The Human Monocyte-A Circulating Sensor of Infection and a Potent and Rapid Inducer of Inflammation

G0S2 Promotes PD-L1 Expression in Monocytes and Influences the Efficacy of PD-1 Inhibitors in Hepatocellular Carcinoma

Background: Hepatocellular carcinoma (HCC) is a prevalent and highly lethal form of liver cancer, with limited effective treatment options, particularly in the advanced stages. Immunotherapy using PD-1 inhibitors has emerged as a promising treatment modality, yet a substantial proportion of patients exhibit resistance or fail to respond to such therapies. This study aimed to elucidate the role of G0/G1 Switch 2 (G0S2) in regulating PD-L1 expression in monocytes within the HCC tumor microenvironment and to investigate its impact on the efficacy of PD-1 inhibitors. Methods: Gene expression data among HCC patients treated with PD-1 inhibitors were obtained from the HCC single-cell sequencing database; immunohistochemistry was performed to detect G0S2 expression in liver cancer tissues and adjacent non-tumorous tissues of HCC patients; flow cytometry was utilized to analyze the expression of G0S2, PD-L1, CD206, and CD14 in PBMCs from HCC patients; and CD8+T cell proliferation and IFN-γ secretion were used to evaluate the impact of G0S2 knockdown. Results: Utilizing single-cell sequencing data from HCC patients, we identified that G0S2 expression was significantly elevated in the non-responders (NR) compared to responders (R) to PD-1 inhibitor therapy. The immunohistochemical analysis confirmed higher levels of G0S2 in HCC tumor tissues and adjacent non-tumorous tissues, while the flow cytometry revealed the increased expression of G0S2, PD-L1, and CD206 in peripheral blood mononuclear cells (PBMCs) from NR patients compared to R patients and healthy controls. The functional experiments involving the knockdown of G0S2 in the THP-1 monocyte cell line resulted in a significant reduction in PD-L1 expression and a concomitant increase in CD8+T cell proliferation and IFN-γ production. Conclusions: These findings indicate that G0S2 facilitates the upregulation of PD-L1 in monocytes, thereby suppressing T cell activity and contributing to resistance against PD-1 inhibitors in HCC. The high expression of G0S2 in peripheral blood monocytes offers a non-invasive and easily detectable biomarker for predicting the efficacy of PD-1 inhibitor therapy. Consequently, targeting G0S2 may enhance the responsiveness to immunotherapy in HCC patients, providing a new avenue for optimizing treatment strategies and improving patient outcomes.

Cordyceps Sinensis Reduces Inflammation and Protects BEAS-2B Cells From LPS-Induced THP-1 Cell Injury

Introduction

Cordyceps sinensis, an entomogenous fungus with unique biological properties, has demonstrated significant anti-inflammatory potential. However, its effects on inflammation regulation need to be further investigated in detail.

Methods

In this study, we aimed to analyze the Cordyceps sinensis extract (CSE) obtained via ethanol extraction and to assess its effects on inflammation regulation. The secretion of pro-inflammatory cytokines (IL-6, TNF-α, IL-8, and IL-1β) and the level of MMP9, Nrf2/HO-1 and ROS were evaluated. A transwell system with THP-1 and BEAS-2B cells was used to explore the inflammatory damage. Gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) enrichment analyses were conducted on the differentially expressed genes.

Results

CSE exhibited no cytotoxicity to THP-1 cells at concentrations ≤ 1.6 mg/mL. Treatment of LPS-induced THP-1 cells with CSE significantly inhibited the secretion of pro-inflammatory cytokines. CSE reduced inflammation-related protein MMP9, while upregulating the anti-inflammatory Nrf2/HO-1 signaling pathway. Fluorescence assays using DCF and JC-1 further confirmed that CSE help mitigate oxidative stress-induced inflammation. CSE treatment protected BEAS-2B cells from inflammatory damage. Moreover, the immune system process was a shared GO term between LPS-only treatment and combined LPS and CSE treatment. KEGG enrichment analysis showed that CSE is capable of regulating genes associated with inflammatory and anti-inflammatory responses.

Conclusion

These findings highlight the potential of CSE as an immune-regulating agent in functional foods and health products.

Food Allergy Genetics and Epigenetics: A Review of Genome-Wide Association Studies

In this review, we provide an overview of food allergy genetics and epigenetics aimed at clinicians and researchers. This includes a brief review of the current understanding of genetic and epigenetic mechanisms, inheritance of food allergy, as well as a discussion of advantages and limitations of the different types of studies in genetic research. We specifically focus on the results of genome-wide association studies in food allergy, which have identified 16 genetic variants that reach genome-wide significance, many of which overlap with other allergic diseases, including asthma, atopic dermatitis, and allergic rhinitis. Identified genes for food allergy are mainly involved in epithelial barrier function (e.g., FLG, SERPINB7) and immune function (e.g., HLA, IL4). Epigenome-wide significant findings at 32 loci are also summarized as well as 14 additional loci with significance at a false discovery of < 1 × 10-4. Integration of epigenetic and genetic data is discussed in the context of disease mechanisms, many of which are shared with other allergic diseases. The potential utility of genetic and epigenetic discoveries is deliberated. In the future, genetic and epigenetic markers may offer ways to predict the presence or absence of clinical IgE-mediated food allergy among sensitized individuals, likelihood of development of natural tolerance, and response to immunotherapy.

Characterization of Freshly Isolated Human Peripheral Blood B Cells, Monocytes, CD4+ and CD8+ T Cells, and Skin Mast Cells by Quantitative Transcriptomics

Quantitative transcriptomics offers a new way to obtain a detailed picture of freshly isolated cells. By direct isolation, the cells are unaffected by in vitro culture, and the isolation at cold temperatures maintains the cells relatively unaltered in phenotype by avoiding activation through receptor cross-linking or plastic adherence. Simultaneous analysis of several cell types provides the opportunity to obtain detailed pictures of transcriptomic differences between them. Here, we present such an analysis focusing on four human blood cell populations and compare those to isolated human skin mast cells. Pure CD19+ peripheral blood B cells, CD14+ monocytes, and CD4+ and CD8+ T cells were obtained by fluorescence-activated cell sorting, and KIT+ human connective tissue mast cells (MCs) were purified by MACS sorting from healthy skin. Detailed information concerning expression levels of the different granule proteases, protease inhibitors, Fc receptors, other receptors, transcription factors, cell signaling components, cytoskeletal proteins, and many other protein families relevant to the functions of these cells were obtained and comprehensively discussed. The MC granule proteases were found exclusively in the MC samples, and the T-cell granzymes in the T cells, of which several were present in both CD4+ and CD8+ T cells. High levels of CD4 were also observed in MCs and monocytes. We found a large variation between the different cell populations in the expression of Fc receptors, as well as for lipid mediators, proteoglycan synthesis enzymes, cytokines, cytokine receptors, and transcription factors. This detailed quantitative comparative analysis of more than 780 proteins of importance for the function of these populations can now serve as a good reference material for research into how these entities shape the role of these cells in immunity and tissue homeostasis.

ScRNA-seq and bulk RNA-seq identified NUPR1 as novel biomarkers related to CD4 + T cells infiltration for abdominal aortic aneurysm

BACKGROUND

Developing a molecular signature associated with CD4 + T cell infiltration is essential for identifying biomarkers in abdominal aortic aneurysms (AAA). Establishing such a signature is vital for improving diagnostic accuracy and therapeutic strategies for AAA. This study focuses on CD4 + T cells, which are pivotal in the immune microenvironment of AAA, to pinpoint key targets.

METHODS AND RESULTS

We identified CD4 + T cell-related biomarkers in AAA using bulk and single-cell RNA sequencing data from the GEO database. We employed CIBERSORT to assess immune cell infiltration and applied weighted gene co-expression network analysis and differential expression analyses to pinpoint key genes. A nomogram and related score were developed based on these genes. Single-cell RNA sequencing further analyzed their expression across cell types, and KEGG/GO analyses were conducted for candidate genes. Four genes (NUPR1, CCL4L2, CCL3L3, MMP9) were identified finally. Validation via qPCR and immunohistochemistry showed NUPR1 downregulation in aneurysms and an inverse relationship with CD4 + T cells infiltration. Immunofluorescence results indicated NUPR1 was mainly expressed in the cytoplasm of vascular smooth muscle cells (VSMCs). After VSMCs-specific overexpression of NUPR1 via adeno-associated virus, the AAA diameter decreased, while treatment with the NUPR1 nuclear translocation inhibitor ZZW-115 hydrochloride had no effect on AAA size. Overexpression of NUPR1 in VSMCs suppresses the migration of CD4 + T cells.

CONCLUSION

The four-gene signature accurately predicts CD4 + T cell infiltration in AAA patients and may serve as a clinical index. NUPR1 could be a therapeutic target for the interaction between CD4 + T cells and AAA.

Single-cell transcriptomics delineates the immune cell landscape in equine lower airways and reveals upregulation of FKBP5 in horses with asthma

Equine asthma (EA) is a heterogenous, complex disease, with a significant negative impact on horse welfare and performance. EA and human asthma share fundamental similarities, making EA a useful model for studying the disease. One relevant sample type for investigating chronic lung inflammation is bronchoalveolar lavage fluid (BALF), which provides a snapshot of the immune cells present in the alveolar space. To investigate the immune cell landscape of the respiratory tract in horses with mild-to-moderate equine asthma (mEA) and healthy controls, single-cell RNA sequencing was conducted on equine BALF cells. We characterized the major immune cell populations present in equine BALF, as well as subtypes thereof. Interestingly, the most significantly upregulated gene discovered in cases of mEA was FKBP5, a chaperone protein involved in regulating the activity of the glucocorticoid receptor.

Phenotypic and Functional Heterogeneity of Monocytes and Macrophages

Macrophages are likely to be the first immune cells to have appeared during the evolution of multicellular organisms [...].

Extended cleavage specificities of human granzymes A and K, two closely related enzymes with conserved but still poorly defined functions in T and NK cell-mediated immunity

Granzymes A and K are two highly homologous serine proteases expressed by mammalian cytotoxic T cells (CTL) and natural killer cells (NK). Granzyme A is the most abundant of the different granzymes (gzms) expressed by these two cell types. Gzms A and K are found in all jawed vertebrates and are the most well conserved of all hematopoietic serine proteases. Their potential functions have been studied extensively for many years, however, without clear conclusions. Gzm A was for many years thought to serve as a key component in the defense against viral infection by the induction of apoptosis in virus-infected cells, similar to gzm B. However, later studies have questioned this role and instead indicated that gzm A may act as a potent inducer of inflammatory cytokines and chemokines. Gzms A and K form clearly separate branches in a phylogenetic tree indicating separate functions. Transcriptional analyses presented here demonstrate the presence of gzm A and K transcripts in both CD4⁺ and CD8⁺ T cells. To enable screening for their primary biological targets we have made a detailed analysis of their extended cleavage specificities. Phage display analysis of the cleavage specificity of the recombinant enzymes showed that both gzms A and K are strict tryptases with high selectivity for Arg over Lys in the P1 position. The major differences in the specificities of these two enzymes are located N-terminally of the cleavage site, where gzm A prefers small amino acids such as Gly in the P3 position and shows a relatively relaxed selectivity in the P2 position. In contrast, gzm K prefers large amino acids such as Phe, Tyr, and Trp in both the P2 and P3 positions and does not tolerate negatively charged residues in the P2 position. This major distinction in extended specificities is likely reflected also in preferred in vivo targets of these two enzymes. This information can now be utilized for high-precision screening of primary targets for gzms A and K in search of their highly conserved but still poorly defined functions in vertebrate immunity.

Exploration of genotype-by-environment interactions affecting gene expression responses in porcine immune cells

As one of the keys to healthy performance, robustness of farm animals is gaining importance, and with this comes increasing interest in genetic dissection of genotype-by-environment interactions (G×E). Changes in gene expression are among the most sensitive responses conveying adaptation to environmental stimuli. Environmentally responsive regulatory variation thus likely plays a central role in G×E. In the present study, we set out to detect action of environmentally responsive cis-regulatory variation by the analysis of condition-dependent allele specific expression (cd-ASE) in porcine immune cells. For this, we harnessed mRNA-sequencing data of peripheral blood mononuclear cells (PBMCs) stimulated in vitro with lipopolysaccharide, dexamethasone, or their combination. These treatments mimic common challenges such as bacterial infection or stress, and induce vast transcriptome changes. About two thirds of the examined loci showed significant ASE in at least one treatment, and out of those about ten percent exhibited cd-ASE. Most of the ASE variants were not yet reported in the PigGTEx Atlas. Genes showing cd-ASE were enriched in cytokine signaling in immune system and include several key candidates for animal health. In contrast, genes showing no ASE featured cell-cycle related functions. We confirmed LPS-dependent ASE for one of the top candidates, SOD2, which ranks among the major response genes in LPS-stimulated monocytes. The results of the present study demonstrate the potential of in vitro cell models coupled with cd-ASE analysis for the investigation of G×E in farm animals. The identified loci may benefit efforts to unravel the genetic basis of robustness and improvement of health and welfare in pigs.

Quantitative Transcriptome Analysis of Purified Equine Mast Cells Identifies a Dominant Mucosal Mast Cell Population with Possible Inflammatory Functions in Airways of Asthmatic Horses

Asthma is a chronic inflammatory airway disease and a serious health problem in horses as well as in humans. In humans and mice, mast cells (MCs) are known to be directly involved in asthma pathology and subtypes of MCs accumulate in different lung and airway compartments. The role and phenotype of MCs in equine asthma has not been well documented, although an accumulation of MCs in bronchoalveolar lavage fluid (BALF) is frequently seen. To characterize the phenotype of airway MCs in equine asthma we here developed a protocol, based on MACS Tyto sorting, resulting in the isolation of 92.9% pure MCs from horse BALF. We then used quantitative transcriptome analyses to determine the gene expression profile of the purified MCs compared with total BALF cells. We found that the MCs exhibited a protease profile typical for the classical mucosal MC subtype, as demonstrated by the expression of tryptase (TPSB2) alone, with no expression of chymase (CMA1) or carboxypeptidase A3 (CPA3). Moreover, the expression of genes involved in antigen presentation and complement activation strongly implicates an inflammatory role for these MCs. This study provides a first insight into the phenotype of equine MCs in BALF and their potential role in the airways of asthmatic horses.

Quantitative Analysis of the Transcriptome of Two Commonly Used Human Monocytic Cell Lines—THP-1 and Mono Mac 6—Reveals Their Arrest during Early Monocyte/Neutrophil Differentiation

Cell lines of monocyte/macrophage origin are often used as model systems to study monocyte/macrophage biology. A relevant question is how similar these cell lines are to their in vivo counterparts? To address this issue, we performed a detailed analysis of the transcriptome of two commonly used human monocyte/macrophage cell lines, Mono Mac 6 and THP-1. Both of these cell lines originate from leukemic cells with myelo-monocytic characteristics. We found that both Mono Mac 6 and THP-1 represent cells of very immature origin. Their transcriptomes show more similarities to immature neutrophils than cells of the monocyte/macrophage lineage. They express significant levels of N-elastase, proteinase 3, cathepsin G, and azurocidin but very low levels of CD14, ficolin, and complement factor P. All major MHC class II genes are also expressed at low levels. They show high levels of lysozyme and low levels of one of the immunoglobulin Fc receptors, FCGRIIA, which is characteristic of both neutrophils and monocytes. THP-1, but not Mono Mac 6, also expresses the high-affinity receptor for IgG, FCGRIA. Both cell lines lack the expression of the connective tissue components fibronectin, proteoglycan 4, and syndecan 3, which are characteristics of tissue macrophages but are absent in blood monocytes, indicating that they originate from bone marrow precursors and not yolk sac-derived hematopoietic cells. Both of these cell lines seem, therefore, to represent cells arrested during early myelo-monocytic development, at a branch point between neutrophil and monocyte differentiation. Their very immature phenotype indicates that great care should be taken when using these cell lines as models for normal monocyte/macrophage biology.

Immune micro-environment and drug analysis of peritoneal endometriosis based on epithelial-mesenchymal transition classification

BACKGROUND

Epithelial-mesenchymal transition (EMT) is a complex event that drives polar epithelial cells transform from adherent cells to motile mesenchymal cells, in which are involved immune cells and stroma cells. EMT plays crucial roles in migration and invasion of endometriosis. The interaction of endometrial implants with the surrounding peritoneal micro-environment probably affects the development of peritoneal endometriosis. To date, very few studies have been carried out on peritoneal endometriosis sub-type classification and micro-environment analysis based on EMT. The purpose of this study is to investigate the potential application of EMT-based classification in precise diagnosis and treatment of peritoneal endometriosis.

METHOD

Based on EMT hallmark genes, 76 peritoneal endometriosis samples were classified into two clusters by consistent cluster classification. EMT scores, which calculated by Z score of 8 epithelial cell marker genes and 8 mesenchymal cell marker genes, were compared in two clusters. Then, immune scores and the abundances of corresponding immune cells, stroma scores and the abundances of corresponding stroma cells were analyzed by the "xCell" package. Futhermore, a diagnostic model was constructed based on 9 diagnostic markers which related to immune score and stroma score by Lasso-Logistic regression analysis. Finally, based on EMT classification, a total of 8 targeted drugs against two clusters were screened out by drug susceptibility analysis via "pRRophetic" package.

RESULTS

Hallmark epithelial-mesenchymal transition was the mainly enriched pathway of differentially expressed genes between peritoneal endometriosis tissues and endometrium tissues. Compared with cluster 2, EMT score and the abundances of most infiltrating stroma cell were significantly higher, while the abundances of most infiltrating immune cells were dramatically less. The diagnostic model could accurately distinguish cluster 1 from cluster 2. Pathway analysis showed drug candidates targeting cluster 1 mainly act on the IGF-1 signaling pathway, and drug candidates targeting cluster 2 mainly block the EGFR signaling pathway.

CONCLUSION

In peritoneal endometriosis, EMT was probably promoted by stroma cell infiltration and inhibited by immune cell infiltration. Besides, our study highlighted the potential uses of the EMT classification in the precise diagnosis and treatment of peritoneal endometriosis.