Chung-Yeul-Gue-Soup-Sa-Gan-Tang, traditional Korean medicine, enhances CD4(+) T cell activities and modulates Th1/Th2 lineage development

Chung-Yeul-Gue-Soup-Sa-Gan-Tang (CYT), a traditional Korea herbal medicine, has been widely used in Korea for the treatment of various immunological disorders, including allergic asthma. In this study, CYT was examined in vitro and tested for possible immunological effects. The results demonstrated that CYT had no mitogenic effects on unstimulated CD4(+) T cells, but rather increased CD4(+) T cell proliferation upon activation with anti-CD3/CD28 antibody. Under the Th0 condition, CYT also enhanced expression of interleukin (IL)-2 in purified murine CD4(+) T cells assayed by real-time PCR, suggesting that CYT moderately increases the activity of helper T cells upon T cell receptor ligation under the neutral condition. However, the Th1 cells were overpopulated following CYT treatment under the Th1 condition, while Th2 cells were under-populated in the Th2 driven condition. In addition, under Th1/Th2-skewed conditions, the levels of IL-4 were considerably decreased, while the expression of T-bet and interferon-gamma were increased with CYT treatment. Thus, CYT enhances Th1 lineage development from naive CD4(+) T cells both by increasing Th1 specific cytokine secretion and repressing Th2 specific cytokine production. These results suggest that CYT is a desirable agent for the correction of Th2 dominant pathological disorders.     

Immune mediators in a murine model for occupational asthma: studies with toluene diisocyanate.

Isocyanate-induced asthma, which is the most common type of occupational asthma, has been difficult to diagnose and control, in part, because the biological mechanisms responsible for the disease and the determinants of exposure are not fully defined. To help address these issues, we recently established a murine model of toluene diisocyanate (TDI) asthma using inhalation exposure paradigms consistent with potential workplace exposure. In order to confirm our hypothesis that TDI-induce asthma, like allergic asthma, is predominantly a Th2 response, the ability of mice that were deficient in CD4 or CD8 cells or specific Th1 and Th2 cytokines to develop TDI asthma was examined. The development of allergic asthma was evaluated by monitoring lungs for the presence of eosinophilia, goblet cell metaplasia, epithelial cell alterations, airway hyperreactivity (AHR), and Th2 and Th1 cytokine expression, as well as serum IgE levels and TDI-specific IgG antibodies. Transgenic CD8 or CD4 knockout (KO) mice exhibited significant reductions in AHR, cytokine expression, serum antibody levels, airway inflammation, and histopathological lesions, although in a number of the endpoints the effects were more attenuated in CD4 KO mice. IFNgamma depletion ablated the increase in AHR in TDI-allergic mice, but had only slight to moderate effects on airway histopathology, serum antibody levels, and cytokine expression compared to sensitized/challenged controls. IL-4 and IL-13 deficiency had moderate inhibitory effects, while combined IL-4/IL-13 depletion effectively prevented almost all asthma-associated pathologies. Taken together, these results indicate that TDI asthma, like immune-mediated asthma produced by large-molecular-weight materials, is driven primarily by CD4+ T cells and is dependent upon the expression of Th2 cytokines. However, as with protein-induced asthma models, certain pathologies are influenced by CD8+ T cells and Th1-derived cytokines, such as AHR and cytokine production.     

Staphylococcal enterotoxin burden determines the type of T helper cell response and pathology of the maxillary sinus mucosa in rabbits

Staphylococcal enterotoxin (SE) induces T lymphocyte activation along with nasal allergic inflammation during rhinosinusitis, but it is under debate on which types of T helper (Th) cells respond exclusively or whether they respond synergically. We hypothesize that their responses may vary based on dose of SE. To test this hypothesis, we initiated to determine the nature of the T cell response and pathological feature upon repeated exposure to staphylococcal enterotoxin A (SEA) at different doses in the maxillary sinus of rabbits. SEA (0.6 or 60 ng) was instilled daily into the left maxillary sinus of rabbits for 28 days. The right maxillary sinus receiving normal saline was used as control. Mucosal histological changes were examined by hematoxylin–eosin and toluidine blue staining. Tissue expression of myeloperoxidase (MPO), eosinophil cationic protein (ECP), T-box expressed in T cells (T-bet), and GATA binding protein 3 (GATA-3) were examined using immunohistochemistry. Mucosal levels of representative pro-inflammatory cytokines were measured using ELISA. SEA at 60 ng/day induced acute rhinosinusitis, as confirmed by CT scan. Histopathologic examination revealed epithelial disruption, subepithelial edema, and inflammatory cell infiltration. MPO and T-bet expression, as well as interleukin (IL)-2 and interferon (IFN)-γ levels, were up-regulated. However, 0.6 ng/day SEA did not cause discharge. Histological examination revealed prominent eosinophilic infiltration. ECP and GATA-3 expression, as well as IL-4 and IL-5 levels, were increased at this lower dose. In conclusion, SEA induces acute rhinosinusitis associated with a Th1-type immune response at high dose, and a predominantly Th2-biased allergic inflammation at low dose.     

Administration of mycobacterial Ag85A and IL-17A fusion protein attenuates airway inflammation in a murine model of asthma

Interleukin (IL)-17A contributes to the development of asthma, especially in severe asthma which has characteristic neutrophil infiltration in airways. However, IL-17A-blocking antibody could escalate T helper (Th) 2 cytokines, such as IL-13, IL-4 in murine models. We aimed at determining the effect of mycobacterial Ag85A and IL-17A fusion protein—Ag85A-IL-17A on airway inflammation in a murine model of asthma. IL-17A recombinant protein fused mycobacterial immunodominant antigen Ag85A was constructed, expressed and purified. The fusion protein was then administrated into BALB/c mice and its anti-inflammatory effects in the infiltration of inflammatory cells, Th2/Th17 cytokines in BALF, histopathological changes of lung tissues as well as chemokines in lung tissues were evaluated in the murine model of asthma. We found that administration of mycobacterial Ag85A and IL-17A fusion protein induced IL-17A specific immunoglobulin (Ig)G in sera and significantly decreased IL-17A and IL-6 levels in bronchoalveolar lavage fluid (BALF). Ag85A-IL-17A vaccinated mice also showed marked reduction in the infiltration of inflammatory cells in peribronchiolar region and significant decrease in total cells, eosinophil cells and neutrophil cells in BALF. The increased levels of IL-13 and IL-4 in BALF of ovalbumin-sensitized mice were significantly reduced by the administration of Ag85A-IL-17A. Furthermore, CD3⁺CD4⁺IL-13⁺ splenocytes stimulated with OVA and CXCL1 mRNA, CCL2 mRNA and GATA-3 mRNA expressed in lung tissues were decreased markedly in Ag85A-IL-17A vaccinated group. Our results demonstrate remarkable antiallergic effects of Ag85A-IL-17A in a murine model of asthma and it may have protective effects on allergic asthma.     

Modulation of regulatory T cells by intranasal allergen immunotherapy in an experimental rat model of airway allergy

Allergic airway diseases such as asthma and allergic rhinitis are increasing in prevalence worldwide. The theory of an altered Th1/Th2 balance in allergic diathesis has recently been termed a “procrustean paradigm” as it failed to explain many preclinical findings. Regulatory T cells (Treg) have now been shown to be critical in T-cell homeostasis and in the maintenance of peripheral tolerance to allergens. Allergen specific immunotherapy (SIT) has been shown to induce regulatory T cells in allergic patients. Among various types of SIT, intranasal immunotherapy had not been studied in detail for the treatment of allergic airway diseases. So, there was a need to study the contribution of regulatory T cells and their mechanistic pathways following intranasal immunotherapy in-vivo. It had been previously shown that intranasal allergen immunotherapy using Alstonia scholaris pollen extract abrogates allergic airway inflammation with decline in IgE and Th2 cytokine levels. The present study for the first time offers a multi-targeted approach towards attenuation of airway allergy by the generation of CD4 + CD25 + Foxp3 + T cells and other subsets of Treg cells like Tr1 cells, Th3 cells, CTLA4 + Treg cells, and also modulation of various Treg cell surface molecules like GITR, OX40, CD39 and CD73 by intranasal immunotherapy in the same animal model. This animal experiment will thus help to chart out newer molecular targets for treating allergic asthma or rhinitis.     

T效应细胞通路在哮喘发病机制中的研究进展及靶向治疗前景

哮喘是儿童常见的慢性气道炎症疾病,以气道变异性炎症和高反应性为特点,对哮喘发病机制的研究,从最初的TH1/TH2范围,已扩展至T调节细胞及促炎症TH17细胞系,转录因子T-bet(TH1)、GATA-3(TH2)、FOXP3(Treg)、RORγτ/RORα(TH17)参与各T细胞亚群分化发展及之间的交叉调节,可能成为哮喘临床治疗潜在的药物靶向点。