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Adamus G. Importance of Autoimmune Responses in Progression of Retinal Degeneration Initiated by Gene Mutations. Front Med (Lausanne) 2021; 8:672444. [PMID: 34926479 PMCID: PMC8674421 DOI: 10.3389/fmed.2021.672444] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 11/01/2021] [Indexed: 12/13/2022] Open
Abstract
Inherited retinal diseases (IRDs) are clinically and genetically heterogeneous rare disorders associated with retinal dysfunction and death of retinal photoreceptor cells, leading to blindness. Among the most frequent and severe forms of those retinopathies is retinitis pigmentosa (RP) that affects 1:4,000 individuals worldwide. The genes that have been implicated in RP are associated with the proteins present in photoreceptor cells or retinal pigment epithelium (RPE). Asymmetric presentation or sudden progression in retinal disease suggests that a gene mutation alone might not be responsible for retinal degeneration. Immune responses could directly target the retina or be site effect of immunity as a bystander deterioration. Autoantibodies against retinal autoantigens have been found in RP, which led to a hypothesis that autoimmunity could be responsible for the progression of photoreceptor cell death initiated by a genetic mutation. The other contributory factor to retinal degeneration is inflammation that activates the innate immune mechanisms, such as complement. If autoimmune responses contribute to the progression of retinopathy, this could have an implication on treatment, such as gene replacement therapy. In this review, we provide a perspective on the current role of autoimmunity/immunity in RP pathophysiology.
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Affiliation(s)
- Grazyna Adamus
- Ocular Immunology Laboratory, Casey Eye Institute, School of Medicine, Oregon Health and Science University, Portland, OR, United States
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2
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Shome A, Mugisho OO, Niederer RL, Rupenthal ID. Blocking the inflammasome: A novel approach to treat uveitis. Drug Discov Today 2021; 26:2839-2857. [PMID: 34229084 DOI: 10.1016/j.drudis.2021.06.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 05/24/2021] [Accepted: 06/30/2021] [Indexed: 12/11/2022]
Abstract
Uveitis is a complex ocular inflammatory disease often accompanied by bacterial or viral infections (infectious uveitis) or underlying autoimmune diseases (non-infectious uveitis). Treatment of the underlying infection along with corticosteroid-mediated suppression of acute inflammation usually resolves infectious uveitis. However, to develop more effective therapies for non-infectious uveitis and to better address acute inflammation in infectious disease, an improved understanding of the underlying inflammatory pathways is needed. In this review, we discuss the disease aetiology, preclinical in vitro and in vivo uveitis models, the role of inflammatory pathways, as well as current and future therapies. In particular, we highlight the involvement of the inflammasome in the development of non-infectious uveitis and how it could be a future target for effective treatment of the disease.
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Affiliation(s)
- Avik Shome
- Buchanan Ocular Therapeutics Unit, Department of Ophthalmology, New Zealand National Eye Centre, University of Auckland, Auckland, New Zealand
| | - Odunayo O Mugisho
- Buchanan Ocular Therapeutics Unit, Department of Ophthalmology, New Zealand National Eye Centre, University of Auckland, Auckland, New Zealand
| | - Rachael L Niederer
- Department of Ophthalmology, New Zealand National Eye Centre, University of Auckland, Auckland, New Zealand; Auckland District Health Board, Auckland, New Zealand
| | - Ilva D Rupenthal
- Buchanan Ocular Therapeutics Unit, Department of Ophthalmology, New Zealand National Eye Centre, University of Auckland, Auckland, New Zealand.
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3
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Abstract
Autoimmune uveitis is a sight-threatening, rare disease, potentially leading to blindness. Uveitis is a synonym for intraocular inflammation, presenting as various clinical phenotypes with different underlying immune responses in patients, whereas different animal models usually represent one certain clinical and immunological type of uveitis due to genetic uniformity and the method of disease induction. T cells recognizing intraocular antigens initiate the disease, recruiting inflammatory cells (granulocytes, monocytes/macrophages) to the eyes, which cause the damage of the tissue. The treatment of uveitis so far aims at downregulation of inflammation to protect the ocular tissues from damage, and at immunosuppression to stop fueling T cell reactivity. Uveitis is usually prevented by specific mechanisms of the ocular immune privilege and the blood-eye-barriers, but once the disease is induced, mechanisms of the immune privilege as well as a variety of novel regulatory features including new Treg cell populations and suppressive cytokines are induced to downregulate the ocular inflammation and T cell responses and to avoid relapses and chronicity. Here we describe mechanisms of regulation observed in experimental animal models as well as detected in studies with peripheral lymphocytes from patients.
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4
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Lundy SK, Nikoopour E, Karoukis AJ, Ohara R, Othman MI, Tagett R, Jayasundera KT, Heckenlively JR. T Helper 1 Cellular Immunity Toward Recoverin Is Enhanced in Patients With Active Autoimmune Retinopathy. Front Med (Lausanne) 2018; 5:249. [PMID: 30271775 PMCID: PMC6146138 DOI: 10.3389/fmed.2018.00249] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 08/16/2018] [Indexed: 01/01/2023] Open
Abstract
Autoimmune retinopathy (AIR) causes rapidly progressive vision loss that is treatable but often is confused with other forms of retinal degeneration including retinitis pigmentosa (RP). Measurement of anti-retinal antibodies (ARA) by Western blot is a commonly used laboratory assay that supports the diagnosis yet does not reflect current disease activity. To search for better diagnostic indicators, this study was designed to compare immune biomarkers and responses toward the retinal protein, recoverin, between newly diagnosed AIR patients, slow progressing RP patients and healthy controls. All individuals had measurable anti-recoverin IgG and IgM antibodies by ELISA regardless of disease status or Western blot results. Many AIR patients had elevated anti-recoverin IgG1 levels and a strong cellular response toward recoverin dominated by IFNγ. RP patients and controls responded to recoverin with a lower IFNγ response that was balanced by IL-10 production. Both AIR and RP patients displayed lower levels of total peripheral blood mononuclear cells that were due to reductions of CD4+ TH cells. A comparison of messenger RNA (mRNA) for immune-related genes in whole blood of AIR patients versus RP patients or controls indicated lower expression of ATG5 and PTPN22 and higher expression of several genes involved in TH cell signaling/transcription and adhesion. These data indicate that an immune response toward recoverin is normal in humans, but that in AIR patients the balance shifts dramatically toward higher IFNγ production and cellular activation.
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Affiliation(s)
- Steven K Lundy
- Department of Internal Medicine-Rheumatology, University of Michigan Medical School, Ann Arbor, MI, United States.,Graduate Training Program in Immunology, University of Michigan Medical School, Ann Arbor, MI, United States
| | - Enayat Nikoopour
- Department of Internal Medicine-Rheumatology, University of Michigan Medical School, Ann Arbor, MI, United States.,Department of Ophthalmology and Visual Sciences-Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, MI, United States
| | - Athanasios J Karoukis
- Department of Ophthalmology and Visual Sciences-Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, MI, United States
| | - Ray Ohara
- Department of Internal Medicine-Rheumatology, University of Michigan Medical School, Ann Arbor, MI, United States
| | - Mohammad I Othman
- Department of Ophthalmology and Visual Sciences-Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, MI, United States
| | - Rebecca Tagett
- Biostatistics Core Facility, University of Michigan Medical School, Ann Arbor, MI, United States
| | - K Thiran Jayasundera
- Department of Ophthalmology and Visual Sciences-Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, MI, United States
| | - John R Heckenlively
- Department of Ophthalmology and Visual Sciences-Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, MI, United States
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5
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Massilamany C, Gangaplara A, Reddy J. Environmental microbes and uveitis: is microbial exposure always bad? Scand J Immunol 2015; 81:469-75. [PMID: 25833717 DOI: 10.1111/sji.12297] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 03/21/2015] [Indexed: 01/09/2023]
Abstract
The eye generally is considered to be an immune-privileged organ, but this notion is being increasingly challenged as ocular antigens can be expressed in the generative lymphoid organs, resulting in attainment of self-tolerance. What triggers a break in this tolerant state is a fundamental question in autoimmunity research. The general belief is that exposure to environmental microbes can break self-tolerance in genetically susceptible individuals, leading to the induction of autoimmune responses. The molecular mimicry hypothesis has been proposed as one major mechanistic, pathway through which microbes, by generating cross-reactive immune responses, can induce ocular damage of the kind that might occur in uveitis. However, our recent data suggest that exposure to microbial products containing mimicry epitopes for retinal antigens can potentially be beneficial to the host. In this review, we discuss the immune mechanisms with particular reference to the molecular mimicry hypothesis as it relates to immune-mediated uveitis.
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Affiliation(s)
- C Massilamany
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - A Gangaplara
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, NE, USA.,Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - J Reddy
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, NE, USA
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6
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Schewitz-Bowers LP, Lee RWJ, Dick AD. Immune mechanisms of intraocular inflammation. EXPERT REVIEW OF OPHTHALMOLOGY 2014. [DOI: 10.1586/eop.09.68] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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7
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Gangaplara A, Massilamany C, Steffen D, Reddy J. Mimicry epitope from Ehrlichia canis for interphotoreceptor retinoid-binding protein 201-216 prevents autoimmune uveoretinitis by acting as altered peptide ligand. J Neuroimmunol 2013; 263:98-107. [PMID: 24029580 DOI: 10.1016/j.jneuroim.2013.08.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Revised: 05/28/2013] [Accepted: 08/12/2013] [Indexed: 10/26/2022]
Abstract
We report here identification of novel mimicry epitopes for interphotoreceptor retinoid-binding protein (IRBP) 201-216, a candidate ocular antigen that causes experimental autoimmune uveoretinitis (EAU) in A/J mice. One mimicry epitope from Ehrlichia canis (EHC), designated EHC 44-59, induced cross-reactive T cells for IRBP 201-216 capable of producing T helper (Th)1 and Th17 cytokines, but failed to induce EAU in A/J mice. In addition, animals first primed with suboptimal doses of IRBP 201-216 and subsequently immunized with EHC 44-59 did not develop EAU; rather, the mimicry epitope prevented the disease induced by IRBP 201-216. However, alteration in the composition of EHC 44-59 by substituting alanine with valine at position 49, similar to the composition of IRBP 201-216, enabled the mimicry epitope to acquire uveitogenicity. The data provide new insights as to how microbes containing mimicry sequences for retinal antigens can prevent ocular inflammation by acting as naturally occurring altered peptide ligands.
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Affiliation(s)
- Arunakumar Gangaplara
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, NE 68583, United States
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8
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DeVoss J, Hou Y, Johannes K, Lu W, Liou GI, Rinn J, Chang H, Caspi RR, Caspi R, Fong L, Anderson MS. Spontaneous autoimmunity prevented by thymic expression of a single self-antigen. J Exp Med 2006; 203:2727-35. [PMID: 17116738 PMCID: PMC2118158 DOI: 10.1084/jem.20061864] [Citation(s) in RCA: 207] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2006] [Accepted: 10/26/2006] [Indexed: 12/20/2022] Open
Abstract
The expression of self-antigen in the thymus is believed to be responsible for the deletion of autoreactive T lymphocytes, a critical process in the maintenance of unresponsiveness to self. The Autoimmune regulator (Aire) gene, which is defective in the disorder autoimmune polyglandular syndrome type 1, has been shown to promote the thymic expression of self-antigens. A clear link, however, between specific thymic self-antigens and a single autoimmune phenotype in this model has been lacking. We show that autoimmune eye disease in aire-deficient mice develops as a result of loss of thymic expression of a single eye antigen, interphotoreceptor retinoid-binding protein (IRBP). In addition, lack of IRBP expression solely in the thymus, even in the presence of aire expression, is sufficient to trigger spontaneous eye-specific autoimmunity. These results suggest that failure of thymic expression of selective single self-antigens can be sufficient to cause organ-specific autoimmune disease, even in otherwise self-tolerant individuals.
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Affiliation(s)
- Jason DeVoss
- Diabetes Center and Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA
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9
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Charukamnoetkanok P, Brady JP, Wawrousek EF, Egwuagu CE, Zigler JS, Vistica BP, Whitcup SM, Gery I. Immunotolerance toward native alphaA-crystallin in knockout mice deficient in the functional protein. Immunol Lett 2004; 89:259-65. [PMID: 14556987 DOI: 10.1016/s0165-2478(03)00153-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Immune response against self antigens is normally prevented by an elaborate immunotolerance mechanism. A potential problem for recipients of gene therapy is, therefore, an immune response against the newly introduced gene product. To examine this issue we tested the immune response to the native proteins in knockout (KO) mice in which the genes for alphaA- or alphaB-crystallin were disrupted by partial or complete gene deletion, respectively. alphaA- and alphaB-crystallins are two immunologically distinct polypeptides which form the large ( approximately 800 kDa) complex in the lens referred to as alpha-crystallin. When immunized with murine alpha-crystallin, alphaB-crystallin KO mice, in which the corresponding gene was completely deleted, responded well to the absent self antigen. In contrast, alphaA-crystallin KO mice, with the partial gene deletion, resembled wild type (WT) mice in being immunotolerant toward the native crystallin. Although no functional alphaA-crystallin could be detected in the lens of alphaA-crystallin KO mice, mRNA transcript coding for a truncated alphaA-crystallin gene was found in thymi of these mice, suggesting that thymic expression of a residual fragment of the protein is responsible for the tolerance induction. These data suggest that nonfunctional proteins may induce immunotolerance and protect recipients of gene therapy from immunity against the native proteins.
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Affiliation(s)
- Puwat Charukamnoetkanok
- The National Eye Institute, National Institutes of Health, Bldg 10, Rm 10N112, Bethesda, MD 20892-1857, USA
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10
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Gelderman MP, Charukamnoetkanok P, Brady JP, Hung L, Zigler JS, Wawrousek EF, Vistica BP, Fortin E, Chan CC, Gery I. A novel inflammatory eye disease induced by lymphocytes from knockout mice sensitized against the deleted ocular antigen. Clin Exp Immunol 2003; 133:177-81. [PMID: 12869022 PMCID: PMC1808771 DOI: 10.1046/j.1365-2249.2003.02218.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Lens-associated uveitis (LAU), a severe inflammatory eye disease, is thought to be mediated by autoimmunity against lens crystallins. Previously described animal models for this disease are antibody-mediated, since no cellular response to self crystallins could be induced in experimental animals. Here, we describe a new model for LAU, in which lymphocytes from knockout mice deficient in alphaB-crystallin are sensitized against the deleted protein and induce severe ocular inflammation when adoptively transferred into wild type recipients. Similar to LAU, the experimental disease developed only following rupture of the lens capsule, produced in this study by capsulotomy; no disease was detected in recipient eyes with no capsulotomy, or in those treated with cautery, or in eyes affected by systemic treatment with sodium iodate, lipopolysaccharide or X-irradiation. The ocular changes in affected eyes included heavy cellular infiltration and proteinaceous exudate in both the anterior and posterior segments of the eye, that reached their peak on day 4 following cell transfer and subsided quite rapidly thereafter.
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Affiliation(s)
- M P Gelderman
- National Eye Institute, National Institutes of Health, Bethesda, Maryland 20892-1857, USA
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11
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Bhat SP. Crystallins, genes and cataract. PROGRESS IN DRUG RESEARCH. FORTSCHRITTE DER ARZNEIMITTELFORSCHUNG. PROGRES DES RECHERCHES PHARMACEUTIQUES 2003; 60:205-62. [PMID: 12790344 DOI: 10.1007/978-3-0348-8012-1_7] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Far from being a physical entity, assembled of inanimate structural proteins, the ocular lens epitomizes the biological ingenuity that sustains an essential and near-perfect physical system of immaculate optics. Crystallins (alpha, beta, and gamma) provide transparency by dint of their high concentration, but it is debatable whether proteins that provide transparency are any different, biologically or structurally, from those that are present in non-transparent structures or tissues. It is becoming increasingly clear that crystallins may have a plethora of metabolic and regulatory functions, both within the lens as well as outside of it. Alpha-crystallins are members of a small heat shock family of proteins and beta/gamma-crystallins belong to the family of epidermis-specific differentiation proteins. Crystallin gene expression has been studied from the perspective of the lens specificity of their promoters. Mutations in alpha-, beta-, and gamma-crystallins are linked with the phenotype of the loss of transparency. Understanding catalytic, non-structural properties of crystallins may be critical for understanding the malfunction in molecular cascades that lead to cataractogenesis and its eventual therapeutic amelioration.
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Affiliation(s)
- Suraj P Bhat
- Jules Stein Eye Institute and Brain Research Institute, Geffen School of Medicine at UCLA, Los Angeles, CA 90077-7000, USA.
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12
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Thyagarajan T, Kulkarni AB. Transforming growth factor-beta1 negatively regulates crystallin expression in teeth. J Bone Miner Res 2002; 17:1710-7. [PMID: 12211442 DOI: 10.1359/jbmr.2002.17.9.1710] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Previously, we have reported that targeted overexpression of transforming growth factor (TGF) beta1 in the teeth of the transgenic mice (dTGF-beta1) results in a novel tooth phenotype phenomimicking the most prevalent tooth disorders in human. This phenotype was associated with discoloration and attrition of teeth due to defective mineralization. Here, we report a novel expression of crystallin family members in developing mouse teeth and its regulation by TGF-beta1 in these transgenic mice. AlphaB- and beta-crystallins were found to be elevated in dTGF-beta1 mouse teeth, whereas gamma-crystallin (gammaB, gammaC, and gammaF), a marker of cell differentiation, was significantly reduced. Because crystallins are believed to be stress-related proteins, their expression in teeth implicates them in a similar role because teeth are constantly subjected to physical friction and temperature fluctuations.
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Affiliation(s)
- Tamizchelvi Thyagarajan
- Functional Genomics Unit, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland 20892, USA
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13
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Katsuta H, Okada M, Nakauchi T, Takahashi Y, Yamao S, Uchida S. Cancer-associated retinopathy associated with invasive thymoma. Am J Ophthalmol 2002; 134:383-9. [PMID: 12208250 DOI: 10.1016/s0002-9394(02)01598-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
PURPOSE To report a case of cancer-associated retinopathy associated with invasive thymoma. DESIGN Interventional case report. METHOD A 41-year-old Japanese woman was observed between February 1998 and May 2001. Ophthalmologic examinations and systemic examinations were performed. The patient received treatment including corticosteroid pulse therapy, plasmapheresis, and thymectomy. RESULTS The patient developed progressive visual dysfunction including bilateral visual acuity loss, concentric contraction of visual fields, and color vision loss. In both eyes, retinal vessel attenuation and retinal pigment epithelium degeneration were observed with fundus ophthalmoscopy and fluorescein angiography. Response in electroretinogram was reduced, suggesting both rod and cone dysfunction. Autoantibody against 23-kD cancer-associated retinopathy (CAR) antigen (antirecoverin antibody) was detected in the patient's serum. A mediastinal tumor that was histopathologically diagnosed as invasive thymoma was detected and was surgically resected. During more than 3 years of follow-up, no other malignancy was detected despite extensive systemic evaluation. The patient also suffered from subclinical myasthenia gravis. Although temporary improvement of visual function was observed after treatment with steroid pulse therapy and plasmapheresis' light perception of each eye was lost in the end. CONCLUSIONS The patient was diagnosed as having CAR. Invasive thymoma was considered to be the causative tumor because there had been no evidence that suggested other systemic malignancy during more than 3 years of follow-up.
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Affiliation(s)
- Hideto Katsuta
- Department of Ophthalmology, Kurashiki Central Hospital, Okayama, Japan.
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14
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Kuchroo VK, Anderson AC, Waldner H, Munder M, Bettelli E, Nicholson LB. T cell response in experimental autoimmune encephalomyelitis (EAE): role of self and cross-reactive antigens in shaping, tuning, and regulating the autopathogenic T cell repertoire. Annu Rev Immunol 2002; 20:101-23. [PMID: 11861599 DOI: 10.1146/annurev.immunol.20.081701.141316] [Citation(s) in RCA: 269] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
T cells that can respond to self-antigens are present in the peripheral immune repertoire of all healthy individuals. Recently we have found that unmanipulated SJL mice that are highly susceptible to EAE also maintain a very high frequency of T cells responding to an encephalitogenic epitope of a myelin antigen proteolipid protein (PLP) 139-151 in the peripheral repertoire. This is not due to lack of expression of myelin antigens in the thymus resulting in escape of PLP 139-151 reactive cells from central tolerance, but is due to expression of a splice variant of PLP named DM20, which lacks the residues 116-150. In spite of this high frequency, the PLP 139-151 reactive cells remain undifferentiated in the periphery and do not induce spontaneous EAE. In contrast, SJL TCR transgenic mice expressing a receptor derived from a pathogenic T cell clone do develop spontaneous disease. This may be because in normal mice, autoreactive cells are kept in check by an alternate PLP 139-151 reactive nonpathogenic repertoire, which maintains a balance that keeps them healthy. If this is the case, selective activation of one repertoire or the other may alter susceptibility to autoimmune disease. Since T cells are generally cross-reactive, besides responding to nonself-antigens, they also maintain significant responses to self-antigens. Based on the PLP 139-151 system, we propose a model in which activation with foreign antigens can result in the generation of pathogenic memory T cells that mediate autoimmunity. We also outline circumstances under which activation of self-reactive T cells with foreign antigens can generate selective tolerance and thus generate protective/regulatory memory against self while still maintaining significant responses against foreign antigens. This provides a mechanism by which the fidelity and specificity of the immune system against foreign antigens is improved without increasing the potential for developing an autoimmune disease.
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Affiliation(s)
- Vijay K Kuchroo
- Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, 77 Avenue Louis Pasteur, Boston, Massachusetts 02115, USA.
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15
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Gery I, Egwuagu CE. Central tolerance mechanisms in control of susceptibility to autoimmune uveitic disease. Int Rev Immunol 2002; 21:89-100. [PMID: 12424838 DOI: 10.1080/08830180212061] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Igal Gery
- Laboratory of Immunology, National Eye Institute, NIH, 10 Center Drive, Bethesda, MD 20892-1857, USA.
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16
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Shinohara T, Singh DP, Chylack LT. Review: Age-related cataract: immunity and lens epithelium-derived growth factor (LEDGF). J Ocul Pharmacol Ther 2000; 16:181-91. [PMID: 10803429 DOI: 10.1089/jop.2000.16.181] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
This short review summarizes our recent work and relevant publications on autoimmunity and cataract. A complete review of this subject is beyond the scope of this paper. Age-related cataract (ARC) is the leading cause of world blindness. In spite of more than fifty years of basic and clinical research, there is no nonsurgical intervention to prevent or treat ARC, but there is a better understanding of the manifold complexities of this age-related condition. ARC is a multifactorial condition in which incidence and progress are modified by factors such as age, sex, radiation [visible, ultraviolet (UV), and X-ray], oxidation, physical trauma, diet, and medications. The lens contains at least three different cell types: central epithelial cells, dividing germinative epithelial cells, and fiber cells. The central epithelial cells covering the anterior axial part of the lens do not divide but survive throughout life. The bulk of the lens comprises anucleate fiber cells, differentiated germinative epithelial cells, which have undergone an apoptosis-like change "diffoptosis" to become elongated, crystallin-rich, organelle-deficient, cells. The epithelial cells and their active transport mechanisms maintain lens homeostasis and clarity. The survival mechanisms of the central lens epithelial cells (LECs) are unknown. In other cells, growth or survival factors, when present, enhance survival and, when absent or deficient, induce programmed cell death "apoptosis". Many developing mammalian cells produce signal proteins, or require signal proteins from other cells, to avoid apoptosis. Although much is known about the role of growth factors in the lens, less is known about how such signals are involved in the survival and death of LECs. We have hypothesized that LECs, like other mammalian cells, use signal proteins to regulate growth, survival, and apoptosis, and we have begun a search for such molecules. Furthermore, we have hypothesized that such factors, if found, may also be involved in the death of LECs, the consequent alteration of lens homeostasis and, eventually, certain types of ARC.
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Affiliation(s)
- T Shinohara
- Center for Ophthalmic Research, Brigham and Women's Hospital, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts 02115, USA.
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17
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Abstract
There are several thyroid antigens including human sodium iodide symporter (hNIS), thyrotropin receptor (TSH-R), thyroid peroxidase (TPO), and thyroglobulin (Tg) that have been considered to be thyroid-specific proteins involved in the pathogenesis of autoimmune thyroid diseases. We examined the expression of these thyroid-tolerance related genes in normal human thymus, the lymphoid organ responsible for the induction of central T-cell self. Reverse transcription-polymerase chain reaction (RT-PCR) amplifications were performed with 4 pairs of oligonucleotide primers specific for the hNIS, TSH-R, TPO, and Tg genes, respectively. Gene-specific transcripts were confirmed by Southern hybridization using digoxigenin-labeled internal oligonucleotide probes. To monitor cDNA integrity and quantity, all samples were coamplified with a pair of intron-spanning human beta-actin-specific oligonucleotide primers. Furthermore, using a highly sensitive immunostaining technique and antibodies specific for these 4 antigens, we examined whether NIS-, TSH-R-, TPO-, and Tg-specific immunoreactivity can be detected and localized in normal human thymus. RT-PCR and Southern hybridization revealed expression of each of these 4 thyroid-related genes in normal human thymus. In addition, immunohistochemical analysis of frozen tissue sections derived from normal human thymus showed marked immunoreactivity for NIS, TSH-R, and Tg as well as weaker staining for TPO. Control reactions using isotype matched nonimmune immunoglobulins were consistently negative. Taken together, our results suggest that NIS-, TSH-R-, TPO-, and Tg-RNA are present and actively processed to immunoreactive NIS-, TSH-R-, TPO-, and Tg-like protein in human thymus. These data support the concept that pre-T lymphocytes may be educated to recognize thyroid-related epitopes expressed in thymus, and, thus, to generate self-tolerance against these thyroid-related antigens.
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Affiliation(s)
- C Spitzweg
- Department of Endocrinology, Mayo Clinic, Rochester, Minnesota, USA
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