CD4+ CD25+ CD127dim/-调节性T淋巴细胞对肝星状细胞增殖及功能的影响

目的 了解CD4+ CD25+ CD127dim/-调节性T淋巴细胞在体外对肝星状细胞(HSC)增殖以及功能的影响，初步探讨调节性T淋巴细胞促肝纤维化的机制。方法传代培养HSC LX-2，将免疫磁珠细胞分选(MASC)法分离所得慢性乙型肝炎患者调节性T淋巴细胞与HSC LX-2按不同方式共培养5d，以单独培养的HSC作为对照，细胞计数试剂盒-8（CCK-8）法检测共培养HSC增殖情况，ELISA法检测上清液中转化生长因子(TGF)β1含量，放射免疫法检测HSC分泌HA、PCⅢ水平。统计学处理采用LSD-t检验。结果 5例调节性T淋巴细胞与HSC比例为1.5∶1时HSC增殖最为明显，10例直接接触共培养与使用Transwell系统共培养调节性T淋巴细胞与HSC吸光度值分别为(0.713±0.032)、(0.735±0.028) cpm，均较对照组的（0.677±0.029）cpm增殖明显(t=5.4003，8.7878；均P＜0.01)。10例直接接触共培养与Transwell组细胞上清液中TGFβ1浓度分别为(781.59±76.45)、（813.53±60.62）pg/mL，显著高于对照组的(722.51±59.66) pg/mL（t=4.0014，6.1653;均P＜0.01）；HA浓度分别为（433.57±27.90）、（445.40±23.73）ng/mL，显著高于对照组的（415.83±19.44）ng/mL（t=3.3124，5.5231;均P＜0.01）；PCⅢ浓度分别为(21.93±1.71)、(23.12±1.87) ng/mL，显著高于对照组的（20.10±1.49）ng/mL(f=4.8082,7.9436;均P＜0.01)。且Transwell组各项结果均显著高于直接接触组(t=3.3875，2.1639，2.2107，3.1354;均P＜0.05)。结论CD4+ CD25+ CD127dim调节性T淋巴细胞可促进共培养的HSC增殖及其HA、PCⅢ的分泌。体外实验证明，CD4+ CD25+ CD127dim/-调节性T淋巴细胞具有促进肝纤维化的重要作用。

CD4+ CD25+ CD127dim/- regulatory T lymphocytes promote the proliferation and functions of hepatic stellate cells

Objective To 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. Methods HSC 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. Results HSC 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 PC Ⅲ 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).Conclusions The 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.