Objective:To detect the effects of recombinant BCG-Em Ⅱ/3 vaccine on apoptosis of splenocytes in mice challenged with protoscoleces of Echinococcus multilocularis.Methods:BALB/C mice were immunized with rBCG-Em Ⅱ/3 vaccine by subcutaneous injection or intranasal inoculation.After 8 weeks of immunization

all the mice were challenged with 50 protoscoleces of Echinococcus multilocularis by intraperitoneal injection.On the 18th week after infection

mice were killed to separate splenocytes and stimulated with ConA for 16～18h

then apoptosis of splenocytes was detected by Annexin V-FITC staining methods.Results:Apoptotic rate of splenocytes in all groups with or without ConA stimulation was obviously lower than that of PBS group(P<0.05 or P<0.01);Apoptotic rate of splenocytes in each group with ConA stimulation was greatly higher than that in the group without ConA stimulation(P<0.05 or P<0.01).Apoptotic rate in intranasal inoculation group was also lower than that in subcutaneous injection group(P<0.01).Conclusions:rBCG-EmⅡ/3 vaccine may inhibit apoptosis of splenocytes in mice challenged with Echinococcus multilocularis

increase the number of CD4+ T lymphocyte subsets

and enhance host’s protection against the challenge with protoscoleces of Echinococcus multilocularis.