摘要
目的探讨胆红素对新生儿T淋巴细胞功能的影响。方法收集并分离21例正常足月新生儿脐血单个核细胞(cord blood mononuclear cell,CBMC),按培养液中胆红素的浓度相应分为A、B、C、D四组。A组:胆红素终浓度205.2μmol/L(12mg/dl);B组:胆红素终浓度153.9μmol/L(9mg/d1);C组:胆红素终浓度102.6μmol/L(6mg/d1);D组:胆红素终浓度0μmol/L。培养后检测细胞凋亡率和CD25^+细胞百分率,ELISA法检测培养上清液中可溶性Fas(soluble Fas,sFas)、可溶性Fas配体(soluble Fasligand,sFasL)、IFN-γ及IL-4水平,并分析它们之间的相关性。结果(1)A、B组细胞凋亡率分别为(61.49±8.93)%和(56.36±9.24)%,高于C、D组,分别为(32.44±8.72)%和(28.72±6.21)%,差异均有统计学意义(P〈0.01);(2)A、B组CD25^+细胞百分率分别为(19.89±6.72)%和(22.12±4.61)%,低于C、D组,分别为(61.28±4.87)%和(64.25±6.18)%,差异均有统计学意义(P〈0.01);(3)A、B组sFas、sFasL水平低于C、D组,C组sFas、sFasL水平低于D组,差异均有统计学意义(P〈0.01);(4)A、B组IFN-γ水平和IFN-γ/IL-4比值低于C、D组,差异有统计学意义(P〈0.01)C组IFN-γ水平和IFN-γ/IL-4比值低于D组,差异有统计学意义(P〈0.05);四组间IL-4水平差异无统计学意义(q=0.47~3.30,P〉0.05);(5)CD25^+细胞百分率、培养上清液sFas、sFasL、IFN-γ水平及IFN-γ/IL-4比值均与凋亡细胞百分率呈负相关(r=0.79~-0.37,P〈0.01),而IL-4水平与细胞凋亡率无相关性(r=0.20,P〉0.05)。结论胆红素具有明显的免疫抑制活性,在生理性黄疸状态的较高水平[血清蛋红素≥153.9μmol/L(9mg/dl)]即能促进T淋巴细胞凋亡,进一步加重新生儿时期辅助性T细胞亚群失衡状态,导致细胞免疫功能下降。
Objective To study the effects of bilirubin on the functions of neonatal T- lymphocytes. Methods Cord blood mononuclear cells (CBMC) of 21 full-term neonates were in vitro preincubated with various levels of unconjugated bilirubin. Levels of unconjugated bilirubin in group A were 205.2μmol/L(12 mg/dl) , 153.9μmol/L(9 mg/dl) in group B, 102.6μmol/L in group C (6 mg/dl)and 0 μmol/L in group D. The apoptosis rate of lymphocytes in CBMC after cultivation was determined by morphological methods. The positive expression rate of CD25 was detected by indirect immuno-fluorescence procedure. The levels of soluble Fas(sFas), soluble Fas ligand(sFasL), interferon-γ(IFN-γ) and interleukin-4(IL-4) in the supernatants of CBMC were detected by ELISA. Results (1)The apoptosis rate of lymphocytes in group A and B (61. 49 ± 8. 93)% and (56. 36± 9.24)%]was higher than those in group C and D[(32. 44± 8. 72)% and (28. 72 ± 6. 21)%], respectively(P〈0. 01). (2)The positive expression rate of CD25 in lymphocytes in group A and B [(19.89±6.72)% and (22.12±4.61)%] was lower than those in group C and D[(61.28±4.87)% and (64.25±6.18)%] ,respectively(P〈0.01). (3)The levels of sFas,sFasL in group A and B were lower than those in group C and D,and which in group C were lower than group D(P〈0.01). (4)The level of IFN-γ and the ratio of IFN-γ/IL-4 in group A and B were lower than those in group C and D(P〈0.01) ,and which in group C were lower than group D(P〈0.05). No significant difference of IL-4 level in supernatants of CBMC was found among the four groups (q=0.47~3.30, P〉0.05). (5)The positive expression rate of CD25, the levels of sFas, sFasL and IFN-γ in the supernatants had negative correlation with the apoptosis rate of lymphocytes (r= -0. 79-0. 37,P〉0.01). However, the IL-4 level did not correlate with the apoptosis rate of lymphocytes (r = -0. 20, P 〉0. 05). Conclusions Bilirubin has obvious immune inhibitory activity. It could promote apoptosis and inhibit activities of T-lymphocytes, and result in further imbalance of Th1/Th2 even in neonates with physical jaundice. The effects are more significant when the level of bilirubin is higher than 153.9μmol/L.
出处
《中华围产医学杂志》
CAS
2008年第1期45-48,共4页
Chinese Journal of Perinatal Medicine