紫外线照射诱导人外周血淋巴细胞凋亡的研究

Experimental study of ultraviolet-induced apoptosis of human-derived peripheral blood lymphocytes

目的 探讨紫外线照射充氧自血疗法（ＵＢＩＯ）引起的免疫抑制机制。方法 使用不同剂量中、短波紫外线（ＵＶＢ、ＵＶＣ） 照射诱导人外周血淋巴细胞凋亡，采用电镜、ＤＮＡ 电泳、流式细胞仪ＴＵＮＥＬ凋亡定量检测，了解被照射细胞凋亡情况。结果 ＵＶＢ照射细胞发生典型凋亡。定量检测证实ＵＶＢ２００ Ｊ／ｍ２ 照射淋巴细胞凋亡发生率４８ ．２％ ，５００ Ｊ／ｍ２ 凋亡发生率７８．５ ％ 。ＵＶＣ照射细胞未见凋亡改变。双标记检测发现ＵＶＢ照射诱导的淋巴细胞凋亡几乎全部发生于ＣＤ３ ＋ Ｔ 细胞，随着照射剂量的加大，ＣＤ４＋ ／ＣＤ８ ＋ 比值逐渐减小。表明ＵＶＢ照射可诱导人Ｔ 细胞，特别是ＣＤ４ ＋ Ｔ 细胞发生凋亡，ＵＶＣ照射无凋亡诱导作用。结论 诱导淋巴细胞凋亡可能是ＵＢＩＯ引起免疫抑制机制之一，建议ＵＢＩＯ 采用短波紫外线。

Objective To study the immunosuppression mechanism caused by ultraviolet blood irradiation and oxygenation(UBIO).Methods The human peripheral blood lymphocytes in vivo were separately radiated with ultraviolet B(UVB) and ultraviolet C(UVC) to induce the apoptosis of human-derived peripheral blood lymphocytes.Electron microscope,DNA electrophoresis,TUNEL flow cytometric quantitative determination and double labelled flow cytometric analysis were adopted to find the state of irradiated cell apoptosis in vivo.Results There was a typical apoptosis in the lymphocyte cells radiated by UVB.TUNEL flow cytometric quantitative determination had proved that the died rate of lymphocytes radiated by UVB 200 J/m 2 and UVB 500 J/m 2 was respectively 48.2% and 78.5%.But there was no apoptosis in the lymphocytes radiated by UVC.On double labelled flow cytometric analysis,the lymphocyte apoptosis induced by UVB irradiation all was nearly CD3+T cells.As the increasing of UV irradiation,ratio of CD4+/CD8+ cells was gradually decreased.The study showed that UVB irradiation could induce the apoptosis of human T-lymphocytes,especially in the CD4+T cells.However,UVC irradiation used had no such effect.Conclusion It is demonstrated that UV-induced apoptosis of human-derived peripheral blood lymphocytes may be one of mechanisms of immunosuppression caused by UBIO.