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

Polymerase chain reaction (PCR) was applied as a quick assay for herpes simplex virus-I (HSV-I) ocular infection and trigeminal ganglionic latent infection. A pair of primers derived from the sequence of HSV-I latency associated transcript (LAT) gene were designed and synthesized to detect HSV-I DNA, the gene fragment increased being 452bp. The primers were used for the assays of 30 corneal swabs taken from experimental rabbits with herpes simplex keratitis (HSK), 28 ocular swabs from 23 patients with HSK and from 5 with HSV lid infection and 8 trigeminal ganglionic specimens from experimental rabbits with quiet HSK. Simultaneously, the tissue cultures of all the same above specimens were made. The results of PCR were compared with those of the tissue culture. The comparison indicates that PCR is specific and sensitive. It not only can be used as a quick assay and an objective criterion for clinical diagnosis of HSK, but also can be applied as a powerful weapon for investigation of HSV-I latent infection.
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PMID:[Application of polymerase chain reaction for quick assay of herpes simplex viral acute ocular infection and ganglionic latent infection]. 784 25

Replication-defective mutants of herpes simplex virus type 1 (HSV-1) were used as a new means to immunize mice against HSV-1-mediated ocular infection and disease. The effects of the induced immune responses on pathogenesis of acute and latent infection by challenge virus were investigated after corneal inoculation of immunized mice with virulent HSV-1. A single subcutaneous injection of replication-defective mutant virus protected mice against development of encephalitis and keratitis. Replication of the challenge virus at the initial site of infection was lower in mice immunized with attenuated, wild-type parental virus (KOS1.1) or replication-defective mutant virus than in mice immunized with uninfected cell extract or UV-inactivated wild-type virus. Significantly, latent infection in the trigeminal ganglia was reduced in mice given one immunization with replication-defective mutant virus and was completely prevented by two immunizations. Acute replication in the trigeminal ganglia was also prevented in mice immunized twice with wild-type or mutant virus. The level of protection against infection and disease generated by immunization with replication-defective mutant viruses was comparable to that of infectious wild-type virus in all cases. In addition, T-cell proliferative and neutralizing antibody responses following immunization and corneal challenge were of similar strength in mice immunized with replication-defective mutant viruses or with wild-type virus. Thus, protein expression by forms of HSV-1 capable of only partially completing the replication cycle can induce an immune response in mice that efficiently decreases primary replication of virulent challenge virus, interferes with acute and latent infection of the nervous system, and inhibits the development of both keratitis and systemic neurologic disease.
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PMID:Immunization with replication-defective mutants of herpes simplex virus type 1: sites of immune intervention in pathogenesis of challenge virus infection. 828 72

We have investigated the mechanisms by which subcutaneous immunization of mice with a replication-defective mutant of herpes simplex virus 1 protects against infection of the eye and latent infection of the trigeminal ganglion following corneal challenge. First, we have shown that immunization reduces the number of trigeminal ganglion neurons in challenged animals that express the latency-associated transcript. This indicates that the reduction in the incidence of latent infection by challenge virus is likely due to immune mechanisms and not saturation of the potential sites of latent infection by the immunizing mutant virus itself. Second, the duration of protective immunity against acute infection, keratitis, and latent infection was similar in mice immunized with replication-defective or -competent virus; thus, the replication-defective mutant virus is able to induce durable immunity apparently without spread in the host. Third, although the mutant virus showed no evidence of replication in vivo, it was present in footpad tissue in an infectious form for several days. This surprising observation raises the possibility that continued infection events by input virus over an extended period of time may have a boosting effect on the developing immune response which could explain, at least in part, the capacity of these replication-defective mutant viruses to elicit a robust and durable immunity despite their inability to spread within the host.
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PMID:Mechanisms of immunization with a replication-defective mutant of herpes simplex virus 1. 866 91

An experimental study was performed on animal models for evaluation of the possibility of herpes simplex virus-1 (HSV-1) corneal latency by in situ nucleic acid hybridization. 20 normal New Zealand white (NZW) rabbits were used, and 3 x 10(6) PFU/ml of McKrae strain HSV-1 was inoculated bilaterally into the corneal stroma in 14 rabbit eyes. Of the 28 eyes, 22 developed typical herpes simplex keratitis (HSK). On the postoperative 60th day, 4 corneas with latent infection were transplanted into one unilateral eyes of each 4 non-infected NZW rabbits respectively and removed 2 weeks postoperatively. The corneal buttons were individually detected for the presence of HSV-1 antigen and nucleic acid sequences by using clonal IgG HSV-1 antibody and biotinylated HSV-1 DNA probe respectively. The results showed that the HSV-1 DNA sequences retained only within the corneal stromal layer with negative HSV-1 antigen staining. These results strongly suggest that the cornea be capable of harboring latent HSV-1.
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PMID:[An experimental study on HSV-1 corneal latency by in situ nucleic acid hybridization]. 870 87

Replication-defective mutants of herpes simplex virus 1 (HSV-1) elicit immune responses in mice that reduce acute and latent infection after corneal challenge and are protective against development of disease. To understand the basis for the protective immunity induced by this new form of immunization, we investigated the contribution of various components of the immune response to protection against corneal infection and disease. Passive transfer of sera from mice immunized with the replication-defective mutant virus, d301, its parental HSV-1 strain, or uninfected cell lysate was used to examine the role of antibody. Despite posttransfer neutralizing antibody titers equivalent to those in control mice directly immunized with mutant virus, recipients of immune serum showed no reductions in primary replication in the eye, keratitis, or latent infection of the nervous system. However, immune serum protected mice from encephalitis and death. To examine the contribution of T cell subsets to protection, mice were immunized once with mutant virus and then were depleted in vivo of CD4+ or CD8+ T cells prior to corneal challenge. CD4 depletion resulted in higher titers of challenge virus in the eye at 3 to 4 days after challenge compared to control mice. Latent infection of the nervous system was increased by depletion of CD4+ T cells but not by depletion of CD8+ T cells keratitis developed only in a portion of the CD8+ T cell-depleted mice, suggesting that an immunopathologic potential of CD4+ T cells is held in check when immune CD8+ T cells are also present. Taken together, these data support a role for antibody induced by immunization with a replication-defective virus principally in protecting the central nervous system from disease, roles for CD4+ T cells in reducing primary replication in the eye and protecting against latent infection of the nervous system, and a role for CD8+ T cells in regulating the immunopathologic activity of CD4+ T cells.
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PMID:Contributions of antibody and T cell subsets to protection elicited by immunization with a replication-defective mutant of herpes simplex virus type 1. 943 23

Herpes simplex virus type 1 (HSV-1) is a prevalent microbial pathogen infecting 60% to 90% of the adult world population. The co-evolution of the virus with humans is due, in part, to adaptations that the virus has evolved to aid it in escaping immune surveillance, including the establishment of a latent infection in its human host. A latent infection allows the virus to remain in the host without inducing tissue pathology or eliciting an immune response. During the acute infection or reactivation of latent virus, the immune response is significant, which can ultimately result in corneal blindness or fatal sporadic encephalitis. In fact, HSV-1 is one of the leading causes of infectious corneal blindness in the world as a result of chronic episodes of viral reactivation leading to stromal keratitis and scarring. Significant inroads have been made in identifying key immune mediators that control ocular HSV-1 infection and potentially viral reactivation. Likewise, viral mechanisms associated with immune evasion have also been identified and will be discussed. Lastly, novel therapeutic strategies that are currently under development show promise and will be included in this review. Most investigators have taken full advantage of the murine host as a viable working in vivo model of HSV-1 due to the sensitivity and susceptibility to viral infection, ease of manipulation, and a multitude of developed probes to study changes at the cellular and molecular levels. Therefore, comments in this review will primarily be restricted to those observations pertaining to the mouse model and the assumption (however great) that similar events occur in the human condition.
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PMID:The immune response to ocular herpes simplex virus type 1 infection. 1139 65

Ocular herpes simplex virus type-1 (HSV-1) infections remain an important cause of corneal disease which may result in a loss of vision. Meliacine (MA), an antiviral activity present in crude leaf extracts of Melia azedarach L. that inhibits HSV-1 multiplication in vitro, was studied in a murine herpetic stromal keratitis experimental model. Adult Balb/c mice were inoculated with HSV-1 at their corneas after abrasion. MA was administered topically three times a day for 3 consecutive days, beginning at 24 and 96 hr after infection. Infected animals treated or not with MA were monitored for the development of ocular disease by a binocular microscope for 16 days. MA significantly reduced the incidence and the severity of blepharitis, neovascularization and stromal keratitis with respect to untreated infected mice, regardless the schedule of treatment assayed. Histological examination of corneas from MA-treated animals revealed no tissue damage, whereas corneal samples from untreated infected mice showed inflammation, vascularization and necrosis. In uninfected mice treated with MA, we found no evidence of corneal damage and histopathological studies showed no changes in the corneas of these mice. Treatment with MA at 24 hours post-infection (h.p.i.) reduced viral multiplication in the eye by 1-1.5 orders of magnitude. Studies on latency revealed that MA sligthly affected the establishment of a latent infection. Thus, MA proved to exert an antiviral action on the development of herpetic stromal keratitis when supplied by post-treatment. Unexpectedly, treatment with MA after 96h.p.i prevented ocular disease, suggesting an in vivo immunomodulating activity of MA.
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PMID:Therapeutic action of meliacine, a plant-derived antiviral, on HSV-induced ocular disease in mice. 1238 95

The role that T cell subsets play in herpetic stromal keratitis (HSK) has been the subject of intense research efforts. While most studies implicate CD4(+) T cells as the principal cell type mediating primary corneal disease, recent reports using knockout mice have suggested that both CD4(+) and CD8(+) T cell subsets may play integral roles in modulating the disease. Furthermore, recent studies suggest that CD8(+) T cells are directly involved in maintaining virus latency in infected trigeminal ganglia. This work has addressed these discrepancies by infecting the corneas of mice lacking CD4(+) and CD8(+) T cells with herpes simplex virus type 1 (HSV-1) and monitoring both corneal disease and latent infection of trigeminal ganglia. Results indicated that mice lacking CD8(+) T cells had more severe corneal disease than either BALB/c or B6 parental strains. In contrast, mice lacking CD4(+) T cells had a milder disease than parental strains. When mice were evaluated for persistence of infectious virus, only transient differences were observed in periocular tissue and corneas. No significant differences were found in persistence of virus in trigeminal ganglia or virus reactivation from explanted ganglia. These data support the following conclusions. CD4(+) T cells are not required for resistance to infection with HSV-1 and probably mediate HSK. Mice lacking CD8(+) T cells do not display differences in viral loads or reactivation and thus CD8(+) T cells are not absolutely required to maintain latency. Finally, CD8(+) T cells probably play a protective role by regulating the immunopathological response that mediates HSK.
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PMID:CD8(+) T cells control corneal disease following ocular infection with herpes simplex virus type 1. 1521 91

Ocular infection with HSV-1 continues to be a serious clinical problem despite the availability of effective antivirals. Primary infection with HSV-1 can involve ocular and adenaxial sites and can manifest as blepharitis, conjunctivitis, or corneal epithelial keratitis. After initial ocular infection, HSV-1 can establish latent infection in the trigeminal ganglia for the lifetime of the host. During latency, the viral genome is retained in the neuron without producing viral proteins. However, abundant transcription occurs at the region encoding the latency-associated transcript, which may play significant roles in the maintenance of latency as well as neuronal reactivation. Many host and viral factors are involved in HSV-1 reactivation from latency. HSV-1 DNA is shed into tears and saliva of most adults, but in most cases this does not result in lesions. Recurrent disease occurs as HSV-1 is carried by anterograde transport to the original site of infection, or any other site innervated by the latently infected ganglia, and can reinfect the ocular tissues. Recurrent corneal disease can lead to corneal scarring, thinning, stromal opacity and neovascularization and, eventually, blindness. In spite of intensive antiviral and anti-inflammatory therapy, a significant percentage of patients do not respond to chemotherapy for herpetic necrotizing stromal keratitis. Therefore, the development of therapies that would reduce asymptomatic viral shedding and lower the risks of recurrent disease and transmission of the virus is key to decreasing the morbidity of ocular herpetic disease. This review will highlight basic HSV-1 virology, and will compare the animal models of latency, reactivation, and recurrent ocular disease to the current clinical data.
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PMID:Ocular HSV-1 latency, reactivation and recurrent disease. 1858 63

Latent canine herpesvirus-1 (CHV-1) infection is common in domestic dogs, but recrudescent CHV-1 diseases are poorly characterized. To determine if administration of an immunosuppressive dosage of prednisolone to adult dogs latently infected with CHV-1 results in recurrent ocular disease, adult beagles with and without experimentally induced CHV-1 latent infection were divided into groups: group 1 latently infected and administered prednisolone, group 2 latently infected and administered placebo, and group 3 not latently infected and administered prednisolone. Prednisolone (3.0 mg/kg/day) was administered to dogs in groups 1 and 3 for seven consecutive days beginning on study day 1. Samples for CHV-1 polymerase chain reaction and serum neutralization (SN) assays were collected, and physical, ophthalmologic, and in vivo ocular confocal microscopic examinations were performed at intervals for 42 days. Bilateral ocular disease (i.e., conjunctivitis or keratitis) was detected in 83% of group 1 dogs between study days 3 and 18. In vivo confocal microscopic abnormalities included conjunctival leukocyte infiltration and corneal leukocyte infiltration, abnormal epithelial cell morphology, and Langerhans cell infiltration. Ocular viral shedding was detected in 50% of group 1 dogs on study days 10 and 13. Fourfold elevations in CHV-1 SN titers were detected in 100% of group 1 dogs by study day 14. Dogs in control groups did not develop clinical ocular disease (P<0.05), CHV-1 titer elevations (P<0.005), or viral shedding. Administration of an immunosuppressive dosage of systemic prednisolone to adult dogs latently infected with CHV-1 may result in viral reactivation and ocular disease recrudescence.
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PMID:Experimental reactivation of latent canine herpesvirus-1 and induction of recurrent ocular disease in adult dogs. 1934 21


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