Article

The Clinical Time-Course of Experimental Autoimmune Uveoretinitis Using Topical Endoscopic Fundal Imaging with Histologic and Cellular Infiltrate Correlation

Academic Unit of Ophthalmology, Department of Clinical Sciences at South Bristol, UK.
Investigative ophthalmology & visual science (Impact Factor: 3.66). 09/2008; 49(12):5458-65. DOI: 10.1167/iovs.08-2348
Source: PubMed

ABSTRACT EAU is an established preclinical model for assessment of immunotherapeutic efficacy toward translation of therapy for posterior uveitis. Reliable screening of clinical features that correlate with underlying retinal changes and damage has not been possible to date. This study was undertaken to describe, validate, and correlate topical endoscopic fundus imaging (TEFI) with histologic features of murine experimental autoimmune uveoretinitis (EAU), with the intent of generating a rapid noninvasive panretinal assessment of ocular inflammation.
EAU was induced in B10.RIII mice by immunization with the peptide RBP-3(161-180). The clinical disease course (days 0-63) was monitored and documented using TEFI. Disease severity and pathology were confirmed at various time points by histologic assessment. The composition of the cell infiltrate was also examined and enumerated by flow cytometry.
TEFI demonstrated the hallmark features of EAU, paralleling many of the clinical features of human uveitis, and closely aligned with underlying histologic changes, the severity of which correlated significantly with the number of infiltrating retinal leukocytes. Leukocytic infiltration occurred before manifestation of clinical disease and clinically fulminant disease, as well as cell infiltrate, resolved faster than histologic scores. During the resolution phase, neither the clinical appearance nor number of infiltrating retinal leukocytes returned to predisease levels.
In EAU, there is a strong correlation between histologic severity and the number of infiltrating leukocytes into the retina. TEFI enhances the monitoring of clinical disease in a rapid and noninvasive fashion. Full assessment of preclinical immunotherapeutic efficacy requires the use of all three parameters: TEFI, histologic assessment, and flow cytometric analysis of retinal infiltrate.

Full-text

Available from: David Copland, Apr 17, 2015
0 Followers
 · 
80 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Experimental autoimmune uveoretinitis is a model for noninfectious posterior segment intraocular inflammation in humans. Although this disease is CD4(+) T cell dependent, in the persistent phase of disease CD8(+) T cells accumulate. We show that these are effector memory CD8(+) T cells that differ from their splenic counterparts with respect to surface expression of CD69, CD103, and Ly6C. These retinal effector memory CD8(+) T cells have limited cytotoxic effector function, are impaired in their ability to proliferate in response to Ag-specific stimulation, and upregulate programmed death 1 receptor. Treatment with fingolimod (FTY720) during the late phase of disease revealed that retinal CD8(+) T cells were tissue resident. Despite signs of exhaustion, these cells were functional, as their depletion resulted in an expansion of retinal CD4(+) T cells and CD11b(+) macrophages. These results demonstrate that, during chronic autoimmune inflammation, exhausted CD8(+) T cells become established in the local tissue. They are phenotypically distinct from peripheral CD8(+) T cells and provide local signals within the tissue by expression of inhibitory receptors such as programmed death 1 that limit persistent inflammation.
    The Journal of Immunology 04/2014; 192(10). DOI:10.4049/jimmunol.1301390 · 5.36 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The eye, as currently viewed, is neither immunologically ignorant nor sequestered from the systemic environment. The eye utilises distinct immunoregulatory mechanisms to preserve tissue and cellular function in the face of immune-mediated insult; clinically, inflammation following such an insult is termed uveitis. The intra-ocular inflammation in uveitis may be clinically obvious as a result of infection (e.g. toxoplasma, herpes), but in the main infection, if any, remains covert. We now recognise that healthy tissues including the retina have regulatory mechanisms imparted by control of myeloid cells through receptors (e.g. CD200R) and soluble inhibitory factors (e.g. alpha-MSH), regulation of the blood retinal barrier, and active immune surveillance. Once homoeostasis has been disrupted and inflammation ensues, the mechanisms to regulate inflammation, including T cell apoptosis, generation of Treg cells, and myeloid cell suppression in situ, are less successful. Why inflammation becomes persistent remains unknown, but extrapolating from animal models, possibilities include differential trafficking of T cells from the retina, residency of CD8(+) T cells, and alterations of myeloid cell phenotype and function. Translating lessons learned from animal models to humans has been helped by system biology approaches and informatics, which suggest that diseased animals and people share similar changes in T cell phenotypes and monocyte function to date. Together the data infer a possible cryptic infectious drive in uveitis that unlocks and drives persistent autoimmune responses, or promotes further innate immune responses. Thus there may be many mechanisms in common with those observed in autoinflammatory disorders.
    Seminars in Immunopathology 05/2014; 36(5). DOI:10.1007/s00281-014-0433-9 · 6.48 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    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 Cx 3 cr1 GFP/+ , 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.ResultsIn the normal C57Bl/6 J Cx 3 cr1 GFP/+ 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.
    Journal of Neuroinflammation 01/2015; 12(1):17. DOI:10.1186/s12974-015-0235-6 · 4.90 Impact Factor