| ObjectiveObserving the diversities of the number of the CD4+CD25+ Treg cells and the expression of the Foxp3 and the effect on the airway inflammation and airway remodeling after the intervention of the Inactivated Bacillus Calmette-Guerin Vaccine in the rat model of chronic asthma so as to explore the mechanisms of the Inactivated Bacillus Calmette-Guerin Vaccine to improve the airway inflammation and airway remodeling of asthmatic rat.Methods1. Thirty adult male Sprague-Dawley (SD) rats aged 4 weeks and weighted 200±20g were choosen and divided randomly into three groups:the asthmatic model group,the physiological saline group,the Inactivated Bacillus Calmette-Guerin Vaccine group.2. On the first day and fifteenth day, the other two groups except the physiological saline group were sensitized to be injected intraperitioneally with 10% OVA (1ml) (OVA,10% aluminium hydroxide and the inactive pertussis bacillus); On the 22th day, they were challenged with 2% OVA through Nebulized Pump, twenty minutes for each time, three times for every week, lasting six weeks to built the chronic rat asthma model. the physiological saline group were sensitized and challenged by the physiological saline.3.The Inactivated Bacillus Calmette-Guerin Vaccine group were intradermally injected with the Inactivated Bacillus Calmette-Guerin Vaccine,25μg for each time(100μl for each time), two times for every week, lasting nine weeks. the other two groups were intradermally injected with the physiological saline, 100μl for each time, two times for every week, lasting nine weeks. 4. All rats were anesthetized within 24 hours after the last challenge,①Some parts of the spleen tissue were cut off to scavenge the karyocyte and incubate with fluorescent antibody for the detection to the number of the CD4+CD25+ Treg cells;②the other parts of the spleen tissues were used to detect the expression of the Foxp3mRNA and CTLA-4mRNA through the RT-PCR;③Combined with the counts and the classifications of the bronchoalveolar lavage fluids, the airway inflammation and remodeling were analyzed by histochemistry staining with HE, Masson and AB-PAS;④The contents of TGF-P in blood plasma was detected by ELISA.Result1. The building of the rat model of chronic asthma:①All rats in the model group appeared the symptoms of the dysphoria, scratching the nose, shortness of breath, breathing nodding cyanosis, eating little, quiescence, piloerection even depilation;②The bronchoalveolar lavage fluids of the model group were prominently increased after the challenge (P<0.05); as were the percentage of the eosinophile;③The histopathology of lung tissue of the model group were manifested significantly the inflammation around the airway, the hyperplasia of the airway smooth muscle,the deposition of collagen and the increase of the goblet cells(P<0.05).2. The detection of the number of the CD4+CD25+ Treg cells:compared with the physiological saline group, the number of the CD4+CD25+ Treg cells in the model group accounted for the CD4+T cells were increasingly lowered(P<0.05); the number of the CD4+CD25+ Treg cells in the Inactivated Bacillus Calmette-Guerin Vaccine group accounted for the CD4+T cells were prominently increased compared with the physiological saline group and the model group (P<0.05).3. The content of TGF-βin blood plasma:compared with the physiological saline group, the content of TGF-βin blood plasma in the model goup were increasingly lowered(P<0.05); The content of TGF-P in blood plasma in the Inactivated Bacillus Calmette-Guerin Vaccine group were prominently increased compared with the physiological saline group and the model group (P<0.05).4. The counts and the classifications of the bronchoalveolar lavage fluids:compared with the physiological saline group, the number of the bronchoalveolar lavage fluids and the percentage of the Eosinophils in the model goup were increasingly higher(P <0.05); the number of the bronchoalveolar lavage fluids and the percentage of the Eosinophils the Inactivated Bacillus Calmette-Guerin Vaccine group were increasingly lower than those in the physiological saline group and the model group (P<0.05).5. The histopathology of lung tissue:compared with the physiological saline group, the degree of inflammatory cell around the airway in the model group were significantly higher(P<0.05), the degree of inflammatory cell around the airway in the Inactivated Bacillus Calmette-Guerin Vaccine group were significantly lower than those of the model group (P<0.05); The area of smooth muscle, the percentage of goblet cells accounting for the epithelia cell and the deposition of collagen in the model group were prominently higher than those in the physiological saline group, all of those in the Inactivated Bacillus Calmette-Guerin Vaccine group were significantly lower than those of the model group respectively (P<0.05).Conclusion1. The sensitization and challenge with OVA for six weeks can construct successfully the rat model of the chronic asthma.2. The number of the CD4+CD25+ Treg cells, the expression of the Foxp3mRNA and CTLA-4Mrna, the contents of TGF-βin blood plasma were lowered in the asthmatic rat.3. The number of the CD4+CD25+ Treg cells, the expression of the Foxp3mRNA and CTLA-4mRNA, the contents of TGF-βin blood plasma were increased in the asthmatic rat after the intervention of the Inactivated Bacillus Calmette-Guerin Vaccine.4. The Inactivated Bacillus Calmette-Guerin Vaccine can improve the airway inflammation and the airway remodeling in the asthmatic rat, the mechanisms were correlated with the the number and the function of the CD4+CD25+ Treg cells. Hong LI(Pediatrics)Directed by Yun LI... |
PDF Full Text Request