IL-4 regulates neutrophilic pulmonary inflammation in a mouse model of bronchial asthma.

Neutrophilic pulmonary inflammation in asthmatics substantially exacerbates the severity of the disease leading to resistance to conventional corticosteroid therapy. Many studies established the involvement of Th1- and Th17-cells and cytokines produced by them (IFNg, IL-17A, IL-17F etc.) in neutrophilic pulmonary inflammation. Recent studies revealed that IL-4 - a Th2-cytokine regulates neutrophil effector functions and migration. It was showed that IL-4 substantially reduces neutrophilic inflammation of the skin in a mouse model of cutaneous bacterial infection and blood neutrophilia in a mouse model systemic bacterial infection. However, there are no data available regarding the influence of IL-4 on non-infectious pulmonary inflammation. In the current study we investigated the effects of IL-4 in a previously developed mouse model of neutrophilic bronchial asthma. We showed that systemic administration of IL-4 significantly restricts neutrophilic inflammation of the respiratory tract probably through the suppression of Th1-/Th17-immune responses and downregulation of CXCR2. Additionally, pulmonary neutrophilic inflammation could be alleviated by IL-4-dependant polarization of N2 neutrophils and M2 macrophages, expressing anti-inflammatory TGFß. Considering these, IL-4 might be used for reduction of exaggerated pulmonary neutrophilic inflammation and overcoming corticosteroid insensitivity of asthma patients.

The Role of Interleukin-37 in the Pathogenesis of Allergic Diseases.

Cytokines of the interleukin-1 (IL-1) family play an important role in the realization of the protective functions of innate immunity and are the key mediators involved in the pathogenesis of a wide range of diseases, including various manifestations of allergy. The IL-1 family includes more than 11 members. However, the functions of many of them remain to be elucidated. Recently, new members of the IL-1 family have been discovered. In 2000, several independent research groups reported the discovery of a new interleukin of this family, which was named IL-37, or IL-1F7 (according to the new nomenclature). IL-37 was assigned to the IL-1 family based on its structural similarity with other members of this family. The study of its biological properties showed that its activity changes in inflammatory diseases, such as rheumatoid arthritis, psoriasis, as well as allergic diseases (allergic rhinitis, bronchial asthma, and atopic dermatitis). However, unlike most members of the IL-1 family, IL-37 acts as a negative regulator of inflammation. Activation of IL-37 suppresses inflammation, resulting in the suppression of inflammatory cytokines and chemokines, which in turn prevents infiltration of pro-inflammatory cells, mainly eosinophils and neutrophils. The exact molecular and cellular mechanisms of the anti-inflammatory effect of IL-37 in the development of allergic diseases (AD) have not been fully studied. This review summarizes and analyzes the accumulated experimental data on the role of IL-37 in the pathogenesis of AD, such as allergic rhinitis, bronchial asthma, and atopic dermatitis.

[Gene expression levels of cytokines in different phenotypes of CRSwNP]. / Uroven' ékspressii genov tsitokinov pri raznykh fenotipakh polipoznogo rinosinusita.

INTRODUCTION: Rhinosinusitis with nasal polyps (CRSwNP) is often followed by a range of comorbid states, influence of which on the course of the main pathology process remains insufficiently studied. PURPOSE: To study the gene expression level of cytokines potentially talking part in the development of inflammation in nasal polyps with different phenotypes of CRSwNP. MATERIAL AND METHODS: All the patients with CRSwNP were divided into 4 equal groups, 36 patients in each subgroup: group 1 - CRSwNP without comorbid pathology; group 2 - CRSwNP+atopy; group 3 - CRSwNP + non-allergic bronchial asthma (BA); control group 4 - 36 patients diagnosed with hypertrophic rhinitis without atopy and without bronchial asthma. Using the real-time polymerase chain reaction (Real-Time PCR) method, the study of expression level of mRNA genes coding proteins IL-1ß, IL-4, IL-5, IL-13, IL-17F, IL-25, IFN-y, TSLP in polyp tissue was conducted. RESULTS: The statistically proved difference of expression level of cytokines depending on the CRSwNP phenotype was educed. If CRSwNP and atopy were combined, the gene expression level of all studied cytokines was statistically higher than that of CRSwNP without comorbid pathology; and the expression level of IL-17F, IL-25 and TSLP was more intense that in the group of CRSwNP + BA. There was no difference between the patients with comorbid allergy and comorbid BA regarding the gene expression of IFN-y, IL-5 and IL-13 cytokines. Among different phenotypes of CRSwNP no difference in IL-1ß expression level was detected, which evidences of persisting inflammatory process, and the IL-4 gene expression level was lower than the detection level in all the groups. CONCLUSION: With different CRSwNP phenotypes different inflammatory patterns are detected, which indicates different character of the pathology process course among these groups of patients. Higher expression level of cytokine genes, which are a marker of epithelial damage of IL-25 and TSLP, is found only among the patients with CRSwNP and atopy. It suggests that forming of CRSwNP without comorbid pathology is connected with other pathologic mechanisms, not with the damage to epithelial barrier. If CRSwNP + BA and CRSwNP + atopy were combined, the expression level of IFN-y, IL-5, IL-13 and IL-17F genes was higher than the one in the group of patients with CRSwNP without comorbid pathology. In view of obtained data, all the patients with CRSwNP shall be screened for bronchial asthma and the allergy diagnostic shall be conducted.