Expression of immune molecule forkhead box P3 in the small intestine of lupus-prone BXSB mice

Objective To observed the expression of immune molecule forkhead/winged helix transcription factor forkhead box P3 (Foxp3) and certain cytokines in the small intestine and serum of BXSB mice in order to explore the potential role of Foxp3 in the pathogenesis of lupus associated enteritis in BXSB mice.Methods The expression of Foxp3 mRNA was detected by using quantitative real-time polymerase chain reaction (Real-time PCR) in normal controls,8-week-old and 16-week-old BXSB male mice.Serum and tissue levels of interleukin (IL)-10,transformation growth factor beta (TGF-β),IL-4 and interferon gamma (IFN-γ) were measured by enzyme-linked immunosorbent assay (ELISA).Results As compared with normal controls,8-week-old and 16-week-old BXSB mice all had significantly lower expression of ileum Foxp3 mRNA in the ileum (7.33 ± 1.00,5.22 ±0.88 vs.9.72 ±0.69,P ＜0.01),and significantly higher levels of IL-10 and TGF-β in the ileum [IL-10:(60.94 ±4.93),(71.00 ±9.66) ng/(g·protein) vs.(48.83±5.71) ng/(g·protein),P＜0.01; TGF-β:(37.77±4.21),(39.53 ±4.47) ng/(g·protein) vs.(27.85 ±2.79) ng/(g·protein),P ＜0.01].In addition,serum IL-4 level and the ratio of serum IL-4 to IFN-γwere all significantly higher in 8-week-old and 16-week-old BXSB mice than those in normal controls [IL-4:(39.18 ±5.47),(48.30 ±6.16) ng/L vs.(27.60 ±3.50) ng/L,P ＜0.01 ; IL-4/IFN-γ:0.61 ±0.09,0.68 ±0.12,vs.0.45 ±0.08,P＜0.05].Conclusion Decreased Foxp3 mRNA expression and imbalanced cytokines could play a role in the pathogenesis of lupus associated enteritis in BXSB mice. Key words: Cytokines;  Lupus enteritis