Immune modulation by rural exposures and allergy protection.

BACKGROUND: Growing up on traditional farms protects children from the development of asthma and allergies. However, we have identified distinct asthma-protective factors, such as poultry exposure. This study aims to examine the biological effect of rural exposure in China. METHODS: We recruited 67 rural children (7.4 ± 0.9 years) and 79 urban children (6.8 ± 0.6 years). Depending on the personal history of exposure to domestic poultry (DP), rural children were further divided into those with DP exposure (DP+ , n = 30) and those without (DP- , n = 37). Blood samples were collected to assess differential cell counts and expression of immune-related genes. Dust samples were collected from poultry stables inside rural households. In vivo activities of nasal administration of DP dust extracts were tested in an ovalbumin-induced asthma model. RESULTS: There was a stepwise increase in the percentage of eosinophils (%) from rural DP+ children (median = 1.65, IQR = [1.28, 3.75]) to rural DP- children (3.40, [1.70, 6.50]; DP+ vs. DP- , p = .087) and to the highest of their urban counterparts (4.00, [2.00, 7.25]; urban vs. DP+ , p = .017). Similarly, rural children exhibited reduced mRNA expression of immune markers, both at baseline and following lipopolysaccharide (LPS) stimulation. Whereas LPS stimulation induced increased secretion of Th1 and proinflammatory cytokines in rural DP+ children compared to rural DP- children and urban children. Bronchoalveolar lavage of mice with intranasal instillation of dust extracts from DP household showed a significant decrease in eosinophils as compared to those of control mice (p < .05). Furthermore, DP dust strongly inhibited gene expression of Th2 signature cytokines and induced IL-17 expression in the murine asthma model. CONCLUSIONS: Immune responses of rural children were dampened compared to urban children and those exposed to DP had further downregulated immune responsiveness. DP dust extracts ameliorated Th2-driven allergic airway inflammation in mice. Determining active protective components in the rural environment may provide directions for the development of primary prevention of asthma.

Immunoregulatory and Anti-cancer Activities of Combination Treatment of Novel Four-Herb Formula and Doxorubicin in 4T1-Breast Cancer Bearing Mice.

OBJECTIVE: To investigate the in vivo immunomodulatory and anti-tumor mechanisms of the combined treatment of novel Four-Herb formula (4HF) and doxorubicin in triple-negative breast cancer (TNBC). METHODS: Murine-derived triple-negative mammary carcinoma cell line, 4T1 cells, was cultured and inoculated into mouse mammary glands. Sixty-six mice were randomly assigned into 6 groups (n=11 in ench): naïve, control, LD 4HF (low dose 4HF), HD 4HF (high dose 4HF), LD 4HF + D (low dose and doxorubicin), and D (doxorubicin). Apart from the naïve group, each mouse received subcutaneous inoculation with 5 × 105 4T1 cells resuspended in 100 µL of normal saline in the mammary fat pads. Starting from the day of tumor cell inoculation, tumors were grown for 6 days. The LD and HD groups received daily oral gavage of 658 and 2,630 mg/kg 4HF, respectively. The LD 4HF+D group received daily oral gavage of 658 mg/kg 4HF and weekly intraperitoneal injection of doxorubicin (5 mg/kg). The D group received weekly intraperitoneal injections of doxorubicin (5 mg/kg). The treatment naïve mice received daily oral gavage of 0.2 mL double distilled water and 0.1 mL normal saline via intraperitoneal injection once a week. The control group received daily oral gavage of 0.2 mL double-distilled water. The treatment period was 30 days. At the end of treatment, mice organs were harvested to analyze immunological activities via immunophenotyping, gene and multiplex analysis, histological staining, and gut microbiota analysis. RESULTS: Mice treated with the combination of 4HF and doxorubicin resulted in significantly reduced tumor and spleen burdens (P<0.05), altered the hypoxia and overall immune lymphocyte landscape, and manipulated gut microbiota to favor the anti-tumor immunological activities. Moreover, immunosuppressive genes, cytokines, and chemokines such as C-C motif chemokine 2 and interleukin-10 of tumors were significantly downregulated (P<0.05). 4HF-doxorubicin combination treatment demonstrated synergetic activities and was most effective in activating the anti-tumor immune response (P<0.05). CONCLUSION: The above results provide evidence for evaluating the immune regulating mechanisms of 4HF in breast cancer and support its clinical significance in its potential as an adjunctive therapeutic agent or immune supplement.

Adjuvant activities of immunostimulating natural products: Astragalus membranaceus (Fisch.) Bge. and Coriolus versicolor in BNT162b2 vaccination against COVID-19 infection.

The global pandemic of COVID-19, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been developing all over the world for more than 3 years. In late 2020, several variants of concern of SARS-CoV-2 virus emerged, with increased viral fitness and transmissibility by mutations of the spike proteins of the viral particle, denting hopes of the use of early-generation vaccines for a widespread protective immunity against viral infection. The use of adjuvants may enhance the immune responses of the conventional application of the COVID-19 vaccine. We have shown that the water extract of 2 ß-glucan-enriched immunostimulating natural products, Astragalus membranaceus (Fisch.) Bge. (AM) and Coriolus versicolor (CV), could induce innate immunity-related cytokines from human monocytes (CCL5, interleukin [IL]-6, IL-10, and tumor necrosis factor α) and monocyte-derived dendritic cells (IL-1ß, IL-10, IL-12, and tumor necrosis factor α). Using BALB/c mice, orally administrated AM and CV (1,384 and 742 mg/kg/d) for 4 d after vaccination, respectively, could enhance (1) the immunoglobulin G binding activities of BNT162b2 vaccination against ancestral and Delta SARS-CoV-2 spike proteins by 5.8- and 4.3-fold, respectively; (2) the immunoglobulin G3 subclass production of BNT162b2 vaccination against ancestral and variant SARS-CoV-2 spike proteins; and (3) the in vitro antibody-neutralizing activities of BNT162b2 vaccinated mice. In conclusion, combining AM and CV was effective in acting as an oral adjuvant with the messenger RNA vaccine BNT162b2 to improve the antigen binding activities against SARS-CoV-2 ancestral and variant SARS-CoV-2 spike proteins, probably via trained immunity of macrophages and dendritic cells.

Creating a Vaccine-like Supplement against Respiratory Infection Using Recombinant Bacillus subtilis Spores Expressing SARS-CoV-2 Spike Protein with Natural Products.

Vaccination is the most effective method of combating COVID-19 infection, but people with a psychological fear of needles and side effects are hesitant to receive the current vaccination, and alternative delivery methods may help. Bacillus subtilis, a harmless intestinal commensal, has recently earned a strong reputation as a vaccine production host and delivery vector, with advantages such as low cost, safety for human consumption, and straightforward oral administration. In this study, we have succeeded generating "S spores" by engineering B. subtilis with spore coat proteins resembling the spike (S) protein of the ancestral SARS-CoV-2 coronavirus. With the addition of two immunostimulating natural products as adjuvants, namely Astragalus membranaceus (Fisch.) Bge (AM) and Coriolus versicolor (CV), oral administration of S spores could elicit mild immune responses against COVID-19 infection without toxicity. Mucosal IgA against the S protein was enhanced by co-feeding with AM and CV in an S spores-inoculated mouse model. Faster and stronger IgG responses against the S protein were observed when the mice were fed with S spores prior to vaccination with the commercial COVID-19 vaccine CoronaVac. In vitro studies demonstrated that AM, CV, and B. subtilis spores could dose-dependently activate both macrophages and dendritic cells by secreting innate immunity-related IL-1ß, IL-6, and TNF-α, and some other proinflammatory chemokines and cytokines. In conclusion, the combination of S spores with AM and CV may be helpful in developing a vaccine-like supplement against respiratory infection.

Meteorin-ß/Meteorin like/IL-41 attenuates airway inflammation in house dust mite-induced allergic asthma.

We sought to examine the regulatory effect of Meteorin-ß (Metrnß)/Meteorin like (Metrnl)/IL-41 on lung inflammation in allergic asthma. We found that Metrnß was elevated significantly in asthmatic patients and in mice with allergic asthma induced by house dust mite (HDM) extract. Upon exposure to HDM, Metrnß was secreted predominantly by airway epithelial cells and inflammatory cells, including macrophages and eosinophils. The increased Metrnß effectively blocked the development of airway hyperreactivity (AHR) and decreased inflammatory cell airway infiltration and type 2 cytokine production, which was associated with downregulated DC-mediated adaptive immune responses. Moreover, Metrnß impaired the maturation and function of bone marrow-derived dendritic cells in vitro. Asthmatic mice adoptively transferred with dendritic cells isolated from Metrnß-treated allergic mice displayed decreased AHR, airway inflammation, and lung injury. Metrnß also displayed anti-inflammatory properties in immunodeficient SCID mice with allergic asthma and in in vitro 3D ALI airway models. Moreover, blockade of Metrnß by anti-Metrnß antibody treatment promoted the development of allergic asthma. These results revealed the unappreciated protective roles of Metrnß in alleviating DC-mediated Th2 inflammation in allergic asthma, providing the novel treatment strategy of therapeutic targeting of Metrnß in allergic asthma.

Effects of topical application of a tri-herb formula on inflammatory dry-skin condition in mice with oxazolone-induced atopic dermatitis.

BACKGROUND: Atopic dermatitis (AD) is a chronic relapsing inflammatory and pruritic skin disease, affecting 10-20% of the population worldwide. Paeonia suffruticosa Andrews (Paeoniaceae) (Cortex Moutan) and Mentha haplocalyx Briq. (Labiatae) (Herba Menthae) have shown beneficial effects on AD. Calendula officinalis L. (Asteraceae) is commonly used for treating skin rashes and wounds. PURPOSE: In the present study, a three-herbs formula including Cortex Moutan and Herba Menthae, together with C. officinalis at 1:1:1 weight ratio was used as a topical agent and its therapeutic effects on AD was investigated. METHODS: In vitro effects of individual herbs and three-herbs formula (0.125-1 mg/ml) were examined using cytokine release assay on human mast HMC-1 cells, inflammation test on murine macrophage RAW cells and human keratinocyte (HaCaT) cells, and migration scratch assay on human umbilical vein endothelial cells (HUVEC). The contributing functional pathway of three-herbs formula in AD was explored using Western Blot assay in HMC-1 cells. Oxazolone-induced AD-like mice model was also used to investigate the in vivo therapeutic effect of the topical application of the three-herbs formula. RESULTS: Herba Menthae, Cortex Moutan, and three-herbs formula significantly reduced the production of IL-6 and tumor necrosis factor (TNF)-α in HMC-1 cells, inhibited the expression of IL-6, IL-8 and CCL2 in TNF-α/IFN-γ stimulated HaCaT cells, and suppressed the lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW 264.7 cells. Moreover, Herba Menthae and three-herbs formula significantly suppressed CCL2 and TNF-α production in LPS-induced RAW 264.7 cells. C. officinalis and three-herbs formula promoted wound healing in HUVEC. For intracellular mechanisms, three-herbs formula inhibited the expressions of molecules in STAT1 and STAT3-dependent pathways. In vivo model showed that topical application of three-herbs formula on challenged ear reduced ear swelling and mice scratching frequencies. H&E and toluidine blue staining of the challenged ear tissue demonstrated that three-herbs formula reduced the epidermal thickness and mast cell infiltration, respectively. CONCLUSION: The three-herbs formula of Cortex Moutan, Herba Menthae and C. officinalis at 1:1:1 (w/w) exhibited anti-inflammatory effect and promotion of cell migration in vitro. It also alleviated ear redness, swelling, epidermal thickness and inflammation of the OXA-induced AD mice. These findings suggest a potential beneficial role of the topical application of the three-herbs formula for treatment of AD.

IL-37 Targets TSLP-Primed Basophils to Alleviate Atopic Dermatitis.

Atopic dermatitis (AD) represents a severe global burden on physical, physiological and mental health. Innate immune cell basophils are essential for provoking allergic inflammation in AD. However, the roles of novel immunoregulatory cytokine IL-37 in basophils remain elusive. We employed in vitro co-culture of human basophils and human keratinocyte HaCaT cells and an in vivo MC903-induced AD murine model to investigate the anti-inflammatory mechanism of IL-37. In the in vitro model, IL-37b significantly decreased Der p1-induced thymic stromal lymphopoietin (TSLP) overexpression in HaCaT cells and decreased the expression of TSLP receptor as well as basophil activation marker CD203c on basophils. IL-37 could also reduce Th2 cytokine IL-4 release from TSLP-primed basophils ex vivo. In the in vivo model, alternative depletion of basophils ameliorated AD symptoms and significantly lowered the Th2 cell and eosinophil populations in the ear and spleen of the mice. Blocking TSLP alleviated the AD-like symptoms and reduced the infiltration of basophils in the spleen. In CRISPR/Cas9 human IL-37b knock-in mice or mice with direct treatment by human IL-37b antibody, AD symptoms including ear swelling and itching were significantly alleviated upon MC903 challenge. Notably, IL-37b presence significantly reduced the basophil infiltration in ear lesions. In summary, IL-37b could regulate the TSLP-mediated activation of basophils and reduce the release of IL-4. The results, therefore, suggest that IL-37 may target TSLP-primed basophils to alleviate AD.

Immunological Roles of NLR in Allergic Diseases and Its Underlying Mechanisms.

Our understanding on the immunological roles of pathogen recognition in innate immunity has vastly increased over the past 20 years. Nucleotide-binding oligomerization domain (NOD)-like receptors (NLR) are cytosolic pattern recognition receptors (PRR) that are responsible for sensing microbial motifs and endogenous damage signals in mammalian cytosol for immune surveillance and host defense. The accumulating discoveries on these NLR sensors in allergic diseases suggest that the pathogenesis of allergic diseases may not be confined to the adaptive immune response. Therapy targeting NLR in murine models also shields light on its potential in the treatment of allergies in man. In this review, we herein summarize the recent understanding of the role of NLR sensors and their molecular mechanisms involved in allergic inflammation, including atopic dermatitis and allergic asthma.

Skewed inflammation is associated with aberrant interleukin-37 signaling pathway in atopic dermatitis.

BACKGROUND: Atopic dermatitis (AD) is a severe global burden on physical, physiological, and mental health. The role of IL-37, a fundamental inhibitor of immunity, in AD was herein explored. METHOD: Serum levels of IL-37 and T helper (Th) 2-related inflammatory mediators were quantified in subjects with or without AD. The expression of IL-37 receptors was determined by flow cytometry. Proteomics was employed to explore the serum protein profile and novel biomarkers. In vitro cell model, 3D-keratinocytes mimicking skin model, and the serum of subjects with or without AD were investigated to verify the proteomic results. RESULTS: AD patients were found to present with higher levels of total and specific IgE as well as Th2 inflammatory mediators compared with healthy controls (HC). IL-37 level and its receptor IL18Rɑ expression in AD patients were significantly decreased, together with increased population of eosinophils, indicating that the signaling of IL37/IL18Rɑ was dampened. In addition, proteomic analysis revealed a significantly differential protein profile of AD patients compared with HC. IL-37 showed the strongest negative correlation with involucrin, a keratinizing epithelia protein. IL-37 was verified to suppress induced involucrin expression in in vitro skin cell models. AD patients show a significantly higher serum concentration of involucrin compared with HC. Together, our results demonstrated that IL-37 plays a regulatory role in AD. Its deficiency may lead to the aberrant involucrin expression in AD. CONCLUSIONS: The dysregulation of serum protein and skin disruption in AD is related to the insufficiency of IL-37 and its attenuated anti-inflammatory signaling.

Interleukin-38 ameliorates poly(I:C) induced lung inflammation: therapeutic implications in respiratory viral infections.

Interleukin-38 has recently been shown to have anti-inflammatory properties in lung inflammatory diseases. However, the effects of IL-38 in viral pneumonia remains unknown. In the present study, we demonstrate that circulating IL-38 concentrations together with IL-36α increased significantly in influenza and COVID-19 patients, and the level of IL-38 and IL-36α correlated negatively and positively with disease severity and inflammation, respectively. In the co-cultured human respiratory epithelial cells with macrophages to mimic lung microenvironment in vitro, IL-38 was able to alleviate inflammatory responses by inhibiting poly(I:C)-induced overproduction of pro-inflammatory cytokines and chemokines through intracellular STAT1, STAT3, p38 MAPK, ERK1/2, MEK, and NF-κB signaling pathways. Intriguingly, transcriptomic profiling revealed that IL-38 targeted genes were associated with the host innate immune response to virus. We also found that IL-38 counteracts the biological processes induced by IL-36α in the co-culture. Furthermore, the administration of recombinant IL-38 could mitigate poly I:C-induced lung injury, with reduced early accumulation of neutrophils and macrophages in bronchoalveolar lavage fluid, activation of lymphocytes, production of pro-inflammatory cytokines and chemokines and permeability of the alveolar-epithelial barrier. Taken together, our study indicates that IL-38 plays a crucial role in protection from exaggerated pulmonary inflammation during poly(I:C)-induced pneumonia, thereby providing the basis of a novel therapeutic target for respiratory viral infections.

The Immuno-Modulatory Activities of Pentaherbs Formula on Ovalbumin-Induced Allergic Rhinitis Mice via the Activation of Th1 and Treg Cells and Inhibition of Th2 and Th17 Cells.

Allergic rhinitis (AR) is a highly prevalent allergic disease induced by immunoglobulin (Ig) E-mediated hypersensitivity reaction at the nasal epithelium against inhaled allergens. Previous studies have demonstrated that Pentaherbs formula (PHF), a modified herbal formula comprising five herbal medicines (Flos Lonicerae, Herba Menthae, Cortex Phellodendri, Cortex Moutan and Rhizoma Atractylodis), could suppress various immune effector cells to exert anti-inflammatory and anti-allergic effects in allergic asthma and atopic dermatitis. The present study aimed to further determine the anti-inflammatory activities of PHF in an ovalbumin (OVA)-induced AR BALB/c mouse model. Nasal symptoms such as sneezing and nose rubbing were recorded and the serum total IgE and OVA-specific IgG1, as well as interleukin (IL)-4, IL-5, IL-10, IL-13, chemokines CXCL9 CXCL10, and tumor necrosis factor (TNF)-α concentrations in nasal lavage fluid (NALF) were measured during different treatments. Effects of PHF on the expression of inflammatory mediators in the sinonasal mucosa were quantified using real-time QPCR. PHF was found to suppress allergic symptoms, infiltration of inflammatory cells, and hyperplasia of goblet cells in the nasal epithelium of the OVA-induced AR mice. PHF could reduce OVA-specific IgG1 level in serum, and TNF-α and IL-10 in nasal lavage fluid (NALF), significantly up-regulate the splenic regulatory T (Treg) cell level, increase the Type 1 helper T cell (Th1)/Type 2 helper T cell (Th2) ratio, and reduce the Th17 cells (all p < 0.05). PHF could also alleviate in situ inflammation in sinonasal mucosa of OVA-induced AR mice. In conclusion, oral treatment of PHF showed immuno-modulatory activities in the OVA-induced AR mice by regulating the splenic T cell population to suppress the nasal allergy symptoms and modulating inflammatory mediators, implicating that PHF could be a therapeutic strategy for allergic rhinitis.

Current Advances in Mechanisms and Treatment of Dry Eye Disease: Toward Anti-inflammatory and Immunomodulatory Therapy and Traditional Chinese Medicine.

Dry eye is currently one of the most common ocular surface disease. It can lead to ocular discomfort and even cause visual impairment, which greatly affects the work and quality of life of patients. With the increasing incidence of dry eye disease (DED) in recent years, the disease is receiving more and more attention, and has become one of the hot research fields in ophthalmology research. Recently, with the in-depth research on the etiology, pathogenesis and treatment of DED, it has been shown that defects in immune regulation is one of the main pathological mechanisms of DED. Since the non-specific and specific immune response of the ocular surface are jointly regulated, a variety of immune cells and inflammatory factors are involved in the development of DED. The conventional treatment of DED is the application of artificial tears for lubricating the ocular surface. However, for moderate-to-severe DED, treatment with anti-inflammatory drugs is necessary. In this review, the immunomodulatory mechanisms of DED and the latest research progress of its related treatments including Chinese medicine will be discussed.

The Active Compounds and Therapeutic Mechanisms of Pentaherbs Formula for Oral and Topical Treatment of Atopic Dermatitis Based on Network Pharmacology.

To examine the molecular targets and therapeutic mechanism of a clinically proven Chinese medicinal pentaherbs formula (PHF) in atopic dermatitis (AD), we analyzed the active compounds and core targets, performed network and molecular docking analysis, and investigated interacting pathways. Information on compounds in PHF was obtained from the Traditional Chinese Medicine Systems Pharmacology (TCMSP) database, and target prediction was performed using the Drugbank database. AD-related genes were gathered using the GeneCards and Online Mendelian Inheritance in Man (OMIM) databases. Network analysis was performed by Cytoscape software and protein-protein interaction was analyzed by the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING). The Database for Annotation, Visualization and Integrated Discovery (DAVID) Bioinformatics Resources were applied for the enrichment analysis of the potential biological process and pathways associated with the intersection targets between PHF and AD. Autodock software was used to perform protein compound docking analysis. We identified 43 active compounds in PHF associated with 117 targets, and 57 active compounds associated with 107 targets that form the main pathways linked to oral and topical treatment of AD, respectively. Among them, quercetin, luteolin, and kaempferol are key chemicals targeting the core genes involved in the oral use of PHF against AD, while apigenin, ursolic acid, and rosmarinic acid could be used in topical treatment of PHF against AD. The compound-target-disease network constructed in the current study reveals close interactions between multiple components and multiple targets. Enrichment analysis further supports the biological processes and signaling pathways identified, indicating the involvement of IL-17 and tumor necrosis factor signaling pathways in the action of PHF on AD. Our data demonstrated the main compounds and potential pharmacological mechanisms of oral and topical application of PHF in AD.

The flavonoids of Sophora flavescens exerts anti-inflammatory activity via promoting autophagy of Bacillus Calmette-Guérin-stimulated macrophages.

Tuberculosis (TB), a highly infectious air-borne disease, has remained a global health problem. Conventional treatment and preventions such as antibiotics and Bacilli Calmette-Guerin (BCG) vaccine can be unreliable. In view of the increasing prevalence of anti-TB drug resistance, adjunctive therapy may be necessary to shorten the recovery time. We have previously shown that flavonoids in the medicinal herb Sophora flavescens exhibit anti-inflammatory and bactericidal activities. The aim of this study was to investigate the molecular and cellular characteristics of flavonoids of S. flavescens (FSF) in BCG-stimulated macrophages for assessing their roles in anti-inflammation and autophagy. Mouse alveolar macrophage (MH-S) cell line and primary mouse peritoneal macrophages were stimulated in vitro with heat-inactivated BCG and treated with FSF, with or without autophagy inhibitor Bafilomycin A1 (BafA1). Gene expression was analyzed using quantitative PCR, and cytokine/chemokine release was analyzed by Milliplex assay and ELISA. Autophagy-related proteins were quantified by Western blot and flow cytometry, and autophagolysosomes were detected using fluorescence microscopy. In both MH-S cell line and mouse peritoneal macrophages stimulated by heat-inactivated BCG, FSF was found to up-regulate autophagy-related proteins microtubule-associated protein 1A/1B-light chain 3 (LC3) and protein 62 (p62), and suppress the induced proinflammatory cytokine TNF-α, CCL5, and IL-6. FSF actively modulates immune processes through suppressing BCG-mediated inflammation by promoting autophagy in MH-S cells and mouse peritoneal macrophages. We suggest that FSF may be useful as an adjunctive therapeutic agent for TB infection by modulating cell survival through autophagy and reducing inflammation.

The Role of New IL-1 Family Members (IL-36 and IL-38) in Atopic Dermatitis, Allergic Asthma, and Allergic Rhinitis.

PURPOSE OF REVIEW: Since the discovery of its very first member in 1974, the IL-1 family has expanded into a group of 11 potent molecules which are essential in both innate and acquired immunity. Pro-inflammatory cytokines IL-36α, IL-36ß, and IL-36γ and their receptor antagonists IL-36Ra and IL-38, which belong to the IL-36 subfamily, are some of the most recently identified members. Recent studies show that these members possess pro-inflammatory and anti-inflammatory activities and may take part in the pathogenesis of allergy. In this review, the involvement and importance of these newly described IL-1 family members in the most common allergic diseases, i.e., atopic dermatitis (AD), allergic asthma, and allergic rhinitis, will be discussed. RECENT FINDINGS: Dysregulation of IL-36 and IL-38 was observed in the skin and respiratory tract of AD, allergic rhinitis, and allergic asthma individuals. Although the upregulation in IL-36α and IL-36γ observed in the lesional skin of AD patients was unexpectedly small, IL-36 may play an important role in AD pathogenesis especially upon Staphylococcus aureus colonization. While IL-36γ regulates eosinophils to induce an inflammatory response in allergic rhinitis, IL-36α was found to regulate Th17 immunity. IL-36 receptor antagonists, IL-36Ra and IL-38, however, both show promising anti-inflammatory activities against allergic asthma. Of note, IL-38 in allergic asthmatic children is significantly lower than their healthy counterparts, while the anti-inflammatory effects of IL-38 in allergic asthma exacerbation upon viral-like infection were demonstrated in in vitro, HDM-induced, and humanized mice models. Dysregulated expression of IL-36 and IL-38 observed in allergic patients and mice models revealed that they may have essential roles in the pathogenesis in AD, allergic rhinitis, and allergic asthma, especially during the host defense against pathogens at inflammatory sites. Their receptor antagonists, IL-36Ra and IL-38, could also be promising biologics in the control of allergy. Since allergic diseases are phenotypically complex, contradictory data obtained in different studies may be explained if further stratification of disease endotypes is explored. Genetically modified mice model and investigation in anti-IL-36 treatment may be useful to characterize the therapeutic potential of these cytokines in the regulation of allergy in the future.

IL-37 Ameliorating Allergic Inflammation in Atopic Dermatitis Through Regulating Microbiota and AMPK-mTOR Signaling Pathway-Modulated Autophagy Mechanism.

Interaction between eosinophils and dermal fibroblasts is essential for provoking allergic inflammation in atopic dermatitis (AD). In vitro co-culture of human eosinophils and dermal fibroblasts upon AD-related IL-31 and IL-33 stimulation, and in vivo MC903-induced AD murine model were employed to investigate the anti-inflammatory mechanism of IL-1 family cytokine IL-37 in AD. Results showed that IL-37b could inhibit the in vitro induction of AD-related pro-inflammatory cytokines IL-6 and TNF-α, and chemokines CXCL8, CCL2 and CCL5, increase autophagosome biogenesis-related LC3B, and decrease autophagy-associated ubiquitinated protein p62 by regulating intracellular AMP-activated protein kinase (AMPK) and mammalian target of rapamycin (mTOR) signaling pathway. In CRISPR/Cas9 human IL-37b knock-in mice, IL-37b could significantly alleviate MC903-stimulated ear tissue swelling, itching sensation and the level of circulating cytokine IL-6 and ear in situ expression of AD-related TNF-α, CCL5 and transforming growth factor-ß. Moreover, IL-37b could significantly upregulate Foxp3+ regulatory T cells (Treg) in spleen and ear together with significantly increased serum Treg cytokine IL-10, and decrease eosinophil infiltration in ear lesion. IL-37b knock-in mice showed a distinct intestinal microbiota metabolic pattern upon MC903 stimulation. Furthermore, IL-37b restored the disordered gut microbiota diversity, through regulating the in vivo autophagy mechanism mediated by intestinal metabolite 3-methyladenine, adenosine monophosphate, 2-hydroxyglutarate, purine and melatonin. In summary, IL-37b could significantly ameliorate eosinophils-mediated allergic inflammation via the regulation of autophagy mechanism, intestinal bacterial diversity and their metabolites in AD. Results therefore suggest that IL-37 is a potential anti-inflammatory cytokine for AD treatment.

Anti-inflammatory mechanisms of the novel cytokine interleukin-38 in allergic asthma.

We elucidated the anti-inflammatory mechanisms of IL-38 in allergic asthma. Human bronchial epithelial cells and eosinophils were cocultured upon stimulation with the viral RLR ligand poly (I:C)/LyoVec or infection-related cytokine TNF-α to induce expression of cytokines/chemokines/adhesion molecules. House dust mite (HDM)-induced allergic asthma and humanized allergic asthma NOD/SCID murine models were established to assess anti-inflammatory mechanisms in vivo. IL-38 significantly inhibited induced proinflammatory IL-6, IL-1ß, CCL5, and CXCL10 production, and antiviral interferon-ß and intercellular adhesion molecule-1 expression in the coculture system. Mass cytometry and RNA-sequencing analysis revealed that IL-38 could antagonize the activation of the intracellular STAT1, STAT3, p38 MAPK, ERK1/2, and NF-κB pathways, and upregulate the expression of the host defense-related gene POU2AF1 and anti-allergic response gene RGS13. Intraperitoneal injection of IL-38 into HDM-induced allergic asthma mice could ameliorate airway hyperreactivity by decreasing the accumulation of eosinophils in the lungs and inhibiting the expression of the Th2-related cytokines IL-4, IL-5, and IL-13 in the bronchoalveolar lavage fluid (BALF) and lung homogenates. Histological examination indicated lung inflammation was alleviated by reductions in cell infiltration and goblet cell hyperplasia, together with reduced Th2, Th17, and innate lymphoid type 2 cell numbers but increased proportions of regulatory T cells in the lungs, spleen, and lymph nodes. IL-38 administration suppressed airway hyperreactivity and asthma-related IL-4 and IL-5 expression in humanized mice, together with significantly decreased CCR3+ eosinophil numbers in the BALF and lungs, and a reduced percentage of human CD4+CRTH2+ Th2 cells in the lungs and mediastinal lymph nodes. Together, our results demonstrated the anti-inflammatory mechanisms of IL-38 and provided a basis for the development of a regulatory cytokine-based treatment for allergic asthma.

High-Throughput Immunological Analysis of Dictamni Cortex: Implication in the Quality Control of Herbal Medicine.

Quality inconsistency of herbal medicine is an obstacle that limits the extensive use and study of traditional Chinese medicine. Differences in environmental conditions and processing methods of herbal medicine often result in varying clinical outcomes in patients. Standard chemical markers used for the quality control (QC) of herbal medicine are usually the most abundant and characteristic components, which may not be therapeutically relevant or cannot comprehensively reflect the biological quality of the herbs. In view of this, a novel QC method for better assessment of herbal medicine has been developed via bioactivities analysis. Immunological activities of Dictamni Cortex, a typical herbal medicine for the treatment of various inflammatory diseases, from different geographical locations in China, were evaluated. Upon in vitro treatment of their water and ethanol extracts, distinct patterns of inflammatory cytokines including tumor necrosis factor (TNF)-α, interleukin (IL)-10, IL-6, IL-12p70, IL-1ß, and chemokine CXCL8 were released from the lipopolysaccharides- and/or phytohaemagglutinin-stimulated human peripheral blood mononuclear cells (PBMC). Thus, in addition to the commonly used morphological, chemical, or DNA markers, the novel high-throughput profiling of inflammatory cytokines and chemokines of PBMC upon treatment with herbal extracts could be an important reference to help for the quality control of herbal medicine in the future.