可溶性B、T淋巴细胞衰减因子及其配体在单纯疱疹性角膜基质炎小鼠体内的异常表达

目的 研究B、T淋巴细胞衰减因子(B and T lymphocyte attenuator,BTLA)及其配体疱疹病毒侵入介体(herpes virus entry mediator,HVEM)在单纯疱疹性角膜基质炎(herpetic stromal keratitis,HSK)小鼠角膜组织中及外周血CD4+T细胞上的表达水平,探讨共抑制信号BTLA-HVEM是否参与了CD4+T细胞介导的HSK免疫病理反应.方法 将106 PFU的单纯疱疹病毒Ⅰ型(herpes simplex virus type 1,HSV-1)KOS毒株接种于BALB/c鼠的角膜上建立HSK动物模型,分别于角膜接种病毒前(0 d),接种病毒后的第3、7、10、14、21天,用毛细管取小鼠的左眼眼眶静脉窦血1 mL,分离淋巴细胞,行荧光抗体染色,用流式细胞仪检测CD3+ CD4+ BTLA+T细胞和CD3+ CD4+ HVEM+T细胞阳性率;在裂隙灯显微镜下观察小鼠角膜变化;免疫组织化学方法检测BTLA蛋白及HVEM蛋白在角膜组织中的表达.结果 BALB/c鼠的角膜接种HSV-1后的1～5d,角膜擦拭液中均检测出HSV-1复制,表明小鼠感染了单纯疱疹病毒.裂隙灯显微镜观察显示:角膜接种HSV-1后第3天,所有小鼠均患了急性上皮性角膜炎,并于感染后1周内痊愈,自病毒接种后第8天起,小鼠出现角膜基质炎的改变,表现为角膜基质呈灰白色混浊,角膜基质混浊于病毒接种后的第10天达到高峰,持续至第14天后逐渐减轻.流式细胞仪检测显示,小鼠外周血淋巴细胞中CD3+CD4+BTLA+T细胞和CD3+ CD4+ HVEM+T细胞的阳性率,在角膜接种病毒前(0 d)分别为(3.15±0.60)％和(9.84±1.06)％,在角膜接种病毒后第10天(HSK疾病程度最严重时)分别增加到(20.47±3.15)％和(45.18±3.90)％(与0d相比差异均有显著统计学意义,均为P＜0.01).免疫组织化学方法检查HSK小鼠角膜组织中BTLA和HVEM的蛋白表达结果一致:HSK临床表现最严重时,即病毒接种后第10天时,BTLA蛋白和HVEM蛋白在角膜组织中表达最强,主要表达于角膜基质层内浸润的炎性细胞上,角膜上皮层和内皮层也有表达.结论 在HSK小鼠模型中,BTLA及其配体HVEM蛋白在角膜组织中及外周血CD4+T细胞上表达明显增强,共抑制信号BTLA-HVEM参与了CD4+T细胞介导的HSK的免疫病理过程.     

白细胞介素10对小鼠单纯疱疹性角膜基质炎作用的实验研究

研究白细胞介素10(IL-10)在小鼠单纯疱疹性角膜基质炎(herpetic stromal keratitis,HSK)中的作用。方法雌性BALB／c小鼠80只分为2组,每组40只;将单纯疱疹病毒1型接种于小鼠角膜上建立HSK动物模型;分别于鼠角膜接种病毒前的6h、当日及接种后2、4d,向实验组鼠的角膜内注射重组IL-10 20ng,腹腔内注射鼠重组IL-10 500 ng;对照组同步注射生理盐水;观察IL-10对小鼠HSK的发病率、临床特征、角膜病毒滴度、角膜细胞因子含量、角膜病理改变及迟发型超敏反应(DTH)的影响。结果IL-10降低了HSK发病率,减轻了HSK角膜混浊程度、角膜新生血管化程度及角膜内炎性细胞浸润,降低了角膜内IL-2和IL-6的含量,抑制了鼠的DTH反应。IL-10不影响病毒在角膜内的复制和清除。结论IL-10可抑制鼠的DTH反应和HSK的发病进展。     

细胞因子在鼠复发性单纯疱疹性角膜基质炎角膜组织中的表达

目的探讨CD4^ T辅助细胞1型(Th1)和T辅助细胞2型(Th2)分泌的细胞因子在鼠复发性单纯疱疹性角膜基质炎(HSK)角膜组织中的表达水平,及其与复发性HSK的关系。方法制备复发性HSK的BALB／c鼠模型,用紫外线B光照射鼠的角膜诱导HSK复发;分别于紫外线照射前,照射后第3、7、10、14、21及28天,取角膜中央直径为2mm的角膜环,用逆转录聚合酶链反应(RT-PCR)检测Th1型细胞因子(IFN-γ、IL-12)和Th2型细胞因子(IL4、IL-10)的表达水平。结果处于病毒潜伏感染期的小鼠经紫外线照射诱导病毒复发后,角膜基质混浊于紫外线照射后的7～14d达到高峰;在此期间,IFN-γ、IL-12、IL-10和IL-4mRNA在角膜组织中均有表达。其中,IFN—γ和IL-10在临床疾病的发生、发展过程中(病毒激活后第3～14天)高表达,在疾病恢复期(14d后)表达减弱,与角膜基质混浊程度密切相关;IL-12是角膜组织内表达最丰富的细胞因子,在病毒激活后的第3天即开始高表达,高表达持续经过整个观察期;IL-4在病毒激活后的第3～14天有明显表达。结论在复发性HSK的角膜损伤早期,Th1型细胞因子和Th2型细胞因子同时表达于角膜组织中,与T细胞的免疫记忆性有关。IL-10的表达趋势平行于IFN-γ的表达,其表达水平与HSK的疾病程度密切相关。复发性HSK无法严格区分是由Th1细胞介导的还是由Th2细胞介导的,角膜的损伤与修复可能依赖于损伤性细胞因子和保护性细胞因子在病毒复发位置上的平衡。     

OX40-Ig融合蛋白对鼠单纯疱疹性角膜基质炎的抑制作用

目的研究OX40-Ig融合蛋白对鼠单纯疱疹性角膜基质炎(HSK)的免疫抑制作用。方法将1×106PFU的单纯疱疹病毒1型(HSV-1)Mckrae毒株接种于BALB/c鼠的角膜上建立HSK模型;分别于接种病毒的当天、接种后第2、4d将OX40-Ig融合蛋白100μg注射到鼠的腹膜下,观察OX40-Ig融合蛋白对鼠HSK的影响。结果OX40-Ig融合蛋白使鼠外周血中CD4 T细胞减少了78·2%,使鼠HSK发病率由83·3%下降到20·0%。OX40-Ig治疗组的小鼠角膜基质混浊程度较对照组明显减轻,角膜内炎性细胞浸润也明显减少,迟发型超敏反应能力显著下降。结论OX40-Ig融合蛋白能够阻断OX-40/OX-40L协同刺激途径,抑制CD4 T细胞增生,阻止HSK的发病,减轻HSK的严重程度。     

协同刺激分子在单纯疱疹性角膜基质炎鼠外周血中的表达

目的研究鼠单纯疱疹性角膜基质炎发生和发展过程中协同刺激分子在外周血中的表达水平,探讨协同刺激分子的表达与单纯疱疹性角膜基质炎之间的关系。方法用单纯疱疹病毒1型(herpessimplexvirustype1,HSV1)接种于BALB/c鼠角膜上建立单纯疱疹性角膜基质炎(herpeticstromalkeratitis,HSK)动物模型,分别于角膜接种病毒前和接种病毒后的第1d、3d、7d、10d、14d、21d及28d,用毛细管取小鼠的左眼眼眶静脉窦血1mL,提取淋巴细胞,用半定量逆转录聚合酶链反应检测协同刺激分子B71、B72、CD28、CTLA4的表达水平;同时,在裂隙灯显微镜下观察鼠角膜的临床变化。结果HSV1感染鼠的角膜后,小鼠均患了急性角膜上皮炎,并于感染后1周内痊愈。86.7%(78/90)的小鼠自感染病毒后第10d起开始出现角膜基质炎改变,典型的表现为灶状角膜基质混浊,局部角膜新生血管化,炎性细胞浸润。角膜基质混浊逐渐进展,于3周时达到高峰,4周时开始修复。鼠在感染病毒之前,外周血中表达微弱的CD28mRNA,不表达CTLA4、B71及B72mRNA。鼠感染病毒后,外周血中CD28、CTLA4和B71的表达量均显著增加,B72仍无表达;CD28在HSK的发生和发展过程中表达水平较高,在疾病愈合过程中表达减弱;B71表达的高峰时间是病毒感染后的3～21d,以稍低的表达水平平行于CD28的表达。结论在鼠单纯疱疹性角膜基质炎的发病过程中,协同刺激分子CD28/CTLA4:B71在外周血中的表达明显增强,在诱导CD4 T细胞介导的单纯疱疹性角膜基质炎中起关键性作用。     

转录因子T-bet在单纯疱疹病毒感染小鼠外周血中的表达

目的研究单纯疱疹病毒Ⅰ型(herpes si mplex virus type1,HSV-1)感染小鼠眼球以后转录因子T-bet在小鼠外周血中的表达,探讨T-bet的表达与单纯疱疹性角膜基质炎之间的关系。方法将106空斑单位(plague forming unit,PFU)·L-1的HSV-1Mckrae毒株接种于BALB/c鼠的角膜上建立单纯疱疹性角膜基质炎(herpetic stromal keratitis,HSK)动物模型,分别于角膜接种病毒后的第1d、3d、7d、10d、14d、21d及28d,用毛细管取小鼠的左眼眼眶静脉窦血1mL,提取淋巴细胞,用半定量逆转录聚合酶链反应(RT-PCR)检测T-bet mRNA的表达水平;在裂隙灯显微镜下观察小鼠角膜的临床变化,组织学检查角膜的病理改变;用ELISA法检测T-bet蛋白在角膜组织中的表达水平。结果BALB/c鼠的角膜接种HSV-1后的1~5d,角膜擦拭液中均检测出HSV-1复制,表明小鼠感染了单纯疱疹病毒;裂隙灯显微镜观察:HSV-1感染鼠的角膜后,小鼠均患了急性角膜上皮炎,并于感染后1周内痊愈。其中81.7%(49/60)的小鼠自感染病毒后第10d起开始出现角膜基质炎改变,表现为灶状角膜基质混浊,局部角膜新生血管化,角膜基质内大量的炎性细胞浸润。角膜基质混浊逐渐进展,在病毒感染后的第14~21d达到高峰。RT-PCR检测的数据显示:未感染HSV-1的对照组小鼠的外周血中不表达T-bet mRNA;HSV-1感染小鼠的早期即可诱导T-bet mRNA在小鼠外周血中的表达,并且表达持续存在;T-bet mRNA表达的高峰时间(10~28d),位于角膜基质炎发生和发展的过程中。ELISA法检测角膜提取物中的T-bet蛋白显示了相似的结果。结论HSV-1上调T-bet mRNA在小鼠外周血中的表达;T-bet的表达与角膜基质炎的发生和发展密切相关。     

单纯疱疹病毒性角膜炎小鼠模型的建立及鉴定

目的：探讨建立不同感染时期HSK小鼠动物模型,为HSK的深入研究建立基础。方法：Balb/c小鼠125只麻醉后在显微镜下用刀片背面尖端于角膜＂#＂字划痕,其中100只小鼠接种HSV-Ⅰ病毒,另25只小鼠不接种病毒作为正常对照组。术后每天用10g/L荧光素钠染色后裂隙灯显微镜下观察角膜病变发生情况,并取角膜表面泪液进行HEK293T细胞检测以确定裂隙灯显微镜下有无病毒复制。对潜伏感染期小鼠模型采用紫外线B光照射以诱导HSK复发。结果：接种HSV-Ⅰ病毒的小鼠模型眼于接种后3d内全部出现急性上皮性角膜炎表现。经阿昔洛韦滴眼液治疗1wk后角膜炎症消失,但角膜和三叉神经节中PCR检测病毒仍为阳性。潜伏感染期小鼠模型经紫外线B光照射后也都在1wk内复发,并表现为以基质型角膜炎为主要临床表现的角膜病变。结论：采用角膜划痕法对Balb/c小鼠接种HSV-Ⅰ病毒和紫外线B光照射可以成功地制作出原发感染期、潜伏感染期和复发感染期等不同感染时期的HSK模型,而且操作相对简单、方便易行。     

细胞毒性T淋巴细胞相关抗原-4融合蛋白对鼠单纯疱疹性角膜基质炎抑制作用的研究

研究细胞毒性T淋巴细胞相关抗原-4融合蛋白(cytotoxic Tlymphocyte-associated antigen-4 immunoglobulin,CTIA-4Ig)对鼠单纯疱疹性角膜基质炎(herpetic stromal kerafifis,HSK)的抑制作用。方法用单纯疱疹病毒1型(herpes simplex virus type 1,HSV-1)接种于BALB／c鼠角膜上建立HSK动物模型,采用CTIA-4Ig阻断B7：CD28／CTIA-4协同刺激途径,抑制T淋巴细胞增殖、分化为效应细胞;观察HSK的发病率、临床特征、角膜组织学改变、角膜病毒滴度、迟发型超敏反应及抗原刺激脾细胞分泌细胞因子的情况。结果CTIA-4Ig可减少小鼠外周血中CD4^ T淋巴细胞(81．6％)及CD8^ T淋巴细胞(67．9％),阻止鼠发生HSK、减轻角膜混浊程度及角膜内炎性细胞的浸润、损伤鼠的迟发型超敏反应能力,抑制鼠脾细胞分泌辅助性T淋巴细胞1型(T-helper 1,Th1)细胞因子;但不影响角膜病毒滴度及小鼠死亡率。结论用CTIA-4Ig阻断B7：CD28／CTIA-4协同刺激途径,能够抑制T淋巴细胞增殖并抑制CIM^ Th1细胞的功能,阻止HSK发病,减轻HSK的严重程度。     

羊膜移植对实验性HSK中基质金属蛋白酶表达的影响

目的研究羊膜移植（AMT）对单纯疱疹性角膜炎（HSK）中基质金属蛋白酶（MMP-2，-9）表达的影响。方法40只BALB／c小鼠角膜感染Ⅰ型单纯疱疹病毒（HSV-1），实验组角膜行AMT。术后第0、2、7、14d取出角膜。常规病理切片、免疫组化染色和计算机图像分析检测角膜中MMP-2及-9的表达及平均光度值的变化。结果对照组20只鼠眼中17只发生HSK；AMT组仅有9只眼发生，差异有显著统计学意义（P〈0．01）。AMT组角膜上皮、基质病变程度及新生血管发生率明显低于对照组（P〈0．05）。免疫组化及图像分析显示对照组角膜细胞和浸润炎性细胞中表达的MMP-2及-9在第2d增加，14d时达高峰。AMT组各时间点MMP-2及-9表达低于对照组，差异有显著统计学意义（P〈0．05）。结论羊膜移植可能通过抑制角膜细胞及浸润的炎症细胞产生MMPs，从而抑制HSK的发生和发展。     

HSV-1上调白细胞介素-18 mRNA在小鼠角膜组织中表达的研究

目的研究单纯疱疹病毒Ⅰ型(HSV-1)感染小鼠眼球后,白细胞介素-18(IL-18)在角膜组织中的表达及IL-18的表达与单纯疱疹性角膜基质炎之间的关系。方法用106PFU的HSV-1感染BALB/c鼠的角膜后,在裂隙灯显微镜下观察角膜的临床变化,组织学检查角膜的病理改变;用RT-PCR和ELISA法检测IL-18在角膜组织中的表达水平。结果HSV-1引起的角膜基质炎在病毒感染后的第10d明显可见,在病毒感染后的第14~21d达到高峰。RT-PCR检测的数据显示:HSV-1感染的早期即可诱导IL-18mRNA在角膜组织中的表达,并且表达持续存在;IL-18mRNA的表达高峰时间(3~21d)位于临床疾病出现之前和临床疾病发展的过程中。ELISA检测角膜提取物中的IL-18蛋白显示了相似的结果。结论HSV-1上调IL-18在小鼠角膜组织中的表达;IL-18的表达与角膜基质炎的发生和发展密切相关;IL-18诱导Th1细胞介导的对单纯疱疹病毒特异性的免疫反应,导致单纯疱疹性角膜基质炎。     

CD8 T cells mediate transient herpes stromal keratitis in CD4-deficient mice

PURPOSE: To evaluate the role of CD4(+) T cells in the development of murine herpes stromal keratitis (HSK). METHODS: The corneas of wild-type (WT) BALB/c mice and three types of CD4-deficient BALB/c mice (CD4(-/-), CD4-depleted, CD4 and CD8 double-depleted) were infected with different doses of HSV-1 RE, and HSK incidence and severity were monitored. Corneal infiltrates were quantitatively and functionally assayed by flow cytometric analysis of individually digested diseased corneas and documented histologically. RESULTS: At a relatively high infectious dose (1 x 10(5) pfu/cornea): (1) CD4-deficient and WT BALB/c mice had severe HSK with a similar incidence (80%-100%), whereas HSK did not develop in mice deficient in both CD4(+) and CD8(+) T cells; (2) neutrophils were the predominate leukocyte in the corneas of CD4-deficient and WT mice; (3) the corneas of WT mice had activated, HSV-1-specific CD4(+) T cells, but few if any CD8(+) T cells; (4) the corneas of CD4-deficient mice had activated, HSV-1-specific CD8(+) T cells; and (5) HSK in CD4-deficient mice was transient, showing loss of CD8(+) T cells at 2 to 3 weeks after infection (pi) followed by a loss of neutrophils. At a relatively low infectious dose of HSV-1 (10(3) pfu/cornea) severe HSK developed in 80% to 90% of WT mice, but in only 30% to 40% of CD4-deficient mice. CONCLUSIONS: CD4(+) T cells preferentially mediate HSK, but, in their absence, a high infectious dose of HSV-1 can induce histologically similar but transient HSK that is mediated by CD8(+) T cells.     

Influence of dimethylfumarate on experimental HSV-1 necrotizing keratitis

Background This study was performed to investigate the influence of fumaric acid esters on the course of herpes stromal keratitis (HSK).Methods The corneas of BALB/c mice were inoculated with 105 plaque-forming units of herpes simplex virus 1 (HSV-1, KOS strain). Groups of mice were treated intraperitoneally with phosphate buffered saline (PBS) (control mice), or with dimethylfumarate (DMF) at 15 mg/kg of body weight dissolved in PBS daily for 28 days pre-infection and for 14 days post-infection. The course of HSV-1 keratitis was studied clinically. Corneal sections were examined for inflammatory cell infiltration. The numbers of CD3, GR-1, CD11b and F4/80-expressing cells infiltrating the corneas were analyzed by immunohistochemistry.Results On day 14 after HSV infection, 72% of the mice in the control group had severe HSK. The development of HSK was reduced by DMF treatment in the DMF group (22%) (P=0.004). The total number of inflammatory cells and infiltration of polymorphonuclear-neutrophils (PMNs) were reduced in the corneas of DMF-treated mice. Compared to the PBS-treated mice, numbers of CD3, CD11b, GR-1 and F4/80-positive cells were reduced in the DMF group of mice.Conclusions The course of experimental herpes stromal keratitis can be improved with systemic fumaric acid ester treatment. The improvement of keratitis correlates with a reduced corneal infiltration of T cells and mononuclear cells.The authors have no financial interest in any of the reagents used in this study     

Activated inflammatory infiltrate in HSV-1-infected corneas without herpes stromal keratitis

PURPOSE: To investigate herpes stromal keratitis (HSK) immunopathology by studying HSV-1-infected corneas that fail to develop HSK. METHODS: Plaque assay quantified HSV-1 in the tear film of infected mice. FACS analysis enumerated corneal leukocytic infiltrate and characterized infiltrate phenotypically after staining for activation and regulatory T cell (Treg) markers and for markers of antigen-presenting cell (APC) maturation. Treg cells were depleted in vivo using anti-CD25 mAb. Luminex analysis quantified the amount of cytokines and chemokines expressed in corneal tissue homogenate. RESULTS: Infected corneas without HSK exhibited a pronounced leukocytic infiltrate containing a significantly higher proportion and nearly identical absolute number of activated CD4+ T cells 15 days after infection when compared with those with HSK. Moreover, the frequency and absolute number of regulatory CD4+ T cells (Tregs) was lower in nondiseased corneas, and Treg depletion did not influence HSK incidence. The frequency of mature, immunogenic DCs and the ratio of mature DCs to CD4+ T cells were nearly identical in corneas with and without HSK. The authors observed a reduced population of neutrophils and reduced expression of neutrophil chemoattractants MIP-1beta and keratinocyte chemoattractant and the neutrophil-attracting cytokine IL-6 in corneas without HSK. CONCLUSIONS: These findings demonstrate that HSV-1-infected corneas can retain clarity in the presence of a substantial secondary leukocytic infiltrate, that activated CD4+ T cells, while necessary, are not sufficient for HSK development, that susceptibility to HSK is not determined by Tregs, and that clinical disease correlates with the accumulation of a critical mass of neutrophils through chemoattraction.     

Immunomodulation by topical particle-mediated administration of cytokine plasmid DNA suppresses herpetic stromal keratitis without impairment of antiviral defense

Background We investigated whether the course of herpetic stromal keratitis (HSK) in BALB/c mice could be altered by topical gene-gun-mediated administration of interleukin (IL)-4 or IL-10 plasmid DNA. Methods Corneas of BALB/c mice were transfected with plasmids expressing β-galactosidase (β-gal), IL-4, IL-10, granulocyte-macrophage colony-stimulating factor (GM-CSF), and pCR3.1 (control) 2 days before Herpes simplex virus-1 (HSV-1; KOS) infection. Development of keratitis and cell infiltration were studied. HSV-1 replication was monitored by plaque assay. Expression of cytokines was detected by enzyme-linked immunosorbent assay. HSV-specific proliferation in the regional lymph nodes and spleens was measured. HSV-1 neutralizing antibody titers and IgG2A/IgG1 ratios were determined. Results Expression of β-gal was found in the treated corneas, but not in other tissues. IL-4 or IL-10 plasmid administration induced cytokine production in the corneas. After treatment with 300 psi, the severity of HSK was attenuated (each P<0.05), and the numbers of infiltrating inflammatory cells were lower than in the pCR3.1-treated controls (P<0.001). IL-6, but not IL-1α, expression in the cornea was reduced after treatment with IL-4 or IL-10 plasmid DNA. The HSV-1-specific DTH response, corneal Th1 cytokine profile, IgG/IgG2a/IgG1 ratio, neutralizing antibody titers, and virus clearance did not differ between the groups. Conclusions Thus, topically administered IL-4 and IL-10 plasmid DNA can lead to a milder course of HSK without impeding viral clearance. The gene gun technique for corneal delivery of plasmid cytokine DNA may be useful for modulating local immune responses without affecting antiviral defense. Supported by the Ernst and Berta Grimmke Foundation, Deutsche Forschungsgemeinschaft He 1877/12–1     

Immunogenetic influence of Igh-1 phenotype on experimental herpes simplex virus type-1 corneal infection

Patterns of herpes simplex virus type-1 (HSV-1) infection were studied in BALB/c congenic, Igh-1 disparate murine strains to establish the influence of Igh-1 phenotype on the development of keratopathy, trigeminal ganglionic latency and keratocyte permissivity. Eighty-two percent of C.AL-20 (Igh-1d) mice, 40% of BALB/cByJ (Igh-1a) mice and 12% of the C.B-17 (Igh-1b) mice developed herpes simplex keratitis (HSK) following corneal challenge with 2.5 X 10(4) PFU HSV-1 strain KOS. While disease frequency was directly proportional to HSV-1 challenge dose, relative resistance and susceptibility patterns in the congenic mice were constant and highly significant. F1 progeny from C.AL-20 X C.B-17 matings demonstrated the HSK pattern of the C.B-17 parent suggesting that Igh-1 linked resistance to HSK is dominantly inherited. Equivalent trigeminal ganglionic latency was established following ocular HSV-1 inoculation in the three congenic Igh-1 disparate murine strains. Cultured keratocytes from the three Igh-1 disparate murine strains demonstrated equivalent in vitro permissivity to HSV-1 replication. These data illustrate a strong correlation between Igh-1 phenotype and the development of a HSK in congenic mice. The susceptibility/resistance to HSK in these mice is unrelated to trigeminal ganglionic latency or keratocyte permissivity.     

Improvement of HSV-1 necrotizing keratitis with amniotic membrane transplantation

PURPOSE: Stromal herpes simplex virus keratitis (HSK) is an immune-mediated disease. Previous studies have indicated that T cells, neutrophils, and macrophages contribute to the tissue damage in HSK. It has been shown that human amniotic membrane promotes epithelial wound healing and has diverse anti-inflammatory effects. In this study, the effect of amniotic membrane transplantation (AMT) on corneal wound healing and on inflammation in mice with necrotizing HSK was examined. METHODS: BALB/c mice were corneally infected with 10(5) plaque-forming units (PFU) of HSV-1 (KOS strain). In 16 mice that exhibited severe ulcerating HSK, the cornea was covered with a preserved human amniotic membrane as a patch. Corneas in 16 infected mice remained uncovered and served as a control. On days 2 and 7 after surgery, the amniotic membrane was removed (eight mice in each group), the HSV-1-infected cornea was evaluated clinically, and the eye was enucleated. Tissue sections were analyzed histologically for epithelialization and cellular infiltration and immunohistochemically with anti-CD3 mAb to T cells, anti-CD11b mAb to both macrophages and neutrophils, or anti-F4/80 mAb to macrophages. RESULTS: Profound regression of corneal inflammation and rapid closure of epithelial defects were observed clinically within 2 days in the amniotic membrane-covered eyes, whereas HSV-1 keratitis and ulceration progressed in all mice in the control group (P < 0.001). Histologically, corneal edema and inflammatory infiltration, and immunohistochemically the number of CD3(+), CD11b(+), and F4/80(+) cells in the cornea were markedly decreased at 2 and 7 days after amniotic membrane application, compared with the uncovered control corneas (P < 0.001). CONCLUSIONS: AMT promotes rapid epithelialization and reduces stromal inflammation and ulceration in HSV-1 keratitis. AMT in mice with HSV necrotizing stromal keratitis appears to be a useful model for investigating the effect and the action mechanism of human amniotic membrane.     

Herpes simplex virus entry receptor nectin-1 is widely expressed in the murine eye

PURPOSE: Nectin-1 belongs to the immunoglobulin superfamily, mediates cell-cell adhesion in cadherin-based adherens junctions, and acts as a receptor for herpes simplex virus (HSV). The goals of this study were (1) to determine whether nectin-1 is expressed in ocular tissue that is an important target of HSV infections and (2) to determine whether HSV type 1 (HSV-1) infection affects nectin-1 expression in the eye. METHODS: Expression of nectin-1 and HSV-1 protein was determined by immunohistochemical analysis of ocular tissues of untreated BALB/c mice and mice that were euthanized either 7 days or 7 months after corneal inoculation of HSV-1 or sterile tissue-culture medium (mock). RESULTS: In ocular tissues derived from untreated and mock-infected mice, widespread nectin-1 expression was detected among cells of the corneal epithelium and endothelium, conjunctiva, lens epithelium, ciliary body, iris, choroid, and retina. However, fibroblasts in the corneal stroma and the sclera did not express detectable levels of nectin-1. Ocular tissues from mice euthanized 7 days after corneal inoculation of HSV-1 frequently demonstrated corneal ulceration and inflammation and HSV-1 protein expression in the corneal epithelium, stroma, endothelium, conjunctiva, iris, and ciliary body but rarely in the retina. Ocular tissues from mice euthanized 7 months after HSV-1 inoculation demonstrated corneal epithelial and stromal inflammation, but HSV-1 protein expression was not detected. HSV-1 infection did not lead to a loss of nectin-1 expression in any of the tissues examined. In contrast to uninfected corneas, the inflamed and vascularized stroma of infected corneas contained mononuclear inflammatory cells, vascular cells, and fibroblasts that stained positive for nectin-1. CONCLUSIONS: Findings report that nectin-1 is widely expressed in murine ocular tissues. Only fibroblasts in the corneal stroma and sclera of uninfected tissues were devoid of nectin-1 expression. HSV-1-infected inflamed corneas contained some stromal fibroblasts with detectable nectin-1 expression, which potentially could be targeted by the virus. Widespread nectin-1 expression in the eye suggests that this receptor may play a role in the pathogenesis of ocular HSV infections.     

Granulocyte macrophage colony-stimulating factor expression in human herpetic stromal keratitis: implications for the role of neutrophils in HSK

PURPOSE: Granulocyte macrophage colony-stimulating factor (GM-CSF) is thought to play a key role in chronic inflammatory diseases by governing the survival and function of infiltrating neutrophils. The objective of this study was to determine the putative role of GM-CSF in the pathogenesis of human herpetic stromal keratitis (HSK). METHODS: Primary human corneal fibroblast (HCF) cultures and a telomerase-immortalized human corneal epithelial (HCE) cell line representative of native HCE were stimulated with the known HSK-inducing cytokines interferon (IFN)-gamma, interleukin (IL)-1beta, and tumor necrosis factor (TNF)-alpha. Alternatively, the T-cell cytokine IL-17 was added solely or simultaneously. Human neutrophils were incubated with conditioned medium (CM) of the HCF and HCE stimulated with the aforementioned cytokines, or recombinant GM-CSF, and their viability or activation status was determined by flow cytometry. GM-CSF and IL-8 secretion levels in the CM were determined by ELISA. The antibody-dependent cellular cytotoxicity (ADCC) of neutrophils toward herpes simplex virus (HSV)-infected HCFs was determined by flow cytometry. The expression of GM-CSF was determined in HSK and control corneal buttons by real-time RT-PCR and immunohistology. RESULTS: Compared with IFN-gamma, CM of either cell type stimulated with IL-1beta, or in the case of HCE cells, stimulated with TNF-alpha or IL-17, delayed neutrophil apoptosis significantly. Only in HCFs did IL-17 exhibit a synergistic effect with TNF-alpha. The antiapoptotic activity was attributable in part to the GM-CSF secreted by the activated HCFs and HCE cells. GM-CSF stimulation of neutrophils induced their activation and the secretion of IL-8. GM-CSF did not increase significantly the ADCC reaction of neutrophils toward HSV-infected HCFs. Finally, GM-CSF was expressed in corneas of the patients with HSK but not in control subjects. CONCLUSIONS: The data suggest that GM-CSF, expressed by cornea-resident cells such as HCFs and HCE cells, may play a role in the immunopathogenesis of HSK by prolonging the survival and modulating the effector function of corneal infiltrating neutrophils.