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)

Herpetic stromal keratitis (HSK) appears to represent an immunopathologic response in the cornea of the eye to HSV-1. T cells of the CD4+ subset were shown to be involved in the mediation of HSK, but how they subserve an immunopathologic role is uncertain. In the present report, we have isolated cells from eyes in the active phase of HSK and studied their cytokine profile after culture in vitro or stimulation with Ag or nonspecific mitogens. Inflammatory cells recovered from eyes consist of polymorphonuclear leukocytes, macrophages, and lymphocytes. As reported before, all the lymphocyte recovered were of the CD4+ phenotype. After stimulation in vitro with Ag or mitogen the cytokines IL-2, IFN-gamma, and TNF-alpha/beta were produced, but not the cytokines IL-4 and IL-10. Thus, on the basis of cytokine profile, ocular lymphocytes were identified as Th1 cells. Ocular cells were also stimulated with PMA and shown to produce IL-1. The results were discussed in terms of the possible means by which the Th1 cells induce tissue damage in HSK as well as in terms of the possible means by which a preferential accumulation of Th1 cell occurs in the eye.
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PMID:Predominance of Th1 cells in ocular tissues during herpetic stromal keratitis. 135 34

HSV-1 topical infection on the murine cornea can induce herpetic stromal keratitis (HSK), a T cell-mediated inflammatory response that results in blindness. To begin to decipher the molecular interactions involved in this infection, extracts of infected corneas were assayed for the presence of seven different cytokines by ELISA. The most prominent cytokines detected were IL-1 alpha and IL-6. Both were elevated by day 2 after infection, reached peak levels of 82 and 538 pg/cornea, respectively, at day 10, and then diminished over the next 10 days. In contrast, TNF-alpha concentrations were not elevated over that seen in uninfected corneas at any time during the 20-day observation period. IFN-gamma and granulocyte-macrophage CSF corneal concentrations were below the sensitivity of the assay. We investigated whether passive transfer of antibody to viral glycoprotein D, which prevents HSK, influenced the production of IL-1 alpha and IL-6. It was found that corneal concentrations of IL-1 alpha were reduced threefold and IL-6 was undetectable at day 10 in the antibody-treated hosts. The levels of IL-10 and IL-4 in uninfected control and antibody-treated hosts were also monitored. Neither of these two regulatory cytokines was associated with HSK development or effective antibody therapy. Naive corneas cultured in vitro spontaneously produced IL-1 and IL-6, indicating that cells resident in the cornea had the ability to synthesize these proinflammatory cytokines. Collectively, our results imply that IL-1 alpha and IL-6 may be important contributors to the development of HSK pathogenesis.
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PMID:Cytokine expression in vivo during murine herpetic stromal keratitis. Effect of protective antibody therapy. 839 96

Acanthamoeba spp. are free-living amebae associated with amebic keratitis and chronic granulomatous amebic encephalitis. The present studies were undertaken to compare the pathogenicity of three species of Acanthamoeba in B6C3F1 mice after intranasal challenge with Acanthamoeba-induced cytopathogenicity for different macrophage populations. The ability of murine macrophage cell lines and activated murine peritoneal macrophages to lyse Acanthamoeba has been assessed by coincubating macrophages with 3H-uridine labeled amebae. Conversely, destruction of macrophages by Acanthamoeba was determined by measuring the release of chromium-51 from radiolabeled macrophages. Acanthamoeba culbertsoni, which is highly pathogenic for mice, destroys macrophage cultures in vitro. Activated primary peritoneal macrophages were more resistant to Acanthamoeba-mediated destruction than macrophage cell lines activated in vitro. Activated macrophages were capable of limited destruction of Acanthamoeba polyphaga and Acanthamoeba castellanii. Acanthamoeba-specific antibodies increased the amebicidal activity of activated macrophages. Macrophage-mediated destruction was by contact-dependent cytolysis and by ingestion of amebae. Conditioned medium obtained from macrophage cultures after treatment with lipopolysaccharide and interferon gamma was neither cytolytic nor cytostatic for Acanthamoeba spp. Purified recombinant cytokines including tumor necrosis factor alpha, interleukin 1 alpha, and interleukin 1 beta, alone or in combination, were not cytolytic for Acanthamoeba trophozoites.
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PMID:The interaction of Acanthamoeba spp. with activated macrophages and with macrophage cell lines. 970 82

Langerhans cells (LC) belong to the dendritic cell family and mediate Ag presentation in the cornea and ocular surface. Under normal physiological conditions, the central cornea is devoid of LC. Centripetal migration of LC plays a critical role in promoting immunoinflammatory responses in the eye including allograft rejection and herpetic keratitis. The molecular mechanisms responsible for ocular LC migration are poorly understood. To examine whether TNF-alpha mediates corneal LC migration and to establish the interaction of IL-1 and TNF-alpha in regulating LC migratory capacity, we utilized gene-targeted knockout mice lacking IL-1 receptor I (IL-1RI-/-), TNF receptor I (p55-/-), TNF receptor II (p75-/-), or both (p55-/-p75-/-). LC migration was induced by thermal cautery or cytokine injection and enumerated by an immunofluorescence assay. Migration of LC after cauterization and TNF-alpha injection was significantly depressed in both p55-/- and p75-/- mice. Similarly, in the first 72 h after intracorneal injection of IL-1alpha, LC migration was reduced in p55-/-, p75-/-, and p55-/-p75-/- mice. In contrast, injection of TNF-alpha in IL-1RI-/- mice led to normal migration of corneal LC indistinguishable from wild-type controls. These results suggest that the IL-1 induction of corneal LC migration is largely mediated by TNFR function, whereas TNF-alpha induction of LC migration is independent of IL-1RI activity. Moreover, the data suggest that both p55 and p75 signaling pathways are important in mediating LC migration in the cornea.
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PMID:TNF-alpha regulates corneal Langerhans cell migration. 1020 52

Herpetic stromal keratitis (HSK) is an immunopathologic disease triggered by infection of the cornea with HSV. Key events in HSK involve the interaction between cornea-infiltrating inflammatory cells and resident cells. This interaction, in which macrophages, producing IL-1 and TNF-alpha, and IFN-gamma-producing Th1 cells play a crucial role, results in the local secretion of immune-modulatory factors and a major influx of neutrophils causing corneal lesions and blindness. The Th1-derived cytokine IL-17 has been shown to play an important role in several inflammatory diseases characterized by a massive infiltration of neutrophils into inflamed tissue. Here we show that IL-17 is expressed in corneas from patients with HSK and that the IL-17R is constitutively expressed by human corneal fibroblasts (HCF). IL-17 exhibited a strong synergistic effect with TNF-alpha on the induction of IL-6 and IL-8 secretion by cultured HCF. Secreted IL-8 in these cultures had a strong chemotactic effect on neutrophils. IL-17 also enhanced TNF-alpha- and IFN-gamma-induced secretion of macrophage-inflammatory proteins 1alpha and 3alpha, while inhibiting the induced secretion of RANTES. Furthermore, considerable levels of IFN-gamma-inducible protein 10 and matrix metalloproteinase 1 were measured in stimulated HCF cultures, while the constitutive secretion of monocyte chemotactic protein 1 remained unaffected. The data presented suggest that IL-17 may play an important role in the induction and/or perpetuation of the immunopathologic processes in human HSK by modulating the secretion of proinflammatory and neutrophil chemotactic factors by corneal resident fibroblasts.
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PMID:IL-17 expression in human herpetic stromal keratitis: modulatory effects on chemokine production by corneal fibroblasts. 1242 73

Pseudomonas aeruginosa (P. aeruginosa) is a common organism associated with bacterial keratitis, especially in those who use extended wear contact lenses. Recent advances in our understanding of host innate and adaptive immune responses to experimental infection have been made using a variety of animal models, including inbred murine models that are classed as resistant (cornea heals) vs. susceptible (cornea perforates). Evidence has been provided that sustained IL-12-driven IFN-gamma production in dominant Th1 responder strains such as C57BL/6 (B6) contributes to corneal destruction and perforation, while IL-18-driven production of IFN-gamma in the absence of IL-12 is associated with bacterial killing and less corneal destruction in dominant Th2 responder strains such as BALB/c. The critical role of IL-1 and chemotactic cytokines such as MIP-2 in PMN recruitment and the critical role of this cell in the innate immune response to bacterial infection is reviewed. Regulation of PMN persistence is also discussed and evidence provided that persistence of PMN in B6 cornea is regulated by CD4+ T cells, while macrophages regulate PMN number in the cornea of BALB/c mice. The studies provide a better understanding of the inflammatory mechanisms that are operative in the cornea after P. aeruginosa challenge and are consistent with long-term goals of providing targets for alternative or adjunctive treatment for this disease. Future studies will be aimed at better defining the role of Toll receptors, neuropeptides (as unconventional modulators of the immune response) and exploitation of disease control by new techniques, such as RNA silencing.
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PMID:Corneal response to Pseudomonas aeruginosa infection. 1476 15

Ocular infection with HSV may result in the blinding immunoinflammatory lesion stromal keratitis (SK). This represents a CD4+ T cell-mediated immunopathologic lesion in both humans and a mouse model. Early events in the pathogenesis that set the stage for SK are poorly understood. The present study evaluates the role of IL-1 using a transgenic mouse that overexpresses the IL-1 receptor antagonist (IL-1ra) protein. Such transgenic mice were markedly resistant to SK compared with IL-1ra(-/-) and C57BL/6 control animals. The resistance was shown to be the consequence of reduced expression of molecules such as IL-6, macrophage-inflammatory protein-2, and vascular endothelial growth factor, normally up-regulated directly or indirectly by IL-1. A critical event impaired in IL-1ra transgenic mice was vascular endothelial growth factor production with a consequent marked reduction in angiogenesis, an essential step in SK pathogenesis. Targeting IL-1 could prove to be a worthwhile therapeutic approach to control SK, an important cause of human blindness.
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PMID:Mice transgenic for IL-1 receptor antagonist protein are resistant to herpetic stromal keratitis: possible role for IL-1 in herpetic stromal keratitis pathogenesis. 1500 78

Herpetic stromal keratitis (HSK) is a T cell-orchestrated, immunoinflammatory lesion that results from corneal Herpes simplex virus infection. Previous reports indicate an essential role for proinflammatory cytokine interleukin (IL)-1 in HSK pathogenesis. The present study evaluates the efficacy of IL-1 receptor antagonist (IL-1 ra) protein in the management of HSK. Mice receiving IL-1 ra had diminished disease severity. The administration of IL-1 ra was shown to reduce the influx into the cornea of cells of the innate and adaptive immune response. In addition, the treatment diminished corneal vascular endothelial growth factor levels, resulting in reduced angiogenic response. Our results show the importance of targeting early proinflammatory molecules such as IL-1 to counteract HSK and advocate IL-1 ra as an effective agent to achieve this.
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PMID:Counteracting corneal immunoinflammatory lesion with interleukin-1 receptor antagonist protein. 1525 92

Pseudomonas aeruginosa keratitis is one of the most destructive diseases of the cornea. The host response to this infection is critical to the outcome, and is regulated by cytokines produced in the ocular tissue. In this study, we assessed the relative contribution of the cytokines produced in the cornea to the inflammatory response of the whole eye to gain a better understanding of the inflammatory and regulatory processes in the ocular environment during localized corneal infection. C57BL/6 mice were challenged by topical application of P. aeruginosa to wounded corneas. Corneas and whole eyes were harvested 24 h post-challenge and bacterial numbers, myeloperoxidase levels and the levels of cytokines known to be important in keratitis were determined. The site of production of IL-6 and KC in the retina was determined by in situ hybridization. Before infection, 90% of macrophage inflammatory protein (MIP)-2 and approximately 80% of all IFN-gamma and IL-10 produced constitutively in the eye was found outside the cornea. Twenty-four hours after infection, bacterial numbers, levels of myeloperoxidase, and levels of MIP-2 and IL-1 were not different, whether measured in cornea or whole eye. However, expression of IL-6, KC, IFN-gamma and IL-10 was significantly greater in whole eyes than in the corneas of infected eyes. The cells expressing IL-6 and KC in the retina were identified by in situ hybridization. This study indicates that during corneal inflammation, the response of the whole eye as well as the cornea needs to be considered.
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PMID:Contribution of the cornea to cytokine levels in the whole eye induced during the early phase of Pseudomonas aeruginosa challenge. 1587 9

Pseudomonas aeruginosa is a common organism associated with bacterial keratitis primarily resulting from contact lens usage. Advances in our understanding of host innate and adaptive immune responses to experimental infection have been achieved using animal models, including inbred mouse models that are classed as resistant (cornea heals) vs. susceptible (cornea perforates). Evidence has shown that sustained IL-12-driven IFN-gamma production in dominant Th1 responder strains such as C57BL/6 (B6) contributes to corneal destruction and perforation. In contrast, in Th2-responder BALB/c mice, IL-18-driven IFN-gamma production regulates bacterial killing with less corneal destruction. IL-1 and chemotactic cytokines (e.g., MIP-2) recruit PMN to the cornea. The critical role of these cells in the innate immune response and their regulation after bacterial infection has been established. The studies provide a better understanding of the regulatory mechanisms that operate in the cornea after P. aeruginosa challenge, determining susceptibility vs. resistance to disease, and are consistent with long-term goals of providing targets for better treatment of disease.
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PMID:Role of innate and adaptive immunity in the pathogenesis of keratitis. 1601 72


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