High frequency of macrophages expressing elevated level of CD80, PD-Ls and TLR1 in nasal polyps of CRS patients

Macrophages in CRSwNP: Do they deserve more attention?

Chronic rhinosinusitis (CRS) represents a heterogeneous disorder primarily characterized by the persistent inflammation of the nasal cavity and paranasal sinuses. The subtype known as chronic rhinosinusitis with nasal polyposis (CRSwNP) is distinguished by a significantly elevated recurrence rate and augmented challenges in the management of nasal polyps. The pathogenesis underlying this subtype remains incompletely understood. Macrophages play a crucial role in mediating the immune system's response to inflammatory stimuli. These cells exhibit remarkable plasticity and heterogeneity, differentiating into either the pro-inflammatory M1 phenotype or the anti-inflammatory and reparative M2 phenotype depending on the surrounding microenvironment. In CRSwNP, macrophages demonstrate reduced production of Interleukin 10 (IL-10), compromised phagocytic activity, and decreased autophagy. Dysregulation of pro-resolving mediators may occur during the inflammatory resolution process, which could potentially hinder the adequate functioning of anti-inflammatory macrophages in facilitating resolution. Collectively, these factors may contribute to the prolonged inflammation observed in CRSwNP. Additionally, macrophages may enhance fibrin cross-linking through the release of factor XIII-A (FAXIII), promoting fibrin deposition and plasma protein retention. Macrophages also modulate vascular permeability by releasing Vascular endothelial growth factor (VEGF). Moreover, they may disrupt the balance between Matrix Metalloproteinases (MMPs) and Tissue Inhibitors of Metalloproteinases (TIMPs), which favors extracellular matrix (ECM) degradation, edema formation, and pseudocyst development. Accumulating evidence suggests a close association between macrophage infiltration and CRSwNP; however, the precise mechanisms underlying this relationship warrant further investigation. In different subtypes of CRSwNP, different macrophage phenotypic aggregations trigger different types of inflammatory features. Increasing evidence suggests that macrophage infiltration is closely associated with CRSwNP, but the mechanism and the relationship between macrophage typing and CRSwNP endophenotyping remain to be further explored. This review discusses the role of different types of macrophages in the pathogenesis of different types of CRSwNP and their contribution to polyp formation, in the hope that a better understanding of the role of macrophages in specific CRSwNP will contribute to a precise and individualized understanding of the disease.

The Assessment of TLR1 Gene Polymorphism Association with the Risk of Allergic Rhinitis in the Chinese Han Population from Northern China

Background

Environmental factors and genetic predisposition can influence the occurrence and development of AR. Toll-like receptor 1 (TLR1) belongs to the TLR receptor family, which plays a fundamental role in the activation of innate immunity. This study aimed to explore the association between TLR1 genetic loci and AR susceptibility in the Han Chinese from northern China.

Methods

Genotyping of three SNPs in the TLR1 has proceeded using the Agena MassARRAY platform. Odds ratio (OR) and 95% confidence interval (CI) were used to assess the correlation between candidate SNPs and AR susceptibility. Using FPRP (false-positive report probability analysis) to detect whether the positive results are noteworthy findings. The SNP-SNP interactions were detected by multifactor dimensionality reduction (MDR).

Results

TLR1-rs72493538 (Allele "G": OR=0.77, p = 0.034) and -rs76600635 (Allele "G": OR=0.75, p = 0.024) were associated with reducing the risk of AR among Han Chinese in northern China. In addition, we found evidence that TLR1-rs72493538 (males, participants with aging > 43 years, or coming from the wind-blown sand region) and -rs76600635 (males, participants with BMI ≤ 24 kg/m2, or coming from the wind-blown sand region) were associated with AR risk in stratified analyses. FPRP showed that all positive results are noteworthy findings. MDR analysis showed that a two-loci genetic model composed of rs72493538 and rs76600635 can be chosen as the best genetic model to predict the risk of AR.

Conclusion

TLR1-rs72493538 and -rs76600635 have a close association with reducing the risk of AR.

Immunological Aspects of Chronic Rhinosinusitis

Chronic rhinosinusitis (CRS) is related to persistent inflammation with a dysfunctional relationship between environmental agents and the host immune system. Disturbances in the functioning of the sinus mucosa lead to common clinical symptoms. The major processes involved in the pathogenesis of CRS include airway epithelial dysfunctions that are influenced by external and host-derived factors which activate multiple immunological mechanisms. The molecular bases for CRS remain unclear, although some factors commonly correspond to the disease: bacterial, fungal and viral infections, comorbidity diseases, genetic dysfunctions, and immunodeficiency. Additionally, air pollution leads increased severity of symptoms. CRS is a heterogeneous group of sinus diseases with different clinical courses and response to treatment. Immunological pathways vary depending on the endotype or genotype of the patient. The recent knowledge expansion into mechanisms underlying the pathogenesis of CRS is leading to a steadily increasing significance of precision medicine in the treatment of CRS. The purpose of this review is to summarize the current state of knowledge regarding the immunological aspects of CRS, which are essential for ensuring more effective treatment strategies.

Spatial Distribution and Predictive Significance of Dendritic Cells and Macrophages in Esophageal Cancer Treated With Combined Chemoradiotherapy and PD-1 Blockade

Background

The first clinical study (NCT03671265) of first-line chemoradiotherapy combined with PD-1 blockade showed promising treatment outcomes in locally advanced esophageal squamous cell carcinoma (ESCC). However, partial patients did not respond to the combination treatment. The roles of dendritic cells (DCs) and macrophages in this combination treatment remain poorly understood.

Methods

We performed multiplexed immunofluorescence method to identify CD11c⁺ DCs, CD68⁺ macrophages, and their PD-L1^- or PD-L1⁺ subpopulations in paired tumor biopsies (n = 36) collected at baseline and during the combination treatment (after radiation, 40 Gy) from the phase Ib trial (NCT03671265). We applied whole exome sequencing in the baseline tumor biopsies (n = 14) to estimate tumor mutation burden (TMB). We dynamically investigated the spatial distribution of DCs and macrophages under chemoradiotherapy combined with PD-1 blockade, and evaluated the association between their spatial distribution and combination outcome, and TMB.

Results

The results showed that high percentages of PD-L1^- DCs and macrophages in the baseline tumor compartment, but not in the stromal compartment, predicted improved OS and PFS. Chemoradiotherapy combined with PD-1 blockade promoted DCs and macrophages to migrate closer to tumor cells. During combination treatment, PD-L1^- tumor cells were nearest to PD-L1^- DCs and macrophages, while PD-L1⁺ tumor cells were next to PD-L1⁺ DCs and macrophages. High TMB was closely associated with a shorter distance from tumor cells to DCs and macrophages. Shorter distance between PD-L1⁺ tumor cells and PD-L1⁺ DCs or PD-L1^- macrophages during the combination was correlated with better OS. Shorter distance between PD-L1^- tumor cells and PD-L1^- macrophages during combination was associated with both longer OS and PFS.

Conclusions

PD-L1^- or PD-L1⁺ DCs and macrophages exhibit distinct spatial distribution in ESCC. The close distance between tumor cells and these antigen-presenting cells (APCs) is critical to the clinical outcome in chemoradiotherapy combined with PD-1 blockade in ESCC patients. Our results highlight the predictive potential of spatial patterns of APCs in chemoradiotherapy combined with immunotherapy and reveal the underlying mechanism of APCs participating in chemoradiotherapy-induced antitumor immune response in ESCC.

Alteration of blood monocyte subsets in chronic rhinosinusitis with regard to anti-inflammatory 1,8-Cineol treatment

Background: Chronic rhinosinusitis (CRS) affects about 10% of the european population causing considerable disease burden. The inflammatory microenvironment is mainly Th2 driven, but the impact of monocytes is still poorly understood. Aim of this study was to comprehensively investigate the composition of circulating monocytes and T cells in CRSwNP and CRSsNP patients, particularly with regard to the therapeutic herbal monoterpene 1,8-Cineol. Methodology: We analyzed the distribution of CD14 and CD16 classified monocyte subsets and the T-cell subset composition with respect to their PD-1 and PD-L1 expression in the peripheral blood of CRS patients using flow cytometry. Additionally, the M1/M2 like macrophage infiltration in nasal tissue and polyps was examined by immunofluorescence staining. Results: Data revealed a decrease of classical monocytes accompanied by a significant increase of intermediate CD16+ monocytes in CRSwNP and CRSsNP patients compared to healthy donors. PD-L1 expression on overall monocytes was also significantly increased in CRSwNP and CRSsNP patients. CRS patients with a severe drop of the proportion of classical monocytes showed a significant restoration of this subset in response to two-week 1,8-Cineol treatment. Conclusions: Our data indicate a CRS-induced shift of peripheral monocyte subsets to more inflammatory phenotypes that might be reversed by the herbal drug 1,8-Cineol.