SLE患者Th1/Th2平衡状态及与外周血淋巴细胞CD28及CTLA-4分子表达的关系

Relationship between Th1/Th2 balance and CD28/CTLA-4 expression on peripheral blood T cells in patients with systemic lupus erythematosus

目的:了解SLE患者Th1/Th2平衡状态以及共刺激分子CD28/CTLA-4与Th1/Th2平衡状态的关系。方法:研究对象为18例SLE患者(活跃期12例、缓解期6例)。对照组14例,为健康体检者。外周血单个核细胞(PBMCs)经梯度密度离心法分离后置于含PMA(5μg/L)及ionomycin(500μg/L)培养液中培养72 h。采用ELISA方法检测培养的PBMCs上清液中IFN-γ及IL-10的含量。应用流式细胞技术检测培养的淋巴细胞CD28及CTLA-4分子的表达。结果:活跃期SLE患者培养的PBMCs分泌IL-10的量(351.29 ng/L±153.31 ng/L)较对照组(254.48 ng/L±120.69 ng/L)有一定程度的升高,但差异无显著(P>0.05),IFN-γ的分泌量(25.76 ng/L±16.09 ng/L)明显低于对照组(50.71 ng/L±27.92 ng/L,P<0.05),IL-10/IFN-γ比值(18.74±13.77)明显高于对照组(6.66±4.95,P<0.05)。培养前、后SLE患者CD3+及CD8+T细胞CD28分子表达量与对照组比较均无显著差异。培养前活跃期SLE患者CD3+T细胞CTLA-4分子表达量(0.79%+0.37%)较对照组(1.31%+0.61%)明显降低(P<0.05)。培养后SLE患者CD3+T细胞及CD8+T细胞CTLA-4分子表达量仍低于对照组,但差异无显著(P>0.05)。活跃期SLE患者培养的PBMCs中CD3+T细胞CTLA-4分子的表达量与上清液中IFN-γ含量呈明显的直线正相关关系(r=0.681,P<0.05)、与上清液中IL-10及IL-10/IFN-γ比值呈明显的直线负相关关系(r=-0.624,P<0.05;r=-0.738,P<0.01)。结论:SLE患者存在Th1/Th2平衡向Th2方向偏移,即Th2优势状态。CTLA-4分子可能通过抑制CD28的信号转导参与Th2优势状态的形成。

AIM： To investigate the pattern of Th1/Th2 balance in systemic lupus erythematosus（SLE） patients and the relationship between CD28/CTLA-4（cytotoxic T-lymphocyte antigen-4） molecule expression and Th1/Th2 balance.METHODS： Eighteen SLE patients met the ARA 1997 updated SLE criteria were selected in the study.According to Bombardier＇s SLEDAI criteria,all patients were classified into two groups： active group（12 cases） and static group（6 cases）.Fourteen normal individuals,matched for age and sex of the patients,served as controls.The peripheral blood mononuclear cells（PBMCs） were isolated by density gradient centrifugation and cultured in RPMI-1640 culture medium.After treated with PMA（5 μg/L） and ionomycin（500 μg/L） for 72 h,the PBMCs were collected,the contents of IFN-γ and IL-10 in the supernatant of cultured PBMCs were detected using enzyme linked immunosorbent assay（ELISA）.The expression of CD28 and CTLA-4 molecules on T cells were detected by flow cytometric technique with double staining by FITC or PE labeled monoclonal antibodies.RESULTS： The level of IL-10 was higher in the PBMCs of active and static SLE patients（351.29 ng/L±153.31 ng/L and 319.37 ng/L±153.39 ng/L） than that in controls（254.48 ng/L±120.69 ng/L）,but the difference did not reach statistical significance（P0.05）.The level of IFN-γ was significantly lower in the PBMCs of active SLE patients（25.76 ng/L±16.09 ng/L） than that in controls（50.71 ng/L±27.92 ng/L,P0.05）.The ratio of IL-10/IFN-γ was significantly higher in active SLE patients（18.74±13.77） than that in controls（6.66±4.95,P0.05）.Either before or after culture,the expression of CD28 molecule on CD3＋and CD8＋ T cells from all SLE patients was not remarkably different from that in the cells of controls.Before culture,the expression of CTLA-4 molecule on CD3＋T cells of active SLE patients（0.79%＋0.37%） was significantly lower than that in the cells of controls（1.31%＋0.61%,P0.05）.After culture,the expression of CTLA-4 molecule on CD3＋ T cells of SLE patients was still lower than that in the cells of normal controls without statistical significance（P0.05）.The expression level of CD28 molecule on CD3＋ or CD8＋ T cells in active SLE patients and controls was not correlated with the levels of IFN-γ and IL-10 in the supernatants（P0.05）.The level of CTLA-4 molecule expression on CD3＋ T cells of active SLE patients was positively correlated with IFN-γ level（r=0.681,P0.05）,while was negatively correlated with IL-10 levels（r=-0.624,P0.05） and the ratio of IL-10/IFN-γ（r=-0.738,P0.01）.The level of CTLA-4 molecule expression on CD3＋ or CD8＋ T cells of controls showed no correlation with IFN-γ levels,while showed negative correlations with IL-10 level（r=-0.587,P0.05;r=-0.563,P0.05,respectively）.CONCLUSION： There is a bias in the differentiation of Th0 cells towards Th2 in SLE patients.CTLA-4 probably plays an important role in this mechanism through suppressing the signal transmitted by CD28.