Wang Jun, van Dongen Henrike, Scherer Hans Ulrich, Huizinga Tom W J, Toes Rene E M
Leiden University Medical Center, Leiden, The Netherlands.
Arthritis Rheum. 2008 Jun;58(6):1609-18. doi: 10.1002/art.23460.
Previous studies have shown that the suppressive capacity of CD4+,CD25++ T cells is compromised in patients with rheumatoid arthritis (RA) and restored by anti-tumor necrosis factor alpha (anti-TNFalpha) therapy. Given the lack of specific cell surface markers for human Treg cells, this study aimed to define surface markers for identifying and enriching Treg cells with enhanced regulatory ability within the CD4+,CD25++ T cell compartment and to provide additional understanding of the effects of anti-TNFalpha antibodies in humans.
The expression of membrane-bound TNFalpha in human peripheral blood CD4+ T cells was analyzed by flow cytometry in healthy individuals and RA patients before and after anti-TNFalpha treatment. Membrane-bound TNFalpha-positive and TNFalpha-negative CD4+,CD25++ T cells were purified by fluorescence-activated cell sorting, and their suppressive capacity was assessed in vitro by a standard suppression assay.
A substantial number of CD4+,CD25++ T cells expressed membrane-bound TNFalpha. Membrane-bound TNFalpha-positive CD4+,CD25++ T cells displayed reduced antiinflammatory cytokine production and less potent suppressor capacity, since 4 times more cells were required to achieve 50% inhibition compared with their membrane-bound TNFalpha-negative counterparts. Treatment of RA patients with TNFalpha-specific antibodies led to a reduction in the number of membrane-bound TNFalpha-positive CD4+,CD25++ T cells from peripheral blood.
Our data indicate that the absence of membrane-bound TNFalpha on CD4+,CD25++ T cells can be used to characterize and enrich for Treg cells with maximal suppressor potency. Enrichment of membrane-bound TNFalpha-negative CD4+,CD25+ cells in the CD4+,CD25++ T cell compartment may contribute to restoring the compromised suppressive ability of CD4+,CD25++ T cell populations in RA patients after anti-TNFalpha treatment.
既往研究表明，类风湿关节炎（RA）患者体内CD4+、CD25++ T细胞的抑制能力受损，而抗肿瘤坏死因子α（抗TNFα）治疗可使其恢复。鉴于人类调节性T细胞（Treg细胞）缺乏特异性细胞表面标志物，本研究旨在确定用于识别和富集CD4+、CD25++ T细胞亚群中具有增强调节能力的Treg细胞的表面标志物，并进一步了解抗TNFα抗体在人体内的作用。
采用流式细胞术分析健康个体及抗TNFα治疗前后RA患者外周血CD4+ T细胞中膜结合型TNFα的表达。通过荧光激活细胞分选技术纯化膜结合型TNFα阳性和阴性的CD4+、CD25++ T细胞，并采用标准抑制试验体外评估其抑制能力。
大量CD4+、CD25++ T细胞表达膜结合型TNFα。膜结合型TNFα阳性的CD4+、CD25++ T细胞产生抗炎细胞因子的能力降低，抑制能力较弱，因为与膜结合型TNFα阴性的细胞相比，需要4倍数量的细胞才能达到50%的抑制率。用TNFα特异性抗体治疗RA患者可导致外周血中膜结合型TNFα阳性的CD4+、CD25++ T细胞数量减少。
我们的数据表明，CD4+、CD25++ T细胞上缺乏膜结合型TNFα可用于表征和富集具有最大抑制效力的Treg细胞。CD4+、CD25++ T细胞亚群中膜结合型TNFα阴性的CD4+、CD25+细胞的富集可能有助于恢复抗TNFα治疗后RA患者CD4+、CD25++ T细胞群体受损的抑制能力。
