Involvement of T-Helper 9 Activation in a Mouse Model of Allergic Rhinitis

Pathogenesis and Key Cells in Allergic Rhinitis

BACKGROUND

Allergic rhinitis (AR) is one of the most common chronic diseases worldwide, with prevalence rates as high as 50% in high-income countries. Patients with AR often have symptoms such as runny nose, itchy nose, nasal congestion, sneezing, and signs of edema and pallor of the nasal mucosa, and these pathologies have a major impact on the patient's learning, sleep, and quality of life, often resulting in significant pain and a huge economic burden for the patient.

SUMMARY

Among the current treatments for AR, immunotherapy is able to achieve satisfactory clinical outcomes. This shows the importance of immune cells in AR. However, current therapies do not provide a complete cure for AR. The reason for this is that current research on AR focuses on the mechanism of Th1 and Th2 immune cells in AR, ignoring the role of other key cells in AR.

KEY MESSAGES

Group 2 innate lymphoid cells, B cells, T cells, and macrophages can play a role in the pathogenesis of AR by producing appropriate cytokines and mediating the inflammatory response. M2 macrophages can promote Th2 cells and eosinophils in AR to enhance the type 2 inflammatory response and further promote AR.

Th9/IL-9 may participate in the pathogenesis of multiple myeloma

INTRODUCTION

This research is aimed to evaluate the correlation between Th9-associated cytokine levels in MM patients, clinical features, and therapy.

METHODS

Peripheral blood samples were taken in 52 MM patients and 20 healthy volunteers matched by sex and age. The patients with MM were separated into two groups: the untreated group (27) and the remission group (25). An enzyme-linked immunosorbent assay (ELISA) was used to measure the IL-9 plasma levels. The levels of Th9-associated cytokines' mRNA expression (IL-9, PU.1, and IRF4) were measured in RT-qPCR. We also analyzed the correlations between the IL-9 plasma levels and the clinical parameters of newly diagnosed MM patients.

RESULTS

The IL-9 plasma levels and the Th9-associated cytokines (IL-9, PU.1, and IRF4) mRNA levels in newly diagnosed MM patients were significantly elevated than those in healthy volunteers and significantly decreased after achieving remission. Moreover, PU.1 and IRF4 had a positive correlation with the IL-9 mRNA expression. Then, we found that the upregulation of IL-9 plasma levels correlates with the severity of anemia and decreased albumin Levels.

CONCLUSION

The results demonstrate that Th9/IL-9 may be involved in the pathogenesis of MM and is correlated with worse patient conditions such as lower hemoglobin and serum albumin. More work is necessary to confirm whether they might serve as a useful therapeutic target and prognostic marker for MM.

Role of LINC00240 on T-helper 9 differentiation in allergic rhinitis through influencing DNMT1-dependent methylation of PU.1

BACKGROUND

Allergic rhinitis (AR) is a common allergic disease with increasing prevalence globally. However, the molecular mechanism underlying AR pathogenesis remains largely undefined.

METHODS

Peripheral blood and nasal mucosa samples obtained from patients with AR (n = 22), and ovalbumin-induced AR mouse model (n = 8 per group) were prepared for subsequent detection. qRT-PCR and western blot were used to detect the expression of LINC00240, miR-155-5p, PU.1 and other key molecules. ELISA assay and flow cytometry were employed to evaluate the secretion of IL-9 and T-helper 9 (Th9) cell ratio, respectively. Bioinformatics analysis, RNA immunoprecipitation (RIP), chromatin immunoprecipitation (ChIP) and luciferase reporter assays were employed to further elucidate the regulatory network of LINC00240/miR-155-5p/DNMT1. The methylation of PU.1 promoter was assessed by methylation-specific PCR (MSP). This signaling axis was further validated in the mouse model of AR.

RESULTS

LINC00240 was downregulated, while miR-155-5p and PU.1 were upregulated in the peripheral blood and nasal mucosa of AR patients, as well as in AR mice. This was accompanied with the increased ratio of Th9 cells and elevated IL-9 secretion. Mechanistically, LINC00240 served as a miR-155-5p sponge, and DNMT1 was a target of miR-155-5p. In addition, DNMT1 mediated the methylation of PU.1 promoter. In vivo studies verified that LINC00240 mitigated AR progression, possibly via miR-155-5p/DNMT1/PU.1-dependent Th9 differentiation.

CONCLUSION

The involvement of LINC00240 in AR pathogenesis is closely associated with Th9 differentiation through modulating DNMT1-dependent methylation of PU.1 by sponging miR-155-5p.

Recent advances in understanding the effects of T lymphocytes on mucosal barrier function in allergic rhinitis

Allergic rhinitis is a non-infectious chronic inflammatory disease of the nasal mucosa that affects T cells and their cytokines. T cells play significant roles in the development of allergic inflammatory diseases by orchestrating mechanisms underlying innate and adaptive immunity. Although many studies on allergic rhinitis have focused on helper T cells, molecular makeup, and pathogenesis-related transduction pathways, pathological mechanisms have not yet been completely explored. Recent studies have suggested that T cell status may play an important role in the interaction between T cells and the nasal mucosal barrier in allergic rhinitis. This study aimed to explore the interactions between T cells and nasal mucosal barriers in allergic rhinitis and to review the therapeutic modalities of pertinent biological agents involving T cells.

T Helper 9 Cells: A New Player in Immune-Related Diseases

The helper T cell 9 (Thelper-9, Th9), as a functional subgroup of CD4⁺T cells, was first discovered in 2008. Th9 cells expressed transcription factor PU.1 and cytokine interleukin-9 (IL-9) characteristically. Recent researches have shown that the differentiation of Th9 cells was coregulated by cytokine transforming growth factor β, IL-4, and various transcription factors. Th9 cells, as a new player, played an important role in various immune-related diseases, including tumors, inflammatory diseases, parasite infection, and other diseases. In this article, we summarize the related research progress and discuss the possible prospect.

Nonylphenol can aggravate allergic rhinitis in a murine model by regulating important Th cell subtypes and their associated cytokines

Nonylphenol (NP) is a widely distributed, toxic endocrine-disrupting chemical exhibiting estrogenic activity. However, its effect on allergic rhinitis (AR) remains unclear. In this study, the effects of NP on a murine model of AR were investigated. Mice were divided into ovalbumin (OVA), NP, and control groups. OVA was used for sensitization and challenge. Mice in the NP group were administered NP during the sensitization period. Allergic nasal symptoms and eosinophil counts in nasal mucosa were measured. Serum levels of OVA-specific IgE were determined by enzyme-linked immunosorbent assay. The mRNA levels of transcription factors of Th cells were determined with real-time polymerase chain reaction. Th cell subtypes and Treg numbers were counted with the aid of multi-color flow cytometry. Cytokine concentrations in nasal mucosa were determined using the cytometric bead array method. Subcutaneous injection of NP into mice exhibiting AR enhanced not only the nasal allergic symptoms, but also eosinophil infiltration and OVA-specific IgE. Moreover, NP upregulated IL-4, IL-5, IL-13, IL-9, IL-6 and IL-17, and downregulated IL-10, in the AR mouse model; IFN-γ and IL-23 were not affected. Transcription factors and Th cell percentages were evaluated to determine whether NP regulates Th cell subtypes in an AR mouse model. GATA3, PU.1, and RORγt levels were significantly increased, but FoxP3 and Helios were decreased. In addition, Th2, Th9, and Th17 subtype percentages significantly increased, and Treg cell percentages decreased, in NP administration groups; the percentage of Th1 subtypes was not affected. NP enhanced allergic inflammation in the AR mouse model through upregulation of Th2, Th9, and Th17 responses and negative regulation of Treg responses. These results suggest that NP may be trigger AR.