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Reina-Torres E, De Ieso ML, Pasquale LR, Madekurozwa M, van Batenburg-Sherwood J, Overby DR, Stamer WD. The vital role for nitric oxide in intraocular pressure homeostasis. Prog Retin Eye Res 2020; 83:100922. [PMID: 33253900 DOI: 10.1016/j.preteyeres.2020.100922] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 11/13/2020] [Accepted: 11/23/2020] [Indexed: 02/07/2023]
Abstract
Catalyzed by endothelial nitric oxide (NO) synthase (eNOS) activity, NO is a gaseous signaling molecule maintaining endothelial and cardiovascular homeostasis. Principally, NO regulates the contractility of vascular smooth muscle cells and permeability of endothelial cells in response to either biochemical or biomechanical cues. In the conventional outflow pathway of the eye, the smooth muscle-like trabecular meshwork (TM) cells and Schlemm's canal (SC) endothelium control aqueous humor outflow resistance, and therefore intraocular pressure (IOP). The mechanisms by which outflow resistance is regulated are complicated, but NO appears to be a key player as enhancement or inhibition of NO signaling dramatically affects outflow function; and polymorphisms in NOS3, the gene that encodes eNOS modifies the relation between various environmental exposures and glaucoma. Based upon a comprehensive review of past foundational studies, we present a model whereby NO controls a feedback signaling loop in the conventional outflow pathway that is sensitive to changes in IOP and its oscillations. Thus, upon IOP elevation, the outflow pathway tissues distend, and the SC lumen narrows resulting in increased SC endothelial shear stress and stretch. In response, SC cells upregulate the production of NO, relaxing neighboring TM cells and increasing permeability of SC's inner wall. These IOP-dependent changes in the outflow pathway tissues reduce the resistance to aqueous humor drainage and lower IOP, which, in turn, diminishes the biomechanical signaling on SC. Similar to cardiovascular pathogenesis, dysregulation of the eNOS/NO system leads to dysfunctional outflow regulation and ocular hypertension, eventually resulting in primary open-angle glaucoma.
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Affiliation(s)
| | | | - Louis R Pasquale
- Eye and Vision Research Institute of New York Eye and Ear Infirmary at Mount Sinai, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | | | | | - Darryl R Overby
- Department of Bioengineering, Imperial College London, London, UK.
| | - W Daniel Stamer
- Department of Ophthalmology, Duke University, Durham, NC, USA.
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Chen X, Kezic JM, Forrester JV, Goldberg GL, Wicks IP, Bernard CC, McMenamin PG. In vivo multi-modal imaging of experimental autoimmune uveoretinitis in transgenic reporter mice reveals the dynamic nature of inflammatory changes during disease progression. J Neuroinflammation 2015; 12:17. [PMID: 25623142 PMCID: PMC4336748 DOI: 10.1186/s12974-015-0235-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 01/05/2015] [Indexed: 12/22/2022] Open
Abstract
Background Experimental autoimmune uveoretinitis (EAU) is a widely used experimental animal model of human endogenous posterior uveoretinitis. In the present study, we performed in vivo imaging of the retina in transgenic reporter mice to investigate dynamic changes in exogenous inflammatory cells and endogenous immune cells during the disease process. Methods Transgenic mice (C57Bl/6 J Cx3cr1GFP/+, C57Bl/6 N CD11c-eYFP, and C57Bl/6 J LysM-eGFP) were used to visualize the dynamic changes of myeloid-derived cells, putative dendritic cells and neutrophils during EAU. Transgenic mice were monitored with multi-modal fundus imaging camera over five time points following disease induction with the retinal auto-antigen, interphotoreceptor retinoid binding protein (IRBP1–20). Disease severity was quantified with both clinical and histopathological grading. Results In the normal C57Bl/6 J Cx3cr1GFP/+ mouse Cx3cr1-expressing microglia were evenly distributed in the retina. In C57Bl/6 N CD11c-eYFP mice clusters of CD11c-expressing cells were noted in the retina and in C57Bl/6 J LysM-eGFP mice very low numbers of LysM-expressing neutrophils were observed in the fundus. Following immunization with IRBP1–20, fundus examination revealed accumulations of Cx3cr1-GFP+ myeloid cells, CD11c-eYFP+ cells and LysM-eGFP+ myelomonocytic cells around the optic nerve head and along retinal vessels as early as day 14 post-immunization. CD11c-eYFP+ cells appear to resolve marginally earlier (day 21 post-immunization) than Cx3cr1-GFP+ and LysM-eGFP+ cells. The clinical grading of EAU in transgenic mice correlated closely with histopathological grading. Conclusions These results illustrate that in vivo fundus imaging of transgenic reporter mice allows direct visualization of various exogenously and endogenously derived leukocyte types during EAU progression. This approach acts as a valuable adjunct to other methods of studying the clinical course of EAU. Electronic supplementary material The online version of this article (doi:10.1186/s12974-015-0235-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Xiangting Chen
- Department of Anatomy and Developmental Biology, School of Biomedical Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, Australia.
| | - Jelena M Kezic
- Department of Anatomy and Developmental Biology, School of Biomedical Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, Australia.
| | - John V Forrester
- Section of Immunology and Infection, Division of Applied Medicine, School of Medicine and Dentistry, Institute of Medical Science, Foresterhill, University of Aberdeen, Scotland, UK. .,Ocular Immunology Program, Centre for Ophthalmology and Visual Science, The University of Western Australia, Crawley, Western Australia, Australia. .,Centre for Experimental Immunology, Lions Eye Institute, Nedlands, Crawley, Western Australia, Australia.
| | - Gabrielle L Goldberg
- Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.
| | - Ian P Wicks
- Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.
| | - Claude C Bernard
- Australian Regenerative Medicine Institute, Monash University, Clayton, Victoria, Australia.
| | - Paul G McMenamin
- Department of Anatomy and Developmental Biology, School of Biomedical Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, Australia.
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Ho LC, Conner IP, Do CW, Kim SG, Wu EX, Wollstein G, Schuman JS, Chan KC. In vivo assessment of aqueous humor dynamics upon chronic ocular hypertension and hypotensive drug treatment using gadolinium-enhanced MRI. Invest Ophthalmol Vis Sci 2014; 55:3747-57. [PMID: 24764067 DOI: 10.1167/iovs.14-14263] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
PURPOSE Although glaucoma treatments alter aqueous humor (AH) dynamics to lower intraocular pressure, the regulatory mechanisms of AH circulation and their contributions to the pathogenesis of ocular hypertension and glaucoma remain unclear. We hypothesized that gadolinium-enhanced magnetic resonance imaging (Gd-MRI) can visualize and assess AH dynamics upon sustained intraocular pressure elevation and pharmacologic interventions. METHODS Gadolinium contrast agent was systemically administered to adult rats to mimic soluble AH components entering the anterior chamber (AC) via blood-aqueous barrier. Dynamic Gd-MRI was applied to examine the signal enhancement in AC and vitreous body upon microbead-induced ocular hypertension and unilateral topical applications of latanoprost, timolol maleate, and brimonidine tartrate to healthy eyes. RESULTS Gadolinium signal time courses in microbead-induced hypertensive eyes possessed faster initial gadolinium uptake and higher peak signals in AC than control eyes, reflective of reduced gadolinium clearance upon microbead occlusion. Opposite trends were observed in latanoprost- and timolol-treated eyes, indicative of their respective drug actions on increased uveoscleral outflow and reduced AH production. The slowest initial gadolinium uptake but strongest peak signals were found in AC of both brimonidine-treated and untreated fellow eyes. These findings drew attention to the systemic effects of topical hypotensive drug treatment. Gadolinium leaked into the vitreous of microbead-induced hypertensive eyes and brimonidine-treated and untreated fellow eyes, suggestive of a compromise of aqueous-vitreous or blood-ocular barrier integrity. CONCLUSIONS Gadolinium-enhanced MRI allows spatiotemporal and quantitative evaluation of altered AH dynamics and ocular tissue permeability for better understanding the physiological mechanisms of ocular hypertension and the efficacy of antiglaucoma drug treatments.
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Affiliation(s)
- Leon C Ho
- NeuroImaging Laboratory, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Ian P Conner
- UPMC Eye Center, Eye and Ear Institute, Ophthalmology and Visual Science Research Center, Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania, United States Louis J. Fox Center for Vision Restoration, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Chi-Wai Do
- School of Optometry, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, China
| | - Seong-Gi Kim
- NeuroImaging Laboratory, University of Pittsburgh, Pittsburgh, Pennsylvania, United States UPMC Eye Center, Eye and Ear Institute, Ophthalmology and Visual Science Research Center, Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania, United States McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States Center for Neuroscience Imaging Research, Institute for Basic Science, Department of Biological Science, Sungkyunkwan University, Suwon, Korea Center for the Neural Basis of Cognition, University of Pittsburgh and Carnegie Mellon University, Pittsburgh, Pennsylvania, United States
| | - Ed X Wu
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - Gadi Wollstein
- UPMC Eye Center, Eye and Ear Institute, Ophthalmology and Visual Science Research Center, Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States Louis J. Fox Center for Vision Restoration, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Joel S Schuman
- UPMC Eye Center, Eye and Ear Institute, Ophthalmology and Visual Science Research Center, Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania, United States McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States Louis J. Fox Center for Vision Restoration, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Kevin C Chan
- NeuroImaging Laboratory, University of Pittsburgh, Pittsburgh, Pennsylvania, United States UPMC Eye Center, Eye and Ear Institute, Ophthalmology and Visual Science Research Center, Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania, United States McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States Louis J. Fox Center for Vision Restoration, University of Pittsburgh, Pittsburgh, Pennsylvania, United States Center for the Neural Basis of Cognition, University of Pittsburgh and Carnegie Mellon University, Pittsburgh, Pennsylvania, United States
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Swaminathan SS, Oh DJ, Kang MH, Ren R, Jin R, Gong H, Rhee DJ. Secreted protein acidic and rich in cysteine (SPARC)-null mice exhibit more uniform outflow. Invest Ophthalmol Vis Sci 2013; 54:2035-47. [PMID: 23422826 DOI: 10.1167/iovs.12-10950] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
PURPOSE Secreted protein acidic and rich in cysteine (SPARC) is a matricellular protein known to regulate extracellular matrix (ECM) in many tissues and is highly expressed in trabecular meshwork (TM). SPARC-null mice have a 15% to 20% decrease in intraocular pressure (IOP) compared to wild-type (WT) mice. We hypothesized that mouse aqueous outflow is segmental, and that transgenic deletion of SPARC causes a more uniform pattern that correlates with IOP and TM morphology. METHODS Eyes of C57BL6-SV129 WT and SPARC-null mice were injected with fluorescent microbeads, which were also passively exposed to freshly enucleated eyes. Confocal and electron microscopy were performed. Percentage effective filtration length (PEFL) was calculated as PEFL = FL/TL × 100%, where TL = total length and FL = filtration length. IOP was measured by rebound tonometry. RESULTS Passive microbead affinity for WT and SPARC-null ECM did not differ. Segmental flow was observed in the mouse eye. SPARC-null mice had a 23% decrease in IOP. PEFL increased in SPARC-null (70.61 ± 11.36%) versus WT mice (54.68 ± 9.95%, P < 0.005; n = 11 pairs), and PEFL and IOP were negatively correlated (R(2) = 0.72, n = 10 pairs). Morphologically, TM of high-tracer regions had increased separation between beams compared to low-tracer regions. Collagen fibril diameter decreased in SPARC-null (28.272 nm) versus WT tissue (34.961 nm, P < 0.0005; n = 3 pairs). CONCLUSIONS Aqueous outflow in mice is segmental. SPARC-null mice demonstrated a more uniform outflow pattern and decreased collagen fibril diameter. Areas of high flow had less compact juxtacanalicular connective tissue ECM, and IOP was inversely correlated with PEFL. Our data show a correlation between morphology, aqueous outflow, and IOP, indicating a modulatory role of SPARC in IOP regulation.
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Affiliation(s)
- Swarup S Swaminathan
- Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, USA
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Forrester JV, Xu H, Kuffová L, Dick AD, McMenamin PG. Dendritic cell physiology and function in the eye. Immunol Rev 2010; 234:282-304. [PMID: 20193026 DOI: 10.1111/j.0105-2896.2009.00873.x] [Citation(s) in RCA: 137] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The eye and the brain are immunologically privileged sites, a property previously attributed to the lack of a lymphatic circulation. However, recent tracking studies confirm that these organs have good communication through classical site-specific lymph nodes, as well as direct connection through the blood circulation with the spleen. In addition, like all tissues, they contain resident myeloid cell populations that play important roles in tissue homeostasis and the response to foreign antigens. Most of the macrophage and dendritic cell (DC) populations in the eye are restricted to the supporting connective tissues, including the cornea, while the neural tissue (the retina) contains almost no DCs, occasional macrophages (perivascularly distributed), and a specialized myeloid cell type, the microglial cell. Resident microglial cells are normally programmed for immunological tolerance. The privileged status of the eye, however, is relative, as it is susceptible to immune-mediated inflammatory disease, both infectious and autoimmune. Intraocular inflammation (uveitis and uveoretinitis) and corneal graft rejection constitute two of the more common inflammatory conditions affecting the eye leading to considerable morbidity (blindness). As corneal graft rejection occurs almost exclusively by indirect allorecognition, host DCs play a major role in this process and are likely to be modified in their behavior by the ocular microenvironment. Ocular surface disease, including allergy and atopy, also comprise a significant group of immune-mediated eye disorders in which DCs participate, while infectious disease such as herpes simplex keratitis is thought to be initiated via corneal DCs. Intriguingly, some more common conditions previously thought to be degenerative (e.g. age-related macular degeneration) may have an autoimmune component in which ocular DCs and macrophages are critically involved. Recently, the possibility of harnessing the tolerizing potential of DCs has been applied to experimental models of autoimmune uveoretinitis with good effect. This approach has considerable potential for use in translational clinical therapy to prevent sight-threatening disease caused by ocular inflammation.
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Affiliation(s)
- John V Forrester
- Section of Immunology and Infection, Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK.
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Prakasam A, Muthuswamy A, Ablonczy Z, Greig NH, Fauq A, Rao KJ, Pappolla MA, Sambamurti K. Differential accumulation of secreted AbetaPP metabolites in ocular fluids. J Alzheimers Dis 2010; 20:1243-1253. [PMID: 20413851 PMCID: PMC3397687 DOI: 10.3233/jad-2010-100210] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Amyloid-beta (Abeta) accumulates in several types of retinal degeneration and in Alzheimer's disease (AD), but its source has been unclear. We detected the neuronal 695 amino acid form of amyloid-beta protein precursor (AbetaPP) in the normal retina and AbetaPP751 in the retinal pigment epithelium (RPE) and anterior eye tissues. Similar to the brain, alpha- and beta-secretases cleaved AbetaPP to soluble derivatives (sAbetaPP) alpha or beta and membrane-bound C-terminal fragments alpha or beta in the retina and RPE. Levels of sAbetaPP were particularly high in the vitreous and low in aqueous humor revealing a molecular barrier for AbetaPP. In contrast, Abeta40 and Abeta42 levels were only 50% lower in the aqueous than the vitreous humor, indicating relatively barrier-free movement of Abeta. These studies demonstrated a relatively high yield of AbetaPP and Abeta in the ocular fluids, which may serve as a trackable marker for AD. In addition, failure of free clearance from the eye may trigger retina degeneration in a manner similar to Abeta-related neurodegeneration in AD.
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Affiliation(s)
- Annamalai Prakasam
- Department of Neurosciences, Medical University of South Carolina, 173 Ashley Avenue, BSB 403, Charleston, SC 29425
| | - Anusuya Muthuswamy
- Department of Neurosciences, Medical University of South Carolina, 173 Ashley Avenue, BSB 403, Charleston, SC 29425
| | - Zsolt Ablonczy
- Department of Ophthalmology, Medical University of South Carolina, 167 Ashley Avenue, Storm Eye Institute, Rm 518, Charleston, SC 29425
| | - Nigel H. Greig
- Laboratory of Neurosciences, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224
| | - Abdul Fauq
- Department of Neurosciences, Mayo Clinic, 6400 San Pablo Road, Jacksonville, FL 32224
| | - Kosagisharaf Jagannatha Rao
- Department of Neurosciences, Medical University of South Carolina, 173 Ashley Avenue, BSB 403, Charleston, SC 29425
| | - Miguel A. Pappolla
- Department of Neurosciences, Medical University of South Carolina, 173 Ashley Avenue, BSB 403, Charleston, SC 29425
| | - Kumar Sambamurti
- Department of Neurosciences, Medical University of South Carolina, 173 Ashley Avenue, BSB 403, Charleston, SC 29425
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GD-DTPA enhanced MRI of ocular transport in a rat model of chronic glaucoma. Exp Eye Res 2008; 87:334-41. [DOI: 10.1016/j.exer.2008.06.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2008] [Revised: 06/10/2008] [Accepted: 06/23/2008] [Indexed: 11/21/2022]
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McMenamin PG, Kezic J, Camelo S. Characterisation of rat corneal cells that take up soluble antigen: An in vivo and in vitro study. Exp Eye Res 2006; 83:1268-80. [PMID: 16934806 DOI: 10.1016/j.exer.2006.07.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2006] [Revised: 05/16/2006] [Accepted: 07/07/2006] [Indexed: 11/29/2022]
Abstract
The aim of the present study was to determine the capacity of resident corneal and limbal dendritic cells (DC) and macrophages to capture antigen (Ag) in vivo and compare this to their capacity in vitro to take up Ag during organ culture conditions. To investigate Ag uptake in vivo 3 microl (30 microg) of fluorescently labelled Dextran, bovine serum albumin (BSA) or ovalbumin (OVA) were either placed on the intact ocular surface or injected into the anterior chamber (AC) or subconjunctival space of the Lewis rat eye. The presence of Ag+ cells in the cornea was assessed using intravital fluorescence video microscopy. Animals were sacrificed 24h after Ag injections or topical application and the distribution and phenotype of Ag+ cells were analysed ex vivo by fluorescence and confocal microscopic analysis of immunostained and unstained corneal tissue wholemounts or frozen sections. Corneal buttons and corneoscleral rims from naive Lewis rats were placed in organ culture conditions in the presence of LPS with or without FITC-Dextran for 48 h and 72 h. The explants were examined by epi-fluorescence microscopy and the phenotype of Ag+ cells in the supernatant from the organ cultures was analyzed by flow cytometry using a range of macrophage and DC markers. In vivo observations and microscopic examination of corneas 24h following Ag topical application failed to reveal evidence of Ag retention by ocular cells. Those in which Ag had been placed in the AC or subconjunctival space revealed Ag+ cells within the corneal stroma. The distribution of Ag+ cells displayed a centripetal gradient, the most marked uptake of Ag being by cells in the circumferential limbal zone. Immunophenotypic studies revealed that Ag uptake was predominantly performed by cells that were CD68+, CD172+ but rarely MHC class II+, a profile characteristic of macrophages. Occasional Ag+ keratocytes were noted. In vitro studies of corneal buttons placed in culture conditions revealed that cells from the limbal zone, but not the central cornea, were able to take up Ag from the supernatant. Significant numbers of the cells that had migrated from the corneal buttons and captured fluorescent labelled Ag in the presence of LPS were revealed by flow cytometry to consist of CD163+ and CD11b+ macrophages, but none expressed the DC markers CD11c or OX62 and they were also generally MHC class II(-). In conclusion the present study revealed that macrophages and keratocytes in the corneal stroma and limbal episcleral tissue have the capacity to internalise fluorescent mock Ag injected into the AC or subconjunctival space or in culture conditions. The failure to demonstrate significant Ag trapping ability by corneal or limbal stromal or epithelial DC may either be due to the rarity of such cells or their lack of Ag trapping ability.
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Affiliation(s)
- Paul G McMenamin
- School of Anatomy and Human Biology, The University of Western Australia, 35 Stirling Highway, Crawley (Perth), Western Australia 6009, Australia.
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McKenna KC, Anderson KM, Kapp JA. CD8+ T-cell tolerance induced by delivery of antigen to the anterior chamber is not the result of de facto intravenous or mucosal administration of antigen. Ocul Immunol Inflamm 2005; 13:149-57. [PMID: 16019674 DOI: 10.1080/09273940590933520] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
PURPOSE We tested whether antigen administration via the anterior chamber (a.c.) was equivalent to intravenous (i.v.) or mucosal administration antigen. METHODS Ovalbumin (OVA)-specific CD8(+) T cells (OT-I) were enumerated in lymphoid tissues of C57Bl/6 (B6) mice via adoptive transfer after the same amount of antigen was administered via a.c., i.v., or mucosal routes. Lytic activity was measured in B6 and gammadeltaT cell-deficient B6 mice given OVA via a.c., i.v, or mucosal routes after injection with OVA in adjuvant. RESULTS OVA a.c. induced a pattern of T-cell proliferation distinct from i.v. or mucosal administration. A.c. and i.v., but not mucosal, OVA induced cytolytic T lymphocyte (CTL) tolerance. The inhibition of CTL responses was significantly greater in mice given OVA a.c. rather than i.v. gammadeltaT cells contributed to a.c.-, but not i.v.-, induced CTL tolerance. CONCLUSIONS A.c. administration of antigen not de-facto i.v. or mucosal administration of antigen.
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Affiliation(s)
- Kyle C McKenna
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA, USA
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Camelo S, Kezic J, McMenamin PG. Anterior chamber-associated immune deviation: a review of the anatomical evidence for the afferent arm of this unusual experimental model of ocular immune responses. Clin Exp Ophthalmol 2005; 33:426-32. [PMID: 16033366 DOI: 10.1111/j.1442-9071.2005.01044.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Anterior chamber-associated immune deviation (ACAID) is an animal model of tolerance induced experimentally by the injection of antigen into the anterior chamber of the eye. The unusual deviant immune response has both afferent and efferent arms and it is the former that is the focus of this review. The paradigm states that antigen injected into the anterior chamber of the eye is internalized by intraocular antigen presenting cells (APCs) which then migrate largely to the spleen to induce the differentiation of regulatory T cell populations which in turn form the basis of the modified efferent arm to the deviant immune response. However, the migration routes of ocular APCs or free antigen to the secondary lymphoid organs remain unclear. In this review we will discuss the evidence for different possible afferent routes by which antigen (either free or cell-associated) leaves the eye and the pattern of distribution to secondary lymphoid organs.
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Affiliation(s)
- Serge Camelo
- School of Anatomy and Human Biology, The University of Western Australia, Perth, Western Australia, Australia
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Howard OMZ, Dong HF, Su SB, Caspi RR, Chen X, Plotz P, Oppenheim JJ. Autoantigens signal through chemokine receptors: uveitis antigens induce CXCR3- and CXCR5-expressing lymphocytes and immature dendritic cells to migrate. Blood 2005; 105:4207-14. [PMID: 15713799 PMCID: PMC1895027 DOI: 10.1182/blood-2004-07-2697] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
We tested the hypothesis that interaction between autoantigens and chemoattractant receptors may be an important step in the development of autoimmunity. The retinal autoantigens S-antigen (S-Ag) and interphotoreceptor retinoid binding protein (IRBP) can induce autoimmune uveitis in rodent models. We evaluated the chemotactic activity of S-Ag and IRBP and found that both induced migration of human and mouse immature dendritic cells (iDCs) and lymphocytes, but not neutrophils, monocytes, or mature DCs. Cross-desensitization studies and single-receptor transfected cells revealed that subfamily of alpha chemokine receptors CXCR5 and CXCR3 mediated the chemotactic effect of IRBP, while only CXCR3 was required for the chemotactic response to S-Ag. Examination of the relationships between chemoattraction and the ability to elicit pathology at the protein or peptide levels in the mouse uveitis model revealed dissociation of the capacity to induce uveitis, lymphocyte proliferation, and chemoattraction. These studies suggest that IRBP and S-Ag can initiate innate and, in sensitive individuals, adaptive immune response by attracting iDCs and T and B cells expressing CXCR3 and CXCR5.
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Affiliation(s)
- O M Zack Howard
- National Cancer Institute-Center for Cancer Research, Laboratory of Molecular Immunoregulation, Basic Research Program, Science Applications International Corporation, Frederick, MD, USA.
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