Forkhead/winged helix transcription factor P3 gene methylation regulation of regulatory T Cells proliferation and function in murine autoimmune hepatitis

Abstract

Objective To investingate whether T(Treg) cells forkhead/winged helix transcription factor P3(Foxp3)gene promoter CpG island methylation was participated in the Rhesus rotavirus(RRV) inhibiting regulatory Treg cells in BALB/c mice liver, to explore its role in autoimmune liver inflammation. Methods A total of 60 7-9-week-old BALB/c mice were divided randomly into 3 groups(20 each): injected intraperitoneally PFU= 106 RRV infection 24 h and 48 h,and normal control group injected the same volume of saline.Discontinuous Percoll gradient separation of monocytes, Using flow cytometry sorting liver CD4+ CD25+ Foxp3+ Treg cells.Application bisulfite sequencing method modified after sulphate (BSP) to detect BALB/c mouse spleen tissue carve DNA Foxp3 Treg cells selected gene promoter CpG island methylation status, Western blotting assay, spectrophotometer assay respectively. Results In the control group and after injection RRV 24 h or 48 h, accounted for the proportion of CD4+ cells was (5. 26±0. 21)%,(4. 30±0. 46)%,(3. 60±0. 19)% respectively, and the difference were statistically significance(P< 0. 05).Foxp3 gene CpG island methylation were(2. 78±0. 33)%,(26. 70±1. 87)%, (41. 18±3. 67)% respectively and the difference were statistically significance(P< 0. 01).Expression of Foxp3 Treg cells also decreased, with RRV infection time was positively correlated,and the differences were statistically significant(P< 0. 05). Conclusion RRV significantly promote the Treg cells Foxp3 gene promoter CpG island methylation in BALB/c mice liver,and Inhibit the proliferation of Treg cells and normal immune function.That may involved in autoimmune hepatitis in mice. Key words: Regulatory T Cells; Forkhead/winged helix transcription factor P3 gene; CpG island; Methylation; Autoimmune hepatitis