2014-08-012024-05-13https://scholars.lib.ntu.edu.tw/handle/123456789/647721摘要：背景: 異位性皮膚炎，是一種慢性反覆發作的發炎性皮膚疾病。皮膚淋巴球抗原(cutaneous lymphocyte-associated antigen，CLA)，是引導 T 細胞選擇性移動至皮膚的 T 細胞表面受體。T17 細胞，包括 CD4+ T (Th17)細胞及 CD8+ T (Tc17)細胞，會製造發炎性細胞激素 interleukin-17 (IL-17)。IL-17 會引起角質細胞製造抗微生物肽類，因此對於宿主防禦非常重要。T22 細胞，包括 CD4+ T (Th22)細胞及 CD8+ T (Tc22)細胞，會製造發炎性細胞激素 IL-22。IL-22 會引起角質細胞分裂但抑制其分化，因此造成表皮增生與皮膚屏障缺失。Th22 細胞特別會表現 chemokine receptor CCR10。最近關於異位性皮膚炎病人的 T17 細胞與 T22 細胞之數量及功能的一些研究，各自顯示了不同的結果。異位性皮膚炎的皮膚屏障功能有缺失，包括缺乏表皮結構蛋白、脂質、及抗微生物肽類。因此，異位性皮膚炎病人的皮膚上非常容易有金黃色葡萄球菌的增生與感染，此菌會分泌許多外毒素，其中以金黃色葡萄球菌腸毒素 B (staphylococcal enterotoxin B，SEB)最為常見。這些金黃色葡萄球菌外毒素是超級抗原，它們會刺激帶有特定的 T 細胞受體鏈變異區(variable region of  chain of T cell receptor，TCRV)的 T 細胞，造成異位性皮膚炎皮膚過敏性發炎反應的持續與惡化。T 細胞活化後引起的細胞凋亡，可以清除被抗原活化的 T 細胞，使發炎反應得以終止，這對維持免疫反應的恆定很重要。 目的: 在異位性皮膚炎病人、無異位性皮膚炎的呼吸道過敏病病人、及健康人之間，比較金黃色葡萄球菌超級抗原對 skin-homing CLA+ CD4+ T 細胞與 CLA+ CD8+ T 細胞中的CCR10+亞型細胞與 CCR10-亞型細胞之數量比例、細胞激素製造、及細胞凋亡的影響。 方法: 30 位異位性皮膚炎病人、30 位氣喘或過敏性鼻炎病人、及 30 位健康人的周邊血單核細胞，在有或沒有加入 SEB 的刺激下予以培養。之後，以免疫螢光染色法併流式細胞儀進行分析。 初步結果: 我們發現，SEB 的刺激對異位性皮膚炎病人及健康人的 skin-homing CLA+ CD4+ T 細胞之數量並無影響。在異位性皮膚炎病人，SEB 會增加 CLA+ CD4+ T 細胞中 CCR10+ / CCR10- 的數量比例。在 CCR10+亞型之 CLA+ CD4+ T 細胞，SEB 主要引起 Th22 細胞激素 IL-22 的製造。和健康人比起來，異位性皮膚炎病人的 CLA+ CD4+ T 細胞在 SEB刺激後製造較多的 Th22 細胞激素 IL-22 及較少的 Th17 細胞激素 IL-17。 臨床重要性: 本研究的結果，可以提供一個可能的分子機轉來解釋為何金黃色葡萄球菌超級抗原會造成異位性皮膚炎皮膚過敏性發炎反應的持續與惡化，這有助於發展對異位性皮膚炎新的預防與治療之道。<br> Abstract: Background: Atopic dermatitis (AD) is a chronically relapsing inflammatory skin disorder. Cutaneous lymphocyte-associated antigen (CLA) is a skin-homing receptor involved in the selective migration of T cells to the skin. T17 cells, including CD4+ T (Th17) cells and CD8+ T (Tc17) cells, produce pro-inflammatory cytokine interleukin-17 (IL-17). IL-17 induces production of antimicrobial peptides by keratinocytes and thus plays a critical role in host defense. T22 cells, including CD4+ T (Th22) cells and CD8+ T (Tc22) cells, produce pro-inflammatory cytokine IL-22. IL-22 induces proliferation but inhibits terminal differentiation of keratinocytes, thus results in epidermal hyperplasia and skin barrier defect. Th22 cells particularly express chemokine receptor CCR10. Recent studies showed controversial results about the number and function of T17 and T22 cells in AD patients. The skin barrier function of AD is defective, including the deficiency in epidermal structural proteins, lipid composition, and endogenous antimicrobial peptides. Thus, the skin of AD patients exhibits a striking susceptibility to colonization and infection with Staphylococcus aureus, which secrete various exotoxins including staphylococcal enterotoxin B (SEB) being the most common. These exotoxins are staphylococcal superantigens (SsAgs). They stimulate T cells bearing specific variable region of  chain of T cell receptor (TCRV) and contribute to the persistence and exacerbation of allergic skin inflammation in AD. Activation-induced apoptosis of T cells provides a mechanism for the deletion of antigen-activated T cells, thereby leading to the resolution of inflammation and playing an important role in the homeostatic regulation of immune responses. Objective: To compare the effects of SsAgs on the ratio, cytokine production, and apoptosis of CCR10+ and CCR10- subtypes of skin-homing CLA+ CD4+ T cells and CLA+ CD8+ T cells among AD patients, asthma/allergic rhinitis (AR) patients without AD, and healthy subjects. Methods: Using immunofluorescence staining followed by flow cytometric analysis, we analyzed peripheral blood mononuclear cells cultured with or without SEB stimulation in 30 AD patients, 30 asthma/AR patients without AD, and 30 healthy subjects. Preliminary Results: We found that SEB had no effect on the number of skin-homing CLA+ CD4+ T cells in AD patients and healthy subjects. SEB increased CCR10+ / CCR10- ratio in CLA+ CD4+ T cells from AD patients. SEB induced production of Th22 cytokine IL-22 in CCR10+ subtype of CLA+ CD4+ T cells. CLA+ CD4+ T cells from AD patients produced more Th22 cytokine IL-22 and less Th17 cytokine IL-17 after SEB stimulation than those from healthy subjects. Clinical Relevance: The results of this study are helpful to provide a possible mechanism to explain why SsAgs contribute to the persistence and exacerbation of allergic skin inflammation in AD. This is important for developing novel therapies and prevention of AD.