Journal of Jilin University Medicine Edition ›› 2015, Vol. 41 ›› Issue (03): 517-521.doi: 10.13481/j.1671-587x.20150316

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Effect of intradermal inactivated Bacillus Calmette-Guérin vaccine on number of CD4+CD25+Treg cells and expression of CTLA-4 mRNA in asthmatic rats

GONG Ping, LI Yun, LUO Rui, LI Hong, TAN Yupin, LONG Yi   

  1. Department of Pediatrics, Hunan Provincial People's Hospital, Changsha 410005, China
  • Received:2014-12-05 Published:2015-08-01

Abstract:

Objective To observe the changes of number of the CD4+CD25+regulatory T cells, the expression level of CTLA-4 mRNA and the level of serum TGF-β, and to clarify the effect of inactivated Bacillus Calmette-Guerin vaccine(BCG) on the number of the CD4+CD25+regulatory T cells and CTLA-4 mRNA expression. Methods Thirty Sprague-Dawley (SD) rats were randomly divided into control group, model group and BCG group (n=10).The rats in model group and BCG group were sensitized by injecting intraperitioneally with OVA for 3 weeks;On the 22th day, they were challenged with 2% OVA for 6 weeks to built the chronic rasthma models.The rats in control group were sensitized and challenged with normal saline.The rats in BCG group were intradermally injected with inactivated BCG 3 d before sensitizing lasting 9 weeks.The airway resistances of the rats in various groups were assessed after intubation.The number of CD4+CD25+regulatory T cells and the expression level of CTLA-4mRNA were detected.The levels of serum TGF-β were detected by ELISA.The number of cells and the percentage of eosinophil(EOS) in bronchial alveolar lavage fluid (BALF) of the rats in various groups were detected. Results Compared with control group, the total number of cells and the percentage of EOS in BALF of the rats in model group were decreased (P<0.05);compared with model group, the total number of cells and the percentage of EOS in BALF of the rats in BCG group were increased(P<0.05).Compared with control group, the airway resistances of the rats in model group was increased when the concentration of histamine was 0.32 g·L-1;compared with model group, the airway resistance of the rats in BCG group was decreased when the concentration of histamine was 0.64 g·L-1.Compared with control group, the number of CD4+CD25+ regulatory T cells, the expression level of CTLA-4mRNA and the level of serum TGF-β of the rats in model group were decreased (P<0.05);compared with model group, CD4+CD25+ regulatory T cells, the expression level of CTLA-4 mRNA and the level of serum TGF-β of the rats in BCG group were increased (P<0.05). Conclusion The inactivated BCG can improve the airway inflammation and airway hyperresponsiveness in the asthmatic rats, and the mechanisms are correlated with the the number and the function of CD4+CD25+ regulatory T cells.

Key words: inactivated Bacillus Calmette-Guerin, CD4+CD25+regulatory T cells, airway inflammation, airway resistance, asthmas, rats,SD

CLC Number: 

  • R562.25