ABSTRACT
AIM:The bacillus calmette-guerin(BCG) vaccine is the most widely used Th1-inducing vaccine.In recent years,some studies argued that mycobacterium vaccae can be used as adjuvant to induce regulatory T cells(Treg) and then suppress asthmatic airway inflammation.We previously have engineered recombined BCG that expressed Der p2 of house dust mites(Der p2 rBCG) on the cell wall.The aim of this study is to investigate the immune regulatory mechanisms of Der p2 rBCG.METHODS:Mice were vaccined with PS,BCG or rBCG.The relative proportion and the absolute numbers of related Tregs in spleen cells were analyzed.The suppressive activity of Der p2 rBCG-induced CD4+CD25+ T cells was detected both in vitro and in vivo.RESULTS:(1) Der p2 rBCG induced a CD4+CD25+Foxp3+ T cell subtype.(2) Der p2 rBCG-induced CD4+CD25+ T cells suppressed the proliferation of Th2 effector cells in vitro in an antigen-specific way.(3) Der p2 rBCG-induced CD4+CD25+ T cells mediated Der p2 specific suppression of airway allergy in vivo.CONCLUSION:Der p2 rBCG induces a CD4+CD25+Foxp3+ T cell subtype,which suppresses inflammation in allergic airway in a mouse model.