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)

T lymphocytes are critical in mediating herpes simplex stromal keratitis (HSK). Using immunohistologic methods, we studied the T cell subsets and the T cell receptor variable region (TCR V beta) repertoire of T cells in the eye after corneal infection with HSV (KOS strain). We investigated the possibility that there might be differential V beta preferential usage in HSK resistant and susceptible BALB/c congenic mice that differ only in a small region associated with the Igh-1 gene locus. The inflamed corneas of HSK susceptible C.AL-20 mice were mainly infiltrated by CD4+ cells and by V beta 8 expressing cells. Such T cells were not seen in the corneas of resistant C.B-17 mice. Our results indicate that CD4+V beta 8+ cells are involved in mediating HSV-1 stromal keratitis.
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PMID:CD4+V beta 8+ T cells mediate herpes stromal keratitis. 784 19

T-cell responses to pathogenic free-living amoebae, Acanthamoeba sp., were analyzed in healthy Japanese individuals. Of 20 healthy subjects, 10 (50%) showed significant proliferative responses of peripheral blood mononuclear cells to the soluble amoebic antigens in vitro. The antigens used were not mitogenic, and no evidence of amoebic superantigens was available. We established human T-cell clones reactive to Acanthamoeba, all of which were CD3- and CD4-positive, CD8-negative, and TCR-alpha beta-positive. We isolated two strains of Acanthamoeba from two patients, one from a patient with meningoencephalitis (CSF strain) and the other from a patient with keratitis (K strain). Of 13 clones, 11 were reactive to the K-strain as well as to the CSF-strain antigen under human leukocyte antigen (HLA)-DR restriction, whereas the other two were specific for the K-strain antigen. All but one clone tested showed TH1-equivalent functions because these cells produced interferon (IFN)-gamma in response to the amoebic antigen but produced no detectable level of interleukin 4 (IL-4). These results suggest that immunocompetent hosts might have acquired protective immunity mediated by Acanthamoeba-specific T-cells during natural sensitization.
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PMID:Acanthamoeba-specific human T-cell clones isolated from healthy individuals. 785 19

Corneal infection of susceptible mice with HSV-1 causes herpetic stromal keratitis (HSK), which serves as a model of human HSK. To study the properties of the T lymphocytes involved in HSK, susceptible mice were immunized with the synthetic peptide corresponding to the amino terminal of HSV-1-associated glycoprotein D (gD 5-23). A CD4+ long-term T cell line and a clone bearing V beta 8.2 TCR were derived from peptide-primed lymph node cells. These T cells recognize gD 5-23 peptide in the context of I-Ed and require CD4 and LFA-1 for Ag-specific proliferation. Significantly, a truncated peptide gD 15-23 induced vigorous proliferation, indicating that these 9 amino acids constitute an epitope recognized by these T cells. The gD-specific T cells produced IL-4 and used it as the autocrine growth factor and hence belong to the Th2 subtype. Adoptive transfer of gD-specific Th2 cells into susceptible mice increased both the onset and severity of HSK after corneal HSV-1 infection. Injection of gD-specific Th2 cells without HSV-1 infection failed to cause eye damage. In addition, an irrelevant Ag-specific Th2 clone failed to induce similar tissue damage when the corresponding Ag was applied to the eye. These data indicate that the T cell-mediated exacerbation of HSK in these studies is dependent on the specific recognition of gD after corneal HSV-1 infection. Finally, gD-specific Th2 cell transfer also rendered HSK-resistant mice susceptible for HSK, suggesting that the freedom from HSK in resistant mice may primarily be due to their inability to produce the pathogenic Th2 cells. The data collectively implicate an important role for Th2 cells in the induction of HSV-mediated keratitis in mice.
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PMID:Exacerbation of murine herpes simplex virus-mediated stromal keratitis by Th2 type T cells. 822 62

Herpetic stromal keratitis (HSK) is a CD4+ T cell-controlled immunopathologic lesion in the eye that results from infection with herpes simplex virus (HSV). Target Ags involved in HSK remain undefined. In this study, we determined if HSK could be induced in animals genetically incapable of generating HSV Ag-specific CD4+ T cells. Mice bearing transgenic TCR specific to OVA peptide 323-339 (DO11.10) were crossed to SCID mice whose offspring (Tg-SCID) possessed CD4+ T cells, >98% of which expressed the OVA peptide-specific TCR. HSV infection of Tg-SCID mice was lethal, and mice failed to generate detectable T cell responses even after repeated immunization with a mutant avirulent virus (AN-1). Immunization with AN-1 virus followed by ocular challenge with HSV resulted in ocular inflammation before encephalitis, in contrast to the protection conferred in the control BALB/c and DO11.10 mice. These results indicate that clinical HSK may not require viral Ag recognition by CD4+ T cells and that T cells of irrelevant specificity can be recruited, activated, and driven into effector function in the HSV-infected cornea. This is suggested to represent a bystander activation effect resulting from the presence of proinflammatory mediators resulting from HSV replication.
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PMID:Virus-induced immunoinflammatory lesions in the absence of viral antigen recognition. 978 Feb 5

Herpetic stromal keratitis (HSK) is an immunopathological lesion involving herpes simplex virus (HSV) infection and CD4(+) T cells of the Th1 phenotype, but the nature of the target antigens which drive HSK remains uncertain. In the present report we show that ovalbumin TCR-transgenic mice backcrossed to SCID mice unable to recognize HSV show clinical signs of HSK but die of viral encephalitis before the lesions become severe. However, passive transfer of anti-HSV serum at 24 h clears virus and affords protection from both HSK lesions and death. Adoptive transfer of CD8(+) T cells at 72 h usually conferred protection but animals developed severe corneal pathology by 3 weeks post infection. At this time viral antigens were not demonstrable in the cornea and the T cells in the inflammatory lesions were CD4(+)KJ1-26.1 idiotype positive, i. e. OVA peptide specific. These results indicate bystander activation of CD4(+) T cells in a virus-induced inflammatory milieu. This mechanism of immunoinflammation may represent an important component of any lesion which involves CD4(+) T cells.
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PMID:Bystander activation of CD4(+) T cells can represent an exclusive means of immunopathology in a virus infection. 1055 23

Herpes simplex virus infection of mouse corneas can lead to the development of an immunopathological lesion, termed herpetic stromal keratitis (HSK). Such lesions also occur in TCR-transgenic mice backcrossed to SCID (TgSCID) that are unable to mount detectable HSV-specific immune responses. The present study demonstrates that lesion expression in such mice depends on continuous viral replication, whereas in immunocompetent mice, lesions occurred even if virus replication was terminated at 4 days after infection. The continuous replication in TgSCID mice was considered necessary to produce an activating stimulus to CD4(+) T cells that invade the cornea. Lesions in TgSCID were resistant to control by cyclosporin A, but were inhibited by treatment with rapamycin. This result was interpreted to indicate that T cell activation involved a non-TCR-mediated cytokine-driven bystander mechanism. Bystander activation was also shown to play a role in HSK lesions in immunocompetent mice. Accordingly, in immunocompetent DO11.10 mice, lesions were dominated by KJ1.26(+) OVA-specific CD4(+) T cells that were unreactive with HSV. In addition, KJ1.26(+) HSV nonimmune cells parked in ocularly infected BALB/c mice were demonstrable in HSK lesions. These results provide insight for the choice of new strategies to manage HSK, an important cause of human blindness.
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PMID:Bystander activation involving T lymphocytes in herpetic stromal keratitis. 1150 38

Herpetic stromal keratitis (HSK), resulting from ocular infection with herpes simplex virus (HSV), is thought to represent a T cell mediated immunopathologic lesion. Antigens recognized by the inflammatory T cells remain unresolved and non-TCR mediated activation of T cells (bystander activation) is considered as also involved. This report documents further evidence for the bystander activation mechanisms using three T cell transgenic RAG-/- mouse strains. Accordingly HSK occurred in PCC RAG-/-, P14 RAG-/-, and OT-1 RAG-/- mice. In none of the models could HSV specific T cell reactivity be demonstrated and animals were unprotected from lesion development by immunization prior to HSV ocular infection. The results support the role of bystander activation as a mechanism of T cell mediated immunopathology and show that CD8(+) as well as CD4(+) T cells can participate in HSK lesion development.
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PMID:Herpetic stromal keratitis in the absence of viral antigen recognition. 1257 29

Herpetic stromal keratitis (HSK) is a chronic inflammatory process in corneal stroma that results from recurrent HSV type 1 infection. We used the murine model of HSK to demonstrate the importance of the interaction between an inducible T cell costimulatory receptor, 4-1BB, and its ligand, 4-1BB ligand (4-1BBL), in the development of this disease. In BALB/c mice, HSK ordinarily induced by infection with the RE strain of herpes was prevented by blocking 4-1BB/4-1BBL interaction, either by deleting 4-1BB (in mutant 4-1BB(-/-) mice) or by introducing mAbs against 4-1BBL. The majority of T cells infiltrating the infected corneas were 4-1BB(+) activated effector cells that expressed cell surface markers CD44, CD25, and/or CD62L, as well as chemokine receptors CCR1, CCR2, and CCR5, and a limited number of TCR Vbeta chains (Vbeta8.1/8.2, Vbeta8.3, Vbeta10b, and Vbeta5.1/5.2, in order of abundance). Analysis of cell surface phenotypes showed that the failure to develop HSK in the 4-1BB(-/-) mice was associated with a reduced expression of CD62L at the time of T cell migration into the corneal stroma.
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PMID:Blocking 4-1BB/4-1BB ligand interactions prevents herpetic stromal keratitis. 1284 21