2 subtypes using lipopolysaccharides (LPS) and interleukin-4 (IL-4), respectively. Cytokine levels in the culture supernatants were measured by an enzyme linked immunosorbent assay. Epidermal wounds were made on the dorsal surface of rats, and treated with M1 or M2 cell suspensions or phosphate buffered saline. Wound healing was recorded on days 1, 3, 7, 10, and 14 after stamping, and the wound healing rate was measured by haematoxylin-eosin and Masson staining. A total of 3 to 4× 107 bone marrow cells were extracted from each rat femur. The BMDM culture had 87.1% CD45+ cells, 89.2% CD68+ cells, and 86.5% CD45+ CD68+ cells. Furthermore, IL-12 (P< .05) and IL-10 (P≥ .05) levels, respectively, increased and decreased in the culture supernatants of the M1 cells after LPS stimulation compared with those in the M0 (unstimulated) group. Likewise, IL-4 stimulation led to a significant increase in IL-10 levels (P< .01) in the conditioned media of M2 cells, while that of IL-12 decreased slightly (P≥ .05). In the rat model, the infusion of M2 cells accelerated wound healing and tissue regeneration, whereas the M1 cells delayed the recruitment of inflammatory cells, granulation growth, and collagen deposition, which impaired wound healing. Macrophage polarisation and activation are critical for skin wound healing. While exogenous M1 cell infusion delayed wound healing, the M2 cells promoted wound healing in a rat model.