Acquired Immunity in Chronic Rhinosinusitis

IRF4 Knockdown Inhibits the Chronic Rhinosinusitis Without Nasal Polyps Development by Regulating NLRP3/Caspase-1/GSDMD-Mediated Pyroptosis

Chronic rhinosinusitis without nasal polyps (CRSsNP) is a CRS phenotype. However, the mechanisms of CRSsNP remains unclear. Differentially expressed genes (DEGs) were obtained from the GSE36830 and GSE198950 datasets through the GEO2R tool. The six hub genes were screened by the protein-protein interaction (PPI) network analysis and Cytoscape software. Then we constructed the mouse models of CRS and verified the expression levels of hub genes by reverse transcription quantitative PCR (RT-qPCR). Hematoxylin-eosin (HE) staining was employed to observe pathological alterations in mouse tissues. Casepase-3 expression was detected by immunohistochemistry (IHC). The levels of TNF-α, IL-12, IL-6, IL-1β, LDH, and IL-18 were evaluated using enzyme-linked immunosorbent assay (ELISA). Pyroptosis-related protein expressions were measured by western blotting. Cell counting kit-8 (CCK-8) and flow cytometry were performed to assess the proliferation and apoptosis of lipopolysaccharide (LPS)-induced NP69 cells. Six hub DEGs were identified. The expression levels of IRF4, IKZF1, and CD79A were obviously increased in CRSsNP, while those of ADH6, ADH1A, and LDHC were significantly decreased. IRF4 knockdown attenuated the pathologic features of CRSsNP. IRF4 knockdown reduced levels of the TNF-α, IL-12, IL-6 IL-1β, LDH, and IL-18 as well as the proteins expression of Casepase-1, GSDMD, and NLRP3 both in vivo and in vitro, implying that inflammation and pyroptosis were inhibited. IRF4 knockdown hinders the development of CRSsNP by inhibiting the inflammatory response and NLRP3/Caspase-1/GSDMD-mediated pyroptosis, which offers novel promising treatment strategies for clinical intervention.

Pathogenesis of Nasal Polyposis: Current Trends

Chronic Rhinosinusitis (CRS) is characterized by edema of the sub-epithelial layers, but, only specific types of CRS are developing polyps. Nasal polyposis may develop under different pathogenetic mechanisms rendering the typical macroscopic classification of CRS, with or without nasal polyps, rather deficient. Currently, we approach nasal polyposis, in terms of diagnosis and treatment, according to its endotype, which means that we focus on the specific cells and cytokines that are participating in its pathogenesis. It appears that the molecular procedures that contribute to polyp formation, initiating with a Th-2 response of the adaptive immune system, are local phenomena occurring in the sub-epithelial layers of the mucosa. Several hypotheses are trying to approach the etiology that drives the immune response towards Th-2 type. Extrinsic factors, like fungi, Staphylococcus superantigens, biofilms, and altered microbiome can contribute to a modified and intense local reaction of the immune system. Some hypotheses based on intrinsic factors like the elimination of Treg lymphocytes, low local vitamin-D levels, high levels of leukotrienes, epithelial to mesenchymal transition (EMT) induced by hypoxia, and altered levels of NO, add pieces to the puzzle of the pathogenesis of nasal polyposis. Currently, the most complete theory is that of epithelial immune barrier dysfunction. Intrinsic and extrinsic conditions can damage the epithelial barrier rendering sub-epithelial layers more vulnerable to invasion by pathogens that trigger a Th-2 response of the adaptive immune system. Th2 cytokines, subsequently, induce the accumulation of eosinophils and IgE together with the remodeling of the stroma in the sub-epithelial layers leading, eventually, to the formation of nasal polyps.

Sinonasal Outcomes Using Oral Corticosteroids in Patients with Chronic Rhinosinusitis with Nasal Polyps and Positive Sinonasal Cultures

Introduction Patients with chronic rhinosinusitis with nasal polyps (CRSwNP) and positive sinonasal bacterial cultures may be recalcitrant to topical therapy alone due to the additional local inflammatory burden associated with bacterial infection/colonization.

Objective To evaluate sinonasal outcomes in CRSwNP patients with a positive perioperative bacterial culture, who were treated with postoperative intranasal corticosteroids (INCS) alone versus INCS in combination with a short-term course of oral corticosteroids (OCS).

Methods This is a retrospective chart review of CRSwNP patients. A total of 59 patients met inclusion criteria, including positive perioperative bacterial culture and treatment with INCS with or without concomitant use of OCS. Two cohorts were formed based on the chosen postoperative medical treatment; 32 patients underwent postoperative INCS alone, while 27 underwent INCS plus a ≤ 2-week course of OCS. The 22-item sinonasal outcome test (SNOT-22) scores and Lund-Kennedy scores (LKS) were assessed preoperatively, and at 2-week, 4-week, and 4 to 6 months after endoscopic sinus surgery (ESS).

Results There were no statistically significant differences in postoperative sinonasal symptoms or endoscopic scores between the cohorts treated with INCS plus OCS versus those prescribed INCS alone (p > 0.05). Our regression model failed to demonstrate a relationship between the use of OCS and better sinonasal outcomes at 2-week, 4-week, and 4 to 6 months after ESS (p > 0.05).

Conclusion Our study suggests that in a cohort of CRSwNP patients with recent bacterial infections, the postoperative use of combined OCS and INCS did not result in a statistical improvement of endoscopic and symptomatic outcomes over INCS irrigation alone. However, both treatment groups had a clinically significant improvement based on the Minimal Clinically Important Difference.

Characterization of the Notch pathway in nasal polyps of patients with chronic rhinosinusitis: A pilot study

Chronic rhinosinusitis with nasal polyps is a widespread pathology characterized by persistent inflammation of nasal and paranasal mucosa. Although it represents one of the most frequent diseases of the nasal cavities, its etiology is still not completely elucidated. There is evidence suggesting that the Notch signaling, a highly conserved intercellular pathway known to regulate many cellular processes, including inflammation, is implicated in nasal polyps formation. The purpose of this study was to investigate the expression of genes of the Notch pathway in nasal polyps from patients with chronic rhinosinusitis. Nasal polyps and adjacent mucosa tissue were obtained from 10 patients. RNA was analyzed by quantitative reverse transcriptase-polymerase chain reaction for the expression level of (1) Notch pathway components such as receptors (NOTCH1-4), ligands (DLL4, JAGGED-1), and target genes (HEY1, 2, and HES1) and (2) genes providing information on the pathogenesis of polyposis (C-MYC and SCGB1A1) and on eosinophils content (CCL26, IL5, and SAA2). We report a Notch-driven gene expression pattern in nasal polyps which correlates with the expression of genes highly expressed in eosinophils, whose presence is an important parameter to define the pathophysiologic diversity characterizing nasal polyps. Taken together, our results suggest a role for Notch signaling in the pathophysiology of polyposis. Further studies are needed to elucidate the role of Notch in nasal polyps formation and to establish whether it could represent a novel therapeutic target for this pathology.

Long-acting implantable corticosteroid matrix for chronic rhinosinusitis: Results of LANTERN Phase 2 randomized controlled study

Background

Topical steroids are first‐line treatment for chronic rhinosinusitis (CRS), but fail to provide adequate symptom control for all patients. Designed for medical treatment failures, LYR‐210 is an implantable matrix that locally elutes mometasone furoate to inflamed sinonasal tissue for up to 24 weeks in CRS patients. In an open‐label phase 1 study, LYR‐210 demonstrated clinically relevant improvement in the 22‐item Sino‐Nasal Outcome Test (SNOT‐22). Safety and efficacy of LYR‐210 in CRS were evaluated in the LANTERN Phase 2 study.

Methods

Sixty‐seven surgically naive adult CRS patients who were inadequately controlled by previous medical management and seeking an alternative treatment enrolled in a multicenter, blinded, controlled, dose‐ranging study. Patients had moderate‐to‐severe disease based on SNOT‐22 and composite 7‐day average scores of the 4 cardinal CRS symptoms (4CS), with diagnosis confirmed by nasal endoscopy and magnetic resonance imaging. Patients were randomized (1:1:1) to saline irrigation–only control or bilateral in‐office administration of LYR‐210 (2500 μg) or LYR‐210 (7500 μg). Safety and efficacy were evaluated over 24 weeks.

Results

Both LYR‐210 doses were safe and well‐tolerated over the 24‐week treatment period. LYR‐210 demonstrated rapid and durable dose‐dependent symptom improvement based on 4CS and SNOT‐22, with LYR‐210 (7500 μg) achieving statistical significance as early as 8 weeks and out to 24 weeks compared with control. LYR‐210 (7500 μg) reduced rescue treatment use and radiographic ethmoid opacification at week 24.

Conclusions

LYR‐210 is the first implantable sinonasal treatment to achieve up to 24 weeks of benefit from a single administration in surgically naive CRS patients with and without nasal polyps.

The tumor necrosis factor family molecules LIGHT and lymphotoxins in sinus mucosa of patients with chronic rhinosinusitis with or without nasal polyps

BACKGROUND

Little is known about the role of lymphotoxins (LTs) family in the sinonasal mucosa of patients with chronic rhinosinusitis (CRS). This study aims at investigating the expression of LIGHT, LTα, LTβ, and their receptors, LTβR and HVEM in normal and inflammatory sinus mucosa, and the effect of LIGHT and LTalpha1beta2 on chemokine secretion in epithelial cells, epithelial permeability, and leukocyte migration.

MATERIAL AND METHODS

The expression of LTs family in sinonasal mucosa was evaluated with real-time PCR, immunohistochemistry, and western blot. In LTβR, HVEM siRNA, or control siRNA-transfected epithelial cells treated with LIGHT or LTalpha1beta2, the expression of chemokines, the epithelial permeability, and the expression of junctional complex proteins were evaluated using real-time PCR, ELISA, western blot, confocal microscopy, and FITC-dextran. In cultured endothelial cells treated with LIGHT or LTalpha1beta2, the expression of ICAM-1 and VCAM-1, and leukocyte migration were elucidated.

RESULTS

LTs family was expressed in normal mucosa and their levels were increased in inflammatory mucosa of CRS patients. Recombinant LIGHT and LTalpha1beta2 induced chemokine secretion, increased epithelial permeability, and promoted leukocyte migration. However, the activity of LIGHT and LTalpha1beta2 was attenuated in cells transfected with LTβR and HVEM siRNA.

CONCLUSIONS

LIGHT and LTs may participate in the ongoing process of chronic inflammation, inducing chemokine secretion, leukocyte migration, and dysregulated epithelial barrier through LTβR and HVEM in sinonasal mucosa.

Interferon-α action in cytokine profile in eosinophilic nasal polyp cultures

Introduction

Chronic rhinosinusitis is currently classified into two types: chronic rhinosinusitis without nasal polyps and chronic rhinosinusitis with nasal polyps. In the West, approximately 80% of chronic rhinosinusitis with nasal polyps cases are characterized by a predominantly eosinophilic cell infiltrate and a Th2 cytokine pattern.

Objective

To evaluate the effect of Interferon-α on cytokine levels of the eosinophilic nasal polyp cell culture supernatant.

Methods

Cell cultures were performed based on nasal polypoid tissue samples collected from 13 patients with eosinophilic chronic rhinosinusitis with nasal polyps. Polyps were considered eosinophilic according to the histopathological examination. Cell cultures were stimulated with 3000 IU of interferon-α. Before and after the stimulus, concentrations of Interferon-γ, tumor necrosis factor αand IL 2, 4, 6 and 10, using cytometric bead array, were assessed.

Results

Cell samples from eosinophilic nasal polyps from 13 patients were included in the study. Twenty-four hours after interferon-α stimulation, eosinophilic nasal polyp culture supernatants showed significantly decreased IL-4 concentrations and increase in interferon-γ, IL-10 and IL-6 concentrations compared to controls. There were no significant differences in tumor necrosis factor -α and IL-2 concentrations.

Conclusion

We demonstrated that interferon-α in vitro alters the pattern of cytokines in cell cultures of eosinophilic nasal polyps. Analysis of these alterations suggests that interferon-α promotes a rebalancing of inflammatory profiles in cell cultures, favoring the expression of Th1 and regulatory cytokines over Th2 cytokines.