大鼠角膜热烧伤后眼组织平片的免疫组织化学研究

目的:探讨角膜热烧伤后角膜溃烂溶解穿孔以及眼内炎症的免疫学机制。方法:在大鼠角膜上制作热烧伤模型,在烧伤后的不同阶段,制备角膜,虹膜、脉络膜巩膜复合体以及视网膜平片,采用标准的ABC免疫组化方法,观察眼局部T淋巴细胞亚群,巨噬细胞、树突细胞,MHC Ⅱ类抗原阳性细胞的动态变化。结果:烧伤后早期,角膜及虹膜即有T淋巴细胞浸润,以CD3阳性细胞为主,MHCⅡ类抗原阳性细胞也轻度增多;当角膜溶解穿孔阶段,T淋巴细胞浸润达到高峰,在T淋巴细胞亚群中,CD4明显多于CD8阳性细胞;同时,巨噬细胞、树突细胞、MHCⅡ类抗原阳性细胞也大量出现。细胞密集分布于角膜缘,在溃疡溶解处,可见MHCⅡ类抗原阳性细胞及少至中等量CD3阳性淋巴细胞。Ⅱ类抗原阳性细胞在形态学上也发生了些变化,由初期的园形变为多形性,且大小不一。当烧伤恢复期病变稳定时,各种阳性细胞逐渐减少。结论:免疫反应参与了严重角膜烧伤的发病过程,在角膜溶解穿孔的发生中起重要作用。眼科学报 1997;13:70～74。     

IL-2-PE40体外抑制γ-干扰素诱导的角膜内皮细胞MHC抗原表达的研究

目的 了解正常大鼠角膜内皮细胞在体外经γ-干扰素诱导后,主要组织相容性复合体(major histocompatibility complex,MHC )-Ⅰ、Ⅱ类抗原异常表达的情况,并观察比较白细胞介素-2-绿脓杆菌外毒素(interleukin-2-pseudomonas exotoxin 40,IL-2-PE40)、环胞霉素A(cyclosporine A,CsA)对角膜内皮细胞MHC-Ⅰ、Ⅱ类抗原异常表达的免疫抑制作用.方法 采用ACAS-570黏附式细胞分析仪和免疫荧光技术,对体外原代培养经γ-干扰素诱导后的正常大鼠角膜内皮细胞分成A、B 2组进行MHC-Ⅰ、Ⅱ类抗原表达的相对量测定,并在培养液中加入新型免疫抑制剂IL-2-PE40和CsA,进一步测定角膜内皮细胞MHC-Ⅰ、Ⅱ类抗原的表达量.结果 未加入γ-干扰素前,MHC-Ⅰ类抗原的表达量为97.8±8.1,MHC-Ⅱ类抗原无表达;经γ-干扰素诱导后,MHC-Ⅰ类抗原的表达量为1 006.3±13.2,MHC-Ⅱ类抗原表达量为406.5±10.5,γ-干扰素加入前后MHC-Ⅰ、Ⅱ类抗原比较均有统计学意义(P＜0.05).IL-2-PE40组MHC-Ⅰ类抗原的表达量为618.2±13.5,MHC-Ⅱ类抗原表达量为204.5±7.8,CsA组MHC-Ⅰ类抗原的表达量为609.5±12.9,MHC-Ⅱ类抗原表达量为198.5±6.9,IL-2-PE40组、CsA组分别与注射用水比较,MHC-Ⅰ、Ⅱ类抗原间均有统计学意义(P＜0.05).IL-2-PE40组与CsA组比较,MHC-Ⅰ、Ⅱ类抗原间差异无统计学意义(P＞0.05).结论 在体外,γ-干扰素可诱导角膜内皮细胞MHC-Ⅰ、Ⅱ类抗原异常表达;IL-2-PE40及CsA均能不同程度的抑制这种表达.     

两种免疫毒素抑制大鼠角膜内皮细胞MHC抗原表达的疗效比较

目的 了解正常大鼠角膜内皮细胞在体外经γ-干扰素诱导后,MHC-Ⅰ、Ⅱ类抗原异常表达的情况,并观察比较IL-2-PE66、IL-2-PE40对这种异常表达的免疫抑制作用.方法 采用ACAS-570黏附式细胞分析仪和免疫荧光技术,对体外原代培养经γ-干扰素诱导的大鼠角膜内皮细胞进行MHC-Ⅰ、Ⅱ类抗原表达量的测定,并观察加入IL-2-PE66、IL-2-PE40后,MHC-Ⅰ、Ⅱ类抗原表达量的变化.结果 未加入γ-干扰素前,MHC-Ⅰ类抗原的表达量为97.8±8.1、MHC-Ⅱ类抗原无表达;经γ-干扰素诱导后,MHC-Ⅰ类抗原的表达量为1 006.3±13.2、MHC-Ⅱ类抗原表达量为406.5±10.5,γ-干扰素加入前后MHC-Ⅰ、Ⅱ类抗原比较差异均有统计学意义(P<0.01).IL-2-PE66组MHC-Ⅰ类抗原的表达量为598.2±12.5、MHC-Ⅱ类抗原表达量为197.5±6.8,IL-2-PE40组MHC-Ⅰ类抗原的表达量为618.2±13.5、MHC-Ⅱ类抗原表达量为204.5±7.8,IL-2-PE66组、IL-2-PE40组分别与注射用水比较,MHC-Ⅰ、Ⅱ类抗原间差异均有统计学意义(P<0.05),IL-2-PE66组与IL-2-PE40组比较,MHC-Ⅰ、Ⅱ类抗原间差异无统计学意义(P>0.05).结论 IL-2-PE66及IL-2-PE40均能明显抑制大鼠角膜内皮细胞在体外经γ-干扰素诱导后,MHC-Ⅰ、Ⅱ类抗原的异常表达.提示2种免疫毒素IL-2-PE66、IL-2-PE40均是高特异性的强效免疫毒素,是未来抗角膜移植排斥的新型基因药物.     

Lewis鼠视网膜脉络膜巨噬细胞、MHC-Ⅱ类抗原阳性细胞的免疫组织化学研究

在视网膜平片、脉络腆-巩膜复合体平片及眼组织切片上进行了免疫组织化学研究。在平片上发现。视网膜和脉络膜内均有网状分布的巨噬细胞，脉络膜内尚有网状分布的MHC-Ⅱ类抗原阳性细胞，细胞的形态，密度容易辨和计算。切片则未来能显示组织中细胞的分布、确切的形态特征及密度。说明在组织平片上进行免疫组比研究具有重要价值；本研究结果提示：巨噬细胞、MHC-Ⅱ类抗原阳性细胞在维持视网膜和脉络腆免疫环境的稳定性和防御感染等方面可能起重要作用。 （中华眼底病杂志，1995，11：250-253）     

内毒素诱导大鼠葡萄膜炎的组织平片和切片研究

目的：探讨内毒素诱导的视网膜脉络膜改变和平片、切片结果的差异。方法：从内毒素注射的Ｌｅｗｉｓ鼠制备视网膜和脉络膜－巩膜复合体平片以及眼组织冰冻切片，并进行免疫组织化学染色。结果：平片上显示，注射后４小时单核细胞浸润，随后，大量的单核巨噬细胞浸润至整个视网膜和脉络膜，脉络膜中尚有ＭＨＣ－Ⅱ类抗原阳性细胞增多；切片上发现，于注射后一定时期，视网膜和脉络膜中有上述细胞浸润。结论：平片技术为视网膜脉络膜原     

IL-2-PE40体外抑制γ-干扰素诱导的角膜内皮细胞MHC抗原表达的研究

目的了解正常大鼠角膜内皮细胞在体外经γ-干扰素诱导后，主要组织相容性复合体（major histoeompatibility complex，MHC）-Ⅰ、Ⅱ类抗原异常表达的情况。并观察比较白细胞介素-2-绿脓杆菌外毒素（interleukin-2-pseudomonas exotoxin40。IL-2-PE40）、环胞霉素A（cyclosporine A，CsA）对角膜内皮细胞MHC-Ⅰ、Ⅱ类抗原异常表达的免疫抑制作用。方法采用ACAS-570黏附式细胞分析仪和免疫荧光技术，对体外原代培养经γ-干扰素诱导后的正常大鼠角膜内皮细胞分成A、B2组进行MHC-Ⅰ、Ⅱ类抗原表达的相对量测定，并在培养液中加入新型免疫抑制剂IL-2-PE40和CsA，进一步测定角膜内皮细胞MHC-Ⅰ、Ⅱ类抗原的表达量。结果未加入γ-干扰素前，MHC-Ⅰ类抗原的表达量为97．8±8．1，MHC-Ⅱ类抗原无表达；经γ-干扰素诱导后，MHC—Ⅰ类抗原的表达量为1006．3±13．2，MHC-Ⅱ类抗原表达量为406．5±10．5，γ-干扰素加入前后MHC-Ⅰ、Ⅱ类抗原比较均有统计学意义（P〈0．05）。IL-2．PE40组MHC-Ⅰ类抗原的表达量为618．2±13．5，MHC-Ⅱ类抗原表达量为204．5±7．8，CsA组MHC-Ⅰ类抗原的表达量为609．5±12．9，MHC-Ⅱ类抗原表达量为198．5±6．9，IL-2．PE40组、CsA组分别与注射用水比较，MHC—Ⅰ、Ⅱ类抗原间均有统计学意义（P〈0．05）。IL-2．PE40组与CsA组比较．MHC—Ⅰ、Ⅱ类抗原间差异无统计学意义（P〉0．05）。结论在体外，γ-干扰素可诱导角膜内皮细胞MHC-Ⅰ、Ⅱ类抗原异常表达；IL-2-PE40及CsA均能不同程度的抑制这种表达。[眼科新进展20ff7；27（3）：170．172]     

鼠角膜碱烧伤的免疫学研究

目的 探讨角膜碱烧伤后眼局部的免疫反应机制。方法在大鼠角 制作碱烧伤模型。在烧伤后的不同阶段,制备角膜、虹膜组织平片,采用标准的卵白素－生物素过化物酶复合物免疫组方法。观察眼局部Ｔ淋巴细胞亚群,巨噬细胞、树突细胞、主要组织相容性复合物－Ⅱ类怕阳性细胞的动态变化。结果 碱烧伤后早期,角膜及虹膜即有Ｔ淋巴细胞浸润,以ＣＤ３淋巴细胞为主,ＭＨＣ－Ⅱ怕阳性细胞也轻度增多。在角膜溶解穿孔阶段,Ｔ淋巴细胞浸润     

角膜移植免疫排斥反应的免疫病理学研究

目的通过分析角膜移植排斥反应的免疫病理改变，探讨移植失败的相关因素。方法角膜移植术后排斥反应的患者42例，于再次行穿通性角膜移植术时取其排斥的移植片，进行免疫组化及HE染色，观察术后排斥反应的移植片中巨噬细胞、CD4^＋和CD8^＋细胞的浸润和分布、MHC-Ⅱ类主要组织相容性抗原、白介素受体-2和转化生长因子-β的表达，以及移植片的组织病理学改变。结果42例移植片均有上述免疫细胞的表达，并以新生血管周围更加明显；这些细胞表达MHC-Ⅱ类抗原和IL-2R；移植片的上皮和基质细胞中也有MHC-Ⅱ类抗原的表达；角膜上皮细胞可表达TGF-D；所有移植片内皮细胞均不完整甚至大部缺如。结论新生血管使免疫细胞进入移植片，破坏免疫赦免机制，与移植片免疫损害密切相关；免疫细胞和分子直接导致移植片免疫损伤，内皮细胞的严重损伤终将导致移植失败。     

两种免疫毒素抑制大鼠角膜内皮细胞MHC抗原表达的疗效比较

目的了解正常大鼠角膜内皮细胞在体外经γ-干扰素诱导后，MHC-I、Ⅱ类抗原异常表达的情况，并观察比较IL-2-PE66、IL-2-PE40对这种异常表达的免疫抑制作用。方法采用ACAS-570黏附式细胞分析仪和免疫荧光技术，对体外原代培养经μ-干扰素诱导的大鼠角膜内皮细胞进行MHC-I、Ⅱ类抗原表达量的测定，并观察加入IL-2-PE66、IL-2-PE40后，MHC-I、Ⅱ类抗原表达量的变化。结果未加入μ-干扰素前，MHC-I类抗原的表达量为97.8±8.1、MHC-Ⅱ类抗原无表达；经μ-干扰素诱导后，MHC-I类抗原的表达量为l006.3±13.2、MHC-Ⅱ类抗原表达量为406.5±10.5，μ-干扰素加入前后MHC-I、Ⅱ类抗原比较差异均有统计学意义（P〈0.01）。IL-2-PE66组MHC-I类抗原的表达量为598.2±12.5、MHC-Ⅱ类抗原表达量为197.5±6.8，IL-2-PE40组MHC-I类抗原的表达量为618.2±13.5、MHC-Ⅱ类抗原表达量为204.5±7.8，IL-2-PE66组、IL-2-PE40组分别与注射用水比较，MHC-I、Ⅱ类抗原间差异均有统计学意义（P〈0.05），IL-2-PE66组与IL-2-PE40组比较，MHC-I、Ⅱ类抗原间差异无统计学意义（P〉0.05）。结论IL-2-PE66及IL-2-PE40均能明显抑制大鼠角膜内皮细胞在体外经μ-干扰素诱导后，MHC-I、Ⅱ类抗原的异常表达。提示2种免疫毒素IL-2-PE66、IL-2-PE40均是高特异性的强效免疫毒素,是未来抗角膜移植排斥的新型基因药物。     

核因子NF-κB在细菌内毒素诱导的实验性角膜基质炎中的表达

目的 :明确在细菌内毒素 (L PS)诱导的角膜基质炎中是否存在转录调节因子 -核因子 NF-κB的活化表达。方法 :青年 Wistar大鼠右眼及左眼分别给予细菌内毒素 L PS (4μg·μ1- 1 )及其溶剂 -灭菌 PBS各 10μl角膜内注射。注射后分别于 1小时、 3小时、6小时、 1天、 3天及 7天处死动物。每只角膜标本分为 2份 ,一份行石蜡切片病理学检查 ,一份行冰冻切片进行免疫组织化学分析。结果 :病理学检查 :L PS注射后 1小时即可见角膜缘血管内有炎症细胞聚集 ,随时间延长 ,中央角膜基质区域炎症细胞浸润明显 ,基质水肿 ,部分基质细胞溶解坏死 ,被巨噬细胞吞噬 ,至第 3～ 7天中周边基质内有新生血管生成 ,基质水肿渐减轻 ,细胞外胶原排列紊乱 ,呈典型的角膜基质炎的病理改变。免疫组化检查 :L PS注射后 1小时即出现 NF- κB阳性细胞 ,表现为部分基质细胞核内染色阳性 ,染色强度以 3小时和 6小时为最强 ,随时间延长逐渐减弱 ,至 7天时几乎无阳性细胞。结论 :核因子 NF-κB在实验性角膜基质炎早期存在活化表达。NF- κB在细胞核内出现 ,可能通过与相应致炎基因的启动子与增强子结合 ,促进相关基因的转录 ,从而在角膜基质炎中起到重要作用     

角膜移植排斥反应的铺片免疫组化研究

目的 探讨角膜移植排斥反应的发生机制及其参与细胞的表型。方法 制备正常大鼠和穿透性角膜移植鼠的角膜和虹膜睫状体铺片,用８种单克隆抗体,于铺片上进行免疫组化染色。结果 正常周边角膜及角膜缘可见少量的Ｔ细胞（ＣＤ３）、辅助／诱导性Ｔ细胞（ＣＤ４）、抑制／细胞毒Ｔ细胞（ＣＤ８）、巨噬细胞、树突细胞、主要组织相容性复合体Ⅱ类抗原阳性细胞及β转化生长因子阳性细胞;同种角膜移植术后７及１２天角膜和虹膜睫状体中     

Macrophages and MHC class II positive cells in the choroid during endotoxin induced uveitis

AIMS/BACKGROUND—Endotoxin induced uveitis has been regarded as a model for acute anterior uveitis and until now little was known about choroidal involvement. The aim of this study was to investigate changes in macrophages and MHC class II positive cells in the choroid of Lewis rats during endotoxin induced uveitis.METHODS—Choroid-sclera wholemounts were isolated from normal Lewis rats and at different time points—4, 8, 16, 24, 48, 72, and 96 hours, and 7, 10, and 14 days after a footpad injection of 200 µg of lipopolysaccharide (LPS). Immunohistochemistry was performed using the monoclonal antibodies ED1 (monocytes, macrophages, dendritic cells), and OX6 (MHC class II antigen).RESULTS—In normal rats, two layers of macrophages were identified in the choroid; a layer located immediately beneath the retinal pigment epithelium (RPE) and a layer bordering the sclera. The density of ED1 positive cells in the layer bordering the RPE cells was 902 (SD 132) cells/mm² whereas the scleral layer had a cell density of 389 (73) cells/mm². Based on morphology, positive cells could be divided into two main categories; pleomorphic/round cells and dendritiform cells with varying appearances, with the latter being predominant in normal eyes. A network of MHC class II positive dendritic cells was found in the choroid, beneath the RPE, with a density of 659 (96) cells/mm². No MHC class II positive cells were found in the macrophage layer bordering the sclera. LPS injection caused a massive influx of ED1 positive macrophages in the area below the RPE cells but did not result in an influx of macrophages at the scleral side of the choroid. The infiltrate reached a maximum at 16 hours following LPS injection and decreased at 96 hours. The morphology of the infiltrating cells was pleomorphic/round at early stages of inflammation and changed into a dendritiform cell population later. The number of MHC class II positive cells on the anterior side of the choroid increased 8 hours after injection and reached a peak at 72-96 hours. MHC class II positive cells were not observed in the vicinity of the sclera at any time after LPS injection. Both resident and MHC class II positive dendritic cell numbers returned to normal values at day 14 following LPS injection.CONCLUSIONS—These results indicate that the choroid is severely inflamed after systemic LPS administration to Lewis rats and suggests that endotoxin induced uveitis may serve as a model for generalised uveitis in humans.     

Phenotypic Changes and Inflammatory Cell Distribution in the Cornea During Development of Experimental Immune-mediated Blepharoconjunctivitis

Purpose To investigate the morphological changes in the cornea during the development of experimental immune-mediated blepharoconjunctivitis (EC).Methods EC was induced in Brown Norway (BN) rats by active immunization with ovalbumin (OVA) emulsified in complete Freunds adjuvant and a subsequent challenge by OVA eyedrops. The corneas were analyzed immunohistochemically.Results Before the induction of EC, cells stained with OX6 (rat MHC class 2, RT1B), ED1 (tissue macrophages), ED2 (resident macrophages), CD4, or major basic protein were present in the peripheral corneal stroma. ED1- and OX6-stained cells were also observed in the central corneal stroma, and their number increased after the antigen challenge. Infiltration of cells stained with ED1, ED2, OX62 (dendritic cells), CD4, or CD3 (T cells) from the limbus to the peripheral corneal stroma started 6h after the antigen challenge. Expression of MHC class 2 molecules was induced on the corneal epithelium by the antigen challenge.Conclusions The present study demonstrates for the first time the phenotypic changes and distribution of inflammatory cells in the cornea during the development of EC. Jpn J Ophthalmol 2004;48:333–339 © Japanese Ophthalmological Society 2004     

Quantitative Analysis of Major Histocompatibility Complex Class II-Positive Cells in Posterior Segment of Royal College of Surgeons Rat Eyes

Potential antigen-presenting cells in the posterior segment of Royal College of Surgeons (RCS) rat eyes were analyzed quantitatively. Light microscopic immunohistochemistry was performed at postnatal days (P) 10, 20, 28, 42, 63, and 140 in the eyes of RCS rats and their congenic counterparts. Immunohistochemical studies were carried out using monoclonal antibodies against major histocompatibility complex (MHC) class II antigen (OX6), a cytoplasmic antigen in bone marrow-derived macrophages (ED1), a membrane antigen on resident tissue macrophages (ED2), and a microglia/macrophage marker (OX42). Some sections were stained by a double-labeling method using these antibodies. No MHC class II-positive cells were seen in dystrophic RCS rat retinas at P10. They were found, however, in the outer nuclear layer and debris of outer segments at P20. From P20 to P42 the number of cells increased, then decreased until P140. Congenic controls, however, showed no MHC class II-positive cells in the retina. Cells double-labeled with OX6 and ED1 were present in the outer nuclear layer at P42, but no OX6 or OX42 double-labeled cells were detected. Also, no ED2-positive cells were detected. Our results suggest that MHC class II-positive cells may play some role in retinal dystrophy.     

Novel characterization of MHC class II-negative population of resident corneal Langerhans cell-type dendritic cells

PURPOSE: The presence of antigen-presenting cells (APCs) such as Langerhans cells (LCs), an epithelial form of dendritic cells (DCs), in corneal tissue is critical for generation of immune responses, including graft rejection and herpetic keratitis. The purpose of this study was to characterize the distribution and major histocompatibility complex (MHC) antigen expression of corneal LCs. METHODS: Normal and inflamed corneas were excised from BALB/c mice, and immunofluorescence staining for CD11c, CD11b, CD45, CD80 (B7.1), CD86 (B7.2), CD3, and MHC class II (Ia) was performed by confocal microscopy on wholemount corneal epithelium. RESULTS: CD11c(+) MHC class II-positive LCs were found in the limbus and corneal periphery, but not in the center of the normal cornea. These cells were CD45 positive, exhibiting bone marrow derivation, and CD3 and CD11b negative, confirming a DC lineage. Additionally, these cells were CD80 and CD86 negative, reflecting an immature phenotype. In the central and paracentral areas, however, significant numbers of CD11c(+) LCs were detected that expressed no MHC class II. It is important to note that although the density of the LCs declined from the limbus toward the center of the cornea, they were always present. In the inflamed cornea, the expression of MHC class II and costimulatory molecules CD80 and CD86 was significantly enhanced, and present in all parts of the cornea, in contrast to the normal cornea. CONCLUSIONS: The present study demonstrates for the first time the phenotype and distribution of MHC class II-negative LCs in the murine corneal epithelium. In the inflamed cornea, the LCs become activated as reflected by expression of B7 costimulatory markers. These changes in activation markers may provide additional information for devising novel immunomodulatory strategies.     

S100A9-positive granulocytes and monocytes in lipopolysaccharide-induced anterior ocular inflammation

S100A9 is a pro-inflammatory protein expressed in infiltrating granulocytes and monocytes. We determined role of S100A9 in endotoxin (LPS)-induced uveitis (EIU) and keratitis in Wistar rats. Anti-S100A9 antibody decreased partially clinical scores, protein, and cells in the aqueous humor at 18-36 h, compared with the LPS group. S100A9-positive cells were expressed in the iris-ciliary body (ICB) and cornea at 24-48 h. Activated caspase-3 (related to apoptosis) and S100A9 co-expressed in ICB at 18-48 h after LPS injection. S100A9 was not expressed in ED2-positive cells in ICB. Dexamethasone (DEX) increased S100A9 mRNA and protein levels in the circulating blood leukocytes, but reduced S100A9 mRNA and protein levels in ICB after LPS injection. BAY 11-7085 (an inhibitor of I-kappaB phosphorylation) suppressed S100A9 mRNA in leukocytes (43.5%) and ICB (68.5%), respectively, after LPS injection. It is possible that S100A9-positive granulocytes and monocyte/macrophages may play a role in the late phase of EIU and keratitis that DEX may inhibit the migration of S100A9-positive granulocytes and monocytes from the blood into the extravascular tissues, and that nuclear factor (NF)-kappaB pathway may be involved in S100A9 expression. S100A9 could play a role in the clearance of inflammatory cells at the late phase of EIU.     

实验性自身免疫性葡萄膜视网膜炎中浸润细胞的表型及其凋亡的研究

目的探讨实验性自身免疫性葡萄膜视网膜炎(experimental autoimmune uveoretinitis,EAU)中参与的细胞表型及其凋亡。方法用光感受器间维生素A类结合蛋白(interphotoreceptor retinoid-binding protein,IRBP)免疫16只Lewis鼠后，于眼组织切片和平片上进行免疫组织化学染色和原位 凋亡染色，所用抗体为抗单核细胞、巨噬细胞(EDI)、MHC-II类抗原(OX6)、T淋巴细胞(R73)的单克隆抗体，所用原位凋亡试剂盒为TACS1 Klenow。结果用IRBP免疫Lewis鼠后，16只鼠中12只发生了临床可见的葡萄膜炎，炎症平均得分为1.29±0.7级；免疫组织化学染色发现葡萄膜和视网膜中有大量的单核细胞、淋巴细胞及MHC-II⁺细胞浸润，这些组织中均可见浸润细胞的凋亡，虹膜睫状体中凋亡细胞明显多于脉络膜和视网膜中的凋亡细胞。结论单核巨噬细胞、淋巴细胞和MHC-II⁺细胞均参与了EAU的形成，在EAU早期即有浸润细胞发生凋亡，此可能是导致这种炎症迅速消退的重要机制。（中华眼底病杂志，2000，16：1-70）     

Interferon gamma immunoreactivity in iris nerve fibres during endotoxin induced uveitis in the rat

AIMS—Previous studies have implied that interferon gamma (IFN-γ) is involved in the pathogenesis of endotoxin induced uveitis (EIU) in the rat. This study investigated the source of IFN-γ in the iris during EIU.METHODS—Whole mounts of iris were isolated from Lewis rats before and at different times (from 4 hours to 14 days) after foot pad injection of 200 µg Salmonella typhimurium lipopolysaccharide (LPS). Immunohistological analysis was performed using monoclonal antibodies (mAbs) specific to rat IFN-γ (DB12 and DB13). mAbs specific to monocytes, macrophages, and dendritic cells and MHC class II were used to asses the inflammatory response in the eye (ED-1, ED-2, and OX-6). An antibody specific to neurofilaments (2H3) was used to stain nerve fibres in the normal iris.RESULTS—LPS administration induced acute intraocular inflammation, characterised by a massive infiltration of monocytes/macrophages and increased numbers of MHC class II positive cells in the iris. IFN-γ immunoreactive cells were not detected in iris whole mounts of control rats. Strikingly, IFN-γ immunoreactivity was found in fibres from 4 hours until 10 days after LPS injection, with the most intense staining at 48-72 hours. Other DB12 or DB13 positive cells were not detected in the iris. The pattern of DB12 and DB13 staining in the inflamed iris was similar to the 2H3 staining of neurons in the iris of control rats.CONCLUSION—These results show that systemic LPS administration induces IFN-γ immunoreactivity in iris fibres and suggest that iris nerve fibres may be a source of IFN-γ during EIU. The IFN-γ immunoreactive material in the iris nerve fibres may be identical to neuronal IFN-γ.