CD4+ CD25+ CD127dim/- regulatory T lymphocytes promote the proliferation and functions of hepatic stellate cells / 中华传染病杂志

ABSTRACT

ObjectiveTo investigate whether CD4+ CD25+ CD127dim/- regulatory T lymphocytes (Treg) can induce the proliferation of hepatic stellate cells (HSC) and expression of fibrosis-related factors on HSC in vitro and further to explore the mechanism of Treg inducing fibrogenesis. MethodsHSC LX-2 cells were subcultured.CD4+ CD25+ CD127dim/- cells were purified using magnetic cell separation. The HSC were co-cultured with Treg by direct contact or by Transwell system in vitro. The HSC cultured alone was used as control. Cell proliferation was measured by CCK-8 assay.The expression of transforming growth factor (TGF)-β1 was detected by enzyme-linked inmunosorbent assay (ELISA), and the expressions of hyaluronic acid (HA) and precollagen Ⅲ (PC Ⅲ ) were detected by radio immunoassay (RIA). The data were analyzed by LSD-t test. ResultsHSC proliferation was strongest when Treg∶ HSC= 1.5∶ 1. The absorbance in direct contact co-culture group and Transwell system co-culture group was (0. 713±0. 032) cpm and (0. 735±0. 028) cpm, respectively, both of which were higher than that in control group [(0. 677 ± 0. 029) cpm](t = 5. 4003 and 8. 7878,respectively; both P＜0. 01). The concentrations of TGF-β1 in the supernatant were (781. 59 ±76.45) pg/mL and (813. 53±60. 62) pg/mL, respectively in direct contact co-culture group and Transwell system co-culture group, which were significantly higher than that in control group [(722.51±59. 66) pg/mL](t = 4.0014 and 6. 1653, respectively; both P＜0.01).The concentrations of HA were (433. 575±27.90) ng/mL and (445.40±23.73) ng/mL, respectively in direct contact co-culture group and Transwell system co-culture group, which were higher compared to that in control group [-(415. 83±19.44) ng/mL](t =3. 3124 and 5. 5231, respectively; both P＜0.01). Likewise, the concentrations of PCⅢ were (21. 93± 1.71) and (23. 125± 1.87) ng/mL in direct contact group and Transwell group, respectively compared to (20. 10± 1.49) ng/mL in control group (t = 4. 8082 and 7. 9436, respectively; both P ＜ 0.01).Furthermore, the absorbance,concentrations of TGF-β1, HA and PC Ⅲ in Transwell co-culture group were all higher compared to direct contact group (t = 3. 3875, 2.1639, 2. 2107 and 3.1354, respectively; all P＜0. 05).ConclusionsThe cell proliferation and the expressions of fibrosis-related factors in HSC increase greatly after co-cultured with CD4+ CD25+ CD127dim/-Treg. Therefore, Treg may play an important role in inducing liver fibrogenesis.