Expression of Interleukin-17 in Lung and Peripheral Blood of Asthmatic Rats and the Influence of Dexamethasone

The expression of interleukin-17(IL-17) in lung and peripheral blood of asthmatic rats and the influence of dexamethasone,and the role of IL-17 in the pathogenesis of asthma were investigated.Thirty Sprague-Dawley(SD) adult rats were randomly divided into three groups(n=10 in each group):normal group,asthmatic group,and dexamethasone-interfered group.Rat asthmatic model was established by intraperitoneal(i.p.) injection of 10% ovalbumin(OVA) and challenge with 1% OVA via inhalation.Rats in dexamethasone-interfered group were pretreated with dexamethasone(2 mg/kg,i.p.) 30 min before each challenge.The expression of IL-17 protein in serum and bronchoalveolar lavage fluid(BALF) was detected by ELISA.The expression of IL-17 mRNA in peripheral blood mononuclear cells(PBMC) and BALF cells was semi-quantitatively detected by RT-PCR.The expression of IL-17 protein in serum and BALF of asthmatic rats was significantly elevated as compared with normal rats and dexamethsone-interfered rats(P<0.01),and there was significant difference between normal rats and dexamethsone-interfered rats(P<0.05).The expression of IL-17 mRNA in PBMC and BALF cells of asthmatic rats was markedly increased as compared with normal rats and dexamethsone-interfered rats(P<0.01),and significant difference was found between normal rats and dexamethsone-interfered rats(P<0.05).It was concluded that the expression of IL-17 was increased significantly in asthmatic rats and could be inhibited partly by dexamethasone,suggesting that IL-17 might play an important role in the pathogenesis of asthma as an inflammation regulation factor.     

Effect of All-trans Retinoic Acid on Airway Inflammation in Asthmatic Rats and Its Mechanism

The inhibitive effects of all-trans retinoic acid (ARTA) on airway inflammation in asthmatic rats and its mechanism on the basis of the regulation of nuclear factor kappaB (NF-kB) were explored. Thirty-two SD rats were randomly divided into 4 groups: control group, asthma group,dexamethasone treatment group and retinotic acid treatment group. The total and differential cell counts in the collected bronchoalveolar lavage fluid (BALF) were measured. The pathological changes in lung tissues were estimated by scoring. The expression of NF-kB inhibitor (IkBa), NF-kB,intercellular adhering molecule-1 (ICAM-1) in lung tissue was detected by immunohistochemical method. The results showed that in the two treatment groups, the total cell counts and proportion of inflammatory cells in BALF were significantly reduced, but there was no significant difference in differential cell counts in BALF between them. The pathological changes in lung tissues in the treatment groups were significantly attenuated as compared with asthma group. Except the epithelial injury in retinotic acid treatment group was milder than in dexamethasone treatment group, the remaining lesions showed no significant difference between them. In the two treatment groups, the expression of IkBa was increased, while the expression of NF-kB and ICAM-1 decreased with the difference between the two groups being not significant. It was concluded that the similar anti-inflammatory effects and mechanism of ATRA on airway in asthmatic rats to those of dexamethasone were contributed to the increase of cytoplasmic IkBa content and suppression of NF-kB activationand expression.     

Expression of Leukemia Inhibitory Factor in Airway Epithelial Tissue of Asthmatic Rats

In order to investigate the expression of leukemia inhibitory factor(LIF) in airway epithelial tissues of normal and asthmatic rats,the influence of dexamethasone and the role of LIF in pathogenesis of asthma,30 Sprague-Dawley(SD) rats were randomly divided into 3 groups(10 for each group):normal group,asthma model group,and dexamethasone-interfered group.In asthma model group and dexamethasone-interfered group,asthma rat models were established by intraperi-toneal(i.p.) injection of 10% ovalbumin(OVA) and challenge with 1% OVA via inhalation.Rats in dexamethasone-interfered group were pretreated with dexamethasone(2 mg/kg,i.p) 30 min before each challenge.The expression of LIF protein in lung was detected by immunohistochemistry.The results showed that LIF protein was mainly expressed in cytoplasm of bronchial epithelial cells.The expression of LIF protein in the airway epithelial tissue of asthma model group was significantly higher than that in normal group and dexamethasone-interfered group(P<0.01),but there was no sig-nificant difference between normal group and dexamethasone-interfered group(P>0.05).It was con-cluded that the expression of LIF was increased significantly in the airway epithelial tissue of the asthma rats,and dexamethasone could down-regulate the expression of LIF.It was suggested that LIF might play an important role in the pathogenesis of asthma as an inflammation regulator.     

CD69 expression on airway eosinophils and airway inflammation in a murine model of asthma

Background Asthma is a chronic airway disease with inflammation characterized by physiological changes （airway hyper-responsiveness, AHR） and pathological changes （inflammatory cells infiltration and mucus production）. Eosinophils play a key role in the allergic inflammation. But the causative relationship between eosinophils and airway inflammation is hard to prove. One of the reasons is lack of activation marker of murine eosinophils. We investigated the expression of CD69 on murine eosinophils in vitro, the relationship between the expression of CD69 on eosinophils from peripheral blood and bronchoalveolar lavage fluid and on airway inflammation in asthmatic mice. Methods Eosinophils from peripheral blood of IL-5 transgenic mice （NJ.1638） were purified. Mice were divided into five groups： wild type mice sensitized and challenged with saline （WS group）, wild type mice sensitized and challenged with ovalbumin （WO group）, IL-5^-/- mice sensitized and challenged with saline and transferred with purified eosinophils （ISE group）, IL-5^-/- mice sensitized and challenged with OVA and transferred with purified eosinophils （IOE group）, IL-5^-/- mice sensitized and challenged with OVA and transferred with purified eosinophils, pretreated with anti CD4 monoclonal antibody （IOE＋antiCD4mAb group）. IL-5^-/- mice were sensitized with OVA at day 0 and day 14, then challenged with OVA aerosol. On days 24, 25, 26 and 27 purified eosinophils were transferred intratracheally to IL-5^-/- mice. On day 28, blood and BALF were collected and CD69 expression on eosinophils measured by flowcytometry. Results Purified eosinophils did not express CD69. But eosinophils cultured with PMA＋MA, IFN- T, IL-5 or GM-CSF expressed CD69 strongly. Eosinophils from blood of WO, WS group did not express CD69 at all. The numbers of eosinophils in BALF of WO group, IOE group, ISE group and IOE＋antiCD4mAb group were significantly higher than in mice of WS group which did not have eosinophils at all. CD69 expression on eosinophils in BALF of IOE and WO groups was strong. Eosinophils in BALF of ISE and IOE＋antiCDmAb groups did not express CD69. The mucus production result was similar to CD69 expression. There were eosinophils infiltration in lung slides of all groups except WS group. Conclusion Activation in airway of eosinophils could directly lead to airway inflammation.     

Involvement of CD4^＋CD25^＋ regulatory T cells in the pathogenesis of polycythaemia vera

Background Regulatory T cells （mreg） have been shown to play an important role in the regulation of hematopoietic activity. However, there is no information about the effect of Treg cells in the pathogenesis of polycythaemia vera （PV）. Methods In this study, we investigated the percentage and function of Treg cells in the peripheral blood of 21 PV patients and 25 healthy donors, mreg cells were identified and characterized as CD4^＋CD25^＋FOXP3^＋ by flow cytometry. The suppressive activity of CD4^＋CD25^＋ Treg cells was assessed by the proliferation and cytokine secretion of the co-cultured CD4^＋CD25^- fractions. Results The results showed that the percentage of Treg cells in the peripheral blood of PV patients significantly increased compared to healthy controls （（10.93±4.02）% vs （5.86±1.99）%, P 〈0.05）. Moreover, the mRNA and protein expression of FOXP3 was higher in CD4^＋CD25^＋ Treg cells. Coordinately, when co-cultured with the activated CD4^＋CD25^- cells, the CD4^＋CD25^＋ Treg cells showed enhanced suppressive function in PV. Yet, the underlying mechanism for the increased frequency and function of CD4^＋CD25^＋ Treg cells is still to be clarified. Conclusion Treg cells expansion might account for the abnormal T cell immunity in PV patients and thus contribute to the pathogenesis of PV.     

Linker for activation of T cells contributes to airway inflammation in an asthmatic mouse model

Background Allergic asthma is associated with airway inflammation and hyperresponsiveness caused by dysregulated production of cytokines secreted by allergen-specific helper T-type 2 （Th2） cells. The linker for activation of T cells （LAT） is a membrane-associated adaptor protein, which has been shown to take part in regulating T cell receptor （TCR） signaling and T cell homeostasis. In this study, we established an asthmatic mouse model to examine the changes in LAT levels during allergic airway disease and the effects of LAT transgenic expression on airway inflammation. Methods T cells from mouse lung tissues were isolated from allergen challenged （ovalbumin （OVA）） and control mice, and the purity of these isolated T cells was examined by fluorescence-activated cell sorter （FACS）. Semi-quantitative RT-PCR and Western blotting were used to detect the expression of the LAT gene and LAT protein, respectively. After an intranasally administered mixture of pCMV-HA-LAT plasmid and Lipofectamine 2000, 24 hours before and 72 hours after allergen challenge, the BALF cell count and the differential cytologies were studied. In addition, IL-4 and IFN-γ levels in the BALF were determined by ELISA, and pathological changes in lung tissues were observed. Results LAT protein and mRNA expression were decreased in lung T cells in a mouse model of allergen-induced airway disease. After intranasal administration of pCMV-HA-LAT, histopathological examination of the lungs showed that intervention with LAT overexpression prevented mice from developing airway inflammation, and the number of total cells, eosinophils, neutrophils, and lymphocytes in the BALF was reduced significantly compared with the OVA sensitized and challenged group. In addition, the Th2 cytokine IL-4 decreased, while the Thl cytokine IFN-γ increased compared to the OVA sensitized and challenged group or the OVA sensitized group plus pCMV-HA treatment. Conclusion This study demonstrates that LAT might effectively diminish Th2 cytokine responses, lung histopathological changes and lung inflammation to allergen challenge in a model of expedmentally induced asthma.     

Low-intensity aerobic exercise training attenuates airway inflammation and remodeling in a rat model of steroid-resistant asthma

Background Aerobic exercise can improve symptoms,reduce airway inflammation,and even ameliorate airway remodeling in asthmatic animals and patients.However,previous studies have focused mainly on the effect of aerobic exercise on steroid-sensitive asthma （SSA）.The goals of this study were to determine the effect of low-intensity aerobic exercise training on airway hyperresponsiveness,inflammation,and remodeling in a rat model of steroid-resistant asthma （SRA） and to identify the potential mechanisms underlying these effects.Methods Endotoxin-free ovalbumin with or without lipopolysaccharide were applied to establish rat models of SRA and SSA,respectively.Airway hyperresponsiveness,inflammation,remodeling,expression of interleukin （IL）-25,IL-33,thymic stromal lymphopoietin （TSLP）,high mobility group box-1 （HMGB1）,and IL-17 in bronchoalveolar lavage fluid （BALF）,and the role of dexamethasone （DXM） were compared between these two asthmatic rat models.The effect of low-intensity aerobic exercise training and anti-HMGB1 treatment on airway hyperresponsiveness,inflammation,and remodeling in SRA rats also was evaluated.Results SRA rats developed neutrophil-dominated airway inflammation （（29.5±4.1）％ of the total cell numbers in BALF）,whereas SSA rats developed eosinophil-dominated airway inflammation （（24.0±6.1）％ of the total cell numbers in BALF）.Compared with SSA rats,SRA rats had more severe airway hyperresponsiveness,lower levels of IL-25 （（33.6±10.3） vs.（104.8±24.9） pg/ml）,IL-33 （（87.5±25.0） vs.（226.6±40.7） pg/ml）,and TSLP （（1 933.2±899.5） vs.（7 224.0±992.1） pg/ml）,and higher levels of HMGB1 （（21.2±4.5） vs.（5.4±1.6） ng/ml） and IL-17 （（780.5±261.7） vs.（291.4±76.4） pg/ml） in BALF （all P ＜0.05）.However,there was no significant difference in goblet cell hyperplasia,subepithelial collagen thickness,and airway smooth muscle remodeling between the two groups.Compared with control SSA rats,airway hyp     

Functional mechanism of Pingchuanning Decoction on adjustment of clara cell secretory protein in airway remodeling of asthmatic rats

OBJECTIVE:To study the functional mechanism of Pingchuanning Decoction in treatment of airway remodeling in asthmatic rats.METHODS:Eighty healthy Wistar male rats were randomized into eight groups(n=10 rats each):Normal group,Asthma model group,Dexamethasone group,Guilong Kechuanning group,Xiaoqinglong Decoction group,and Pingchuanning Decoction low-,middle-,and high-dose groups.The rats of all but the Normal group were made into asthma models through intraperitoneal injection and aerosol inhalation of ovalbumin.All treatments were administered at the first stimulation of asthma onset(third week of modeling),and the rats were killed after stimulating asthma attacks for 4 weeks.The general conditions of rats and pathomorphological changes of the lung tissues were observed.The expression of nerve growth factor(NGF) of the lung tissues was measured with immunohistochemical methods,and the content of Clara cell secretory protein(CCSP) mRNA was determined with RT-PCR.RESULTS:Compared with the Normal group,the contents of NGF and CCSP mRNA in the lung tissues of the Model group were significantly changed(P<0.01).Compared with the Model group,the indices of Pingchuanning Decoction and other treatment groups were improved to some extent(P<0.05 or P<0.01).CONCLUSIONS:Pathological changes of airway inflammation and remodeling were present in these rat asthma models.Pingchuanning Decoction had an intervention effect on these experimental models.Its functional mechanism may be related to multiple factors,including alleviation of airway inflammation,relief of bronchial smooth muscle spasm,and inhibition of airway remodeling.     

Analysis of CD4^＋CD25^＋ Regulatory T Cells and Foxp3 mRNA in the Peripheral Blood of Patients with Asthma

The changes of CD4 CD25 regulatory T cells (CD4 CD25 Treg) and Foxp3 mRNA in peripheral blood mononuclear cells (PBMCs) from patients with asthma were investigated in order to elucidate the possible roles of CD4 CD25 Treg in the development of asthma. The peripheral blood samples were collected from 29 healthy controls (normal control group) and 78 patients with asthma which included 30 patients in exacerbation group, 25 patients in persistent group, and 23 patients in remission group. By using flow cytometry and RT-PCR, the CD4 CD25 Treg ratio and Foxp3 mRNA in PBMCs were detected. The CD4 CD25 Treg ratio and Foxp3 mRNA in PBMCs of exac-erbation and persistent groups were lower than that of remission and normal control groups (P<0.05). Although the CD4 CD25 Treg ratio and Foxp3 mRNA of remission group were also lower than that of normal control group, there was no significant difference between them (P>0.05). As compared with persistent group, exacerbation group had lower CD4 CD25 Treg ratio and Foxp3 mRNA (P<0.05). It was indicated that the decrease of CD4 CD25 Treg ratio and its function in PBMCs may be responsible for pathogenesis of asthma.     

丹参注射液对哮喘大鼠气道炎症及CD4+CD25+调节性T细胞的影响

目的 观察丹参注射液对支气管哮喘(哮喘)大鼠气道炎症和CD4 CD25 调节性T细胞(CD4 CD25 Tr)的影响,探讨丹参注射液治疗哮喘的新机制.方法 30只Wistar大鼠随机分成正常对照组、哮喘组、丹参治疗组.计数支气管肺泡灌洗液(BALF)中细胞总数并分类,应用苏木精一伊红染色行肺组织病理学检查,流式细胞仪检测外周血单个核细胞(PBMCs)中CD4 CD25 Tr的比例.结果 丹参治疗组BALF细胞总数及淋巴细胞、中性粒细胞和嗜酸性粒细胞(Eos)百分率较哮喘组均明显减少(P<0.05,P<0.01),与正常对照组比较差异无显著性意义(均P>0.05).病理组织学显示:丹参治疗组较哮喘组肺组织炎性细胞浸润明显减少.哮喘组PBMCs中CD4 CD25 Tr的比例较正常对照组明显减少(P<0.05),丹参治疗组CD4 CD25 Tr的比例较哮喘组明显增加(P<0.05).结论 丹参注射液可减轻哮喘大鼠气道炎症反应,其机制可能与促进CD4 CD25 Tr的产生有关.     

特异性免疫治疗对哮喘大鼠转化生长因子-β1和CD4＋CD25＋调节性T细胞的影响

目的 探讨特异性免疫治疗（specific immunotherapy,SIT）对哮喘大鼠转化生长因子-β1（TGF-β1）和CD4＋CD25＋调节性T细胞（CD4＋CD25＋Tr）的影响.方法 40只健康雄性清洁级Wistar大鼠随机分为哮喘组、正常对照组、SIT对照组和SIT治疗组4组,每组10只.通过卵蛋白（OVA）雾吸减敏的方法对致敏大鼠进行SIT,观察各组支气管肺泡灌洗液（BALF）中细胞分类及计数结果、血清和BALF中TGF-β1水平及外周血CD4＋CD25＋Tr百分率变化.结果 哮喘组血清和BALF中TGF-β1水平分别高于正常对照组（均P＜0.01）和SIT治疗组（P＜0.05或0.01）;正常对照组外周血CD4＋CD25＋Tr百分率显著高于哮喘组（P＜0.01）和SIT治疗组（P＜0.01）,而SIT治疗组CD4＋CD25＋Tr百分率高于哮喘组（P＜0.05）.结论 特异性免疫治疗可下调哮喘大鼠体内TGF-β1水平和纠正调节性T细胞的缺失状态.     

哮喘患儿急性发作期CD4+ CD25+ 调节性 T细胞水平和体质量指数的关系

 【目的】 探讨急性发作期哮喘患儿外周血CD4+ CD25+ 调节性T细胞(Tr)的变化及其与体质量指数(BMI)的关系&;#65377; 【方法】 外周血来自70例哮喘发作组患儿&;#65380;30例缓解组和50例正常对照组小儿&;#65377;将哮喘发作组再分为体质量正常组(40例)和超重组(30例)&;#65377;应用流式细胞术检测患儿外周血的Tr细胞数变化,并计算患儿的BMI&;#65377; 【结果】 急性发作期组患儿外周血Tr水平 [(6.17 ± 1.72)%]明显低于缓解期组患儿[(7.56 ± 1.48)%]和对照组儿童[(7.13 ± 1.48)%](P < 0.05),而缓解期患儿外周血Tr水平与对照组儿童无明显差异(P > 0.05)&;#65377;正常体质量哮喘患儿CD4+ CD25+ Tr水平[(6.34 ± 1.71)%]明显高于超重患儿[(4.74 ± 1.20)%](P < 0.05)&;#65377;哮喘组患儿外周血CD4+ CD25+ Tr水平[(6.17 ± 1.72)%]与其BMI水平(16.00 ± 2.14)呈显著的负相关(rp = -0.814,P < 0.05)&;#65377; 【结论】 外周血Tr水平在哮喘患儿发作期显著降低,而在超重的患儿更低,且其水平与患儿的BMI呈显著的负相关&;#65377;     

CD4~+CD25~+调节性T细胞对哮喘大鼠免疫功能影响

目的:观察CD4+CD25+调节性T细胞(CD4+CD25+Treg)对CD4+CD25-T细胞增殖和Th1/Th2细胞因子分泌的影响,探讨其在哮喘气道炎症中的作用机制。方法:将哮喘大鼠CD4+CD25-T细胞分别与卵白蛋白(OVA)免疫耐受大鼠CD4+CD25+Treg细胞和哮喘大鼠CD4+CD25+Treg细胞联合培养,3H胸腺嘧啶核苷(3H-TdR)掺入法测量细胞增殖情况,ELISA检测细胞IL-4、IL-5和IFN-γ含量。结果:OVA耐受大鼠CD4+CD25+Treg细胞能抑制CD4+CD25-T细胞增殖和Th2细胞因子分泌(P<0.05);哮喘大鼠CD4+CD25+Treg细胞可明显抑制IFN-γ的分泌(P<0.05)。结论:OVA免疫耐受大鼠CD4+CD25+Treg细胞可能通过抑制哮喘大鼠CD4+CD25-T细胞增殖和影响Th1/Th2平衡发挥作用,哮喘大鼠CD4+CD25+Treg细胞存在功能异常,可能与哮喘的发病有关。     

Effects of glucocorticoid and cysteinyl leukotriene 1 receptor antagonist on CD34+ hematopoietic cells in bone marrow of asthmatic mice

Background Corticosteroids remain the most effective therapy available for asthma. They have widespread effects on asthmatic airway inflammation. However, little is known about the effects of corticosteroids on the production of bone marrow inflammatory cells in asthma. This study observed the effects of glucocorticoid and cysteinyl leukotriene 1 receptor antagonist on CD34+ hematopoietic cells, so as to explore the possible effectiveness of a bone marrow-targeted anti-inflammatory strategy. Methods Balb/c mice were sensitized and challenged with ovalbumin (OVA) to establish an asthmatic model. For two consecutive weeks, asthmatic mice were challenged with OVA while being given either prednisone, montelukast, prednisone plus montelukast, or sterile saline solution. The mice were killed 24 hours after the last challenge with OVA, and bronchoalveolar lavage fluid (BALF), peripheral blood, and bone marrow were collected. Eosinophils in peripheral blood and BALF, and nucleated cells in BALF, peripheral blood, and bone marrow were counted. The percentages of CD34+ cells, CD4+ T lymphocytes and CD8+ T lymphocytes among nucleated cells in peripheral blood and bone marrow were counted by flow cytometry. Immunocytochemistry and in situ hybridization were employed to detect expression of CD34 and interleukin (IL)-5Rα mRNA (CD34+ IL-5Rα mRNA+ cells) among bone marrow hematopoietic cells. Results Compared with the sterile saline solution group, the number of eosinophils in BALF and peripheral blood, CD34+ cells in peripheral blood and bone marrow, and CD34+ IL-5Rα mRNA+ cells in bone marrow of mice from the prednisone and prednisone plus montelukast groups were significantly lower （P&lt;0.01）. The number of eosinophils in BALF from the montelukast group was also significantly lower （P&lt;0.05）. Conclusions The results suggest that, in this asthmatic mouse model, prednisone probably inhibits proliferation, differentiation, and migration of CD34+ cells in bone marrow, blocks eosinophilopoiesis in bone marrow, and interferes with eosinophil migration into peripheral blood and subsequent recruitment in the airway. In addition, montelukast may suppress eosinophil infiltration into the lungs of asthmatic mice. However, a significant inhibitory effect of montelukast on the proliferation and migration of CD34+ cells and a cooperating effect with prednisone on bone marrow of asthmatic mice were not observed.     

皮内注射灭活卡介苗对哮喘大鼠CD4+CD25+Treg细胞数量和CTLA-4 mRNA表达的影响

目的:探讨皮内注射灭活卡介苗(BCG)后哮喘大鼠CD4⁺CD25⁺Treg细胞数量、细胞毒性T 淋巴细胞抗原4(CTLA-4)的表达及血清转移生长因子β(TGF-β)水平变化,阐明灭活BCG对CD4⁺CD25⁺Treg细胞数量及CTLA-4 mRNA表达的影响。方法:30只健康雄性成年SD大鼠随机分为:对照组、模型组和BCG组,每组10只;除对照组外,模型组和BCG组大鼠采用卵清蛋白(OVA)致敏3周;再激发6周,构建大鼠慢性哮喘模型。BCG组大鼠在致敏前3 d开始皮内注射BCG,共9周。各组大鼠均行气道高反应性检测,检测CD4⁺CD25⁺Treg细胞数量及CTLA-4 mRNA相对表达水平,行肺泡灌洗液(BALF)中细胞总数及嗜酸性粒细胞(EOS)百分比计数,检测各组大鼠血清中TGF-β水平。结果:模型组大鼠BALF中细胞总数及EOS百分比明显高于对照组(P<0.05),BCG组明显低于模型组(P<0.05)。组胺质量浓度从0.32 g·L^-1开始,模型组和BCG组大鼠气道阻力明显高于对照组 (P<0.05);组胺质量浓度从0.64 g·L^-1开始, BCG组大鼠气道阻力明显低于模型组(P<0.05)。模型组大鼠CD4⁺CD25⁺Treg细胞/CD4⁺细胞数量明显低于对照组(P<0.05),BCG组明显高于模型组(P<0.05)。模型组大鼠CTLA-4 mRNA相对表达水平明显低于对照组(P<0.05),BCG组明显高于模型组(P<0.05)。模型组大鼠血清TGF-β水平明显低于对照组(P<0.05),BCG组明显高于模型组(P<0.05)。结论:灭活BCG改善气道炎症和气道阻力作用可能与恢复CD4⁺CD25⁺Treg细胞数量及功能有关联。     

CD8+CD28-T细胞在哮喘小鼠发病机制中的作用及地塞米松对其的影响

目的 探讨CD8+CD28-T细胞在哮喘发病机制中的作用及地塞米松对该细胞的影响.方法 30只BALB/c小鼠随机分为哮喘组、地塞米松组、正常对照组,各10只.哮喘组和地塞米松组给予卵白蛋白致敏后雾化吸入卵白蛋白溶液,地塞米松组每次雾化吸入前腹腔注射地塞米松1 mg/kg,各组分别于末次雾化激发后测定小鼠的气道反应性;对支气管肺泡灌洗液(BALF)行细胞总数、嗜酸性粒细胞(EOS)计数;取肺组织作HE染色病理切片;测BALF中IgE含量;流式细胞仪检测小鼠血、BALF中CD8+CD28-T细胞占淋巴细胞百分比;分析BALF中IgE、EOS计数与血液中CD8+CD28-T细胞百分比的相关性.结果 哮喘组、地塞米松组气道反应性明显高于正常对照组.哮喘组BALF中细胞总数和EOS计数分别为(5.56±4.06)× 102/L和(3.29±2.23)× 102/L,均明显高于地塞米松组[(2.59±1.69)× 102/L,P=0.044和(1.11±0.73)×102/L,P=0.008]及正常对照组[(0.91±0.65)×102/L,P=0.003和(0.43±0.37)× 102/L,P=0.001)];而后两组之间差异均无统计学意义(均P>0.05).哮喘组、地塞米松组、正常对照组BALF中IgE含量分别为(23.85±5.97)g/L、(13.15±2.22)g/L、(6.54±1.03)g/L,三组间差异有统计学意义(F=38.558,P=0.000).哮喘组、地塞米松组、正常对照组CD8+CD28-T细胞百分比在外周血中分别为(18.68±4.12)%、(13.43±2.90)%、(8.43±4.60)%;在BALF中分别为(1.25±0.40)%、(0.66±0.49)%、(0.21±0.19)%,组间差异均有统计学意义(F=11.837,P=0.001;F=12.885,P=0.000).哮喘组BALF中IgE含量和EOS计数与外周血中CD8+CLY28-T细胞百分比均呈正相关(r=0.864,P=0.012和r=0.804,P=0.029).结论 CD8+CD28-T细胞数量与哮喘小鼠气道炎症有明显相关性,地塞米松可有效抑制哮喘气道炎症并可能抑制了CD8+CD28-T细胞的表达和功能.

Abstract：

Objective To explore whether or not CD8+ CD28- T cell play a pathogenic role in asthma and detect the effects of dexamethasone ( DXM ). Methods A total of 30 mice were randomly divided into 3 groups: asthmatic group, DXM group and control group ( n = 10 each). The asthmatic and DXM groups were sensitized twice and inhaled ovalbumin. The DXM Group received an intraperitoneal injection of DXM lmg/kg before inhaling ovalbumin. After successful modeling, 3 mice were selected randomly from each group to measure the airway responsiveness. Also a bronchoalveolar lavage cytological study was performed and lung tissue sections were prepared for histopathologic examination to evaluate the airway inflammation. The content of IgE in bronchoaleolar lavage fluid ( BALF) was detected with a murine IgE ELISA kit. And the fractions of CD8 + CD28- T cell of peripheral blood and BALF were tested by flow cytometry to analyze the correlation between IgE, eosinophils ( EOS) of BALF and CD8 + CD28 - T cell of blood. Results The airway hyperresponsiveness in asthmatic and DXM groups were significantly higher than that in the control group. The number of total cells and EOS of BALF in the asthmatic group [ ( 5. 56 ±4. 06) × 102/L; (3. 29 ±2. 23) × 102/L] were significantly higher than that in control group [ (0. 91 ±0.65)×102/L, P = 0.003; (0.43 ±0.37) × 102/L, P = 0.001] and DXM group [(2.59 ±1.69) ×102/L, P =0.044; (1. 11 ±0.73) ×l02/L, P = 0.008]; while the DXM group was insignificantly higher than the control group (P=0. 234, P=0. 363). There were significant differences in the contents of IgE of BALF for the asthmatic, DXM and control groups [ (23. 85 ±5. 97) g/L, (13. 15 ±2.22) g/L, (6.54±1. 03) g/L, F = 38. 558, P = 0. 000 ] . The percentages of CD8 + CD28- T cell in peripheral blood in asthmatic and DXM groups [ (18. 68 ±4. 12)% and ( 13.43 ± 2. 91) % ] were significantly higher than those in control mice [ (8. 43 ± 4. 60) % , both P < 0. 05 ]. The percentages of CD8 + CD28 - T cell of BALF in asthmatic group and DXM group [(1.25±0. 40)% and (0. 66 ± 0. 49) % ] were also significantly higher than those in control mice [ (0. 21 ± 0. 19) % , both P < 0. 05 ]. The percentages of CD8 + CD28 - T cell of blood and BALF in the DXM mice were significantly lower than those in asthmatic group. The correlations between IgE ( r = 0. 864, P = 0. 012), EOS ( r = 0. 804, P = 0.029) and CD8 + CD28- T cell were significant. Conclusion The fraction of CD8 + CD28- T cell is closely correlated with the inflammation of asthmatic airway. The airway hyperresponsiveness and inflammation in asthmatic mice may be relieved by DXM through its effect of inhibiting the expression of CD8 + CD28- T cell.     

黄芪对哮喘小鼠CD4^＋CD25^＋调节性T细胞及IL-4IFN-γIL-10的影响

目的探讨黄芪对哮喘小鼠CD4^＋CD25^＋调节性T细胞及IL-4、IFN-γI、L-10的影响。方法将BALB/c小鼠30只随机分为对照组、哮喘组和黄芪组。以卵蛋白（OVA）致敏激发法制备小鼠哮喘模型。酶联免疫吸附试验（ELISA）法检测支气管肺泡灌洗液（BALF）中IL-4、IFN-γ、IL-10及血清中IL-10的含量;流式细胞术（FCM）、反转录聚合酶链反应（RT-PCR）分别检测小鼠脾脏中CD4＋CD25＋调节性T细胞数量及FoxP3 mRNA表达情况。结果哮喘组小鼠BALF中IL-4含量明显高于对照组（P〈0.01）而低于黄芪组（P〈0.01）。与对照组相比,哮喘组小鼠BALF中IFN-γI、L-10、血清中IL-10含量及脾脏中CD4＋CD25＋调节性T细胞数量、FoxP3 mRNA表达水平明显降低（P〈0.01）;而黄芪组的上述改变较哮喘组显著增加（P〈0.05）。结论 CD4^＋CD25^＋调节性T细胞参与了支气管哮喘的发病过程,黄芪可通过上调CD4^＋CD25^＋调节性T细胞、FoxP3 mRNA的表达及增加IL-10含量减轻哮喘炎症。     

哮喘小鼠CD4^＋CD25^＋调节性T细胞与气道炎症反应的关系

目的 观察哮喘小鼠外周血CD4^＋CD25^＋调节性T细胞（CD4^＋CD25^＋Treg）数量的改变及其与气道炎症反应的关系。方法健康6周龄SPF级BALB/c小鼠20只,随机分为2组：正常对照组（A组）、哮喘模型组（B组）,B组以卵白蛋白（OVA）致敏激发方法建立小鼠哮喘模型;流式细胞术检测小鼠外周血CD4^＋CD25^＋Treg占淋巴细胞的比例;检测小鼠支气管肺泡灌洗液（BALF）炎症细胞数;BALF炎症细胞总数、嗜酸性粒细胞数分别与外周血CD4^＋CD25^＋Treg作相关分析。结果A组、B组小鼠外周血CD4^＋CD25^＋Treg占淋巴细胞比例分别为（5．81±0．76）％、（3．21±0．74）％,差异有统计学意义（P〈0．05）BALF炎症细胞总数、嗜酸性粒细胞数与外周血CD4^＋CD25^＋Treg呈负相关,相关系数分别为-0．929和-0．920。差异有统计学意义（P〈0．001）结论哮喘小鼠外周血CD4^＋CD25^＋Treg占淋巴细胞比例较正常对照组显著减少。且与哮喘小鼠气道炎症反应密切相关。     

Relationship between bone marrow-derived CD34+ cells expressing interleukin-5 receptor messenger RNA and asthmatic airway inflammation

Background Asthma is clinically related with the degree of eosinophilic inflammation.How asthmatic airway inflammation is affected is still poorly understood. So the effects of bone marrow-derived hematopoietic cells expressing CD34 (CD34+) and interleukin-5 (IL-5) receptor messenger RNA (IL-5R mRNA+) on asthmatic airway inflammation were investigated.Methods Balb/c mice were sensitized and challenged by ovalbumin (OVA) to establish an asthmatic model while control mice were sensitized and exposed to sterile saline. The mice were killed at different time points after being challenged by OVA and sterile saline. Then, bronchoalveolar lavage fluid (BALF), peripheral blood (PB) and bone marrow (BM) were prepared. Eosinophils in PB (PBEOS) and BALF (BALFEOS), nuclear cells in BALF, PB and BM were counted. By flow cytometry, the percentage of CD34+ cells to nucleated cells in PB, BM and the relative number of CD34+ cells in PB (PBCD34+) and BM (BMCD34+) were calculated. Immunocytochemistry and in situ hybridization were used to investigate the hematopoietic cells with co-localized expression of CD34 and IL-5R mRNA in BM (BMCD34+IL-5R mRNA+). The percentage of BMCD34+IL-5R mRNA+ to BMCD34+ was calculated. Results Twelve hours after challenge by OVA, BALFEOS and PBEOS in the experimental group were significantly higher than those in the control group （P&lt;0.01). Twenty-four hours after OVA challenge, BALFEOS, PBEOS and BMCD34+IL-5R mRNA+ were elevated maximally, significantly different from those in the control group （P&lt;0.01). Forty-eight hours after OVA challenge, BALFEOS and BMCD34+IL-5R mRNA+ were still significantly higher than those of the controls （P&lt;0.01). The other markers reverted to normal. In 60 mice, BMCD34+IL-5R mRNA+ was closely correlated with the BALEOS, PBEOS, BMCD34+ and BMCD34+ （%) （P&lt;0.05).Conclusions The amount of CD34+ cells expressing IL-5R mRNA increased in the BM of asthmatic model mice, which favors eosinophilopoiesis and eosinophilic airway inflammation. A signal pathway exists between the lungs and the bone marrow, which is involved in the initiation and maintenance of asthmatic airway inflammation.