Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0022568 (keratitis)
 5,133 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Susceptibility to Herpes simplex virus type 1 (HSV-1) stromal keratitis (HSK) in the mouse has previously been linked to the Igh-1 locus. The role of natural killer cells (NK) in resistance to viral infections is controversial. The authors studied the influence of the Igh-1 locus on in vitro murine NK activity against HSV-1 infected cell lines. The HSV-1 infected targets were lysed better than uninfected cells by murine splenic lymphocytes. Strain had no influence on virus-augmented cell lysis. Spleen cells from naive HSK-susceptible CAL-20 (Igh-1d) and BALB/c (Igh-1a) mice lysed YAC-1 targets better than HSK-resistant C.B-17 (Igh-1b) mice. The reverse was seen 24 hours after in vivo infection intraperitoneally with HSV-1. In contrast, CAL-20 splenocytes lysed PU5-1R targets better than BALB/c and C.B-17 splenocytes 24 hours after intraperitoneal (IP) infection. No significant differences were detected in interferon (IFN) levels after IP challenge with HSV-1 among the Igh-1 congenics. The data show that differences in NK activity were determined by both the Igh-1 genotype and the uninfected target cell. Susceptibility to HSK in these Igh-1-disparate congenics thus cannot be explained simply by differences in NK activity against HSV-1-infected targets.
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PMID:Natural killer cellular cytotoxicity against herpes simplex virus-infected cells in Igh-1-disparate mice. 170 Jul 71

Monoclonal antibodies against HSV (HSV-McAb) were used in the diagnosis of 127 cases of keratitis by immunofluorescence assay (IFA). The positive rate in 43 cases of epithelial and 50 cases of stromal HSK were 100% and 92% respectively. The IFA was negative in 20 cases of keratitis of non-HSV etiology and 38 cases of normal cornea (31 cases of epithelial smears and 7 cases of cornea paraffin sections). Among 14 cases of clinically doubtful HSK, 4 cases were positive. The IFA was completed within 2-3 hours after sampling. The procedure proved rapid, sensitive, and highly specific for etiological diagnosis of HSK.
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PMID:[Ophthalmological application of HSV-monoclonal antibodies]. 196 90

A previously reported cohort of patients was reviewed after mean follow-up of 10.9 years. The overall probability of survival was 45%, but first grafts had a greater probability of survival than second (P = 0.12) or further (P = 0.19) grafts. Preoperative active keratitis adversely affected survival (P = 0.123). The major cause of failure was graft rejection. Regrafts were more likely to fail from rejection episodes (P = 0.0005). Antiviral prophylaxis improved the outcome for rejection (P = 0.005) and reduced the incidence of HSK recurrence complicating rejection. Suppurative keratitis occurred in 12.4% of grafts as a complication of epitheliopathy including HSK recurrence. The outcome in these cases was particularly poor. Loose continuous graft sutures resulted in graft failure in 10.6% of grafts which may be improved by using interrupted suturing. Our results suggest the longterm prognosis for grafting in herpes simplex keratitis are not as good as may have been predicted from previous analyses.
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PMID:Longterm prognosis for corneal grafting in herpes simplex keratitis. 307 67

Recently it has been shown that selective subconjunctival macrophage depletion reduced the incidence and severity of stromal herpes simplex virus (HSV) keratitis in mice. In this study, we examined the effect of conjunctival macrophage depletion on the corneal and systemic T-cell-mediated immune response. BALB/c mice were treated with subconjunctival injections of dichloromethylene diphosphonate (Cl2MDP)-liposomes (Cl2MDP-LIP) or phosphate-buffered saline (PBS) 7 and 2 days before corneal infection with 105 plaque-forming units (PFU) of HSV-1 (KOS strain). Interferon (IFN)-gamma, interleukin (IL)-2, and IL-4 production in the cornea was analysed by enzyme-linked immunosorbent assay (ELISA), and cytokine mRNA levels (IFN-gamma, IL-4) were measured by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR). Cell culture supernatants from submandibular lymph nodes were analysed by ELISA for expression of IFN-gamma, IL-2, and IL-4 and by bioassay for IL-6. The HSV-1-specific proliferative response of lymphocytes from regional lymph nodes and the delayed-type hypersensitivity (DTH) response were tested after corneal infection. Virus-neutralizing antibody titres and HSV-1-specific immunoglobulin G (IgG)2a/IgG1-ratios were measured. Cytokine mRNA expression (IFN-gamma, IL-4) and secretion (IFN-gamma, IL-2, IL-4) in the corneas were decreased after HSV-1 corneal infection in the macrophage-depleted mice. The secretion of IFN-gamma and IL-2 was decreased in the regional lymph nodes from Cl2MDP-LIP-treated animals (P<0.05). Furthermore, Cl2MDP-LIP-treated mice had decreased HSV-1 specific proliferative responses (P<0.05) and DTH response after corneal HSV-1 infection (P<0.05). The virus-neutralizing serum-antibody levels (P<0.05) increased while the HSV-1 specific IgG2a/IgG1-ratio was unaffected after macrophage depletion. Macrophage depletion did not induce a shift between the T helper 1 (Th1) and Th2 response in this HSK model. The data suggest that conjunctival macrophage functions are enhancing the T-cell-mediated immune response after corneal infection. This effect is at least in part responsible for the impaired course of herpetic keratitis after macrophage depletion.
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PMID:Conjunctival macrophage-mediated influence of the local and systemic immune response after corneal herpes simplex virus-1 infection. 1222 70

Herpes simplex virus infection of the eye is the leading cause of blindness due to infection in the US despite the availability of several antiviral drugs. Studies with animal models have shown that three factors, innate host resistance, the host adaptive immune response, and the strain of virus interact to determine whether an infection is asymptomatic or proceeds to the development of blinding keratitis (HSK). Of these, the role of adaptive immunity has received the most attention. This work has clearly shown that stromal keratitis is an immunopathological disease, most likely due to the induction of a delayed type hypersensitivity response. Substantially less is known about the role of specific host genes in resistance to HSK. The fact that different strains of virus display different disease phenotypes indicates that viral 'virulence' genes are critical. Of the 80 plus HSV genes, few have been formally tested for their role in HSV keratitis. Most studies of virulence genes to date have focused on a single gene or protein and large changes in disease phenotypes are usually measured. Large changes in the ability to cause disease are likely to reduce the fitness of the virus, thus such studies, although useful, do not mimic the natural situation. Viral gene products are known to interact with each other, and with host proteins and these interactions are critical in determining the outcome of infection. In reality, the 'constellation' of genes encoded by each particular strain is critical, and how this constellation of genes works together and with host proteins determines the outcome of an infection. The goal of this review is to discuss the current state of knowledge regarding the role of host and viral genes in HSV keratitis. The roles of specific genes that have been shown to influence keratitis are discussed. Recent data showing that different viral genes cooperate to influence disease severity and confirming that the constellation of genes within a particular strain determines the disease phenotype are also discussed, as are the methods used to test the role of viral genes in virulence. It will become apparent that there is a paucity of information regarding the function of many viral genes in keratitis. Improving our knowledge of the role of viral genes is critical for devising more effective treatments for this disease.
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PMID:The role of viral and host genes in corneal infection with herpes simplex virus type 1. 1586 67

Herpes simplex virus (HSV)-1 keratitis (HSK) is a sight-threatening ocular infection with worldwide occurrence. A prompt laboratory diagnosis is often very useful. The purpose of this study was to evaluate molecular methods as rapid diagnostic tools compared with cell culture of HSK. Corneal scrapings from patients with clinically suspected HSK were tested by direct immunofluorescence assay (IFA) for HSV-1 antigen and by polymerase chain reaction (PCR) for HSV-1 DNA, and an attempt for viral isolation was performed on Vero cell line culture. Positive samples by cell culture were 20.8%, whereas PCR was positive in 29.2%, and IFA was positive in 33.3%. IFA had better sensitivity (80%) and negative predictive value (81.8%) than PCR (70% and 76.9%, respectively); however, PCR had better specificity (71.4%) and positive predictive value (63.6%). This indicates that a combination of cell culture, IFA and PCR constitutes the best set of tools for diagnosis of clinically suspected cases of HSK. Documented infection can be further assessed by cell-culture technique or PCR depending laboratory availability.
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PMID:Evaluation of herpes simplex detection in corneal scrapings by three molecular methods. 1658 22

In the stromal keratitis caused by herpes simplex virus (HSV), the formation of new vessels is the essential step for the pathogenesis of keratitis. Inhibition of angiogenesis diminishes the formation of corneal lesion induced by HSV. Procedures which suppress angiogenesis are proposed as a valuable therapeutic approach to control HSK. The mechanism by which HSV ocular infection results in corneal angiogenesis is not understood. Recent reports identified anti-vascular endothelial growth factor (VEGF) as a molecule that is highly expressed in the HSV infected eye and clearly involved in angiogenesis. The advent of VEGF treatments marks a major advancement in the treatment of angiogenic eye disease. Off-label use of bevacizumab (Avastin), a recombinant humanized monoclonal antibody directed against VEGF, in some neovascular disorders of the eye has been associated with promising short term results. Based on these evidences herein we hypothesize topical application of bevacizumab could inhibit corneal neovascularization and also scarring in HSK. We propose this drug as a novel adjunct to current anti-inflammatory strategies in HSK.
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PMID:Therapeutic potential of bevacizumab (Avastin) in herpetic stromal keratitis (HSK). 1736 59

Although many factors that trigger the herpes simplex virus (HSV) reactivation from latency have been reported, how HSV resides in a latent state in the normal human cornea still needs to be defined. We therefore conducted a series of studies regarding various aspects of HSV infections. To understand how patients subjectively perceived changes in their daily life that could have induced HSV reactivation, we first performed a comprehensive survey on the subjective factors in patients who had experienced recurrent herpetic keratitis. The result of our survey revealed that stress, lack of sleep, shoulder stiffness, and physical fatigue were the key factors. There were various causes for stress, and stress associated with reactivation often occurred between spring and summer. Regarding HSV latency in the normal cornea, we used real-time polymerase chain reaction (PCR) to determine the presence of HSV in the donor and host corneas. The findings showed that on average, those host corneas with a history of HSV keratitis had 1.6 x 10(4) copies/mg of HSV DNA, while the host corneas without a history and the donor corneas had 8.7 and 4.9 x 10(2) copies/mg of HSV DNA, respectively. Based on these observations, it is reasonable to infer that latent viruses could have resided in a normal cornea without a history and were transmitted to a host cornea through corneal transplantation. We also quantified the virus load in tears before and after ocular surgery (one week after corneal transplantation or the next day after vitreous surgery). Our results indicated that both the detection rate and the average copy number of HSV DNA had a tendency to increase postperatively. Moreover, we tried to differentiate the HSV strains that were involved in the recurrent lesions. In only one of the studied cases, could we find a single different nucleotide between two HSV strains. It seemed possible that two different strains of HSV had set off the same episode of reactivation. In recent years, chemokines have become known for their action in mediating inflammatory diseases. We suspected that chemokines might also play a role in the antiviral mechanism and examined the chemokine-derived antiviral activity. We used eight chemokines, including RANTES/CCL5, MIP-lalpha/ CCL3, and MIP-1beta/CCL4, in a murine HSK model with Vero cells. These chemokines directly bound to HSV and the chemokine-bound HSV was later resisted by the neutralizing antibody of envelope protein gB. Furthermore, by electron microscope analysis, it became clear that these chemokines had cut an opening in the HSV envelope. Consequently, these chemokines had significantly inhibited the HSV infection on Vero cells. In addition, the virus load in tears was decreased and the corneal opacity was less severe. We concluded in that study that during early infection, chemokines accumulated in the corneal stroma have the ability to protect cells and tissues from HSV infection. As for antiviral therapy, acyclovir (ACV) eye ointment has been effective for patients with herpetic keratitis. However, patients often find it difficult to successfully follow the treatment due to the required frequent application and the blurred vision after application. On the other hand, valaciclovir (VCV), which is the oral prodrug of ACV, has become commercially available in recent years for treating nonocular herpetic diseases. We therefore examined and compared the efficacies of oral VCV, oral ACV, ACV eye ointment, and ACV eye drops in a murine keratitis model; the group treated with oral VCV did show a significantly good antiviral effect. We have proved that oral VCV can be a beneficial alternative antiviral therapy for patients with difficulty in complying with the ACV eye ointment treatment.
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PMID:[Herpes simplex virus latency, reactivation, and a new antiviral therapy for herpetic keratitis]. 1841 13

HSV-1 infection of the cornea leads to a potentially blinding immunoinflammatory lesion of the cornea, termed herpetic stromal keratitis. It has also been shown that one of the factors limiting inflammation of the cornea is the presence of Fas ligand (FasL) on corneal epithelium and endothelium. In this study, the role played by FasL expression in the cornea following acute infection with HSV-1 was determined. Both BALB/c and C57BL/6 (B6) mice with HSV-1 infection were compared with their lpr and gld counterparts. Results indicated that mice bearing mutations in the Fas Ag (lpr) displayed the most severe disease, whereas the FasL-defective gld mouse displayed an intermediate phenotype. It was further demonstrated that increased disease was due to lack of Fas expression on bone marrow-derived cells. Of interest, although virus persisted slightly longer in the corneas of mice bearing lpr and gld mutations, the persistence of infectious virus in the trigeminal ganglia was the same for all strains infected. Further, B6 mice bearing lpr and gld mutations were also more resistant to virus-induced mortality than were wild-type B6 mice. Thus, neither disease nor mortality correlated with viral replication in these mice. Collectively, the findings indicate that the presence of FasL on the cornea restricts the entry of Fas(+) bone marrow-derived inflammatory cells and thus reduces the severity of HSK.
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PMID:Mice with mutations in Fas and Fas ligand demonstrate increased herpetic stromal keratitis following corneal infection with HSV-1. 2215 46

Objective. Corneal neovascularization is a sight-threatening condition affecting more than 1.4 million people per year. Left untreated, it can lead to tissue scarring, oedema, lipid deposition, and persistent inflammation that may significantly affect visual prognosis and quality of life. The aim was to review the recent evidence relating to the pathophysiology, investigations and management of corneal neovascularization. Methods. Literature review of prospective and retrospective studies, clinical trials and animal models relating to the pathophysiology, investigation and management of corneal neovascularization. Results. Corneal neovascularization is characterized by the invasion of new blood vessels into the cornea caused by an imbalance between angiogenic and antiangiogenic factors that preserve corneal transparency as a result of various ocular insults and hypoxic injuries. Risk factors that have been implicated in the pathogenesis of the disease include contact lens wear, ocular surface disease, trauma, previous surgery and herpes. The results highlighted the current and future management modalities of corneal neovascularization, which includes corneal transplantation, laser - phototherapy, injections and topical treatment. Conclusion. The future of corneal neovascularization is promising and this paper discusses the upcoming revolution in local gene therapy. Abbreviations. HSK = herpes stromal keratitis, VEGF = vascular endothelial growth factor, VEGFR-1 = VEGF Receptor-1, FGF = Fibroblast growth factor, PDGF = Platelet-derived growth factor, IL-6 = interleukin-6, IL-7 = interleukin-7, IL-8 = interleukin-8, IRS-1 = insulin receptor substrate-1.
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PMID:Corneal neovascularization: updates on pathophysiology, investigations & management. 3119 93


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