T regulatory cells in atopic dermatitis and subversion of their activity by superantigens
T regulatory cells in atopic dermatitis and subversion of their activity by superantigens
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DOI：
10.1016/j.jaci.2004.01.772
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发表时间：
2004-04-01
影响因子：
14.2
通讯作者：
Leung, DYM
中科院分区：
文献类型：
--
作者：
Ou, LS;Goleva, E;Leung, DYM
背景资料：特应性皮炎（AD）是一种由分泌超抗原（SAg）的金黄色葡萄球菌定植的慢性炎症性皮肤病。目的：探讨AD患者外周血中是否存在Treg细胞缺陷。方法：采用免疫磁珠法分离AD患者外周血单个核细胞（PBMCs）中的CD 4（+）CD 25（+）和CD 4（+）CD 25（-）T细胞。将细胞与抗CD 3或SAg、葡萄球菌肠毒素B（SE B）一起培养72小时。通过氚化胸苷掺入法测定增殖。通过流式细胞术评估PBMC上的CD 4、CD 8、CD 25和皮肤淋巴细胞相关抗原表达。从分离的T细胞亚群中提取RNA，并测定FoxP 3 mRNA的实时PCR结果。令人惊讶的是，CD 4（+）CD 25（+）T细胞显著增加，（P <0.01）AD患者（6.68% +/-0.99%，n = 15）与哮喘患者相比（3.42% +/-0.58%，n = 12）或非特应性健康对照受试者（3.34% +/-0.43%，n = 14）。AD患者皮肤归巢的CD 25（+）、CD 4（+）、皮肤淋巴细胞相关抗原阳性T细胞的表达也高于哮喘和非特应性受试者，分别为35.95%、22.44%和23.03%（P <0.006）。只有CD 4（+）CD 25（+）细胞表达FoxP 3，而CD 4（+）CD 25（-）T细胞和CD 4（-）细胞不表达FoxP 3。与Treg细胞的已知特性一致，CD 4（+）CD 25（+）细胞对抗CD 3刺激无反应性。当来自每个研究组的CD 4（+）CD 25（+）细胞与CD 4（+）CD 25（-）细胞混合时，抗CD 3刺激后增殖反应同样受到抑制。相比之下，在SEB刺激后，CD 4（+）CD 25（+）细胞不再无反应性。当CD 4（+）CD 25（+）细胞与CD 4（+）CD 25（-）细胞混合后，用SEB刺激，Treg细胞的抑制功能被逆转。然而，在SAg刺激后，Treg细胞失去其免疫抑制活性。这些数据表明了一种新的机制，SAgs可以增强AD患者的T细胞活化。
Background: Atopic dermatitis (AD) is a chronic inflammatory skin disease involving colonization by superantigen (SAg)-secreting Staphylococcus aureus. CD4(+)CD25(+) T regulatory (Treg) cells are thought to play an important role in controlling inflammatory responses.Objective: In this study we examined whether Treg cells might he deficient in patients with AD.Methods: CD4(+)CD25(+) and CD4(+)CD25(-) T cells were isolated from PBMCs by using immunomagnetic beads. Cells were cultured with anti-CD3 or SAg, staphylococcal enterotoxin B (SEB), for 72 hours. Proliferation was measured by means of tritiated thymidine incorporation. CD4, CD8, CD25, and cutaneous lymphocyte-associated antigen expression on PBMCs was assessed by means of flow cytometry. RNA was extracted from isolated subsets of T cells, and the results of real-time PCR for FoxP3 mRNA were determined.Results: Surprisingly, CD4(+)CD25(+) T cells were significantly (P < .01) increased in patients with AD (6.68% +/- 0.99%, n = 15) compared with in asthmatic patients (3.42% +/- 0.58%, n = 12) or nonatopic healthy control subjects (3.34% +/- 0.43%, n = 14). Patients with AD also had a higher expression of CD25(+) in skin-homing, CD4(+), cutaneous lymphocyte-associated antigen-positive T cells than asthmatic and nonatopic subjects, with values of 35.95% versus 22.44% versus 23.03%, respectively (P < .006). Only CD4(+)CD25(+) cells expressed FoxP3, whereas CD4(+)CD25(-) T cells and CD4(-) cells did not. Consistent with known properties of Treg cells, CD4(+)CD25(+) cells were anergic to anti-CD3 stimulation. When CD4(+)CD25(+) cells from each study group were mixed with CD4(+)CD25(-) cells, proliferative responses were equally suppressed after anti-CD3 stimulation. In contrast, after SEB stimulation, CD4(+)CD25(+) cells were no longer anergic. Furthermore, when CD4(+)CD25(+) cells were mixed with CD4(+)CD25(-) cells and stimulated with SEB, the suppressive function of Treg cells was reversed.Conclusion: Patients with AD have significantly increased numbers of peripheral blood Treg cells with normal immunosuppressive activity. However, after SAg stimulation, Treg cells lose their immunosuppressive activity. These data suggest a novel mechanism by which SAgs could augment T-cell activation in patients with AD.