The role of fibroblast in chronic rhinosinusitis with nasal polyps: a key player in the inflammatory process.

INTRODUCTION: Fibroblasts are the primary supporting cells in connective tissue and have long been thought to contribute to chronic rhinosinusitis with nasal polyps (CRSwNP) by producing extracellular matrix (ECM), leading to fibrosis and tissue remodeling. However, recent studies have highlighted the critical role of nasal polyp-derived fibroblasts (NPDFs) in triggering and intensifying the inflammatory response in CRSwNP. AREAS COVERED: This review undertook a comprehensive literature search across the PubMed database, Web of Science since 2000, offering an in-depth summary of the pivotal role of NPDFs in tissue remodeling and inflammatory responses in CRSwNP. Additionally, single-cell RNA sequencing data provides a deeper exploration of the heterogeneity and functional mechanisms of fibroblasts in CRSwNP. Consequently, these insights point to fibroblasts as promising therapeutic targets for effectively treating CRSwNP. EXPERT OPINION: Current data underscore the essential role of fibroblasts in the pathogenesis of CRSwNP. Fully elucidating the specific mechanisms by which fibroblasts contribute to the disease process is crucial for developing targeted therapies. Furthermore, advancements in single-cell RNA sequencing pave the way for selectively targeting and depleting pathological fibroblast subpopulations. Despite these advancements, the clinical development of fibroblast-targeted therapies in CRSwNP remains challenging.

DNA origami assembled spheroid for evaluating cytotoxicity and infiltration of chimeric antigen receptor macrophage (CAR-M).

Chimeric antigen receptor (CAR) T-cell therapies have shown remarkable results in patients with hematological malignancies. However, their success in treating solid tumors has been limited. As an alternative candidate for the CAR therapy, CAR-macrophages (CAR-M) have demonstrated activation and phagocytosis directed by tumor-associated antigen (TAA), showing promise in the treatment of solid tumors. Nevertheless, the mechanisms by which CARs direct tumor chemotaxis and invasion of CAR-M remain poorly understood. In this study, we aim to investigate the role of CARs in CAR-M attachment and infiltration using 3D tumor spheroids, which were created by utilizing a novel self-assembling nucleic acid nanostructure decorated living cells (NAC). Our results demonstrated that CAR-M exhibited higher invasion and killing capacity in 2D model and 3D tumor spheroids. In summary, the 3D NAC assembled tumor spheroid model provides a suitable platform for target screening and pharmacodynamic evaluation of CAR-M.

Protocol for generating human CAR-engineered macrophages by Vpx-containing lentivirus.

Human-derived macrophages are notoriously difficult to infect with HIV-1-based lentiviruses, posing a limitation to the advancement of chimeric antigen receptor macrophage (CAR-M) therapy. Here, we present a protocol for generating human chimeric antigen receptor (CAR)-engineered macrophages using the viral protein Vpx (encoded by the Sooty Mangabey simian immunodeficiency virus [SIV] and HIV-2 lineages) incorporated into the lentivirus vector, which enhances infection efficiency. We describe steps for cell cultivation, lentivirus production, concentration, infection procedures, and efficiency assessments. This protocol provides a foundation to study macrophage manipulation, especially with CAR or other immune engagers. For complete details on the use and execution of this protocol, please refer to Gao et al.1.

Anti-IL-4Rα monoclonal antibody (CM310) in patients with chronic rhinosinusitis with nasal polyps (CROWNS-2): Rationale and design of a multicenter, randomized, double-blind, placebo-controlled, parallel-group study.

Background: Chronic rhinosinusitis with nasal polyps (CRSwNP) is a heterogeneous disease that affects a large proportion of the global population. The treatment of CRSwNP, especially eosinophilic CRSwNP (ECRSwNP), has always been of great obstacle. Our previous phase 2 trial showed that CM310, a monoclonal antibody that targets interleukin-4 receptor alpha, was both safe and effective in reducing the size of nasal polyps, improving symptom scores, and increasing the quality of life for those with severe ECRSwNP. Objective: This phase 3 trial aims to evaluate the efficacy, safety, pharmacokinetic, pharmacodynamic, and immunogenicity of CM310 in participants with CRSwNP. Result: The CROWNS-2 is a multicenter, randomized, double-blind, placebo-controlled, parallel-group, phase 3 trial. The study consisted of a screening/run-in period (up to 4 weeks), a treatment period (24-week double-blind treatment period plus 28-week maintenance period), and a safety follow-up period (8 weeks). The study planned to enroll 180 participants with CRSwNP (at least 60% of ECRSwNP) to receive CM310 300 mg/placebo every 2 weeks (Q2W) subcutaneously for a total of 12 doses in double-blind treatment period and 300 mg CM310 Q2W subcutaneously for a total of 14 doses in maintenance period. Enrolled participants continued to use mometasone furoate nasal spray throughout the study. The primary endpoints are a change from baseline in nasal polyp score and nasal congestion score at week 24 between CM310 and placebo in both ECRSwNP and CRSwNP. Conclusion: The CROWNS-2 is a multicenter, randomized, double-blind, placebo-controlled, parallel-group, phase 3 clinical study to evaluate the efficacy and safety of CM310 in patients with CRSwNP. Trial registration: NCT05436275.

Development and validation of a prediction model for malignant sinonasal tumors based on MR radiomics and machine learning.

OBJECTIVES: This study aimed to utilize MR radiomics-based machine learning classifiers on a large-sample, multicenter dataset to develop an optimal model for predicting malignant sinonasal tumors and tumor-like lesions. METHODS: This study included 1711 adult patients (875 benign and 836 malignant) with sinonasal tumors or tumor-like lesions from three institutions. Patients from institution 1 (n = 1367) constituted both the training and validation cohorts, while those from institution 2 and 3 (n = 158/186) made up the test cohorts. Manual segmentation of the region of interest of the tumor was performed on T1WI, T2WI, and contrast-enhanced T1WI (CE-T1WI). Data normalization, dimensional reductions, feature selection, and classifications were performed using ten machine-learning classifiers. Four fusion models, namely T1WI + T2WI, T1WI + CE-T1WI, T2WI + CE-T1WI, and T1WI + T2WI + CE-T1WI, were constructed using the top ten features with the highest contribution in feature selection in the optimal models of T1WI, T2WI, and CE-T1WI. The Delong test compared areas under the curve (AUC) between models. RESULTS: The AUCs of training/validation/test1/test2 datasets for T1WI, T2WI, and CE-T1WI were 0.900/0.842/0.872/0.839, 0.876/0.789/0.842/0.863, and 0.899/0.824/0.831/0.707, respectively. The fusion model from T1WI + T2WI + CE-T1WI had the highest AUC. The AUCs of training/validation/test1/test2 datasets were 0.947/0.849/0.871/0.887. The T1WI + T2WI + CE-T1WI model demonstrated a significantly higher AUC than the T2WI + CE-T1WI model in both cohorts (p < 0.05) and outperformed the T2WI model in test 1 (p = 0.008) and the T1WI model in test 2 (p = 0.006). CONCLUSIONS: This fusion model based on radiomics from T1WI + T2WI + CE-T1WI images and machine learning can improve the power in predicting malignant sinonasal tumors with high accuracy, resilience, and robustness. CLINICAL RELEVANCE STATEMENT: Our study proposes a radiomics-based machine learning fusion model from T1- and T2-weighted images and contrast-enhanced T1-weighted images, which can non-invasively identify the nature of sinonasal tumors and improve the performance in predicting malignant sinonasal tumors. KEY POINTS: Differentiating benign and malignant sinonasal tumors is difficult due to similar clinical presentations. A radiomics model from T1 + T2 + contrast-enhanced T1 images can identify the nature of sinonasal tumors. This model can help distinguish benign and malignant sinonasal tumors.

[Research progress of type 2 inflammation-related tissue remodeling in nasal polyps].

Chronic rhinosinusitis with nasal polyps is a common chronic inflammatory disease with significant tissue remodeling, but the mechanism of remodeling remains unclear. Studies have shown that Type（T） 2 inflammatory network plays a crucial role in tissue remodeling and nasal polyp formation. Clinical trials have been carried out for several biological targets, and a number of potential therapeutic targets have received increasing attention. This paper will summarize the research progress of T2 inflammatory response involved in nasal polyp tissue remodeling to provide ideas for further exploring the mechanism of nasal polyp tissue remodeling.

Tumor micro-environment induced TRAIL secretion from engineered macrophages for anti-tumor therapy.

The high plasticity and long-term persistency make macrophages excellent vehicles for delivering anti-tumor cytokines. Macrophage delivery of chemokines and cytokines shows potential in tumor therapy. TRAIL, a promising anti-tumor cytokine, induces apoptosis in tumor cells with low toxicity to normal cells. However, its off-target toxicity and limited stability have limited its clinical progress. Here, we engineered macrophages with Mono-TRAIL and Tri-TRAIL and found that Tri-TRAIL had higher cytotoxic activity against tumor cells than Mono-TRAIL in vitro. To target the tumor microenvironment (TME), we generated macrophages secreting trimeric TRAIL (Tri-TRAIL-iM) induced by the TME-specific promoter Arg1. The Tri-TRAIL-iM cells displayed high specific activatable activity in cell-based co-culture assay and tumor-baring mice models. In addition, we demonstrated that compared to macrophages over-expressing TRAIL under a non-inducible promoter, Tri-TRAIL-iM could more effectively induce apoptosis in cancer cells, inhibit tumor growth, and reduce systemic side effects. This strategy of inducing TRAIL delivery holds great potential for cancer therapy. It is promising to be combined with other engineering methods to maximize the therapeutic effects of solid tumors.

Astaxanthin Rescues Memory Impairments in Rats with Vascular Dementia by Protecting Against Neuronal Death in the Hippocampus.

Vascular dementia (VaD) is a cognitive disorder characterized by a decline in cognitive function resulting from cerebrovascular disease. The hippocampus is particularly susceptible to ischemic insults, leading to memory deficits in VaD. Astaxanthin (AST) has shown potential therapeutic effects in neurodegenerative diseases. However, the mechanisms underlying its protective effects in VaD and against hippocampal neuronal death remain unclear. In this study, We used the bilateral common carotid artery occlusion (BCCAO) method to establish a chronic cerebral hypoperfusion (CCH) rat model of VaD and administered a gastric infusion of AST at 25 mg/kg per day for 4 weeks to explore its therapeutic effects. Memory impairments were assessed using Y-maze and Morris water maze tests. We also performed biochemical analyses to evaluate levels of hippocampal neuronal death and apoptosis-related proteins, as well as the impact of astaxanthin on the PI3K/Akt/mTOR pathway and oxidative stress. Our results demonstrated that AST significantly rescued memory impairments in VaD rats. Furthermore, astaxanthin treatment protected against hippocampal neuronal death and attenuated apoptosis. We also observed that AST modulated the PI3K/Akt/mTOR pathway, suggesting its involvement in promoting neuronal survival and synaptic plasticity. Additionally, AST exhibited antioxidant properties, mitigating oxidative stress in the hippocampus. These findings provide valuable insights into the potential therapeutic effects of AST in VaD. By elucidating the mechanisms underlying the actions of AST, this study highlights the importance of protecting hippocampal neurons and suggests potential targets for intervention in VaD. There are still some unanswered questions include long-term effects and optimal dosage of the use in human. Further research is warranted to fully understand the therapeutic potential of AST and its application in the clinical treatment of VaD.

GPC3-targeted CAR-M cells exhibit potent antitumor activity against hepatocellular carcinoma.

Chimeric antigen receptor (CAR)-modified macrophages are a promising treatment for solid tumor. So far the potential effects of CAR-M cell therapy have rarely been investigated in hepatocellular carcinoma (HCC). Glypican-3 (GPC3) is a biomarker for a variety of malignancies, including liver cancer, which is not expressed in most adult tissues. Thus, it is an ideal target for the treatment of HCC. In this study, we engineered mouse macrophage cells with CAR targeting GPC3 and explored its therapeutic potential in HCC. First, we generated a chimeric adenoviral vector (Ad5f35) delivering an anti-GPC3 CAR, Ad5f35-anti-GPC3-CAR, which using the CAR construct containing the scFv targeting GPC3 and CD3ζ intracellular domain. Phagocytosis and killing effect indicated that macrophages transduced with Ad5f35-anti-GPC3-CAR (GPC3 CAR-Ms) exhibited antigen-specific phagocytosis and tumor cell clearance in vitro, and GPC3 CAR-Ms showed significant tumor-killing effects and promoted expression of pro-inflammatory (M1) cytokines and chemokines. In 3D NACs-origami spheroid model of HCC, CAR-Ms were further demonstrated to have a significant tumor killing effect. Together, our study provides a new strategy for the treatment of HCC through CAR-M cells targeting GPC3, which provides a basis for the research and treatment of hepatocellular carcinoma.

Decreased histone expression in chronic rhinosinusitis with nasal polyps.

Background: Histones have been associated with human diseases. However, the implication of extranuclear histone proteins and their potential mechanism in the pathophysiology of chronic rhinosinusitis (CRS) have not been thoroughly investigated. This study was designed to evaluate the role of histones in patients with CRS by comparing histone expression between patients and controls. Methods: Nasal polyp (NP) tissues were obtained, and their comprehensive gene expression profiles were investigated by microarray analysis. Differences in expression were verified by reverse transcriptase polymerase chain reaction and immunohistochemical staining. Cell culture and flow cytometry were used to evaluate the role of histones in the pathogenesis of polyps. Results: Significant differences in the microarray analysis were observed between the patient and control groups (P < 0.01). It was found by flow cytometry that the histone (H2BK) can promote cell apoptosis in NPs. Conclusion: Our results indicate that reduced expression of H2BK may contribute to the imbalance process of cell proliferation and apoptosis in CRS with NP.

CircHIF1A induces cetuximab resistance in colorectal cancer by promoting HIF1α-mediated glycometabolism alteration.

Epidermal growth factor receptor (EGFR)-targeted therapy is an important treatment for RAS wild-type metastatic colorectal cancer (mCRC), but the resistance mechanism remains unclear. Here, the differential expression of circRNAs between Cetuximab sensitive and resistant cell lines was analyzed using whole-transcriptome sequencing. We identified that the expression of circHIF1A was significantly higher in LIM1215-R than in LIM1215. When treated with Cetuximab, downregulation of circHIF1A level weakened the proliferation and clonal formation ability of LIM1215-R, caused more cells to enter G0-G1 phase, and significantly reduced the basal respiration, ATP production, and maximal respiration, as well as the glycolytic capacity and glycolytic reserve. The response rate and prognosis of circHIF1A-positive patients were inferior to those of negative patients. Mechanistically, circHIF1A can upregulate the level of hypoxia-inducible factor 1 A (HIF1A) by competitively binding to miR-361-5p, inducing the overexpression of enzymes such as glucose transporter 1 (GLUT1) and lactate dehydrogenase A (LDHA). In a xenograft model, inhibition of circHIF1A expression increased the sensitivity to Cetuximab treatment. In conclusion, circHIF1A can promote HIF1α-mediated glycometabolism alteration to induce Cetuximab resistance in CRC. It has the potential to become a screening indicator for the Cetuximab beneficial population in mCRC and a new therapeutic target for enhancing treatment efficacy.

Anti-thymic stromal lymphopoietin monoclonal antibody in patients with chronic rhinosinusitis with nasal polyps (DUBHE): Rationale and design of a multicenter, randomized, double-blind, placebo-controlled study.

Background: Chronic rhinosinusitis with nasal polyps (CRSwNP) has a complex pathogenesis and is difficult to treat, which brings a huge economic burden to society. Despite all the progress in the treatment of CRSwNP, some patients with CRSwNP still experience recurrence. Therefore, there is an urgent need to develop novel drugs and treatments for CRSwNP. Thymic stromal lymphopoietin (TSLP) is produced by epithelial cells and mediates type 2 and nontype 2 inflammation through various downstream cellular immune and inflammatory pathways. Anti-TSLP treatment with tezepelumab has been proven to be effective in treating patients with uncontrolled asthma, regardless of their peripheral blood eosinophil levels being low or high. However, there is no relevant research on the usage of anti-TSLP monoclonal antibodies for the treatment of uncontrolled CRSwNP. Objective: This is the first phase Ib/IIa study for subjects with uncontrolled CRSwNP, aiming to evaluate the safety, tolerability, pharmacokinetics, pharmacodynamics, immunogenicity, and preliminary efficacy of multiple ascending doses (MAD) of anti-TSLP monoclonal antibody. Methods: The DUBHE is a multicenter, randomized, double-blind, placebo-controlled, phase Ib/IIa clinical study. The study will be composed of 3 periods: a screening/run-in period of 4 weeks, a treatment period of 52 weeks (16 weeks of double-blind treatment period +36 weeks of open-label treatment period), and a safety follow-up period of 12 weeks. No more than 113 subjects with uncontrolled CRSwNP will be divided into 4 groups to receive different doses of CM326 or placebo treatments (55 mg every two weeks [Q2W] group, 110 mg Q2W group, 220 mg Q2W group, and 220 mg every four weeks [Q4W] group). Enrolled patients will be stratified by tissue eosinophil count (TEC). Results: The safety of the monoclonal antibody that targets TSLP in uncontrolled CRSwNP and its preliminary efficacy at 16 weeks of treatment. Conclusion: In this study, for the first time, the safety and preliminary efficacy of MAD of CM326 will be verified. The efficacy of CM326 in patients with eosinophilic CRSwNP (TEC ≥55/high power field [HPF]), as well as noneosinophilic CRSwNP (TEC <55/HPF) will be testified. Trial registration: NCT05324137.

SerpinB3/B4 Abates Epithelial Cell-Derived CXCL8/IL-8 Expression in Chronic Rhinosinusitis with Nasal Polyps.

Background: Serine proteinase inhibitors, clade B, member 3 (SerpinB3) and B4 are highly similar in amino acid sequences and associated with inflammation regulation. We investigated SerpinB3 and B4 expression and their roles in chronic rhinosinusitis with nasal polyps (CRSwNP). Methods: The expression of SerpinB3 and B4 in nasal mucosa tissues, brush cells, and secretions from CRSwNP patients was measured, and their regulation by inflammatory cytokines were investigated. Their functions were also analyzed using air-liquid interface (ALI)-cultured primary human nasal epithelial cells (HNECs) and transcriptomic analysis. Results: Both SerpinB3 and B4 expression was higher in nasal mucosa, brush cells, and secretions from eosinophilic (E) CRSwNP and nonECRSwNP patients than in healthy controls. Immunofluorescence staining indicated that SerpinB3 and B4 were primarily expressed in epithelial cells and their expression was higher in CRSwNP patients. SerpinB3 and B4 expression was upregulated by interleukin-4 (IL-4), IL-5, IL-6, and IL-17a. Transcriptomic analysis identified differentially expressed genes (DEGs) in response to recombinant SerpinB3 and B4 stimulation. Both the DEGs of SerpinB3 and B4 were associated with disease genes of nasal polyps and inflammation in DisGeNET database. Pathway enrichment indicated that downregulated DEGs of SerpinB3 and B4 were both enriched in cytokine-cytokine receptor interactions, with CXCL8 as the hub gene in the protein-protein interaction networks. Furthermore, CXCL8/IL-8 expression was downregulated by recombinant SerpinB3 and B4 protein in ALI-cultured HNECs, and upregulated when knockdown of SerpinB3/B4. Conclusion: SerpinB3/B4 expression is upregulated in nasal mucosa of CRSwNP patients. SerpinB3/B4 may play an anti-inflammatory role in CRSwNP by inhibiting the expression of epithelial cell-derived CXCL8/IL-8.

Microvessel barrier dysfunction in sinonasal inverted papilloma-associated squamous cell carcinoma and its manifestation in dynamic contrast-enhanced MRI.

BACKGROUND: To date, an effective means to preoperatively predict the malignant transformation of sinonasal inverted papilloma (SIP) remains lacking due to similarities in clinical appearance. This study aimed to retrospectively evaluate dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) parameters and microvessel structure in tumors with histologically confirmed SIP and inverted papilloma-associated squamous cell carcinoma (IP-SCC), as well as correlate DCE-MRI findings with angiogenesis biomarkers. METHODS: Absolute quantitative DCE-MRI parameters (Ktrans, Kep, Ve) based on the Tofts model and model-free semi-quantitative indices (Tpeak, WR, MaxSlope) of SIP (n = 22) and IP-SCC (n = 20) were investigated. Regions of interest (ROIs) were oriented according to the tumor subsites in the surgical records. Micro-vessel density (MVD) counts and tight junction protein (claudin-5) expression were evaluated in tumor specimens obtained during surgery. Differences in the above data were compared between the two groups. Correlations between DCE-MRI parameters and angiogenic biomarkers were analyzed. RESULTS: Compared with SIP specimens, IP-SCC specimens were characterized by a significantly higher MVD and a leakier microvessel barrier. The values of Tpeak and Ve were significantly higher for SIP than those for IP-SCC, whereas WR, MaxSlope, and Kep were significantly lower, indicating early enhancement and a faster dispersion model in IP-SCC. MVD was positively correlated with WR and Kep and negatively correlated with Tpeak. Tpeak was slightly positively correlated to claudin-5 expression. CONCLUSION: DCE-MRI can serve as a noninvasive biomarker of angiogenesis in the malignant transformation from SIP to IP-SCC. DCE-MRI may assist in the differentiation of malignancies and treatment selection.

The mucosal concept in chronic rhinosinusitis: Focus on the epithelial barrier.

Chronic rhinosinusitis (CRS) is a common chronic nasal cavity and sinus disease affecting a growing number of individuals worldwide. Recent advances have shifted our understanding of CRS pathophysiology from a physical obstruction model of ventilation and drainage to a mucosal concept that recognizes the complexities of mucosal immunologic variations and cellular aberrations. A growing number of studies have demonstrated the alteration of the epithelial barrier during inflammatory states. Therefore, the current review has focused on the crucial role of epithelial cells within this mucosal framework in CRS, detailing the perturbed epithelial homeostasis, impaired epithelial cell barrier, dysregulated epithelial cell repair processes, and enhanced interactions between epithelial cells and immune cells. Notably, the utilization of novel technologies, such as single-cell transcriptomics, has revealed the novel functions of epithelial barriers, such as inflammatory memory and neuroendocrine functions. Therefore, this review also emphasizes the importance of epithelial inflammatory memory and the necessity of further investigations into neuroendocrine epithelial cells and neurogenic inflammation in CRS. We conclude by contemplating the prospective benefits of epithelial cell-oriented biological treatments, which are currently under investigation in rigorous randomized, double-blind clinical trials in patients with CRS with nasal polyps.

Matrix metalloproteinases in chronic rhinosinusitis.

INTRODUCTION: Matrix metalloproteinases (MMPs) are a group of enzymes that are essential in maintaining extracellular matrix (ECM) homeostasis, regulating inflammation and tissue remodeling. In chronic rhinosinusitis (CRS), the overexpression of certain MMPs can contribute to chronic nasal tissue inflammation, ECM remodeling, and tissue repair. AREAS COVERED: This review provides a comprehensive overview of the biological characteristics and functions of the MMP family, particularly focusing on the expression and activity of MMPs in patients with CRS, and delves into their role in the pathogenesis of CRS and their potential as therapeutic targets. EXPERT OPINION: MMPs are important in tissue remodeling and have been implicated in the pathophysiology of CRS. Previous studies have shown that the expression of MMPs is upregulated in the nasal mucosa of patients with CRS and positively correlates with the severity of CRS. However, there is still a large gap in the research content of MMP in CRS, and the specific expression and pathogenic mechanism of MMP still need to be clarified. The significance and value of the ratio of MMP to tissue inhibitors of metalloproteinase (TIMP) in diseases still need to be demonstrated. Moreover, further studies are needed to assess the efficacy and safety of biologics that target MMPs in patients with CRS.

Interaction of eosinophilic and neutrophilic inflammation in patients with chronic rhinosinusitis.

PURPOSE OF REVIEW: In the past year, the endotype of chronic rhinosinusitis (CRS) has been studied from a new perspective. Eosinophilic and neutrophilic inflammation are not independent processes in the pathogenesis of CRS. In this review, we will focus on recent research on mixed eosinophilic-neutrophilic inflammation in CRS and discuss the mechanism and potential treatments. RECENT FINDINGS: Traditionally, patients with eosinophilic CRS (ECRS) present with severe clinical manifestations, comorbidities, and a higher recurrence rate. Recent studies have found that approximately 40% of patients with ECRS present with neutrophilic infiltration, while patients with predominantly eosinophilic infiltration along with neutrophilic inflammation present with more complex inflammation, clinical manifestations and exhibit refractory characteristics. SUMMARY: The complex inflammatory profile and refractory clinical characteristics of mixed eosinophilic-neutrophilic inflammation in CRS are current challenges for clinicians. We summarize the features of eosinophilic and neutrophilic inflammation and current studies on the mechanisms of mixed eosinophilic-neutrophilic inflammation and suggest potentially effective therapeutic methods. We hope that this review will help with determining precise treatment options for patients.

MZB1-expressing cells are essential for local immunoglobulin production in chronic rhinosinusitis with nasal polyps.

BACKGROUND: The expression of MZB1 genes is significantly elevated in patients who have chronic rhinosinusitis with nasal polyp (CRSwNP) disease compared with healthy controls. OBJECTIVE: To characterize MZB1-positive B cells in CRSwNP and to estimate the contribution of distinct subsets of B cells to the local overproduction of immunoglobulins. METHODS: Single-cell RNA-sequencing with Cellular Indexing of Transcriptomes and Epitopes by Sequencing technology, Switching Mechanism At the 5' end of RNA Template sequencing, flow cytometry, immunohistochemistry and immunofluorescence staining, Western blot, QuantiGene Plex assay, B-cell ImmunoSpot assay, Luminex assay, and enzyme-linked immunosorbent assay were performed. RESULTS: Significantly higher mRNA expression of MZB1 and HSP90B1 was found in type 2 CRSwNP compared with controls. In CRSwNP, MZB1 expression correlated with the local production of IgE. MZB1 could be colocalized with plasma and mature B cells, especially marginal zone (MZ) B cells. Single-cell transcriptome and epitope studies revealed prominent populations of B cells in type 2 CRSwNP with unexpectedly high MZB1 gene expression. The MZ B-cell population was significantly increased in CRSwNP compared with healthy controls in both peripheral blood mononuclear cells and nasal tissue single-cell suspensions. When those single cells were cultured overnight, the MZ B-cell numbers were positively correlated with local IgE production but negatively correlated with local IgM production. In vitro, MZB1 stimulation up-regulated the mRNA expression of IgE. CONCLUSION: MZB1 was primarily expressed by plasma and mature B cells in nasal mucosa. MZB1 expression level was increased in CRSwNP compared with controls. MZB1 contributed to the local IgE production in type 2 CRSwNP.