Major Cell Population Research Articles

Single cell RNA-sequencing of feline peripheral immune cells with V(D)J repertoire and cross species analysis of T lymphocytes

IntroductionThe domestic cat (Felis catus) is a valued companion animal and a model for virally induced cancers and immunodeficiencies. However, species-specific limitations such as a scarcity of immune cell markers constrain our ability to resolve immune cell subsets at sufficient detail. The goal of this study was to characterize circulating feline T cells and other leukocytes based on their transcriptomic landscape and T-cell receptor repertoire using single cell RNA-sequencing.MethodsPeripheral blood from 4 healthy cats was enriched for T cells by flow cytometry cell sorting using a mouse anti-feline CD5 monoclonal antibody. Libraries for whole transcriptome, αβ T cell receptor transcripts and γδ T cell receptor transcripts were constructed using the 10x Genomics Chromium Next GEM Single Cell 5’ reagent kit and the Chromium Single Cell V(D)J Enrichment Kit with custom reverse primers for the feline orthologs.ResultsUnsupervised clustering of whole transcriptome data revealed 7 major cell populations - T cells, neutrophils, monocytic cells, B cells, plasmacytoid dendritic cells, mast cells and platelets. Sub cluster analysis of T cells resolved naive (CD4+ and CD8+), CD4+ effector T cells, CD8+ cytotoxic T cells and γδ T cells. Cross species analysis revealed a high conservation of T cell subsets along an effector gradient with equitable representation of veterinary species (horse, dog, pig) and humans with the cat. Our V(D)J repertoire analysis identified a subset of CD8+ cytotoxic T cells with skewed TRA and TRB gene usage, conserved TRA and TRB junctional motifs, restricted TRA/TRB pairing and reduced diversity in TRG junctional length. We also identified a public γδ T cell subset with invariant TRD and TRG chains and a CD4+ TEM-like phenotype. Among monocytic cells, we resolved three clusters of classical monocytes with polarization into pro- and anti-inflammatory phenotypes in addition to a cluster of conventional dendritic cells. Lastly, our neutrophil sub clustering revealed a larger mature neutrophil cluster and a smaller exhausted/activated cluster.DiscussionOur study is the first to characterize subsets of circulating T cells utilizing an integrative approach of single cell RNA-sequencing, V(D)J repertoire analysis and cross species analysis. In addition, we characterize the transcriptome of several myeloid cell subsets and demonstrate immune cell relatedness across different species.

Abstract 4137829: Comprehensive Single-Cell Atlas of the Human Lung in Pulmonary Arterial Hypertension

Introduction: Pulmonary arterial hypertension (PAH) is a complex cardiopulmonary disease characterized by progressive vascular remodeling. Although various immune and vascular cell populations have been implicated in the pathobiology of PAH, a comprehensive assessment of the various cell types in human PAH lungs is still lacking. Methods: Single-nucleus RNA sequencing was performed on lung samples from the Pulmonary Hypertension Breakthrough Initiative using the 10x Genomics Chromium Fixed RNA Profiling workflow. Rigorous quality control measures were implemented, including the detection and removal of ambient RNA using CellBender and doublets using scDblFinder. Data normalization and dimensionality reduction were performed using Seurat, and alignment by sample and sequencing batch was conducted using Harmony. Cells were annotated by mapping onto the Human Lung Cell Atlas using Azimuth. Differential gene expression analysis was conducted using a robust pseudobulk approach with edgeR to limit false positive findings. Gene set enrichment analysis was performed using the Hallmark pathways. Results: Lung samples from a total of 67 individuals were profiled, including 42 PAH and 25 age- and sex-matched control lungs. After quality control filtering, over 800,000 cells were captured, with a median of 12,000 cells per sample. Clustering uncovered over 30 cell types, representing endothelial, stromal, immune, and epithelial lineages of the lung. A median of 2,500 transcripts and 1,500 genes were detected per cell. Differentially expressed genes between PAH and control were detected in all major cell populations (FDR < 0.05). Comparative analysis across all cell types revealed interferon response in monocyte subpopulations and endothelial-to-mesenchymal transition in endothelial subpopulations as top upregulated pathways. Conclusion: Comprehensive single-nucleus profiling of human lungs in PAH revealed extensive gene and pathway dysregulation across diverse cell types. This rich dataset provides a valuable resource for the research community, offering opportunities to advance and refine our understanding of the cellular pathobiology of PAH.

Single-cell RNA transcriptomics in mice reveals embryonic origin of fibrosis due to maternal obesity

Over 40% of pregnant women in the USA are obese which negatively affects fetal development and offspring health. Maternal obesity (MO) leads to fibrotic infiltration in multiple tissues and organs of offspring during their adulthood although the origin and mechanisms are unclear. C57BL/6J female mice were fed a control and high-fat diet to mimic MO condition. Embryonic somatic tissues were obtained at E9.5, E11.5, and E13.5 (equivalent to 6 weeks of human pregnancy) from control (CON) and MO mice for single-cell RNA-sequencing (scRNA-seq). To explore the role of AMP-activated protein kinase (AMPK), AMPK was activated by metformin and A769662, and knocked out in embryonic mesenchymal cells (EMC) using AMPKα1 floxed mice. Using unsupervised clustering, we identified three major cell populations with fibrogenic capacity. Compared to CON, the population of fibrogenic cells increased dramatically (by ∼125%) due to MO, supporting an embryonic origin of fibrosis in the offspring. MO induced inflammatory response and elevated expression of transforming growth factor β (TGFβ) signalling and fibrogenic genes in embryos. MO inhibited AMPK and its activation by metformin and A769662 inhibited TGFβ signalling and fibrogenesis. MO profoundly enhances embryonic fibrogenesis, explaining the origin of fibrosis in the offspring of mothers living with obesity. Our data underscore the importance of early intervention, before 5-6 weeks of pregnancy, in improving embryonic development, and AMPK is an amiable target for suppressing excessive fibrogenesis in MO embryos to assist increasing populations of obese mothers having healthy children. This work was funded by National Institutes of Health Grant R01HD067449.

Effect of anterior quadratus lumborum block with ropivacaine on the immune response after laparoscopic surgery in colon cancer: a substudy of a randomized clinical trial

BackgroundSurgery induces a temporal change in the immune system, which might be modified by regional anesthesia. Applying a bilateral preoperative anterior quadratus lumborum block has proven to be a safe...

Dissecting the cell microenvironment of ovarian endometrioma through single-cell RNA sequencing.

Ovarian endometrioma (OE), also known as "chocolate cysts," is a cystic mass that develops in the ovaries due to endometriosis and is a common gynecological condition characterized by the growth of endometrial tissue outside the uterus, leading to symptoms such as dysmenorrhea, pelvic pain, and infertility. However, the precise molecular and cellular mechanisms driving this pathophysiology remain largely unknown, posing challenges for diagnosis and treatment. Here, we employed integrated single-cell transcriptomic profiling of over 52,000 individual cells from endometrial tissues of OE patients and healthy donors and identified twelve major cell populations. We identified notable alterations in cell type-specific proportions and molecular signatures associated with OE. Notably, the activation of IGFBP5+ macrophages with pro-inflammatory properties, NK cell exhaustion, and aberrant proliferation of IQCG+ and KLF2+ epithelium are key features and may be the potential mechanisms underlying the pathogenesis of OE. Collectively, our data contribute to a better understanding of OE at the single cell level and may pave the way for the development of novel therapeutic strategies.

Dispensable regulation of brain development and myelination by the immune-related protein Serpina3n.

Serine protease inhibitor clade A member 3n (Serpina3n) or its human orthologue SERPINA3 is a secretory immune-related molecule produced primarily in the liver and brain under homeostatic conditions and up-regulated in response to system inflammation. Yet, it remains elusive regarding its cellular identity and physiological significance in the development of the postnatal brain. Here, we reported that oligodendroglial lineage cells are the major cell population expressing Serpina3n protein in the postnatal murine CNS. Using loss-of-function genetic tools, we found that Serpina3n conditional knockout (cKO) from Olig2-expressing cells does not significantly affect cognitive and motor functions in mice. Serpina3n depletion does not appear to interfere with oligodendrocyte differentiation and developmental myelination nor affects the population of other glial cells and neurons invivo. Interestingly, Serpina3n is significantly up-regulated in response to oxidative stress and its deficiency alleviates oxidative injury and diminishes cell senescence of oligodendrocytes invitro. Together, our data suggest that the immune-related molecule Serpina3n plays a minor role in neural cell development under homeostasis, yet it primes oligodendrocytes for CNS insults and regulates oligodendrocyte health under injured conditions. Our findings raise the interest in pursuing its functional significance in the CNS under disease/injury conditions.

Single-cell transcriptomic resolution of osteogenesis during craniofacial morphogenesis

Craniofacial morphogenesis depends on complex cell fate decisions during the differentiation of post-migratory cranial neural crest cells. Molecular mechanisms of cell differentiation of mesenchymal cells to developing bones, cartilage, teeth, tongue, and other craniofacial tissues are still poorly understood. We performed single-cell transcriptomic analysis of craniofacial mesenchymal cells derived from cranial NCCs in mouse embryo. Using FACS sorting of Wnt1-Cre2 progeny, we carefully mapped the cell heterogeneity in the craniofacial region during the initial stages of cartilage and bone formation. Transcriptomic data and in vivo validations identified molecular determinants of major cell populations involved in the development of lower and upper jaw, teeth, tongue, dermis, or periocular mesenchyme. Single-cell transcriptomic analysis of Meis2-deficient mice revealed critical gene expression differences, including increased osteogenic and cell adhesion markers. This leads to affected mesenchymal cell differentiation and increased ossification, resulting in impaired bone, cartilage, and tongue formation.

Serotonin modulates infraslow oscillation in the dentate gyrus during Non-REM sleep.

Synchronous neuronal activity is organized into neuronal oscillations with various frequency and time domains across different brain areas and brain states. For example, hippocampal theta, gamma and sharp wave oscillations are critical for memory formation and communication between hippocampal subareas and the cortex. In this study, we investigated the neuronal activity of the dentate gyrus (DG) with optical imaging tools during sleep-wake cycles. We found that the activity of major glutamatergic cell populations in the DG is organized into infraslow oscillations (0.01 - 0.03 Hz) during NREM sleep. Although the DG is considered a sparsely active network during wakefulness, we found that 50% of granule cells and about 25% of mossy cells exhibit increased activity during NREM sleep. Further experiments revealed that the infraslow oscillation in the DG was correlated with rhythmic serotonin release during sleep, which oscillates at the same frequency but in an opposite phase. Genetic manipulation of 5-HT receptors revealed that this neuromodulatory regulation is mediated by 5-HT1a receptors and the knockdown of these receptors leads to memory impairment. Together, our results provide novel mechanistic insights into how the 5-HT system can influence hippocampal activity patterns during sleep.

Proteomic Analysis Reveals Oxidative Phosphorylation and JAK-STAT Pathways Mediated Pathogenesis of Pemphigus Vulgaris.

Pemphigus vulgaris (PV) stands as a rare autoimmune bullous disease, while the precise underlying mechanism remains incompletely elucidated. High-throughput proteomic methodologies, such as LC-MS/MS, have facilitated the quantification and characterisation of proteomes from clinical skin samples, enhancing our comprehension of PV pathogenesis. The objective of this study is to elucidate the signalling mechanisms underlying PV through proteomic analysis. Proteins and cell suspension were extracted from skin biopsies obtained from both PV patients and healthy volunteers and subsequently analysed using LC-MS/MS and scRNA-seq. Cultured keratinocytes were treated with PV serum, followed by an assessment of protein expression levels using immunofluorescence and western blotting. A total of 880, 605, and 586 differentially expressed proteins (DEPs) were identified between the lesion vs. control, non-lesion vs. control, and lesion vs. non-lesion groups, respectively. The oxidative phosphorylation (OXPHOS) pathway showed activation in PV. Keratinocytes are the major cell population in the epidermis and highly expressed ATP5PF, ATP6V1G1, COX6B1, COX6A1, and NDUFA9. In the cellular model, there was a notable increase in the expression levels of OXPHOS-related proteins (V-ATP5A, III-UQCRC2, II-SDHB, I-NDUFB8), along with STAT1, p-STAT1, and p-JAK1. Furthermore, both the OXPHOS inhibitor metformin and the JAK1 inhibitor tofacitinib demonstrated therapeutic effects on PV serum-induced cell separation, attenuating cell detachment. Metformin notably reduced the expression of V-ATP5A, III-UQCRC2, II-SDHB, I-NDUFB8, p-STAT1, p-JAK1, whereas tofacitinib decreased the expression of p-STAT1 and p-JAK1, with minimal impact on the expression of V-ATP5A, III-UQCRC2, II-SDHB, and I-NDUFB8. Our results indicate a potential involvement of the OXPHOS and JAK-STAT1 pathways in the pathogenesis of PV.

A patient-derived HCC spheroid system to model the tumor microenvironment and treatment response

Background & AimsHepatocellular carcinoma (HCC) is the third leading and fastest rising cause of cancer-related death worldwide. The discovery and preclinical development of compounds targeting HCC is hampered by the absence of authentic tractable systems recapitulating the heterogeneity of patient HCC tumors and the tumor microenvironment (TME). MethodsWe established a novel and simple patient-derived multicellular tumorspheroid model based on clinical HCC tumor tissues, processed using enzymatic and mechanical dissociation. After quality controls, 22 HCC tissues and 17 HCC serum were selected for tumorspheroid generation and perturbation studies. Cells were grown in 3D in optimized medium in presence of patient serum. Characterization of the tumorspheroid cell populations was performed by flow cytometry, immunohistochemistry and functional assays. As a proof of concept, we treated patient-derived spheroids with FDA approved anti-HCC compounds. ResultsThe model was successfully established independently from cancer etiology and grade from 22 HCC tissues. We show that the use of HCC patient serum was essential for tumorspheroid generation, the TME function and to maintain cell viability. The tumorspheroids comprised the main cell compartments including epithelial cancer cells as well as all major cell populations of the TME (cancer-associated fibroblasts, macrophages and T cells, endothelial cells). Tumorspheroids reflect HCC heterogeneity, including variability in cell type proportions and TME, and mimic the original tumor features. Moreover, we observed differential responses to FDA HCC approved drugs between donors as observed in patients. ConclusionThis patient HCC serum-tumorspheroid model provides novel opportunities for drug discovery and development as well as mechanism of action studies including compounds targeting the TME. This model will likely contribute to improve the dismal outcome of patients with HCC. Impact and implicationsHepatocellular carcinoma (HCC) is a leading and fast rising cause of cancer-related death worldwide. Despite approval of novel therapies, the outcome of advanced HCC remains unsatisfactory. By developing a novel patient-derived tumorspheroid model recapitulating tumor heterogeneity and microenvironment, we provide new opportunities for HCC drug development and analysis of mechanism of action in authentic patient tissues. The application of the patient-derived tumorspheroids combined with other HCC models will likely contribute to drug development and to improve the dismal outcome of patients with HCC.

Characterization of Nasal Mucosal T Cells in Horses and Their Response to Equine Herpesvirus Type 1

Equine herpesvirus type 1 (EHV-1) enters through the upper respiratory tract (URT). Mucosal immunity at the URT is crucial in limiting viral infection and morbidity. Here, intranasal immune cells were collected from horses (n = 15) during an experimental EHV-1 infection. CD4+ and CD8+ T cells were the major intranasal cell populations before infection and increased significantly by day six and fourteen post-infection, respectively. Nasal mucosal T cells were further characterized in healthy horses. Compared to peripheral blood mononuclear cells (PBMC), mucosal CD8+ T-cell percentages were elevated, while CD4+ T-cell percentages were similar. A small population of CD4+CD8+ T cells was also recovered from mucosal samples. Within the URT tissue, CD4+ cells predominantly accumulated in the epithelial layer, while most CD8+ cells resided deeper in the mucosa or the submucosa below the basement membrane. In vitro stimulation of mucosal cells from healthy horses with (n = 5) or without (n = 5) peripheral T-cell immunity against EHV-1 induced IFN-γ production in nasal T cells upon polyclonal stimulation. However, after EHV-1 re-stimulation, mucosal T cells failed to respond with IFN-γ. This work provided the first characterization of mucosal T-cell phenotypes and functions in the URT of healthy horses and during EHV-1 infection.

Impact of Comorbid Pathology and Severity of Clinical Course on Anti-infective Protection in Patients with COVID-19

Objective — to establish and evaluate the impact of comorbid pathology and the severity of the clinical course on the activity of anti-infective protection in patients with coronavirus disease 2019 (COVID-19), based on the analysis of the absolute and relative counts of major immune cell populations in peripheral blood. Materials and methods. A cross-sectional prospective study was conducted involving 204 patients with COVID-19-associated pneumonia of mild, moderate and severe stages. The cohort included 106 (51.97 %) women and 98 (48.03 %) men, with an average age of (55.93 ± 8.75) years. Anti-infective ­protection was studied using comprehensive clinical blood analysis, including the count of major immune-competent cells. Patients were categorised into groups based on comorbi­dity, taking into account the predominant concurrent pathology at the time of examination (endocrine, cardiovascular or other). Results and discussion. More severe COVID-19 cases were characterised by leukopenia, relative and absolute granulocytopenia, neutropenia, a slight hyporegenerative nuclear shift to the right and a reduction in the number of segmented neutrophils by 24.63—34.72 % (p ≤ 0.047—0.009) and eosinophilic granulocytes by 52.94—70.59 % (p ≤ 0.004—0.001). This was accompanied by relative and absolute agranulocytosis due to lymphocytosis (by 20.10—63.33 %; p ≤ 0.05—0.003) and monocytosis (by 40.0—74.12 %; p ≤ 0.046—0.049), indicating an active inflammatory infectious process of viral etiology against a background of decreased resistance and increased activity of the lymphocyte-macrophage link with the beginning of the formation of specific immune protection (cellular and humoral response to coronavirus intervention). Mild cases of COVID-19 showed a higher absolute count of peripheral blood granulocytes (by 48.25 %; p = 0.018), neutrophils, particularly segmented neutrophils and eosinophilic granulocytes, compared to moderate and severe cases (by 32.36—53.18 % (p ≤ 0.049—0.01) and 3.4 times (p ≤ 0.005—0.002)) and the lowest content of monocytes (by 35.41—42.57 %; p ≤ 0.049—0.046). In cases with concurrent endocrine and cardiological pathologies against a background of a more severe clinical course of COVID-19, immunoinflammatory changes intensified due to absolute and relative leukopenia, neutrophilic granulocytopenia, neutropenia, with the presence of relative lymphocytosis and monocytosis, and normal ESR indicators, confirming the inflammatory process of viral etiology, which, in the absence of treatment, may tend to form post-COVID and/or long-term effects of COVID-19 with multisystem involvement. Conclusions. The study found an enhancement of the immunoinflammatory response and an increase in the depletion of cellular factors of non-specific anti-infective protection with the progression of the clinical manifestations of COVID-19, particularly against the backdrop of comorbid endocrine and/or cardiological pathology.

Dispensable regulation of brain development and myelination by the immune-related protein Serpina3n.

Serine protease inhibitor clade A member 3n (Serpina3n) or its human orthologue SERPINA3 is a secretory immune-related molecule produced primarily in the liver and brain under homeostatic conditions and upregulated in response to system inflammation. Yet it remains elusive regarding its cellular identity and physiological significance in the development of the postnatal brain. Here, we reported that oligodendroglial lineage cells are the major cell population expressing Serpina3n protein in the postnatal murine CNS. Using loss-of-function genetic tools, we found that Serpina3n conditional knockout (cKO) from Olig2-expressing cells does not significantly affect cognitive and motor functions in mice. Serpina3n depletion does not appear to interfere with oligodendrocyte differentiation and developmental myelination nor affects the population of other glial cells and neurons in vivo. Together, these data suggest that the immune-related molecule Serpina3n plays a minor role, if any, in regulating neural cell development in the postnatal brain under homeostatic conditions. We found that Serpina3n is significantly upregulated in response to oxidative stress, and it potentiates oxidative injury and cell senescence of oligodendrocytes. Our data raise the interest in pursuing its functional significance in the CNS under disease/injury conditions.

Novel insights from human induced pluripotent stem cells on origins and roles of fibro/adipogenic progenitors as heterotopic ossification precursors.

Fibro/adipogenic progenitors (FAPs) that reside in muscle tissue are crucial for muscular homeostasis and regeneration as they secrete signaling molecules and components of the extracellular matrix. During injury or disease, FAPs differentiate into different cell types and significantly modulate muscular function. Recent advances in lineage tracing and single-cell transcriptomics have proven that FAPs are heterogeneous both in resting and post-injury or disease states. Their heterogeneity may be owing to the varied tissue microenvironments and their diverse developmental origins. Therefore, understanding FAPs' developmental origins can help predict their characteristics and behaviors under different conditions. FAPs are thought to be the major cell populations in the muscle connective tissue (MCT). During embryogenesis, the MCT directs muscular development throughout the body and serves as a prepattern for muscular morphogenesis. The developmental origins of FAPs as stromal cells in the MCT were studied previously. In adult tissues, FAPs are important precursors for heterotopic ossification, especially in the context of the rare genetic disorder fibrodysplasia ossificans progressiva. A new developmental origin for FAPs have been suggested that differs from conventional developmental perspectives. In this review, we summarize the developmental origins and functions of FAPs as stromal cells of the MCT and present novel insights obtained by using patient-derived induced pluripotent stem cells and mouse models of heterotopic ossification. This review broadens the current understanding of FAPs and suggests potential avenues for further investigation.

Abstract P184: Increased Granulopoiesis, Kidney Neutrophil Infiltration, and Renal Damage in a Mouse Model of Psoriasis

Psoriasis is an autoimmune skin disease marked by T cell-mediated hyperproliferation of epidermal keratinocytes. Most psoriasis-related morbidity and mortality stems from an elevated risk of renal and cardiovascular disease, but mechanisms remain unclear. Although neutrophils are not directly targeted with current psoriasis therapies, neutrophils are increased in the skin and circulation of these patients. We hypothesized that excess skin inflammation in psoriasis drives increased G-CSF-dependent granulopoiesis leading to renal neutrophil infiltration and dysfunction. Employing a KC-Tie2 mouse model of psoriasis with keratinocyte-specific overexpression of the angiopoietin receptor Tie2 (KC-Tie2), we observed 2-3-fold elevations in multiple indices of renal damage including urine albumin, urine NGAL, and glomerulosclerosis in KC-Tie2 mice compared to littermate controls (all P<0.05). KC-Tie2 mice also demonstrated 13 mm Hg higher daytime systolic blood pressure compared to littermate controls (P<0.05). Using flow cytometry, we found that KC-Tie2 mice had an increase not only in cutaneous neutrophils but also an approximate 10-fold increase in renal neutrophils (P<0.001). KC-Tie2 kidneys also exhibited increased vital and suicidal neutrophil extracellular trap (NET) formation, representing a potential mechanism for the observed renal damage. Interestingly, the increase in renal neutrophils was selective relative to other major immune cell populations such as dendritic cells, lymphocytes, monocytes, and macrophages. Similar selective increases in neutrophils were noted in the circulation, aorta, and spleen. We thus examined neutrophil production in the bone marrow, and observed significant increases in immature Ly6g low and Ly6g intermediate neutrophils (P<0.0001) as well as total Ly6g + neutrophils (P<0.05), with no change in mature Ly6g high neutrophils in the bone marrow of KC-Tie2 mice. These findings are consistent with increased granulopoiesis, prompting an examination of the key mediator of granulopoiesis, granulocyte colony-stimulating factor (G-CSF). KC-Tie2 mice exhibited marked increases in G-CSF in both the skin and plasma (P<.001 for both). In conclusion, our findings demonstrate increased renal damage in a mouse model of psoriasis, concomitant with increases in granulopoiesis and total and NETotic renal neutrophils, potentially unveiling a novel link between skin inflammation and renal damage via enhanced G-CSF-mediated granulopoiesis.

Insights into Suture Stem Cells: Distributions, Characteristics, and Applications

Stem cells play an indispensable part in bone formation, homeostasis, and regeneration. The origin of skeletal stem cells (SSCs) in long bones has been extensively discussed, and the major cell population is considered to reside in the perivascular niche of the bone marrow. Cranial bones are distinct from long bones in both the origins of their cell lineage and the manner of osteogenesis. Recently, multiple tissue-resident craniofacial stem cell populations have been identified, among which cranial suture-derived stem cells, known as suture mesenchymal stem cells (SuSCs), exhibit unique biological characteristics. Whether SuSCs have potential therapeutic uses to repair cranial bone defects and alleviate congenital skeletal diseases, represented mainly by craniosynostosis, is a question of great research value. This review focuses on craniofacial stem cells, especially SuSCs, with the goal of summarizing the latest progress as well as giving insight into their regulatory molecular mechanisms and potential therapeutic targets.

Investigating immune profile by CyTOF in patients with eosinophilic esophagitis after treatment with orodispersible budesonide.

Eosinophilic esophagitis (EoE) is a chronic Th2-mediated inflammatory disease of the esophagus driven by dietary or inhalant allergens which if left untreated, leads to fibrosis and poor esophageal function. Although the inflammation in the esophagus is dominated by eosinophils, there are also elevated levels of T and B cells. Blood samples from ten patients with EoE before and after treatment with orodispersible budesonide and 10 healthy controls were compared using cytometry by time-of-flight. An antibody panel was designed that covers the major immunological cell populations with a particular focus on eosinophils. The data was analyzed with multivariate methods and cluster analysis. Correlation analysis was done between immune markers and endoscopic, histological, and symptomatologic assessments. Our analysis revealed that patients with EoE had lower levels of effector memory T cells after treatment with orodispersible budesonide to the same level as healthy subjects. In addition, more suppressive eosinophils were present in the circulation of EoE patients before treatment and more immature eosinophils were present after treatment. Furthermore, levels of galectin-10+ eosinophils correlated with histological findings in esophageal tissue from EoE patients. In all patients, the peak eosinophils were decreased after treatment with orodispersible budesonide. Intriguingly, 90% of the patients had remission in the histological assessment and 50% improved in the endoscopic assessment. This study reports a detailed immune profile in patients with EoE before and after treatment with orodispersible budesonide and it is a step toward finding blood-based immune parameters that could be useful to monitor response to treatment.

Role of macrophage polarization in heart failure and traditional Chinese medicine treatment.

Heart failure (HF) has a severe impact on public health development due to high morbidity and mortality and is associated with imbalances in cardiac immunoregulation. Macrophages, a major cell population involved in cardiac immune response and inflammation, are highly heterogeneous and polarized into M1 and M2 types depending on the microenvironment. M1 macrophage releases inflammatory factors and chemokines to activate the immune response and remove harmful substances, while M2 macrophage releases anti-inflammatory factors to inhibit the overactive immune response and promote tissue repair. M1 and M2 restrict each other to maintain cardiac homeostasis. The dynamic balance of M1 and M2 is closely related to the Traditional Chinese Medicine (TCM) yin-yang theory, and the imbalance of yin and yang will result in a pathological state of the organism. Studies have confirmed that TCM produces positive effects on HF by regulating macrophage polarization. This review describes the critical role of macrophage polarization in inflammation, fibrosis, angiogenesis and electrophysiology in the course of HF, as well as the potential mechanism of TCM regulation of macrophage polarization in preventing and treating HF, thereby providing new ideas for clinical treatment and scientific research design of HF.

Single-cell atlas of human gingiva unveils a NETs-related neutrophil subpopulation regulating periodontal immunity

IntroductionExaggerated neutrophil recruitment and activation are the major features of pathological alterations in periodontitis, in which neutrophil extracellular traps (NETs) are considered to be responsible for inflammatory periodontal lesions. Despite the critical role of NETs in the development and progression of periodontitis, their specific functions and mechanisms remain unclear. ObjectivesTo demonstrate the important functions and specific mechanisms of NETs involved in periodontal immunopathology. MethodsWe performed single-cell RNA sequencing on gingival tissues from both healthy individuals and patients diagnosed with periodontitis. High-dimensional weighted gene co-expression network analysis and pseudotime analysis were then applied to characterize the heterogeneity of neutrophils. Animal models of periodontitis were treated with NETs inhibitors to investigate the effects of NETs in severe periodontitis. Additionally, we established a periodontitis prediction model based on NETs-related genes using six types of machine learning methods. Cell-cell communication analysis was used to identify ligand-receptor pairs among the major cell groups within the immune microenvironment. ResultsWe constructed a single-cell atlas of the periodontal microenvironment and obtained nine major cell populations. We further identified a NETs-related subgroup (NrNeu) in neutrophils. An in vivo inhibition experiment confirmed the involvement of NETs in gingival inflammatory infiltration and alveolar bone absorption in severe periodontitis. We further screened three key NETs-related genes (PTGS2, MME and SLC2A3) and verified that they have the potential to predict periodontitis. Moreover, our findings revealed that gingival fibroblasts had the most interactions with NrNeu and that they might facilitate the production of NETs through the MIF-CD74/CXCR4 axis in periodontitis. ConclusionThis study highlights the pathogenic role of NETs in periodontal immunity and elucidates the specific regulatory relationship by which gingival fibroblasts activate NETs, which provides new insights into the clinical diagnosis and treatment of periodontitis.

Cell of origin alters myeloid-mediated immunosuppression in lung adenocarcinoma.

Solid carcinomas are often highly heterogenous cancers, arising from multiple epithelial cells of origin. Yet, how the cell of origin influences the response of the tumor microenvironment is poorly understood. Lung adenocarcinoma (LUAD) arises in the distal alveolar epithelium which is populated primarily by alveolar epithelial type I (AT1) and type II (AT2) cells. It has been previously reported that Gramd2 + AT1 cells can give rise to a histologically-defined LUAD that is distinct in pathology and transcriptomic identity from that arising from Sftpc + AT2 cells1,2. To determine how cells of origin influence the tumor immune microenvironment (TIME) landscape, we comprehensively characterized transcriptomic, molecular, and cellular states within the TIME of Gramd2 + AT1 and Sftpc + AT2-derived LUAD using KRASG12D oncogenic driver mouse models. Myeloid cells within the Gramd2 + AT1-derived LUAD TIME were increased, specifically, immunoreactive monocytes and tumor associated macrophages (TAMs). In contrast, the Sftpc + AT2 LUAD TIME was enriched for Arginase-1+ myeloid derived suppressor cells (MDSC) and TAMs expressing profiles suggestive of immunosuppressive function. Validation of immune infiltration was performed using flow cytometry, and intercellular interaction analysis between the cells of origin and major myeloid cell populations indicated that cell-type specific markers SFTPD in AT2 cells and CAV1 in AT1 cells mediated unique interactions with myeloid cells of the differential immunosuppressive states within each cell of origin mouse model. Taken together, Gramd2 + AT1-derived LUAD presents with an anti-tumor, immunoreactive TIME, while the TIME of Sftpc + AT2-derived LUAD has hallmarks of immunosuppression. This study suggests that LUAD cell of origin influences the composition and suppression status of the TIME landscape and may hold critical implications for patient response to immunotherapy.