Th2 Cytokine Gene Expression Research Articles

IL-10 Neutralization Attenuates Mast Cell Responses in a Murine Model of Experimental Food Allergy.

IgE-mediated mast cell (MC) activation is a critical component of allergic responses to oral Ags. Several T cell-derived cytokines have been shown to promote MC reactivity, and we recently demonstrated a critical role for the cytokine IL-10 in mediating MC responses during food allergy. In this study, we further validate the role of IL-10 using Ab-mediated IL-10 depletion. IL-10 neutralization significantly attenuated MC responses, leading to decreased MC accumulation and activation, as well as inhibition of MC-mediated symptoms such as allergic diarrhea. This was accompanied by decreased Th2 cytokine gene expression, attenuated systemic T cell responses, and fewer CD4 T cells, B cells, and MCs in the spleen. Our data further confirm the role of IL-10 in driving MC responses and suggest that IL-10-responsive MCs may constitute an important player in allergic responses.

Human HLA-DR+CD27+ regulatory T cells show enhanced antigen-specific suppressive function.

Regulatory T cells (Tregs) have potential for the treatment of autoimmune diseases and graft rejection. Antigen specificity and functional stability are considered critical for their therapeutic efficacy. In this study, expansion of human Tregs in the presence of porcine PBMCs (xenoantigen-expanded Tregs, Xn-Treg) allowed the selection of a distinct Treg subset, coexpressing the activation/memory surface markers HLA-DR and CD27 with enhanced proportion of FOXP3+Helios+ Tregs. Compared with their unsorted and HLA-DR+CD27+ double-positive (DP) cell-depleted Xn-Treg counterparts, HLA-DR+CD27+ DP-enriched Xn-Tregs expressed upregulated Treg function markers CD95 and ICOS with enhanced suppression of xenogeneic but not polyclonal mixed lymphocyte reaction. They also had less Treg-specific demethylation in the region of FOXP3 and were more resistant to conversion to effector cells under inflammatory conditions. Adoptive transfer of porcine islet recipient NOD/SCID IL2 receptor γ-/- mice with HLA-DR+CD27+ DP-enriched Xn-Tregs in a humanized mouse model inhibited porcine islet graft rejection mediated by 25-fold more human effector cells. The prolonged graft survival was associated with enhanced accumulation of FOXP3+ Tregs and upregulated expression of Treg functional genes, IL10 and cytotoxic T lymphocyte antigen 4, but downregulated expression of effector Th1, Th2, and Th17 cytokine genes, within surviving grafts. Collectively, human HLA-DR+CD27+ DP-enriched Xn-Tregs expressed a specific regulatory signature that enabled identification and isolation of antigen-specific and functionally stable Tregs with potential as a Treg-based therapy.

Zfp281 and Zfp148 control CD4 + T cell thymic development and T H 2 functions

How CD4 + lineage gene expression is initiated in differentiating thymocytes remains poorly understood. Here, we show that the paralog transcription factors Zfp281 and Zfp148 control both this process and cytokine expression by T helper cell type 2 (T H 2) effector cells. Genetic, single-cell, and spatial transcriptomic analyses showed that these factors promote the intrathymic CD4 + T cell differentiation of class II major histocompatibility complex (MHC II)–restricted thymocytes, including expression of the CD4 + lineage–committing factor Thpok. In peripheral T cells, Zfp281 and Zfp148 promoted chromatin opening at and expression of T H 2 cytokine genes but not of the T H 2 lineage–determining transcription factor Gata3. We found that Zfp281 interacts with Gata3 and is recruited to Gata3 genomic binding sites at loci encoding Thpok and T H 2 cytokines. Thus, Zfp148 and Zfp281 collaborate with Gata3 to promote CD4 + T cell development and T H 2 cell responses.

Molecular and Cellular Evaluation of Horses With Summer Pasture Associated Asthma Syndrome

Equine asthma is an airway disease that affects a large number of horses annually leading to considerable economic losses in the horse industry. Despite advances in research in this area, there is still a lack of information on its etiology and molecular characterization in pasture associated asthma. The objective of the current study was to characterize the inflammatory disease of lower airways in horses maintained on pasture through cytologic and immunologic profile during the summer in a tropical environment by analysis of the gene expression of Th1 cytokines (IFN- λ, IL-8), Th2 cytokines (IL-4 and IL-5), and pro-inflammatory cytokines (IL-1, TNF-α) in the bronchoalveolar lavage (BAL) fluid in healthy and asthma horses on pasture. A group 39 of clinically healthy horses maintained on native pasture and supplemented with concentrate was evaluated by BAL analyzed for differential cellular count and assigned into a control and an asthma group. The gene expression of pro-inflammatory cytokines was analyzed in the BAL by reverse time PCR (RT-PCR) (IL-1α (alpha), IL-4, IL-5, IL-8, TNF-α alpha and IFN-λ), using β-actin as housekeeping gene. Higher gene expression of IL-1, IL-4, IL-5, IL-8, IFN-λ in the BAL of asthma horses was found. Current results indicate an increase in Th2, characterizing an allergic inflammatory reaction due to the significant increase in IL-5 in asthmatic horses (10.3 ± 1.13), when compared to the values ​​obtained in normal horses (3.27 ± 0.46). The only down regulated cytokine in the asthma group was TNF-α, suggesting a chronic antigenic reaction.

An Andrographis paniculata Burm. Nees extract standardized for three main Andrographolides prevents house dust mite-induced airway inflammation, remodeling, and hyperreactivity by regulating Th1/Th2 gene expression in mice

Ethnopharmacological relevanceAndrographis paniculata Burm. Nees (AP) is an herb used traditionally in Indian and Chinese traditional medicine for the treatment of various inflammatory and respiratory tract diseases. However, the anti-inflammatory potential of standardized Andrographis paniculata 50% ethanol extract (APEE50) in the murine model of asthma has not been investigated. Aim of the studyThis study aimed to evaluate the protective anti-inflammatory potential and better understand the underlying mechanism of action of APEE50 in a clinically-relevant mouse asthma model. Thereafter, develop the ethanolic extract of AP as a supplement for asthma prophylaxis. Materials and methodAPEE50 was prepared and standardized for AGP, NAG, and DDAG using a high-performance liquid chromatography system. Asthma was induced according to a 14-day house dust mite (HDM) induction protocol. The prophylactic potential of APEE50 (50 mg/kg – 200 mg/kg) was determined by assessing cardinal asthma features, which included BALF leukocyte and differential cell count, BALF cytokine assay, histology, gene expression, and airway hyperreactivity study. ResultsAPEE50 significantly inhibited HDM-induced airway eosinophilia and neutrophilia. In addition to decreased levels of IL-4, IL-5, IL-13, and eotaxin in bronchoalveolar fluid, APEE50 abrogated HDM-induced airway mucus over-secretion and airway hyper-responsiveness. Administration of APEE50 downregulated HDM-induced upregulation of the oxidative stress enzyme Duox1 (dual oxidase 1) and marginally induced Nfe2l2 (nuclear factor erythroid 2-related factor 2) gene expressions. Similarly, Th2-related (Serpinb2, Clca3a1, Il4 and Il13) and Muc5ac gene expression were significantly downregulated. ConclusionProphylactic administration of APEE50 prevented the progression of HDM-induced asthmatic responses by down-regulating Th2 cytokine gene expression and oxidative stress level.

The Potential Role of Lipopeptide Biosurfactant Generated by Acinetobacter junii B6 on Leishmania Tropica: The Synergy of Lipopeptide Biosurfactant and Glucantime

An in vitro investigation was carried out to assess how the lipopeptide biosurfactant (LPB) produced by Acinetobacter junii B6 affects Leishmania tropica infection and the associated cytokine gene expression in macrophages infected with L. tropica. Glucantime® (meglumine antimoniate, MA) and LPB were investigated for their leishmanicidal effect, alone and in combination (LPB + MA), using a colorimetric test and a macrophage model. Immunomodulatory impact was also evaluated through analysis of Th1 and Th2 cytokine gene expression in infected macrophages after treatment with MA and LPB, individually and in combination. The MA/LPB combination showed higher inhibitory impacts on L. tropica amastigotes and promastigotes than each alone. Cytokine gene expression confirmed LPB’s affinity to IFN-γ, affirming the elevated IL-12p40 and IFN- γ concentrations in addition to a reduction in the secretion of IL-10 in a dose-dependent manner, particularly in combined treatment. The results indicated higher effectiveness of LPB along with MA in the reduction of the parasite growth and promoting the immune reaction level, which may be considered as a possible therapeutic strategy to treat those with anthroponotic cutaneous leishmaniasis.

Leptospira borgpetersenii Leucine-Rich Repeat Proteins Provide Strong Protective Efficacy as Novel Leptospiral Vaccine Candidates.

Leucine-rich repeat (LRR) proteins are advocated for being assessed in vaccine development. Leptospiral LRR proteins were identified recently in silico from the genome of Leptospira borgpetersenii serogroup Sejroe, the seroprevalence of leptospiral infections of cattle in Thailand. Two LRR recombinant proteins, rKU_Sej_LRR_2012M (2012) and rhKU_Sej_LRR_2271 (2271), containing predicted immunogenic epitopes, were investigated for their cross-protective efficacies in an acute leptospirosis model with heterologous Leptospira serovar Pomona, though, strains from serogroup Sejroe are host-adapted to bovine, leading to chronic disease. Since serovar Pomona is frequently reported as seropositive in cattle, buffaloes, pigs, and dogs in Thailand and causes acute and severe leptospirosis in cattle by incidental infection, the serogroup Sejroe LRR proteins were evaluated for their cross-protective immunity. The protective efficacies were 37.5%, 50.0%, and 75.0% based on the survival rate for the control, 2012, and 2271 groups, respectively. Sera from 2012-immunized hamsters showed weak bactericidal action compared to sera from 2271-immunized hamsters (p < 0.05). Therefore, bacterial tissue clearances, inflammatory responses, and humoral and cell-mediated immune (HMI and CMI) responses were evaluated only in 2271-immunized hamsters challenged with virulent L. interrogans serovar Pomona. The 2271 protein induced prompt humoral immune responses (p < 0.05) and leptospiral tissue clearance, reducing tissue inflammation in immunized hamsters. In addition, protein 2271 and its immunogenic peptides stimulated splenocyte lymphoproliferation and stimulated both HMI and CMI responses by activating Th1 and Th2 cytokine gene expression in vaccinated hamsters. Our data suggest that the immunogenic potential renders rhKU_Sej_LRR_2271 protein a promising candidate for the development of a novel cross-protective vaccine against animal leptospirosis.

Topical Administration of a Novel Acetylated Tetrapeptide Suppresses Vascular Permeability and Immune Responses and Alleviates Atopic Dermatitis in a Murine Model.

Although the pathogenesis of atopic dermatitis (AD) remains to be fully deciphered, skin barrier abnormality and immune dysregulation are known to be involved. Recently, the vascular endothelial growth factor (VEGF)/VEGF receptor (VEGFR) system has also been implicated in the pathogenesis of this multifactorial chronic inflammatory skin disorder. Previously, we showed that a novel tetrapeptide, N-acetyl-Arg-Leu-Tyr-Glu (Ac-RLYE), inhibits angiogenesis and vascular permeability effectively by selectively antagonizing VEGFR-2. The current study aimed to investigate the pharmacological effect of Ac-RLYE on AD in vitro and in vivo. The in vitro experiments demonstrated that Ac-RLYE inhibited VEGF-induced vascular permeability in endothelial cells. Moreover, in an in vivo animal model of AD, Ac-RLYE relieved AD-like symptoms such as ear thickness and dermatitis severity scores and infiltration of immune cells, including mast cells and eosinophils. Ac-RLYE inhibited IgE secretion, restored the skin barrier protein filaggrin level, and markedly downregulated gene expression of AD-related Th1, Th2, and Th17 cytokines. Collectively, these findings suggest that Ac-RLYE would be useful for the treatment of AD and associated inflammatory skin disorders.

David John Austin

Differentiation of naive CD4⁺ cells into Th2 cells is accompanied by chromatin remodeling at the Th2 cytokine locus allowing the expression of the IL-4, IL-5, and IL-13 genes. In this...

Induction of Severe Eosinophilic Esophagitis and Multi-Organ Inflammation by Airborne Allergens is Associated with IL-4/IL-13 and CCL11 but Not IgE in Genetic Susceptible Mice.

BackgroundEosinophilic Esophagitis (EoE) is an increasingly common chronic inflammatory disease. The pathological mechanisms underlying EoE are largely unknown.ObjectiveWe sought to understand the mechanisms underlying aeroallergen-induced EoE in Sharpin gene deficient (Sharpin-/-) mice that is prone to inflammatory response.MethodsSharpin-/-mice were exposed with Aspergillus fumigatus and ovalbumin intranasally every alternate day for 4 weeks. Wild type (WT) naïve mice, WT exposed, and un-exposed Sharpin-/- mice were controls. Histopathological analysis was performed by H&E, trichrome and major basic protein staining. Total and specific IgE, IgG, and IgA levels were measured by ELISA and Th2 cytokine and CCL11 chemokine gene expression were determined.ResultsAirborne allergen exposed Sharpin-/- mice showed severe eosinophilic inflammation in the esophagus (p < 0.001), and markedly increased epithelial thickening (p < 0.0001) compared to WT normal controls, whereas airborne allergen exposed WT mice and unexposed Sharpin-/- mice only showed mild eosinophilic inflammation in the esophagus. These exposed Sharpin-/- mice also showed over 7-fold increase in blood eosinophils (p < 0.0001), 60-fold increase in eosinophils in bronchoalveolar lavage fluid (p < 0.0001) and 4-fold increase in eosinophils in the skin (p < 0.0001) compared to normal controls. Surprisingly, exposed Sharpin-/- mice did not show elevation of serum total or antigen-specific IgE levels but reduced total IgA and IgG levels than normal controls There was a marked increase in IL-4, IL-13 and CCL11 gene expression in esophageal tissue (p < 0.001) in exposed Sharpin-/- mice compared to WT normal mice.ConclusionTh2 cytokines and chemokines, but not IgE may play an important pathologic role in aeroallergen-induced EoE. This study may provide insight into new therapeutics for EoE.

Adeno-Associated Virus-Mediated Interleukin-12 Gene Expression Alleviates Lung Inflammation and Type 2 T-Helper-Responses in Ovalbumin-Sensitized Asthmatic Mice.

High levels of allergen exposure increase the prevalence of asthma in developed countries. The asthmatic type 2 T-helper (Th2) response is characterized with high eosinophil infiltration, elevated Th2 cytokines, and immunoglobulin (Ig) E secretion resulting in local or systemic inflammation. However, the treatment with palliative Th2 inhibitor drugs cannot completely control asthma and that is why the development of novel approaches is still important. Based on type 1 T-helper (Th1) and Th2 immune homeostasis, the enhanced Th1 immune response has high potential to alleviate Th2 immune response. Thus, we aimed to overexpress single chain IL-12 (scIL-12) through recombinant adeno-associated virus (rAAV) vector (as rAAV-IL-12) and test the efficacy in an ovalbumin (OVA)-induced asthmatic murine model. We firstly demonstrated the bioactivity of exogenous scIL-12. The expression of exogenous scIL-12 was also detected in the lungs of rAAV-IL-12 transduced mice. The data demonstrated that overexpression of exogenous scIL-12 significantly suppressed total number of cells and eosinophil infiltration, as well as the mucus secretion in rAAV-IL-12-treated mice. The decreased OVA-specific IgE in bronchoalveolar lavage fluid and gene expression of Th2-cytokines or C-C motif ligand (CCL) 11 (also eotaxin-1) in lung were observed. In addition, the production of cytokines in the supernatants of OVA-stimulated splenocytes were suppressed with rAAV-IL-12 treatment. Thus, scIL-12 expression by rAAV vector was able to modulate Th2 activity and has the potential to be developed as a feasible strategy in modulating allergic diseases.

Single-cell transcriptome profile of mouse skin undergoing antigen-driven allergic inflammation recapitulates findings in atopic dermatitis skin lesions

Allergic skin inflammation elicited in mice by epicutaneous (EC) sensitization with antigen shares characteristics with human atopic dermatitis (AD). We characterized gene expression by single cells in mouse skin undergoing antigen-driven allergic inflammation and compared the results with findings in AD skin lesions. Mice were EC sensitized by application of ovalbumin (OVA) or saline to tape-stripped skin. Single-cell RNA sequencing was performed on skin cells 12 days later. Flow cytometry analysis was performed to validate results. Sequencing identified 7 nonhematopoietic and 6 hematopoietic cell subsets in EC-sensitized mouse skin. OVA sensitization resulted in the expansion in the skin of T cells, dendritic cells, macrophages, mast cells/basophils, fibroblasts, and myocytes cell clusters, and in upregulation of TH2 cytokine gene expression in CD4+ T cells and mast cells/basophils. Genes differentially expressed in OVA-sensitized skin included genes important for inflammation in dendritic cells and macrophages, collagen deposition, and leukocyte migration in fibroblasts, chemotaxis in endothelial cells and skin barrier integrity, and differentiation in KCs-findings that recapitulate those in AD skin lesions. Unexpectedly, mast cells/basophils, rather than T cells, were the major source of Il4 and ll13 in OVA-sensitized mouse skin. In addition, our results suggest novel pathways in fibroblast and endothelial cells that may contribute to allergic skin inflammation. The gene expression profile of single cells in mouse skin undergoing antigen-driven shares many features with that in AD skin lesions and unveils novel pathways that may be involved in allergic skin inflammation.

The Potential of Medicinal Plants and Bioactive Compounds in the Fight Against COVID-19

The Potential of Medicinal Plants and Bioactive Compounds in the Fight Against COVID-19

Differential Cytokine Expression in the Duodenum and Rectum of Children with Non-Immunoglobulin E-Mediated Cow's Milk Protein Allergy.

Cow's milk protein allergy (CMPA) is the most prevalent food allergy in children, and its pathogenesis remains poorly understood. It has been shown that the combination of genetic predisposition, perinatal factors, and intestinal imbalance of the immune response mediated by cytokines may play an essential role in CMPA pathogenesis. To characterize the gene expression of Th1, Th2, and Th17 cytokines in the duodenum and rectum in patients with CMPA. This is an observational, descriptive, cross-sectional, prospective study. We used specific IgE (ImmunoCAP®) in serum and biopsies from the rectum and duodenum for the detection of cytokine messenger RNA levels by real-time PCR in patients with a positive oral food challenge for CMPA. We analyzed the relative quantification of the gene expression of cytokines by real-time PCR, and we used the housekeeping gene GAPDH for normalization purposes. Thirty children (13 male and 17 female) were evaluated. All patients had an open challenge for CMPA. IgE specific to casein, alfa-lactalbumin, and beta-lactoglobulin was negative in all patients. In terms of cytokine levels, the levels of TNFα, IL-6, IL-12 (Th1), IL-4, IL-10, IL-13 (Th2), and IL-17 were found to be higher in the rectum than in the duodenum (p < 0.05). IL-15 was found to be higher in the duodenum than in the rectum (p < 0.05). In the present study we observed that the immune response in CMPA seems to be mediated by a Th1, Th2, and Th17 cytokine profile, with the rectum being the main affected site.

Protein Nanoparticles with Enzymatic and Antigen-Binding Activities Induce Th1 Cytokine Gene Expression

To improve protein stability and membrane permeability the protein nanoparticles (NP) were fabricated from enzymes or virus-specific antibodies by nanoprecipitation. Lysozyme NP destroyed bacterial cellular walls. RNase-based NP hydrolyzed RNA. Lipase, catalase and horseradish peroxidase activities were also registered for corresponding protein NP. NP from polyclonal antibodies against the influenza A virus and monoclonal antibodies against hemagglutinin H1, H3; proteins NS and NP could interact with their specific antigens. NP from monoclonal antibodies against the hepatitis B surface antigen bound with the antigen as shown by ELISA. The protein NP were stable in water at 4°C for several months and in the presence of blood sera or saliva for more than 5 days. The protein NP were not toxic for human cells and mice. The protein NP could penetrate and accumulate in cells in 2 hours with maximum after 2 days and subsequent gradual decline until background values. Entry of foreign protein NP into the eukaryotic cells induced cytokine gene expression. RNA of interferon (IFN) a, b and l but not IFN g were detected by reverse transcription with real time PCR. Polarization index (Th2:Th1 cytokine RNA) was near 0. Accordingly, cellular uptake of non-toxic protein NP induced Th1 polarization of immune response.

Innate and adaptive immunity in wild rodents spontaneously and experimentally infected with the tick-borne encephalitis virus

Two dominant species of wild small rodents trapped in Novosibirsk region, South-Western Siberia, Russia differed in their susceptibility to the tick-borne encephalitis virus (TBEV) infection. TBEV RNA average detection rate for Northern red-backed vole Myodes rutilus (Pallas, 1779) (82.2 ± 5.8% blood samples and 63.1 ± 2.7% organ samples) significantly exceeded the corresponding values for the striped field mouse Apodemus agrarius (Pallas, 1771) (47.0 ± 8.7% blood and 24.5 ± 2.8% organ samples) (p <0.001). Innate immunity may be one of possible reasons of the differences. Th1 cytokine gene expression distinguished between M. rutilus (12.5 ± 8.5%) and A. agrarius (66.6 ± 11.4%), whereas Th2 cytokine frequencies were statistically similar (81.8 ± 12.2% and 100.0%, respectively). Polarization indexes (PI) of the innate immunity calculated as ratio of Th2 to Th1 cytokine RNA detection rates for both M. rutilus (6.5) and A. agrarius (1.5) suggested Th2 mainly humoral immune response against persistent TBEV in natural mammalian hosts. Therefore, the TBEV-induced antibodies were analyzed by ELISA and hemagglutination inhibition (HI) tests. The TBEV-specific antibodies were detected in 74.8 ± 4.3% sera of M. rutilus and 67.3 ± 6.8% of A. agrarius. Among them HI antibodies were found in 4.8 ± 2.1% of the same analyzed sera of M. rutilus and in 6.0 ± 3.4% blood samples of A. agrarius only.To model the TBEV persistence both M. rutilus and A. agrarius were infected with the suspensions of the TBEV-infected ticks with further observations during 4 subsequent months. Detection rate of the TBEV RNA and antigen E remained high during the whole period, however, pathogenic for laboratory suckling mice virus was isolated up to 8 days postinfection. At late stages of the persistent infection (1–4 months) the TBEV RNA detection rate in northern red-backed voles remained high 70.6 ± 7.9% whereas in striped field mice significantly declined to 26.7 ± 9.2% (p < .001). Comparative analysis of the innate immunity of the wild rodents in 2 months postinfection showed similar frequencies of Th2 cytokine gene expression for M. rutilus (77.8 ± 10.1%) and A. agrarius (71.4 ± 12.5%) (p > .05) but Th1 cytokine mRNA detection rates were different (44.4 ± 12.5% and 85.7 ± 9.7%, respectively) (p < .05). In 2 months PI decreased from 6.5 until 1.75 for M. rutilus and from 1.5 until 0.83 for A. agrarius. Nevertheless, Th2 mainly humoral immune response was confirmed by direct detection of the TBEV-specific antibodies. HI and neutralizing antibodies were revealed in blood sera of the small rodents of both studied species in 30 days postinfection and remained at detectable levels during 4 months of observations. Accordingly, Th2 polarized innate immunity of small rodents might facilitate the TBEV intracellular persistence in the presence of HI and neutralization antibodies.

Hypergravity stimuli alleviate the Th2 allergic reaction: potential as an adjuvant anti-allergic therapy

Recent studies suggest that changes in gravity can cause immunological effects. We investigated the changes of Th2 allergic inflammation in murine model of allergic asthma, after exposure to hypergravity. Group A (control group) was intraperitoneally and intranasally injected with physiological saline. Group B (allergic group) received intraperitoneal and nasal ovalbumin for the induction of allergic asthma. Mice in group C (normogravity control) were exposed to mild rotational stimulation (for rotational stimulus stress, but gravity itself 1G) while inducing allergy through ovalbumin administration. Finally, group D (hypergravity group) was exposed to 5 G of hypergravity through rotation throughout the period of allergic induction (4 weeks). To determine the effects of hypergravity on Th2 allergic inflammation, we measured total and OVA-specific IgE in serum. We also measured the number of inflammatory cells (eosinophils, neutrophils, lymphocytes and macrophages) in the broncho-alveolar lavage (BAL). We performed real-time PCR to detect the genetic expression of IL-4, IL-5, and IL-13 using lung homogenate tissue. We could find a significant decrease in serum total IgE in Group D compared to Groups B and C (p<0.05). Group D also showed significant decrease in eosinophil count in BAL fluid. Real-time PCR revealed that Th2 cytokine gene expression (IL-4, IL-5, IL-13) was significantly inhibited in Group D, compared to Groups B and C (p<0.05). Moderate, proper hypergravity could have beneficial effect in individuals with allergy.

Protective Effects of Casticin From Vitex trifolia Alleviate Eosinophilic Airway Inflammation and Oxidative Stress in a Murine Asthma Model.

Casticin has been isolated from Vitex trifolia and found to have anti-inflammatory and anti-tumor properties. We also previously discovered that casticin can reduce pro-inflammatory cytokines and ICAM-1 expression in inflammatory pulmonary epithelial cells. In the present study, we evaluated whether casticin reduced airway hyper-responsiveness (AHR), airway inflammation, and oxidative stress in the lungs of a murine asthma model and alleviated inflammatory and oxidative responses in tracheal epithelial cells. Female BALB/c mice were randomly divided into five groups: normal controls, ovalbumin (OVA)-induced asthma, and OVA-induced asthma treated with intraperitoneal injection of casticin (5 or 10 mg/kg) or prednisolone (5 mg/kg). Casticin reduced AHR, goblet cell hyperplasia, and oxidative responses in the lungs of mice with asthma. Mechanistic studies revealed that casticin attenuated the levels of Th2 cytokine in bronchoalveolar lavage fluids and regulated the expression of Th2 cytokine and chemokine genes in the lung. Casticin also significantly regulated oxidative stress and reduced inflammation in the lungs of mice with asthma. Consequently, inflammatory tracheal epithelial BEAS-2B cells treated with casticin had significantly suppressed levels of pro-inflammatory cytokines and eotaxin, and reduced THP-1 monocyte cell adherence to BEAS-2B cells via suppressed ICAM-1 expression. Thus, casticin is a powerful immunomodulator, ameliorating pathological changes by suppressing Th2 cytokine expression in mice with asthma.

GATA3, SATB1, IRF4 complex binds to the Th2 cytokine locus through cis-acting element RHS6, regulating allergic airway inflammation.

Abstract Rad50 hypersensitive site 6 (RHS6) is a cis-acting element in the Th2 locus control region which is essential for the expression of Th2 cytokine genes. However, molecular mechanisms how it regulates the genes are poorly understood. We found that RHS6 recruits transcription factors GATA3, SATB1, and IRF4 during Th2 cell differentiation. GATA3, SATB1, and IRF4 have a crucial role in regulating Th2 cytokine genes. Knock-out or knock-down of each of GATA3, SATB1, and IRF4 genes significantly decrease the expression of Th2 cytokine genes. Mechanistically RHS6 mediates the transcription factor-induced regulation of Th2 cytokine genes. GATA3, SATB1, and IRF4 physically associates with each other, and forms a protein complex at RHS6 sequence. They directly bind to the many regulatory elements throughout the Th2 cytokine locus, RHS6 dependent manner. Furthermore, deletion of RHS6 caused a dramatic resistance to airway inflammation in ovalbumin-induced allergic inflammation model. Together, RHS6 recruits GATA3, SATB1, and IRF4 coordinating their regulation of Th2 cytokine genes, so is essential for Th2-mediated allergic airway inflammation.

Esculetin from Fraxinus rhynchophylla attenuates atopic skin inflammation by inhibiting the expression of inflammatory cytokines

Atopic dermatitis (AD) is a common chronic inflammatory skin disorder afflicting from infancy to adults with itching, scratching, and lichenification. We aimed to investigate the effects of esculetin from Fraxinus rhynchophylla on atopic skin inflammation. For induction of atopic skin inflammation, we exposed the ears of female BALB/c mice to house dust mite (Dermatophagoides farinae extract, DFE) and 2,4-dinitrochlorobenzene (DNCB) for 4 weeks. Oral administration of esculetin reduced the symptoms of DFE/DNCB-induced atopic skin inflammation, which were evaluated based on ear swelling and number of scratch bouts. The immunoglobulin (Ig) E, IgG2a, and histamine levels in serum were decreased and inflammatory cell infiltration in skin tissue was reduced by the esculetin. It suppressed production of Th1, Th2 and Th17-related cytokines such as tumor necrosis factor (TNF)-α, interferon (IFN)-γ, interleukin (IL)-4, IL-13, IL-31 and IL-17 in the ear tissue. Furthermore, we investigated the effects of esculetin on activated keratinocytes, which are representative cells used for studying the pathogenesis of acute and chronic atopic skin inflammation. As results, esculetin suppressed gene expression of Th1, Th2 and Th17 cytokines and the activation of nuclear factor-κB and signal transducer and activator of transcription 1 in TNF-α/IFN-γ-stimulated keratinocytes. Taken together, these results imply that esculetin attenuated atopic skin inflammation, suggesting that esculetin could be a potential therapeutic candidate for the treatment of AD.