The Mechanism of UVA1-induced T cell apoptosis and the clinical application

我们以前曾报道，UVA-1光疗诱导皮肤浸润性T细胞凋亡，因此可以有效地用于治疗皮肤T细胞淋巴瘤患者。实际上，UVA-1光疗对皮肤T细胞淋巴瘤（CTCL）非常有效。无论是否给予130 Jcm^2 UVA-1，都可以达到等效的临床反应。因此，我们推测，这是治疗特应性皮炎的常规剂量，或者给予60 Jcm ^2 UVA-1。因此，我们推测，恶性T细胞可能是更敏感的UVA-1光疗相比，正常的T细胞。使用磁性细胞分选法从成人T细胞白血病（ATL）患者或正常健康个体中分离出CD4 ^+ T细胞，并在体外UVA-1照射后24小时分析这些细胞中UVA-1辐射诱导的凋亡。与正常的CD4 ^+ T细胞相比，恶性T细胞对UVA-1辐射诱导的比较显示出更高的易感性。 ...更多信息 与正常的CD4 ^+ T细胞相比，恶性T细胞对UVA-1辐射诱导的凋亡表现出更高的敏感性。当UVA-1的剂量为20 Jcm ^2时，35%的恶性T细胞发生凋亡，而正常T细胞仅为16%。此外，恶性T细胞比正常T细胞对UVA-1辐射诱导的凋亡表现出更高的敏感性。为了更好地理解恶性T细胞的这种精致的敏感性，进一步分析了UVA-1诱导的细胞凋亡的光生物学和分子机制，在恶性（Jurkat）与正常T细胞中。然而，用FAS抗体或FASL转染子治疗恶性T细胞以下调FAS表面表达，将Jurkat细胞对UVA 1诱导的细胞凋亡的敏感性降低至正常水平，表明FAS系统的参与。Fas诱导的细胞凋亡在下游由caspase-3介导。因此，与恶性T细胞相比，正常T细胞具有显著较低的半胱天冬酶原-3水平，并且加入半胱天冬酶-3抑制剂完全阻止了恶性细胞中UVA-1诱导的细胞凋亡，这是非常有趣的。最后，增加对细胞凋亡的敏感性，也观察到在恶性细胞与正常相比，当T细胞被留下未照射，但与单线态氧，这是通过热分解的NDPO 2的内过氧化物产生的处理。这些发现表明，在单线态氧诱导的激活Fas信号通路决定了一个给定的T细胞对UVA-1诱导的细胞凋亡的易感性，可能在caspase-3的表达水平。为了评估我们研究结果的临床意义，我们启动了一项随机对照多中心试验，以比较UVA 1光疗与UVB和PUVA治疗CTCL患者的效果。少

We have previously reported that UVA-1 phototherapy induces apoptosis in skin-infiltrating T-cells and can thus be effectively used to treat patients with cutaneous T-cell lymphoma. Acutually, UVA-1 phototherapy was highly effective for cutaneous T-cell lymphoma (CTCL). Equivalent clinical responses could be achieved regardless of whether 130 Jcm^2 UVA-1 were given. We therefore speculated that which is the dose routinely used to treat atopic dermatitis, or 60 Jcm^2 UVA-1 were given. We therefore speculated that malignant T-cells might be more sensitive to UVA-1 phototherapy as compared with normal T-cells. CD4^+ T-cells were isolated using magnetic cell sorting either from a patient with Adult T-cell leukemia (ATL) or from normal healthy individuals and UVA-1 radiation-induced apoptosis was analyzed in these cells 24 hrs after in-vitro UVA-1 irradiation. In comparison with normal CD4^+ T-cells, malignant T-cells showed a higher susceptibility towards UVA-1 radiation-induced comparison … More with normal CD4^+ T-cells, malignant T-cells showed a higher susceptibility towards UVA-1 radiation-induced apoptosis. At a dose of 20 Jcm^2 UVA-1, 35 % of malignant, but only 16 % of normal T-cells were apoptotic. In addition, malignant T-cells exhibited a higher susceptibility to UVA-1 radiation-induced apoptosis than normal T-cells. In order to better understand this exquisite sensitivity of malignant T-cells, the photobiological and molecular mechanisms underlying UVA-1-induced apoptosis were further analyzed in malignant (Jurkat) versus normal T-cells. Treatment of malignant T-cells with FAS antibody or FASL-transfectant to downregulate FAS surface expression, however, decreased the susceptibility of Jurkat cells towards UVA1-induced apoptosis to normal levels, indicating the involvement of the FAS system. FAS-induced apoptosis is mediated further downstream by caspase-3. It was therefore of great interest that normal T-cells had significantly lower procaspase-3 levels as compared with malignant T-cells, and that addition of caspase-3 inhibitor completely prevented UVA-1-induced apoptosis in malignant cells. Finally, an increased sensitivity towards apoptosis was also observed in malignant cells in comparison with normals, when T-cells were left unirradiated but treated with singlet oxygen, which was generated through thermal decomposition of the endoperoxide of NDPO2. These findings indicate that upon singlet oxygen-induced activation the Fas signaling pathway determines the susceptibility of a given T cell towards UVA-1 induced apoptosis, possibly at the level of caspase-3 expression. In order to assess the clinical relevance of our findings, we have initiated a randomized, controlled multi-center trial in order to compare UVA1 phototherapy with UVB and PUVA in the treatment of patients with CTCL. Less