A Study On The Relationship Between Cd4~+ Cd25~+ T Regulatory Cell And Immune Tolerance In Lymph In Bronchial Asthmatic Rat

Aim:To observe the expression of CD4+CD25+Treg,IL-10 and TGF-βin lymph and blood at different time points of bronchial asthmatic and immunologic tolerated rat, as well as the effect of dexamethasone on it and investigate the relationship between asthma and immunologic tolerance.Methods:Rat model of asthma and immunologic tolerance were established in the study. Lymph and blood samples of 0h,24h,48h after the last challenge were collected from the asthma,immunologic tolerance,therapy and control groups. The percentage of CD4+CD25+Treg were detected by flow cytometer(FCM), while the levels of IL-10 and TGF-βwere determined by ELISA.Results:1. We successfully establish the rat model of asthma and immunologic tolerance, and the lymph draining experimental method.2. The percentage of CD4+CD25+Treg in the lymph and blood in cases of asthma group were significantly lower than that of the control,therapy and tolerance groups at different time points (P<0.05), there were no significant differences in the three groups (P>0.05). The percentage of CD4+CD25+Treg in lymph were significantly higher than that of blood in all the groups (P<0.05), the levels which it in lymph were 1.49,1.62,1.61 and 1.63 times of blood. There were no significant differences which the percentage of CD4+CD25+Treg in the lymph and blood of all the groups at different time points (P>0.05)3. The level of IL-10 in the lymph and plasma in cases of asthma group were significantly lower than that of the control,therapy and tolerance groups at different time points (P<0.05), there were no significant differences in the three groups (P>0.05). The level of IL-10 in lymph were significantly higher than that of plasma in all the groups(P<0.05), the levels which it in lymph were 3.33,2.74,2.26 and 2.80 times of plasma. There were no significant differences which the level of IL-10 in the lymph and plasma of all the groups at different time points (P>0.05)4. The level of TGF-B in the lymph and plasma in cases of asthma group were significantly lower than that of the control,therapy and tolerance groups at different time points (P<0.05), there were no significant differences in the three groups (P>0.05). The level of TGF-βin lymph were significantly lower than that of plasma in all the groups (P<0.05), the levels which it in plasma were 1.57,1.42,1.43 and 1.44 times of lymph. There were no significant differences which the level of TGF-βin the lymph and plasma of all the groups at different time points (P>0.05)Conclusions:1. We successfully establish the rat model of asthma and immunologic tolerance, which witnessed by pathology,differential count of BALF and detection of cytokine.2. There is a disbalance both quantity and function of CD4+CD25+Treg in the lymph of bronchial asthmatic rat, and the decrease of TGF-βwas more obviously than IL-10, to indicate the disbalance of function of CD4+CD25+Treg in lymph was more significantly than that of in blood.3. The percentage of CD4+CD25+Treg in the lymph and blood were higher than that of asthma group after constructing immunologic tolerance, which essentially achieved the level of control group; at the same time, the levels of IL-10 and TGF-βin the lymph and plasma were also higher than that of asthma group. Accordingly, we can infer immunologic tolerance may avoid the development of allergic asthma, and the establishment of immunologic tolerance can be an effective way of treating asthma.4. Which after the effect of dexamethasone on asthmatic rat, the percentage of CD4+CD25+Treg in the lymph and blood and the levels of IL-10 and TGF-βin the lymph and plasma were significantly increase at different time points, and to recover the level of control group. We can infer dexamethasone may effectively improve the quantity and function of CD4+CD25+Treg in bronchial asthmatic rat, and play an inhabitation of inflammation action of asthma.