Allergic immune-regulatory effects of Adlay Bran on an OVA-immunized mice allergic model

Allergy is an inflammation associated with an elevated T helper (Th) 2 lymphocyte responses to allergens and elevated serum IgE levels and cytokines. In one of our previous studies using a cell model, various flavonoids were found to be involved the anti-inflammatory effects of adlay bran. The present study investigated the effect of the ethyl-acetate fraction of ethanolic extract of adlay bran (ABE-EtOAc) in an ovalbumin (OVA)-immunized murine model. Six-week-old female BALB/c mice underwent OVA sensitization and were used as an allergy model. An orogastric gavage was used to force feed these mice with 240 mg/kg ABE-EtOAc from their sixth week through their twelfth week. Immune reactions were determined by measuring changes in Th2-type cytokine (IL-4 and IL-5) levels and production of antibodies. ABE-EtOAc was found capable of regulating the Th1/Th2 immune reaction through its regulation of IL-2 and IL-4. It also significantly reduced the production of anti-OVA IgE antibodies (10%), increased the secretion of IFN-γ and decreased the secretion of IL-6 (38%). These results suggest that adlay bran extract can reduce an allergic reaction by balancing Th1/Th2 immune responses and that it might be used in the treatment of this condition.     

Panax ginseng ameliorates airway inflammation in an ovalbumin-sensitized mouse allergic asthma model

Ethnopharmacological relevance

Panax ginseng (PG) is a medicinal herb that has been used to treat various immune diseases including asthma and COPD. In this study, we investigated the inhibitory mechanism of PG on asthma parameters in mice.

Materials and methods

BALB/c mice were sensitized with 20 μg/200 μl OVA adsorbed on 1.0 mg/50 μl aluminum hydroxide gel adjuvant by i.p. injection on days 0 and 14. Mice were then challenged with 5% OVA in PBS to the nose for 30 min once a day for 3 days, from day 20 until day 22, using a nebulizer. PG (20 mg/kg) or vehicle was administrated by i.p. injection once a day 10 min before every OVA challenge for 3 days. The recruitment of inflammatory cells into bronchoalveolar lavage fluid or lung tissues was measured. The expression of EMBP, Muc5ac, CD40, and CD40 ligand (CD40L) in lung tissues was investigated. In addition, the cytokines and mitogen activated protein (MAP) kinases were measured by RT-PCR and Western blot.

Results and conclusions

PG restored the expression of EMBP, Muc5ac, CD40, and CD40L, as well as the mRNA and protein levels of interleukin (IL)-1β, IL-4, IL-5, and tumor necrosis factor (TNF)-α. In addition, PG inhibited the numbers of goblet cells and further small G proteins and MAP kinases in bronchoalveolar lavage cells and lung tissues increased in ovalbumin-induced allergic asthma in mice. These results suggest that PG may be used as a therapeutic agent in asthma, based on reductions of various allergic responses.     

Solutes, but not cells, drain from the brain parenchyma along basement membranes of capillaries and arteries: significance for cerebral amyloid angiopathy and neuroimmunology

Elimination of interstitial fluid and solutes plays a role in homeostasis in the brain, but the pathways are unclear. Previous work suggests that interstitial fluid drains along the walls of arteries. Aims: to define the pathways within the walls of capillaries and arteries for drainage of fluid and solutes out of the brain. Methods: Fluorescent soluble tracers, dextran (3 kDa) and ovalbumin (40 kDa), and particulate fluospheres (0.02 microm and 1.0 microm in diameter) were injected into the corpus striatum of mice. Brains were examined from 5 min to 7 days by immunocytochemistry and confocal microscopy. Results: soluble tracers initially spread diffusely through brain parenchyma and then drain out of the brain along basement membranes of capillaries and arteries. Some tracer is takenf up by vascular smooth muscle cells and by perivascular macrophages. No perivascular drainage was observed when dextran was injected into mouse brains following cardiac arrest. Fluospheres expand perivascular spaces between vessel walls and surrounding brain, are ingested by perivascular macrophages but do not appear to leave the brain even following an inflammatory challenge with lipopolysaccharide or kainate. Conclusions: capillary and artery basement membranes act as 'lymphatics of the brain' for drainage of fluid and solutes; such drainage appears to require continued cardiac output as it ceases following cardiac arrest. This drainage pathway does not permit migration of cells from brain parenchyma to the periphery. Amyloid-beta is deposited in basement membrane drainage pathways in cerebral amyloid angiopathy, and may impede elimination of amyloid-beta and interstitial fluid from the brain in Alzheimer's disease. Soluble antigens, but not cells, drain from the brain by perivascular pathways. This atypical pattern of drainage may contribute to partial immune privilege of the brain and play a role in neuroimmunological diseases such as multiple sclerosis.     

A soluble thymic stromal lymphopoietin (TSLP) antagonist, TSLPR-immunoglobulin, reduces the severity of allergic disease by regulating pulmonary dendritic cells

Recent studies show that thymic stromal lymphopoietin (TSLP) plays a critical role in the upstream phase of the allergic cascade to induce T helper type 2 cell (Th2)-dominant allergic diseases. However, the effect of blocking TSLP signalling with the soluble TSLP receptor (TSLPR), TSLPR-immunoglobulin (Ig), on asthma development needs further investigation. Here, we examined the effects of TSLPR-Ig on asthmatic airway inflammation and dendritic cell (DC) function. TSLPR-Ig (comprising the extracellular domain of murine TSLPR and an IgG2a Fc tail) purified from transfected COS-7 cells reduced the expression of CD40, CD80 and CD86 on TSLP-activated DCs in vitro. We also investigated the mechanisms underlying TSLPR-Ig-mediated amelioration of allergic airway inflammation in a murine asthma model. When TSLP signalling was blocked by intratracheal administration of TSLPR-Ig prior to sensitization, allergen-specific serum IgE levels, airway tissue inflammation, inflammatory cell infiltration and Th2 cytokine levels in the bronchiolar lavage fluid (BALF) were reduced significantly. This was because of the TSLP-Ig-mediated down-regulation of co-stimulatory molecule expression on pulmonary DCs. We also transferred bone marrow-derived mature DCs (mDCs) into the airways of asthmatic mice. Intratracheal administration of TSLPR-Ig prior to the transfer of mDCs reduced eosinophilic airway inflammation and Th2 differentiation significantly. Collectively, these data suggest that local use of TSLPR-Ig prevents airway inflammation, at least in part, by regulating DC function, and that blocking TSLP signalling using TSLPR-Ig may be a novel strategy for the treatment of asthma bronchiale.     

毛大丁草抗卵清蛋白诱导的小鼠支气管哮喘作用的活性部位筛选

目的 通过卵清蛋白(ovalbumin，OVA)诱导的支气管哮喘小鼠模型，筛选毛大丁草抗哮喘的活性部位。方法 采用D101大孔吸附树脂法对毛大丁草50%乙醇提取物进行分段富集，依次洗脱得到水、60%乙醇、95%乙醇3个洗脱部位。小鼠通过腹腔注射OVA致敏、雾化吸入OVA激发来复制哮喘动物模型，在激发阶段连续6 d进行灌胃给药治疗。采用行为学评分考察不同部位对哮喘行为学的影响，利用酶联免疫吸附法测定血清、肺泡灌洗液(bronchoalveolar lavage fluid，BALF)中IL-5的浓度和血清免疫球蛋白IgE的浓度，采用HE染色对肺组织进行组织病理学评价。结果 模型组小鼠哮喘症状评分升高，血清中IgE和IL-5的水平显著升高，BALF中IL-5的水平显著升高；与模型组比较，60%乙醇段高剂量组小鼠哮喘症状明显改善，血清中IL-5的水平显著降低，BALF中IL-5的水平也显著降低。结合病理学切片观察，60%乙醇段治疗的小鼠较之模型组小鼠肺泡间隔增厚程度降低，血管周围和支气管周围炎症细胞浸润显著减少。结论 毛大丁草50%乙醇提取物的60%乙醇洗脱部位为其抗哮喘的活性部位，其化学成分主要是酚酸类、黄酮类和香豆素类。     

Involvement of brain-derived neurotrophic factor (BDNF) in MP4-induced autoimmune encephalomyelitis

The role of brain-derived neurotrophic factor (BDNF) in multiple sclerosis and experimental autoimmune encephalomyelitis (EAE) is still unclear. Here we investigate the clinical course, CNS histopathology and peripheral antigen-specific immunity in MP4-induced EAE of BDNF (−/+) mice. We demonstrate that these mice displayed less severe disease compared to BDNF (+/+) mice, reflected by decreased inflammation and demyelination. In correspondence to diminished frequencies of T and B cells in CNS infiltrates, the peripheral MP4-specific T_H1/T_H17 response was attenuated in BDNF (−/+), but not in wild-type animals. In contrast, immunization with ovalbumin triggered similar frequencies of IFN-γ- and IL-17-secreting T cells in both groups. The cytokine secretion and proliferative activity upon mitogen stimulation did not reveal any global defect of T cell function in BDNF (−/+) mice. By influencing the antigen-specific immune response in autoimmune encephalomyelitis, BDNF may support and maintain the disease in ways that go beyond its alleged neuroprotective role.     

Immunoglobulin E synthesis in parasite infection.

The infection of rats with Nippostrongylus brasiliensis (Nb) larvae enhanced IgE synthesis prior to the formation of IgE antibody specific for parasite antigens. As early as the eighth to tenth day of infection, IgE-bearing lymphocytes appeared in lymph nodes and spleen. At this time, even bone marrow contained IgE-bearing blast cells. The IgE-forming plasma cells were detected in the lymph nodes and spleen at the tenth day and their number reached maximum at the fourteenth day. The proliferation of IgE-bearing lymphocytes in the lymphoid tissues was observed in neonatally thymectomized animals, indicating that T cells are not essential for the development of IgE-B cells in the infected animals. It appears, however, that T cells are involved in the differentiation of IgE-B cells to IgE-forming plasma cells. Nonspecific proliferation of IgE-B cells and their differentiation to IgE-forming plasma cells may explain potentiation of IgE antibody formation against unrelated antigens after infection with N. brasiliensis (Nb). It was also found that T cells specific for parasite antigens were primed by infection with Nb. Evidence was obtained tht Nb-specific T cells raised by the infection collaborated with hapten-specific IgE-B cells and IgG-B cells for the secondary antihapten antibody responses. By contrast, T cells primed by immunization with parasite antigen included in alum exerted the helper function for IgG antibody response but failed to collaborate with IgE-B cells. Dissociation between the helper function for IgE and IgG antibody response indicated that parasite infection generated a favorable condition for priming T cells for the IgE antibody response.     

建立支气管哮喘大鼠模型的新方法及评价

目的 探讨建立支气管哮喘动物模型的新方法.方法 20只清洁级SD大鼠随机分为哮喘组和对照组,每组10只,哮喘组以小剂量卵蛋白(OVA)1 mg致敏并激发为大鼠哮喘模型,对照组以氢氧化铝凝胶致敏,以0.9％氯化钠溶液激发.观察2组大鼠肺组织病理、支气管肺泡灌洗液(BALF)细胞分类及血清OVA-specific IgE水...