Expression of toll-like receptor 4 and its associated lipopolysaccharide receptor complex by resident antigen-presenting cells in the human uvea

PURPOSE: To investigate the in vivo expression of toll-like receptor 4 (TLR4) and its associated lipopolysaccharide (LPS) receptor complex in the human eye. METHODS: Normal human ocular tissues were evaluated for in vivo TLR4, MD-2, and CD14 mRNA and protein expression by RT-PCR and immunohistochemistry, respectively. The distribution patterns and phenotypes of the cells expressing these proteins were further characterized by confocal microscopy and double-label immunofluorescence studies. RESULTS: Normal human uvea, retina, sclera, and conjunctiva constitutively expressed TLR4, MD-2, and CD14 mRNA. The protein expression of these molecules was restricted, however, to resident antigen-presenting cells (APCs) in the normal human uvea, consisting mainly of HLA-DR(+) dendritic cells (DCs). These APCs endowed with the complete LPS receptor complex appeared to be strategically positioned in perivascular and subepithelial locations for surveying blood-borne or intraocular LPS. In contrast, other cell types of the normal human cornea, conjunctiva, retina, and sclera did not express TLR4/MD-2 protein in vivo as detectable by immunohistochemistry. CONCLUSIONS: The present study demonstrates for the first time that resident APCs in the normal human uvea express TLR4 and its associated LPS receptor complex. This has significant implications for the understanding of normal ocular immunity as well as unraveling the potential role of Gram-negative bacteria in the pathogenesis of acute anterior uveitis (AAU).     

Suppression of ocular inflammation in endotoxin-induced uveitis by blocking the angiotensin II type 1 receptor

PURPOSE: To examine whether the angiotensin II type 1 receptor (AT1-R) signaling plays a role in ocular inflammation in endotoxin-induced uveitis (EIU). METHODS: EIU was induced in C57BL/6 mice by a single intraperitoneal injection of 150 mug lipopolysaccharide (LPS). Tissue localization, mRNA expression, and protein levels of AT1-R in murine retinas were examined by immunohistochemistry, RT-PCR, and Western blot analyses, respectively. Telmisartan, an AT1-R antagonist widely used as an antihypertensive agent, was administered intraperitoneally at a dose of 10 mg/kg daily for 5 days until the injection of LPS. Twenty-four hours after administration, leukocyte adhesion to the retinal vasculature was evaluated with a concanavalin A lectin perfusion-labeling technique. Retinal mRNA and protein levels of intercellular adhesion molecule (ICAM)-1 were examined by RT-PCR and ELISA, respectively. Protein concentration and inflammatory cells in the aqueous humor were also measured. RESULTS: Retinal vessels were positive for AT1-R. In mice with EIU, retinal AT1-R mRNA and protein levels were significantly increased when compared to the normal control. EIU animals also showed significant increases in the number of inflammatory cells infiltrating the anterior chamber and adhering to the retinal vessels and in retinal ICAM-1 levels. Administration of telmisartan to EIU mice resulted in significant suppression of retinal ICAM-1 expression and leukocyte adhesion and infiltration compared with vehicle treatment. Protein concentration in the aqueous humor of telmisartan-treated EIU mice tended to be lower than that of vehicle-treated EIU mice, but the difference was not statistically significant. CONCLUSIONS: AT1-R signaling blockade inhibited retinal ICAM-1 upregulation and leukocyte adhesion and infiltration in the EIU model. These results suggest the potential use of an AT1-R antagonist as a therapeutic agent to reduce ocular inflammation.     

Toll样受体-4在内毒素诱导的葡萄膜炎中的表达及意义

目的 探讨Toll样受体-4(TLR4)在内毒素诱导的葡萄膜炎中的表达和意义.设计 实验性研究.研究对象 Wistar大鼠12只,随机分为模型组(n=6)和对照组(n=6).方法 模型组通过足底及腹腔注射霍乱弧菌内毒素诱导出葡萄膜炎,对照组注射磷酸盐缓冲液.注射后4h、10h、16h、24h裂隙灯观察眼前节反应.注射后24h通过免疫组化方法检测眼球冰冻切片及葡萄膜铺片中TLR4的表达.TLR4阳性判定标准:呈棕黄色颗粒定位于胞膜、胞浆.主要指标 眼前节炎症反应程度、葡萄膜铺片中TLR4阳性表达的细胞数量.结果 内毒素注射后4h虹膜血管扩张充血,16h前房可见纤维素渗出.模型组虹膜铺片内可见大量TLR4阳性表达细胞,位于虹膜基质层,对照组虹膜铺片内只见少量TLR4阳性表达细胞,模型组虹膜中阳性细胞数量高于对照组(P＜0.05).冰冻切片中虹膜内偶见少量TLR4表达.脉络膜和视网膜冰冻切片及铺片中均未见阳性细胞.结论 内毒素诱导的葡萄膜炎中TLR4表达增高,提示TLR4可能在急性前葡萄膜炎的发生发展中具有一定作用.(眼科,2008,17:48-51)     

Regulation of lipoxygenase-1 and Dectin-1 on interleukin-10 in mouse Aspergillus fumigatus keratitis

AIM: To investigate the regulation of lipoxygenase (LOX)-1 and Dectin-1 on interleukin-10 (IL-10) production in mice with Aspergillus fumigatus (A. fumigatus) keratitis. METHODS: The corneas of C57BL/6 mice were pretreated with LOX-1 inhibitor Poly(I) or Dectin-1 siRNA separately before the infection of A. fumigatus. Polymerase chain reaction (PCR) and Western blot were used to detect the expression of IL-10. RESULTS: The mRNA and protein expressions of IL-10 were significantly increased in mice with A. fumigatus keratitis. Compared with the group pretreated with sterile water before infection, Poly(I) pretreatment suppressed IL-10 expression significantly. Compared with the group pretreated with scrambled siRNA before infection, Dectin-1 siRNA pretreatment significantly reduced IL-10 expression in response to A. fumigatus infection. CONCLUSION: LOX-1 and Dectin-1 regulate IL-10 production in mouse A. fumigatus keratitis.     

Activation of toll-like receptor (TLR)2, TLR4, and TLR9 in the mammalian cornea induces MyD88-dependent corneal inflammation

PURPOSE: Toll-like receptors (TLRs), which recognize microbial products, have an important role in the host innate immune response. The purpose of the present study was to determine whether activation of these receptors leads to development of keratitis and to assess the role of the common adaptor molecule myeloid differentiation factor-88 (MyD88). METHODS: Corneal epithelium of C57BL/6, TLR2(-/-), TLR9(-/-), and MyD88(-/-) mice was abraded and treated with Pam(3)Cys, LPS, or CpG DNA, which bind TLR2, -4, and -9, respectively, and neutrophil recruitment to the corneal stroma, development of corneal haze, and chemokine production were measured. RESULTS: Activation of TLR2 and -9 stimulated neutrophil recruitment to the corneal stroma of C57BL/6 mice, but not TLR2(-/-) or -9(-/-) mice, respectively. In marked contrast, neutrophil migration to the corneal stroma of MyD88(-/-) mice challenged with Pam(3)Cys, LPS, or CpG DNA was completely ablated. Activation of TLR2, -4, and -9 also caused a significant increase in corneal thickness and haze, indicative of disruption of corneal clarity; however, this response was ablated in MyD88(-/-) mice, which were not significantly different from untreated corneas. Production of CXC chemokines MIP-2 and KC, which mediate neutrophil recruitment to the corneal stroma, was elevated in the corneal epithelium and stroma of control, but not MyD88(-/-) mice. CONCLUSIONS: Together, these findings demonstrate that the corneal epithelium has functional TLR2 and -9, and that TLR2, -4, and -9 signal through MyD88. This pathway is therefore likely to have an important role in the early events leading to microbial keratitis.     

The expression of functional LPS receptor proteins CD14 and toll-like receptor 4 in human corneal cells.

PURPOSE: Gram-negative bacterial infections of the eye can lead to corneal bacterial keratitis, visual impairment, and blindness. Many of these pathologic changes may be mediated by bacterially derived products such as lipopolysaccharide (LPS). In this investigation, it has been established for the first time that human corneal cells are capable of expressing the functional LPS receptor complex proteins, CD14 and Toll-like receptor 4 (TLR4). METHODS: CD14 and TLR4 mRNA expression in human corneal cells was determined by RT-PCR and Northern blot analysis, and cell surface expression of these proteins was measured by flow cytometry. LPS-mediated corneal cell activation was determined by measuring intracellular calcium mobilization. Cellular cytokine and chemokine secretion in response to LPS was measured by ELISA. The expression and localization of CD14 in whole human cornea was determined by immunohistochemistry. RESULTS: Human corneal epithelial, stromal, and endothelial cells expressed CD14 mRNA and cell surface CD14. LPS binding to cornea CD14 resulted in a rapid intracellular calcium response and the secretion of multiple proinflammatory cytokines and chemokines. CD14 mRNA expression in corneal epithelial cells was upregulated by LPS. In addition to CD14, corneal epithelial cells expressed the functional LPS receptor-signaling protein TLR4, which was also augmented by LPS. CONCLUSIONS: The cornea expresses functional CD14 and TLR4 LPS receptor proteins. Understanding the function and biology of the corneal LPS receptor complex may lead to novel therapies for the management of ocular Gram-negative bacterial infections.     

Anti-inflammatory effect of angiotensin type 1 receptor antagonist on endotoxin-induced uveitis in rats

Background Angiotensin II type 1 (AT1) receptor-antagonists are widely used for treatment of hypertension. Recent studies have demonstrated a protective effect of renin angiotensin system (RAS) antagonism against immune-mediated inflammatory diseases such as myocarditis, chronic allograft rejection, antiglomerular basement membrane nephritis, colitis, and arthritis. However, only a few reports have demonstrated the effect of RAS in ocular inflammatory conditions. The purpose of this study was to investigate the anti-inflammatory effect of a selective AT1 receptor antagonist, losartan, on endotoxin-induced uveitis (EIU) and compare the effect on experimental autoimmune uveoretinitis (EAU). Methods To induce EIU, 7-week-old Lewis rats were injected subcutaneously with 200 μg lipopolysaccharide (LPS). Losartan was administered intravenously at the same time. The aqueous humor was collected from eyes 24 h after LPS injection. The number of infiltrating cells, protein concentration, and levels of tumor necrosis factor (TNF)-α and monocyte chemoattractant protein-1 (MCP-1) in the aqueous humor were determined. The collected eyes were immunohistochemically stained with monoclonal antibody for activated nuclear factor (NF)-κB. To induce EAU, C57BL/6 mice (6–8 weeks old) were immunized with human interphotoreceptor retinoid binding protein (hIRBP)-derived peptide emulsified in complete Freund’s adjuvant (CFA) and concomitantly injected with purified Bordetella pertussis toxin (PTX). Clinical severity of EAU and T cell proliferative response were analyzed. Results Losartan significantly suppressed the development of EIU. Numbers of aqueous cells of control EIU rats, those from EIU rats treated with 1 or 10 mg/kg of losratan were 75.3 ± 45.6 × 10⁵, 27.9 ± 8.1 × 10⁵, or 41.3 ± 30.9 × 10⁵ cells/ml respectively (p < 0.01 vs control). Aqueous protein, TNF-α, and MCP-1 levels were also significantly decreased in a manner dependent on the amount of losartan administered (p < 0.01). Treatment of EIU rats with losartan suppressed activation of NF-κB at the iris ciliary body. Thus, the suppressive effect of losartan on ocular inflammation in EIU appeared to result from down-regulation of NF-κB activation and reduction of inflammatory cytokine production. On the other hand, in the EAU model, neither the clinical score nor the antigen-specific T cell proliferative response was significantly influenced by the treatment with losartan. Conclusions The present findings indicate that RAS may be involved in the acute inflammation of the eye, but not in T cell-dependent ocular autoimmunity. Antagonism of the RAS may be a potential prophylactic strategy for treatment of the human acute ocular inflammation.     

Expression of toll-like receptor 4 contributes to corneal inflammation in experimental dry eye disease

Purpose. To investigate the corneal expression of toll-like receptor (TLR) 4 and determine its contribution to the immunopathogenesis of dry eye disease (DED). Methods. Seven to 8-week-old female C57BL/6 mice were housed in a controlled environment chamber and administered scopolamine to induce experimental DED. Mice received intravenous TLR4 inhibitor (Eritoran) to block systemic TLR4-mediated activity. The expression of TLR4 by the corneal epithelium and stroma was evaluated using real-time polymerase chain reaction and flow cytometry. Corneal fluorescein staining (CFS) was performed to evaluate clinical disease severity. The corneal expression of proinflammatory cytokines (IL-1β, IL-6, TNF, and CCL2), corneal infiltration of CD11b(+) antigen-presenting cells, and lymph node frequency of mature MHC-II(hi) CD11b(+) cells were assessed. Results. The epithelial cells of normal corneas expressed TLR4 intracellularly; however, DED significantly increased the cell surface expression of TLR4. Similarly, flow cytometric analysis of stromal cells revealed a significant increase in the expression of TLR4 proteins by DED-induced corneas as compared with normal corneas. DED increased the mRNA expression of TLR4 in corneal stromal cells, but not epithelial cells. TLR4 inhibition decreased the severity of CFS and significantly reduced the mRNA expression of IL-1β, IL-6, and TNF. Furthermore, TLR4 inhibition significantly reduced the corneal infiltration of CD11b(+) cells and the lymph node frequency of MHC-II(hi) CD11b(+) cells. Conclusions. These results suggest that DED increases the corneal expression of TLR4 and that TLR4 participates in the inflammatory response to ocular surface desiccating stress.     

Expression of the chemokines MIP-1alpha, MCP-1, and RANTES in experimental autoimmune uveitis

PURPOSE: To determine the location of the CC chemokines macrophage inflammatory protein (MIP)-1alpha, monocyte chemoattractant protein (MCP)-1, and regulated on activation of normal T-cell-expressed and secreted (RANTES) during disease progression in experimental autoimmune uveitis (EAU) and their relationship with the presence of the T helper cell (Th)1-type cytokine IFNgamma. METHODS: EAU was induced by immunization of Lewis rats with retinal extract. Consecutive cryostat sections were prepared from eyes at different stages of EAU, graded for severity of uveitis and stained by using antibodies to MCP-1, MIP-1alpha, and RANTES and to cell surface markers. Supernatants from superficial cervical lymph node cells were examined by ELISA for IFNgamma, IL-4, and IL-10. RESULTS: MIP-1alpha and IFNgamma were present most frequently and most extensively at peak disease but also were detectable in the choroid 8 days after immunization, before clinical disease onset. MCP-1 and RANTES were present at peak disease, but much less frequently. RANTES was occasionally found in the choroid before clinical disease. By days 19 to 21 after immunization, although infiltrating cells were present, there were only residual low levels of chemokine staining. MCP-1 and RANTES were detected on CD3-positive cells and on some ED1-positive cells, whereas MIP-1alpha was also associated with vessels and areas of exudate. Lymph node cells cultured from animals with peak disease had increased levels of IFNgamma and IL-10, but for IFNgamma this occurred only after stimulation in vitro with retinal extract. CONCLUSIONS: Although MCP-1 and RANTES were associated predominantly with cells infiltrating the retina, MIP-1alpha was also associated with resident cells. All three are likely to exacerbate EAU-MIP-1alpha, to the greatest degree.     

Visualization and characterization of inflammatory cell recruitment and migration through the corneal stroma in endotoxin-induced keratitis

PURPOSE: The infiltration of inflammatory cells into the cornea is a major determinant in the outcome of keratitis. The purpose of this study was to use enhanced green fluorescence protein (EGFP) bone marrow chimeric mice to visualize and characterize the inflammatory cells that migrate to the corneal stroma during endotoxin-induced keratitis and to explore the mechanisms underlying this process. METHODS: Keratitis was induced by injecting endotoxin into the corneas of EGFP chimeric mice. In vivo fluorescence stereomicroscopy was used to visualize in real time the recruitment of EGFP-positive cells at different time points. Immunohistochemistry and three-dimensional (3D) confocal analysis of whole-mount corneas was used for histologic characterization. Macrophage inflammatory protein-2 (MIP-2) chemokine was neutralized in vivo to determine its contribution to this process. RESULTS: Recruitment of EGFP-positive inflammatory cells in the corneal stroma can be detected in vivo by 6 hours after the injection of endotoxin, and these were mainly neutrophils. Full-thickness whole corneal mount confocal image analysis showed a distinct pattern of migration of EGFP inflammatory cells through the anterior corneal stroma. Moreover, inflammatory cells did not colocalize with the injected lipopolysaccharide (LPS) deposits in the stroma but moved from all directions toward LPS, partially in response to the production of the chemokine MIP-2. CONCLUSIONS: EGFP chimeric mice and ex vivo 3D analysis of whole-mount corneas provides unique information on the interaction of infiltrating inflammatory cells in the cornea. These findings demonstrate that a chemotactic gradient triggered in part by MIP-2 is responsible for directing inflammatory cell migration through the corneal stroma.     

Regulation of LOX-1 on adhesion molecules and neutrophil infiltration in mouse Aspergillus fumigatus keratitis

AIM: To review international guidelines and to share our infection control experience during the COVID-19 pandemic at a tertiary eye centre in Hong Kong.METHODS: Infection control guidelines and recommendations from international ophthalmological bodies are reviewed and discussed. The measures at our hospital were drawn up as per international and local health authorities’ guidelines and implemented with the collaboration of doctors, nurses and administrative staff.RESULTS: The aims of our infection control measures are to 1) minimize cross-infection within the hospital; 2) protect and support hospital staff; 3) ensure environmental control. To minimize the risk of cross-infection, outpatient attendance and elective surgery have been reduced by 40%, and general anesthesia procedures were reduced by 90%. Patients entering the hospital are screened for fever, travel history, contact and cluster history, and COVID-19 related symptoms. To protect and support hospital staff, we ensure provision of adequate personal protective equipment (PPE) and provide clear guidelines on the level of PPE needed, depending on the clinical situation. Other protective measures include provision of work uniforms, easy access to alcohol-based hand rub, opening new lunch areas, implementation of self-monitoring and self-reporting systems, and communication via online education and updates. Finally, environmental control is achieved by ensuring regular disinfection of the hospital premise, enhancing ventilation, and usage of disposable ophthalmic instruments.CONCLUSION: Our multi-pronged approach to infection control is, so far, successful in minimizing infection risks, while allowing the maintenance of essential ophthalmic services.     

Acanthamoeba keratitis, clinico-pathological report of 2 cases

Acanthamoebae have in the last 14 years been reported to be responsible for severe keratitis in an increasing number of cases. To our knowledge this is the first report of acanthamoeba keratitis (AK) in Scandinavia. Two young males, both wearing soft contact lenses for extended wear, developed long lasting, therapy resistant keratitis. As the keratitis progressed to risk of perforation, keratoplasty was performed on the clinical, and in the one case biopsy-proven diagnosis of AK. Histopathology on the removed discs demonstrated the presence of typical acanthamoebae in the corneal stroma. The observation period after keratoplasty is at present 5 and 20 months, respectively. Both grafts have remained clear and visual acuity is 6/9-6/12 with glasses.     

Expression of P2Y1, P2Y2, P2Y4, and P2Y6 receptor subtypes in the rat retina

PURPOSE: To elucidate the expression pattern of different types of metabotropic P2Y receptors in the adult rat retina. METHODS: Qualitative RT-PCR was used to investigate the expression profile of different P2Y receptor subtypes (P2Y1, P2Y2, P2Y4, and P2Y6), and in situ hybridization studies were performed to show their cellular localization within the retina. Immunohistochemical staining was used to detect the corresponding P2Y proteins (P2Y1, P2Y2, and P2Y4) and their cellular localization. Southern blot analysis and sequencing verified the identity of the P2Y PCR products. RESULTS: RT-PCR revealed the presence of P2Y1, -2, -4, and -6 mRNA in the neural retina and the retinal pigment epithelium (RPE) and choroid. In situ hybridization showed labeling in the retinal ganglion cell layer for all four P2Y receptor subtypes, although the intensity varied. In addition, staining for P2Y1, -4, and -6 mRNA was shown in the inner nuclear layer, but was absent for the P2Y2 receptor subtype. Immunohistochemistry showed intense staining for P2Y1, -2, and -4 in the ganglion cell layer and the outer plexiform layer. There was also a specific subtype staining in the inner plexiform layer (P2Y2, -4), the inner (P2Y1, -4) and outer (P2Y1) nuclear layers and the inner segments of the photoreceptors (P2Y1, -2). discussion. The data suggest that extracellular nucleotides may play complex roles as autocrine-paracrine mediators and may have neuromodulatory effects in the retina through metabotropic P2Y receptors.     

DR患者外周血趋化因子MIP-1α和MIP-1β水平变化的临床意义

目的：观察糖尿病视网膜病变患者外周血趋化因子巨噬细胞炎症蛋白-1α(macrophage inflammatory protein,MIP-1α)、MIP-1β水平变化,并分析其临床意义。

方法：选取佛山市第五人民医院和佛山市南海区第四人民医院收治的糖尿病无视网膜病变患者(DM组)、非增殖期糖尿病视网膜病变患者(NPDR组)和增殖期糖尿病视网膜病变患者(PDR组),各50例; 选取50例健康体检者作为对照组。观察不同组别患者外周血趋化因子MIP-1α、MIP-1β水平、血糖情况和细胞因子水平的差异,采用Pearson相关分析法分析糖尿病视网膜病变患者外周血趋化因子MIP-1α、MIP-1β水平与血糖和细胞因子水平的相关性。

结果：DM组患者的MIP-1α、MIP-1β和平均血糖(mean blood glucose,MBG)水平均高于对照组,差异有统计学意义(t=6.306、2.954、3.617,均P<0.05); DM组患者的胰岛素样生长因子-1(insulin like growth factor-1,IGF-1)、成纤维细胞生长因子-21(fibroblast growth factor-21,FGF-21)、血管内皮生长因子(VEGF)水平均高于对照组,差异有统计学意义(t=27.216、7.778、3.214,均P<0.05)。PDR组患者的MIP-1α、MIP-1β和MBG水平均高于NPDR组,差异有统计学意义(t=6.620、3.461、3.378,均P<0.05); PDR组患者的IGF-1、FGF-21、VEGF水平高于NPDR组,差异有统计学意义(t=10.260、12.611、4.108,均P<0.05)。糖尿病视网膜病变患者的MIP-1α、MIP-1β水平与MBG、IGF-1、FGF-21、VEGF水平呈正相关。

结论：增殖期糖尿病视网膜病变患者的MIP-1α、MIP-1β水平较高,且与血糖和细胞因子水平呈正相关。     

Human Schlemm's canal cells express the endothelial adherens proteins,VE-cadherin and PECAM-1

Purpose. The majority of resistance to outflow of aqueous humor resides at or near the inner wall of Schlemm's canal (SC). Transmembrane proteins that contribute to the generation of resistance to aqueous outflow likely participate in junctional complexes between SC cells. The purpose of the present study was to examine the expression of cadherins in SC cells that play a significant role in adherens junction complexes that control permeability of vascular endothelia. Methods. Identification of cadherin subtype mRNAs was examined by hybridization screening of three different SC cDNA libraries and by polymerase chain reaction analysis with degenerate primers. Expression of endothelial adherens proteins, vascular endothelial (VE)-cadherin and platelet endothelial cell adhesion molecule-1 (PECAM-1), was examined by western blot analyses of whole cell lysates prepared from SC and trabecular meshwork cells and by immunofluorescence microscopy of frozen sections of human anterior chambers. As controls, bovine retinal, bovine aortic, human umbilical vein and human iliac vein endothelial cells were examined for VE-cadherin expression. Results. Screens of SC cDNAs revealed abundant expression of N-cadherin and VE-cadherin. Expression of VE-cadherin protein was identified in both inner and outer wall SC cells, appropriately localized to SC intercellular borders and appeared as a single band of approximately 130 kDa by western blot analysis. Specific labeling of PECAM-1 was similar to VE-cadherin and appeared as a single band of approximately 130 kDa by western blot analysis. Conclusions. VE-cadherin and PECAM-1 expression in SC suggests that SC cells are vascular in origin and contain adherens protein likely involved in restricting fluid flow across the inner wall of SC.     

Inhibition of leukocyte sticking and infiltration, but not rolling, by antibodies to ICAM-1 and LFA-1 in murine endotoxin-induced uveitis

PURPOSE: Cell-adhesion molecules are critical elements in intravascular rolling and sticking of leukocytes during acute inflammation. In this process, selectins are thought to be involved in initial adhesion and rolling, and integrin-Ig superfamily interactions are believed primarily to mediate stronger adhesion and transendothelial migration. This study clarifies the role of two adhesion molecules, intercellular adhesion molecule (ICAM)-1 and leukocyte functional antigen (LFA)-1, in endotoxin-induced uveitis (EIU). METHODS: Intravital microscopy was used to record the movement and location of leukocytes in the irises of mice with uveitis induced by intravitreal injection of 250 ng Escherichia coli endotoxin. Each mouse concurrently received an intraperitoneal injection of monoclonal neutralizing antibodies for ICAM-1, LFA-1, or both or control irrelevant antibodies. RESULTS: Mice treated with endotoxin and control antibodies had an inflammatory response that was clearly present at the 6- and 24-hour time points and was mostly resolved by 48 hours. Mice that received anti-ICAM-1 or anti-LFA-1 had significantly fewer cells infiltrating their irises at 6 and 24 hours. Detailed analysis of the 6-hour time point recordings revealed that neither anti-ICAM-1 nor anti-LFA-1 significantly reduced the number of leukocytes rolling on venule endothelial surfaces, but the treatments reduced the number of firmly adherent cells. CONCLUSIONS: These data confirm previous reports that ICAM-1 and LFA-1 are important mediators of EIU. The dynamic in vivo images clearly support the hypothesis that integrin-mediated cell adhesion is more critical for the firm adhesion of sticking cells than for leukocyte rolling.     

新型冠状病毒引起的病毒性角膜炎病例观察

目的：报告3例严重急性呼吸综合征冠状病毒2型(SARS-CoV-2)引起的病毒性角膜炎。

方法：对3例新冠感染确诊患者行裂隙灯、眼压、角膜荧光染色、前段照相、活体共聚焦显微镜(IVCM)和常规眼底筛查。治疗包括更昔洛韦眼用凝胶、人工泪液和糖皮质激素滴眼液。

结果：3例SARS-CoV-2角膜炎(SCK)患者经标准治疗后恢复良好。

结论：SARS-CoV-2角膜炎通常表现为角膜上皮下浸润,可导致角膜上皮下神经纤维密度降低和树突状细胞(DC)增加。抗病毒治疗联合糖皮质激素已被证明是有效的。