Regulatory effect of Lentinan on CD4~+CD25~+Foxp3~+ regulatory T cells in BALB/c mice infected with Toxoplasma gondii

Objective To investigate the regulatory effect of Lentinan(Lent) on CD4+CD25+Foxp3+ regulatory T cells(Tregs) in BALB/c mice infected with virulent Toxoplasma gondii(RH).Methods BALB/c mice were treated with Lent at different times(6 d and 0 d before infection).Then the mice were infected by intraperitoneal injection with 1×104 Toxoplasma gondii suspension.Survival rates were dynamically observed during the whole infection course.The dynamic change of Tregs number from the splenocyte supernatants was detected by FACS;IL-10 production from the splenocyte supernatants was determined by ELISA.Results Compared with control group,the groups of mice treated with Lent 6 d before infection had obviously increased survival rate.The number of Tregs reached a peak at day 8.At the same time,the level of IL-10 obviously increased at day 8 and day 10.Conclusion Lent pretreatment can help to regulate Th1/Th2 type immune response efficiently through regulating the immunosupression of Tregs in BALB/c mice infected with Toxoplasma gondii(RH).These results indicate that the regulation of immune response is important for host to fight against Toxoplasma gondii infection.