The Initial Approach Of γδT Cells And CD4+CD25+T Cells In Asthmatic Rat And The Effect Of Dexamethasone

Objectives:to investige the role of Treg cells in the morbility and development of asthmatic rat,including the expression ofγδT cells and Foxp3 and the effect of dexamethasone on them.Methods:(1)To establish a standard rat model with male Wistar rats(200-250g).judge the model as the appearance of symptom and pathological change.(2)28 Wistar rats were randomly divided into four groups:normal control group(A),Dex control group(B),asthmatic group(C),Dex treat group(D).To observe the pathological change and the expression ofγδT cells,Foxp3 and TGF-βin the pulmo tissue with immunity histochemistry.And the change of correlated CKs in BALF with ELISA,cell differential count as well.Results:(1)TCS(total cellular score)of Group B(8.57±0.27×10~5/ml)is manifest supper than group A(2.92±0.17×10~5/ml),P＜0.01;and group C(3.30±0.29×10~5/ml)is descended, P＜0.01.In cell percentage,eosinophile(32.72±2.61%)of Group B,leukomonocyte (9.52±0.48%)and neutrophile(15.30±1.22%)are all increase than group A eosinophile (0.47±0.21%),leukomonocyte(1.30±0.21%)and neutrophile(2.68±0.51%);and in group C the percentage of phlegmonosis is obviously decrease,eosinophile(3.52±0.82%), leukomonocyte(2.40±0.28%)and neutrophile(8.37±1.19%).(2)Cytokines in BALF:Th2 CKs-IL-4,groupB(71.05±3.91)is supper than group A(14.53±3.35),(P＜0.001).Th1 CKs IFN-γ(17.67±3.53)is also more than group A(10.84±2.81),(P＜0.001).But the extent of IFN-γis less than IL-4.That means Th2 ascendent.The expression of TGF-βin lung,group B (0.27±0.02)is more than group A(0.18±0.02),(P＜0.001).In group C IL-4(24.20±3.16) is decreased,but also supper than group A,(P＜0.01);IFN-γ(12.06±3.06)is no significance difference;and TGF-βaslo decreased(0.1927±0.01700).(3)The expression ofγδT and Foxp3 in lung:in group B,they are(0.3376±0.0256)and(0.3567±0.0534)more than group A (0.2187±0.0119)and(0.2143±0.0272),P＜0.001.In group C they are both decreasedγδT cell (0.2639±0.0209),Foxp3(0.2689±0.0422),but haven't reach the normal,P＜0.05.Conclusions:(1)Sensitize rat with OVA intraperitoneal injection,than atomizate with antigen solution to copy asthmatic rat model.Judge the model as the appearance of symptoms and pathological changes for our empirical study.(2)IL-4 in asthma rats BALF are notable increased,and IFN-γ/IL-4 is more lower.It is IFN-γcorrespondence insufficient.And the expression of TGF-βincreased.(3)T regulation cells are play a important role in asthma.γδT cells及CD4+CD25+Tr are take part in asthma.They may cause Th1/Th2 disequilibrium,Th2 CKs increased.And induse inflammatory cell infiltration.(4)Dexamethasone as one of anti-inflammatory agent,is extensively utilized in asthma and other anaphylactic disease.It can inhibit the activation of T cells and the expression of Th2-cytokines.the effect may be that it can cut down the expression ofγδT and Foxp3 in lung.Thus decrease Th2 ascendant respond and reduce its cytokines,IL-4.As well suppress inflammatory cells local infiltration.It may be one mechanism of dexameth to therapy asthma.