Atopic dermatitis (AD) is a prevalent inflammatory skin disorder in which patients experience recurrent eczematous lesions and intense itching. The colonization of Staphylococcus aureus (S. aureus) is correlated with the severity of the disease, but its role in AD development remains elusive. Using single-cell RNA sequencing, we uncovered that keratinocytes activate a distinct immune response characterized by induction of Il24 when exposed to methicillin-resistant S. aureus (MRSA). Further experiments using animal models showed that the administration of recombinant IL-24 protein worsened AD-like pathology. Genetic ablation of Il24 or the receptor Il20rb in keratinocytes alleviated allergic inflammation and atopic march. Mechanistically, IL-24 acted through its heterodimeric receptors on keratinocytes and augmented the production of IL-33, which in turn aggravated type 2 immunity and AD-like skin conditions. Overall, these findings establish IL-24 as a critical factor for onset and progression of AD and a compelling therapeutic target.
Dermatitis, Atopic/genetics* ; Interleukins/metabolism* ; Animals ; Methicillin-Resistant Staphylococcus aureus/immunology* ; Mice ; Keratinocytes/microbiology* ; Humans ; Interleukin-33/immunology* ; Inflammation/microbiology* ; Staphylococcal Infections/microbiology* ; Disease Models, Animal ; Hypersensitivity/microbiology* ; Mice, Inbred C57BL

The aim of this study was to compare the immune responses of C57BL/6 mice immunized with two pathogens, foot-and-mouth disease virus (FMDV) and Senecavirus A (SVA), and to provide clues for revealing the regulatory mechanisms of acquired immunity. Inactivated and purified FMDV and SVA antigens were used to immunize C57BL/6 mice respectively, and the mice immunized with PBS were taken as the control. The percentages of Th1 and Th2 cells in the spleen lymphocytes of mice in each group were analyzed by flow cytometry at 14 and 28 days after immunization. RNA-Seq was performed for the spleen. Mouse macrophages were stimulated with the antigens in vitro to examine the expression of the differentially expressed genes (DEGs) screened out. The results showed that 14 days after immunization, there was no significant difference in the magnitude of the Th1/Th2 immune response elicited by the FMDV and SVA antigens. After 28 days, the magnitudes of the Th1 and Th2 immune responses elicited by the SVA antigen were higher than those elicited by the FMDV antigen. RNA-Seq revealed two common DEGs, Rsad2 and Tspan8, between the two immunization groups, which indicated that the two genes may be involved in the activation of the Th1/Th2 immune responses by FMDV and SVA antigens. FMDV and SVA antigens stimulated macrophages to secrete interleukin (IL)-12 and IL-33 in vitro, and the expression of Tspan8 and Rsad2 was consistent with the RNA-Seq results. The expression of Rsad2 was regulated by type I interferons (IFNα, IFNβ). In this study, we obtained the DEGs involved in the immune responses to the two antigens in mouse spleen, which provides a molecular basis for investigating the immune response mechanisms induced by FMDV and SVA.
Animals ; Foot-and-Mouth Disease Virus/genetics* ; Mice ; Spleen/cytology* ; Mice, Inbred C57BL ; Antigens, Viral/genetics* ; Transcriptome ; Th1 Cells/immunology* ; Immunization ; Viral Vaccines/immunology* ; Th2 Cells/immunology* ; Foot-and-Mouth Disease/immunology* ; Interleukin-33/genetics* ; Female ; Macrophages/immunology* ; Picornaviridae

OBJECTIVES: To investigate the expression of IL-25,IL-33 and EOS in children with allergic rhinitis (AR). METHODS: Ninety-four AR children receiving immunotherapy and 23 healthy people were concluded in the study. The serum levels of IL-25 and IL-33 were detected by Enzyme-linked Immunosorbent Assay (ELISA), and a count of EOS were measured. RESULTS: The serum levels of IL-25 and IL-33 in the mild group were higher than control group (<0.05). The count of EOS showed no difference between the mild group and the control group (>0.05). The serum levels of IL-25 and IL-33 in the severe group were higher than those in mild group (<0.05). The serum levels of IL-25 and IL-33 in the severe group were higher than control group (<0.05). The count of EOS in the severe group were higher than those in mild group (<0.05). The count of EOS in the severe group were higher than those in control group (<0.05). Spearman test showed the serum levels of IL-25 in the children with AR patients have positive correlation with the serum levels of IL-33 (<0.05, =0.238). CONCLUSIONS Expression of IL-25 levels, IL-33 levels and the count of EOS in patients with AR are enhanced, which shows that IL-25, IL-33 and the count of EOS are involved in the AR. If we can understand the mechanism of them, it will profound implications for treatment.
Child ; Enzyme-Linked Immunosorbent Assay ; Eosinophils ; Humans ; Immunotherapy ; Interleukin-17 ; metabolism ; Interleukin-33 ; metabolism ; Rhinitis, Allergic ; immunology ; therapy

OBJECTIVE: To investigate the expression and role of Interleukin-33 (IL-33) and ST2 in the nasal polyps of human Eosinophilic and non-Eosinophilic chronic rhinosinusitis with nasal polyps (ECRS and non-ECRS). METHOD: IL-33 and ST2 protein expression in nasal polyps of ECRS and non-ECRS as well as in seemingly normal mucosa of the inferior turbinate tissue was investigated by immunohistochemical staining and messenger RNA (mRNA) expression of IL-33 and ST2 was assessed by realtime polymerase chain reaction (PCR) in 27 subjects with ECRS, 33 subjects with non-ECRS, and 11 control subjects. RESULT: (1) The ST2 was found both in nasal polyps of ECRS and non-ECRS,especially in ECRS, yet hardly found in the normal mucosa of the inferior turbinate tissue; (2) The expression of ST2 mRNA in nasal polyps of ECRS was higher than that in non-ECRS and normal inferior turbinate tissue, and the difference was both prominent in statistics (P<0.01); (3) The expression patterns of IL-33 at both mRNA and protein levels were not significantly different among the three groups (P>0.05). CONCLUSION The IL-33 and its receptor ST2 were both expressed in human nasal polyps including ECRS and non-ECRS, meanwhile the expression patterns of ST2 at both mRNA and protein levels were significantly higher in nasal polyps of ECRS. The current study suggests that IL-33 and its receptor ST2 may play important roles in the pathogenesis of chronic rhinosinusitis with nasal polyps, especially in ECRS through the increased expression of ST2 in Eosinophils as a hypothesis.
Chronic Disease ; Eosinophils ; immunology ; Humans ; Interleukin-1 Receptor-Like 1 Protein ; Interleukin-33 ; metabolism ; Nasal Mucosa ; metabolism ; Nasal Polyps ; immunology ; RNA, Messenger ; Real-Time Polymerase Chain Reaction ; Receptors, Cell Surface ; metabolism ; Rhinitis ; immunology ; Sinusitis ; immunology ; Turbinates ; metabolism

BACKGROUNDAllergic asthma is a chronic airway inflammatory disease partly characterised by high concentration of T help 2 (Th2) cytokines in bronchoalveolar lavage fluid (BALF). There is no report on the relation of peripherally circulating blood lymphocytes and asthma. We explored the balance of Th2/Th1 cytokines in asthmatic mice. Exogenous recombinant interleukin (IL) 33 acted on murine peripheral circulating blood lymphocytes, IL-5 cytokine was selected for assessing Th2 cytokines and interferon-gamma (IFN-γ) for Th1 cytokines.

METHODSFemale specific pathogen free BABL/c mice were sensitised by intraperitoneal injection of 20 µg of ovalbumin emulsified in 1 mg of aluminium hydroxide gel in a total volume of 200 µl, and challenged for 30 minutes in 7 consecutive days with an aerosol of 2 g ovalbumin in 100 ml of PBS. Then we collected BALF and isolated lymphocytes from the peripheral blood. The lymphocytes were divided into two groups: asthmatic group and normal group. Th1/Th2 cytokines was detected by enzyme-linked immunosorbent assay (ELISA) kits.

RESULTSIn the asthma group, we found numerous eosinophils and lymphocytes on the glass slides. We then confirmed that the optimal concentration of IL-33 was 10 ng/ml and time of IL-33 stimulating lymphocytes was 24 hours. In the asthma group, the production of IL-5 was significantly increased over normal group after stimulation with IL-33 (P < 0.05) and the production of IFNγ was supressed from IL-33 stimulated lymphocytes (P < 0.05).

CONCLUSIONIL-33 acts on lymphocytes of peripheral blood increasing secretion of Th2 cytokines and inhibiting secretion of Th1 cytokines.

Animals ; Asthma ; chemically induced ; immunology ; metabolism ; Enzyme-Linked Immunosorbent Assay ; Female ; Interferon-gamma ; immunology ; metabolism ; Interleukin-33 ; Interleukin-5 ; immunology ; metabolism ; Interleukins ; immunology ; metabolism ; Lymphocytes ; immunology ; metabolism ; Mice ; Mice, Inbred BALB C

OBJECTIVETo study the roles of CD4(+)CD25(+)Foxp3(+) regulatory T cells (Treg) and IL-33 in the pathogenesis of asthma in children.

METHODSFlow cytometry was used to detect peripheral blood CD4(+)CD25(+)Foxp3(+)Treg proportion in CD4(+)T lymphocytes in.45 children with asthma, 50 children with wheezing caused by respiratory syncytial virus infection and 40 healthy children. Serum levels of IFN-γ, IL-4, IL-5 and IL-33 were measured using ELISA.

RESULTSThe level of peripheral blood CD4(+)CD25(+)Foxp3(+)Treg in the asthma group was significantly lower than in the wheezing and control groups (P<0.05). In contrast, serum levels of IL-33 in the asthma group was significantly higher than in the wheezing and control groups (P<0.05). Peripheral blood CD4(+)CD25(+)Foxp3(+)Treg level was negatively correlated with serum IL-33 level in the asthma group(r=-0.156, P<0.01).

CONCLUSIONSCD4(+)CD25(+)Foxp3(+)Treg may interact with IL-33 in the pathogenesis of childhood asthma.

Asthma ; etiology ; immunology ; Child ; Child, Preschool ; Female ; Forkhead Transcription Factors ; analysis ; Humans ; Infant ; Interleukin-2 Receptor alpha Subunit ; immunology ; Interleukin-33 ; Interleukins ; physiology ; Male ; T-Lymphocytes, Regulatory ; physiology

Interleukin-33 (IL-33) is a novel cytokine and belongs to IL-1 family expressed in a wide range of organs and cells. IL-33 is a dual-functional molecule: as a classical cytokine it induces immune response and it also regulates gene transcription in the nucleus. Altered expression of IL-33 has been observed in various human diseases such as inflammation, autoimmune diseases, and virus infection. The article reviews advances on immune function of IL-33 and its relation to a variety of human diseases.
Autoimmune Diseases ; immunology ; Humans ; Inflammation ; immunology ; Interleukin-33 ; Interleukins ; immunology