人类视网膜色素上皮细胞体外培养的转分化

目的:研究人类视网膜色素上皮细胞(human retinal pig-ment epithelium,HRPE)体外培养的转分化现象。方法:倒置显微镜观察体外培养HRPE细胞形态变化;采用免疫细胞化学染色方法检测HRPE细胞角蛋白及α-平滑肌肌动蛋白(α-SMA)的变化。结果:HRPE细胞体外培养时形态由上皮细胞特征变化成为间质样细胞;细胞角蛋白表达与传代代数呈负相关(r=-0.831,P<0.001),α-SMA表达与传代代数呈正相关(r=0.456,P=0.002);角蛋白18表达高密度组较低密度组强(t=2.591,P=0.027);而α-SMA表达高密度组较低密度组弱(t=2.938,P=0.015)。结论:HRPE细胞体外培养转分化主要是体内外环境差异引起。     

PDGF-α受体反义寡核苷酸对体外视网膜色素上皮细胞增殖和凋亡的影响

目的:探讨血小板源性生长因子-α受体反义寡核苷酸(PDGFR-αASODN)对体外人视网膜色素上皮(humanretinal pigment epithelium,HRPE)细胞增殖和凋亡的作用。方法:使用阳离子脂质体lipofectamineTM2000将靶向PDGFR-α基因的ASODN转染至细胞株HRPE细胞,MTT法检测对HRPE细胞增殖的影响;Hoechst33258荧光染色观察凋亡细胞;流式细胞仪检测HRPE细胞的周期和凋亡率。结果:PDGFR-αASODN转染组细胞增殖抑制率和凋亡率均明显高于对照组(P<0.05)。结论:沉默PDGFR-α基因表达可显著抑制HRPE细胞的增殖,并能诱导其凋亡。     

体外诱导人骨髓间充质干细胞向色素上皮样细胞分化的研究

目的 探讨人骨髓间充质干细胞(mesenchymal stem cells,MSC)向色素上皮样细胞诱导、分化的可行性,为视网膜移植提供种子细胞的来源.方法 体外培养人视网膜色素上皮细胞(human retinal pigment epithelium,HRPE)和 MSC,应用免疫细胞化学法检测CD34、CD44 和角蛋白的表达情况,确定2种细胞的来源;通过 Transwell 6孔板非接触共培养的方式,建立 HRPE 和 MSC 共培养体系,显微镜下观察人 MSC 的形态学变化;对于诱导后的 MSC 进行免疫细胞化学鉴定,确定角蛋白的表达情况.结果 MSC呈纤维样克隆样生长,人MSC的CD44(+),CD34(-);HRPE原代培养时细胞内布满色素颗粒,角蛋白表达(+).HRPE和MSC共培养体系中,部分长梭形的MSC逐渐变成多边形,细胞内出现典型的色素颗粒;分化的色素上皮样细胞角蛋白表达阳性.结论 MSC与HRPE在非接触共培养诱导方式下能分化成色素上皮样细胞;分化的细胞具有上皮细胞的特异性标志,诱导后的细胞是否具有HRPE的功能尚有待于进一步研究.     

衰老晶状体上皮细胞对喜树碱诱导凋亡敏感性的研究

目的 探讨体外培养品状体上皮细胞(LECs)的衰老情况以及衰老LECs对凋亡诱导因素的敏感性.方法体外培养兔LECs并传代.对第1、4、7代LECs进行研究,β-半乳糖苷酶组织化学染色检测衰老细胞,分析细胞衰老百分数的差异;原位末端标记法(TUNEL)检测培养过程中细胞的凋亡状况;10μmol/L喜树碱诱导细胞凋亡,比较各代细胞对喜树碱诱导凋亡敏感性的差异. 结果 LECs在体外培养过程中表现为有限生长的特性,经过增生、传代后衰老细胞增加.各代LECs在不受干预的情况下不发生凋亡.第1、4、7代LECs对喜树碱凋亡诱导因素的敏感性差异有统计学意义.结论 LECs在体外培养过程中表现为有限生长的特性,增生的细胞以衰老为结局,衰老的LECs在不受外界干扰的情况下不发生凋亡,但对凋亡诱导因素的敏感性增加.     

Fas和FasL在视神经炎患者表达的研究

目的探讨视神经炎患者外周血淋巴细胞Fas和FasL的表达及意义。方法用流式细胞术检测26例视神经炎患者外周血淋巴细胞Fas和FasL的表达情况,并以26例同期住院的非免疫相关性疾病患者作为对照。结果视神经炎患者淋巴细胞Fas和FasL表达水平高于对照组(t值分别为2932、4647,P<0001)。Fas和FasL表达之间呈正相关(r=0516;P=0003)。结论Fas和FasL可能参与视神经炎的发病过程,Fas系统介导的自身免疫机制和细胞凋亡可能是髓鞘损害的主要原因。     

层粘连蛋白和纤维连接蛋白对人晶状体上皮细胞传代性质和波状蛋白表达的影响

目的:观察层粘连蛋白和纤维连接蛋白对原代和传代培养的人晶状体上皮细胞(hLECs)形态学和波状蛋白表达的影响,探讨更适合的hLECs体外培养条件。方法:以层粘连蛋白(Ln)和纤维连接蛋白(Fn)处理培养皿表面,以倒置显微镜观察原代和传代培养的hLECs生长的时间和形态,MTT法记录传代后第3代细胞的生长曲线,免疫荧光法显示第3代细胞的波形蛋白表达形态的变化。结果:在层粘连蛋白和纤维连接蛋白处理组,原代hLECs长出的时间明显早于对照组;两处理组的原代细胞可以正常传代,对照组细胞传代后不能存活。传代晚期层粘连蛋白处理组细胞发生凋亡,而纤维连接蛋白处理组出现多数晶状体小结。MTT实验显示,传代后4～7d纤维连接蛋白处理组细胞数多于层粘连蛋白处理组。免疫荧光反应中,两组波状蛋白形态有明显差别。结论:层粘连蛋白可以提供适宜hLECs保持上皮细胞状态的体外培养微环境,而纤维连接蛋白可以促进hLECs的增殖和分化。     

高糖诱导视网膜血管周细胞凋亡中线粒体细胞色素C的变化

目的:研究高糖诱导牛视网膜血管周细胞凋亡中线粒体细胞色素C(Cyt-C)的变化.方法:以在体外培养3代近融合的牛视网膜毛细血管周细胞为对象,分别在对照组(5.5mmol/L)与高糖各组(15,25,35mmol/L)中孵育6d,透射电镜观察周细胞超微结构改变,TUNEL法检测培养后周细胞的凋亡情况,分光光度计检测周细胞胞质Cyt-C变化.结果:高糖各组周细胞出现明显凋亡改变,凋亡率明显高于对照组(t1=57.450,t2=83.754,t3=136.403,P＜0.01);高糖各组胞质Cyt-C浓度明显高于对照组(t1=17.361,t2=17.866,t3=24.072,P＜0.01),且Cyt-C浓度与周细胞凋亡率明显正相关(r=0.964,P＜0.01).结论:高糖呈剂量依赖性诱导牛视网膜血管周细胞凋亡,线粒体Cyt-C释放可能参与周细胞凋亡过程.     

内毒素诱导的大鼠葡萄膜炎细胞凋亡的研究

目的探讨大鼠内毒素诱导的葡萄膜炎（EIU）中葡萄膜和视网膜组织浸润细胞的凋亡,及Fas-FasL的表达与细胞凋亡的相关性。方法注射霍乱弧菌内毒素诱发大鼠EIU模型,内毒素注射后6、12、18、24、48h进行临床观察评分并行组织病理学检查。应用TUNEL法检测葡萄膜和视网膜中的凋亡细胞,免疫组织化学法检测Fas和FasL在葡萄膜和视网膜中的表达和变化。结果实验组大鼠均发生了EIU;葡萄膜和视网膜组织浸润细胞中可见TUNEL染色阳性凋亡细胞,18h达高峰,以虹膜和睫状体最为明显,凋亡阳性细胞数与正常对照组相比,差异有统计学意义（P〈0.01）;实验各组中均可见Fas表达,实验各组中FasL表达显著增强,与正常对照组相比差异有统计学意义（P〈0.01）。Fas和FasL的表达与凋亡之间呈正相关（r=0.923,0.807,P〈0.01）。结论EIU中葡萄膜和视网膜的浸润细胞存在凋亡现象,凋亡参与了炎症的迅速消退,Fas和FasL的高表达可能与内毒素诱导的葡萄膜炎眼组织的细胞凋亡有关。     

糖基化终产物诱导牛视网膜毛细血管周细胞凋亡及凋亡调节基因的表达

目的　研究糖基化终产物 (advancedglycosylationendproducts,AGE)对培养的牛视网膜毛细血管周细胞凋亡及凋亡调节基因Bax、bcl 2表达的影响 ,以探讨糖尿病视网膜病变的发病机制。方法　在体外培养 3～ 6代近融合的视网膜毛细血管周细胞中加入不同浓度的AGE(8、32、12 5、5 0 0及2 0 0 0mg/L)液 ,于 4d后检测不同浓度AGE对牛视网膜毛细血管周细胞凋亡及凋亡调节基因Bax、bcl 2表达的影响。结果　周细胞与AGE作用 4d后 ,呈现出典型的细胞凋亡特征 ;AGE促周细胞凋亡(r=0 878,P <0 0 1)和凋亡调节基因Bax的表达 (r=0 85 5 ,P <0 0 1)及抑制凋亡调节基因bcl 2的表达 (r=- 0 85 0 ,P <0 0 1)呈剂量依赖性 ;而周细胞凋亡率与Bax/bcl 2的比率呈正相关 (r=0 80 8,P<0 0 1)。结论　AGE能以剂量依赖的方式促进周细胞的凋亡 ,周细胞的凋亡率取决于凋亡调节基因Bax/bcl 2的比率。细胞凋亡是糖尿病视网膜病变中毛细血管周细胞早期丧失的一种方式。     

骨髓间充质干细胞分化为光感受器样细胞的体外诱导和微环境研究

背景 近年来间充质干细胞(MSCs)在眼科方面已成功诱导分化为角膜细胞、视网膜神经节细胞(RGCs)、视网膜神经样细胞等,但诱导成为光感受器细胞及其微环境的研究尚少. 目的 研究骨髓MSCs(BMSCs)在体外定向分化为光感受器样细胞的可能性及其所需的微环境. 方法 分别将第2代BMSCs细胞株和视网膜色素上皮(RPE)细胞株进行常规培养和传代,取第4代人BMSCs细胞株及第3代RPE细胞株用于实验.将BMSCs分为诱导组和对照组,诱导组的BMSCs与含有20 μg/L碱性成纤维细胞生长因子(bFGF)、20 μg/L表皮生长因子(EGF)及20 μg/L脑源性神经营养因子(BDNF)的骨髓干细胞培养基(MSCM)及RPE细胞的条件培养液共培养进行BMSCs的诱导分化,而对照组的BMSCs仅用MSCM培养基进行培养,倒置显微镜下观察分化细胞的形态学变化.采用免疫细胞化学法检测RPE细胞诱导BMSCs3、5、7d时细胞中视紫红质蛋白的阳性表达率,以鉴定分化细胞的表型.采用逆转录PCR(RT-PCR)法检测RPE细胞诱导BMSCs 5 d、7d时细胞中视紫红质和恢复蛋白mRNA的表达情况. 结果 培养的BMSCs形态均一,呈纺锤形或梭形,RPE细胞形态均一,呈多边形或六边形,细胞内充满色素颗粒,生长良好.诱导后的部分BMSCs呈神经样细胞形态,细胞变圆,突起增长,突起末端可见一级、二级分支,相互间连接呈网状.免疫细胞化学法检测表明,诱导组细胞诱导后第3、5、7天细胞中可见视紫红质的表达,表达率分别为(5.83±0.29)％、(20.36±0.32)％和(29.80±2.30)％,明显高于对照组的(0.71±0.35)％、(2.56±0.24)％和(2.32±0.42)％,差异均有统计学意义(t3 d =41.510,ts d=107.290,t7 d=30.036,P＜0.01).RT-PCR法检测显示,诱导后5d、7d诱导组细胞中视紫红质和恢复蛋白mRNA表达的灰度值均明显高于对照组,差异均有统计学意义(视紫红质mRNA:ts d=103.506,t7 d=122.584,P＜0.01;恢复蛋白mRNA:t5 d=106.674,t7 d=189.992,P＜0.01). 结论 采用含bFGF、EGF及BDNF的条件培养基与RPE细胞培养液体外共培养后BMSCs能够诱导分化成光感受器样细胞.     

烟焦油对体外人视网膜色素上皮细胞的损害

目的:研究烟焦油对体外培养的人视网膜色素上皮细胞(human retinal pigmentepithelium,HRPE)超微形态结构的影响,以及趋化因子MCP-1的细胞外表达水平。方法:将体外培养的HRPE分为空白对照组、二甲亚砜(dime-thylsulfoxide,DMSO)对照组和焦油实验组,其中焦油实验组中焦油浓度分别为1,10,50mg/L,经48h培养后,与空白对照组及DMSO对照组进行比较,使用倒置显微镜及透射型电子显微镜观察HRPE的形态以及超微结构变化,并用ELISA法选择检测各组培养上清中细胞因子MCP-1的表达量。结果:倒置显微镜显示焦油实验组随着焦油浓度的增大,发生变性坏死的HRPE细胞数量逐渐增多,并且细胞的形态发生明显改变;电镜显示焦油实验组随着焦油浓度的增大,RPE细胞形态扁平,微绒毛减少,胞质稀疏、减少,细胞核细长、核染色质稀疏,染色质浓缩,可见空泡,细胞呈萎缩状态;ELISA结果显示随着焦油浓度的增大,RPE分泌至胞外的MCP-1逐渐减少,差异有统计学意义(P<0.05)。结论:烟焦油可改变视网膜色素上皮细胞正常的形态和生理功能,造成色素上皮细胞的严重损害。     

RPE CD14 immunohistochemical,genetic, and functional expression

CD14 is the primary receptor for lipopolysaccharide (LPS)that plays important roles in host defense and subserves other host-related biological functions. We previously identified CD14 on cultured human retinal pigment epithelial (HRPE) cells using immunocytochemical techniques. In this study, we investigated immunoreactive HRPE CD14 expression by immunohistochemically staining HRPE cells and HRPE cells in sections of human eyes with anti-CD14 monoclonal antibodies (mAb). Constitutive HRPE gene and protein expression were confirmed by semiquantitative PCR and western blotting. ELISA for cell-associated and secreted (s) HRPE CD14 revealed that specific digestion by phosphoinositol-specific phospholipase C (PI-PLC) significantly reduced (P<0.01) cell-associated HRPE CD14 which was not modulated by LPS or gamma-IFN. ELISA of the conditioned media (CM) of HRPE cells treated with PI-PLC contained significantly more (P<0.001) sCD14, but sCD14 was not modulated by LPS or gamma-IFN. FACS analysis confirmed HRPE cell surface CD14. To show functional CD14, fluorescently-labelled LPS and CD14 were demonstrated to show significant co-localization on live, cultured HRPE cells in close proximity (<7A) as demonstrated by resonance energy transfer of the fluorescent ligands (P<0.0001). Significant inhibition (P<0.001) of LPS-induced IL-8 secretion, as measured by ELISA, occurred in the presence of function blocking anti-CD14 mAb. Significant inhibition of LPS-induced HRPE IL-8 secretion by PKC, PTK, PI3 kinase, and p38 kinase inhibitors indicated cell mediators responsible for LPS-induced HRPE chemokine secretion. This study demonstrates that HRPE cells express functional CD14 in vitro and in situ along at the outer blood-retina barrier.     

Control of peroxyntrite -induced production of inducible nitric oxide synthase isoforms and antagonism of cholecystokinin octapeptide-8 in retinal pigment epithelial cells in vivo

· AIM: To explore if peroxyntrite (ONOO-) induced iNOS via Fas/ Fas/L pathway in diabetic rats and the effection of cholecystokinin octapeptide-8 (CCK-8) as therapeutic agent for decrease diabetic retinopathy. · METHODS: Thirty-six rats were taken as control group, seventy two were given (streptozotocin) STZ (45mg/kg) and then divided into ONOO-group and CCK-8 group (peritoneal injection CCK-8). STZ-induced diabetic rats were treated with CCK-8 for 60 days. Western blotting analysis, DNA ladder, RT-PCR, immunohistochemistry and flow cytometry were used for determining the expression of nitrotyrosine (NT, the foot print of ONOO-); apoptosis and inducible nitric oxide synthase (iNOS) mRNA as well as Fas/Fasl signal transduction in RPE cells. · RESULTS: Both RPE cells in ONOO- and CCK-8 group developed apoptosis and expressed NT, iNOS mRNA and Fas/Fasl. But latter delayed the all changes in a time-dependent manner compared with control and ONOO- group (P<0.001). iNOS and Fas/Fasl were up-regulated and associated with an increase of expression of ONOO-in vivo. · CONCLUSION: The study suggested that apoptosis of RPE was partly induced by ONOO- may be the new way of oxidative damage to the RPE cells. CCK-8 decreased RPE cells apoptosis partly induced by ONOO- and is a potential drug for therapy of diabetic retinopathy. The mechanism of CCK-8 dealing with RPE cells may be related to its direct inhibition of the formation of iNOS to produce ONOO- and antagnism of damage of ONOO- to RPE cells. ·     

槲皮素对高糖培养牛视网膜周细胞增殖和凋亡的影响

目的:观察槲皮素(Quercetin,Que)对高糖状态下牛视网膜毛细血管周细胞(bovine retinal microvascular pericyte,BRPC)增殖和凋亡的影响。方法:用MTT比色法观察25,50,100μmol/LQue2,4,6d,对高糖(25mmol/L)培养BRPC增殖的影响;TUNEL法检测6d后Que对BRPC凋亡的影响。结果:高糖组较正常组吸光度值降低(P<0.01),槲皮素组较高糖组吸光度值升高(P<0.05),以高浓度槲皮素组吸光度值最高。TUNEL法检测显示:高糖状态下部分BRPC出现凋亡改变,高糖组较正常组凋亡率升高(P<0.01),槲皮素组较高糖组凋亡率降低(P<0.05),以高浓度槲皮素凋亡率最低。结论:Que可减轻高糖对BRPC增殖的抑制作用,减少高糖状态下BRPC的凋亡。     

探讨核心蛋白多糖体外抑制兔晶状体上皮细胞的转分化

目的:探讨核心蛋白多糖(decorin)对体外培养的兔晶状体上皮细胞(lens epithelial cells,LEC)分泌转化生长因子β1(transforming growth factorβ1,TGF-β1)和表达α-平滑肌肌动蛋白(α-SMA)的影响。方法:体外原代培养兔LEC,当细胞接近融合时转板培养,分别设置对照组和实验组,对照组为不用药培养12d;实验组为培养6d后加入不同浓度的decorin(10,1.0,0.1mg/L3个浓度组)继续培养6d,用ELISA法检测各组培养液上清中TGF-β1的水平,免疫细胞化学和计算机图像分析统计各组细胞中α-SMA的表达水平。结果:实验组TGF-β1水平和α-SMA水平均明显低于对照组的水平(117.9±18.1→427.2±41.3,111.7±26.7→427.2±41,236.0±28.6→427.2±41.3;15.7±8.7→97.2±26.9,16.2±9.5→97.2±26.9,54.9±29.6→97.2±26.9,P<0.01),decorin表现出明显的抑制作用;α-SMA的表达量随着TGF-β1水平的下降而下降,两者高度正相关(r=0.995,P<0.01)。结论:Decorin抑制活性TGF-β1的水平,下调α-SMA的表达。     

玻璃体条件培养液对视网膜色素上皮细胞P-ERK的影响

目的:探讨人玻璃体条件培养液(vitreous-conditioned medium,VCM)对体外培养的人视网膜色素上皮(human retinal pigment epithelium,HRPE)细胞内磷酸化的细胞外调节蛋白激酶(phosphorylated-extracellular signal-regulated kinase,P-ERK)的影响。方法:将HRPE细胞培养在含100,250,500,1000mL/L人玻璃体的DMEM条件培养液(VCM)里,用免疫荧光细胞化学技术,Western blot观察VCM作用不同时间及不同体积比的VCM作用下P-ERK的表达和分布情况。结果:VCM促使RPE细胞内ERK发生了磷酸化,且P-ERK发生了由细胞质到细胞核的转位。ERK的磷酸化水平在一定范围内与VCM的玻璃体体积成正比,250mL/L的VCM刺激ERK磷酸化的效果最强。ERK在加入VCM后5min开始磷酸化,10min磷酸化水平达到峰值且持续约2h。结论:一定体积分数的VCM使RPE内的ERK发生了磷酸化,激活后的P-ERKs由细胞质进入细胞核,参与转录的调节。提示MEK/MAPK信号传导途径可能参与了增生性玻璃体视网膜病变(proliferative vitreoretinopthy,PVR)。     

Bcl-2 expression by CD4 T lymphocytes in Vogt-Koyanagi-Harada disease

Purpose: To determine whether Bcl-2 is expressed on CD 4 + lymphocytes in the aqueous humor (AH) and cerebrospinal fluid (CSF) of patients with Vogt-Koyanagi-Harada (VKH) disease, and to determine whether Fas will induce apoptosis of lymphocytes in the CSF. Methods: The percentages of CD4, CD8, CD45RO, Fas, and Bcl-2 positive T lymphocytes in the AH and CSF of eight patients with active VKH and five healthy controls were determined by flow cytometry. Soluble Fas ligand (sFasL) in the CSF was measured by ELISA. Freshly isolated cells from the CSF were cultured with anti-Fas antibody (Ab) and apoptosis was assessed by the TUNEL method. Results: Fas + CD4 + lymphocytes were the predominant lymphocytes in the AH and CSF of VKH patients. Bcl-2 was strongly expressed in these cells. Soluble FasL was also detected in the CSF. The number of apoptotic cells detected by anti-Fas Ab was not significantly increased in the CSF of VKH patients. Conclusions: In spite of the high expression of Fas antigen on CD4 + cells and the presence of sFasL in the CSF, apoptosis was not observed. Bcl-2 expression may contribute to the regulation of apoptosis of inflammatory cells in the CSF of VKH patients.     

The role of Fas-Fas ligand-mediated apoptosis in autoimmune lacrimal gland disease in MRL/MpJ mice

PURPOSE: MRL/MpJ mice spontaneously develop lacrimal gland inflammation and are a model for the human disorder Sj?gren's syndrome. MRL/MpJ-lpr/lpr (MRL/lpr) and MRL/Mp-+/+ (MRL/+) mice are congenic substrains, which differ only by a single autosomal recessive gene, the lpr mutation. This mutation results in defective Fas protein, defective lymphocytic apoptosis, and accelerated autoimmune lacrimal gland disease in MRL/lpr mice. We evaluated apoptosis in the lacrimal glands of MRL/lpr and MRL/+ mice. METHODS: Inflammatory cells in the lacrimal glands of MRL/lpr and MRL/+ mice were evaluated for apoptosis with TUNEL staining and Fas and Fas ligand expression with immunohistochemistry. RESULTS: MRL/lpr mice had a greater percentage of the lacrimal gland replaced by inflammatory infiltrate (30.3% +/- 7.0%) than did MRL/+ mice (13.0% +/- 3.0%, P = 0.02). However, similar amounts of lymphocytic apoptosis were present in the lacrimal glands of MRL/lpr and MRL/+ mice. The mean number of apoptotic cells per unit area of inflammation was 23.8 +/- 2.4 in MRL/lpr mice and 24.6 +/- 6.0 in MRL/+ mice (P = 0.91). Fas expression was absent on lymphocytes in MRL/lpr mice but was present on lymphocytes in MRL/+ mice. Fas ligand expression was present on epithelial structures in both substrains. CONCLUSIONS: The accelerated lacrimal gland disease inflammation in MRL/lpr mice does not appear to be due to decreased apoptosis in the microenvironment of the lacrimal gland of MRL/lpr mice. It appears that in MRL/lpr mice there is defective extrathymic lymphoid apoptosis, permitting a relatively greater expansion of autoreactive T cells, which subsequently invade the lacrimal gland.     

Insufficient expression of Fas antigen on helper T cells in Behçet's disease.

AIMS: To investigate the lack of equilibrium in the regulatory mechanism of the immune system in Behçet's disease (BD), the expression of Fas antigen, an apoptosis related antigen, on peripheral blood lymphocytes from BD patients was analysed. METHODS: Twenty one BD patients were the subjects in this study. Ten healthy adults were examined as controls. Cell surface antigens of lymphocytes were analysed with flow cytometry. RESULTS: There was a significant (p < 0.01) difference in the proportion of CD4 positive cells with CD25 between BD patients with active uveoretinitis (27.6% (SD 8.4%)) and the controls (14.7% (2.3%)), but no significant difference in the proportion of CD4 or CD45RO positive cells with Fas. On the other hand, the proportion of CD8 positive cells with Fas was significantly (p < 0.01) higher in BD patients with active uveoretinitis (45.6% (11.6%)) than in those with inactive uveoretinitis (23.8% (8.1%)) or in the controls (24.4% (2.5%)). The proportion of CD19 positive cells with Fas was also significantly (p < 0.01) higher in BD patients with active uveoretinitis (13.0% (5.0%)) than in the controls (5.1% (2.1%)). CONCLUSION: The insufficient expression of Fas on activated CD4 positive T cells and its high expression on CD8 positive T cells seem to play an important role in the chronic inflammation in BD.