11-cis-retinal and Uveitis

Topics: Animals; Epitopes; Eye Proteins; G-Protein-Coupled Receptor Kinase 1; Guinea Pigs; Mice; Phosphorylation; Protein Kinases; Rabbits; Ranidae; Rats; Retina; Rhodopsin; Uveitis

Retinal pigment epithelium (RPE) builds the outer blood-retinal barrier of the eye. Since one typical feature of the autoimmune disease, equine recurrent uveitis (ERU), is the breakdown of this barrier, we recently performed comparative analysis of healthy and uveitic RPE. We identified for the first time peripherin 2, which is responsible for visual perception and retina development, to be localized in RPE. The purpose of this study was therefore to validate our findings by characterizing the expression patterns of peripherin 2 in RPE and retina. We also investigated whether peripherin 2 expression changes in ERU and if it is expressed by the RPE itself. Via immunohistochemistry, significant downregulation of peripherin 2 in uveitic RPE compared to the control was detectable, but there was no difference in healthy and uveitic retina. A further interesting finding was the clear distinction between peripherin 2 and the phagocytosis marker, rhodopsin, in healthy RPE. In conclusion, changes in the expression pattern of peripherin 2 selectively affect RPE, but not retina, in ERU. Moreover, peripherin 2 is clearly detectable in healthy RPE due to both phagocytosis and the expression by the RPE cells themselves. Our novel findings are very promising for better understanding the molecular mechanisms taking place on RPE in uveitis.

Topics: Animals; Cells, Cultured; Down-Regulation; Horses; Humans; Immunohistochemistry; Peripherins; Phagocytosis; Retinal Pigment Epithelium; Rhodopsin; Uveitis

Equine recurrent uveitis (ERU) is a valuable model for autoimmune diseases, since it develops frequently and occurs spontaneously. We investigated the overall expression level of three major retinal autoantigens in normal retinas and various ERU stages. Analysis of retinal proteomes of both, healthy and diseased retinas revealed an almost unaffected expression of IRBP, S-antigen and cRALBP in ERU cases. Validation of these findings with western blots and immunohistochemistry confirmed constant to increased expression of these autoantigens, although loss of their physiological expression sites within retina is evident. In contrast to stable expression of autoantigens, rhodopsin, the major component of phototransduction in photoreceptors, disappeared from destructed retinas. These results explain persistent uveitic attacks even in severely damaged eyes and draw the attention to further investigations of biological pathways and regulations in autoimmune target tissues.

Topics: Animals; Arrestin; Autoantigens; Carrier Proteins; Eye Proteins; Gene Expression Regulation; Horses; Recurrence; Retina; Retinol-Binding Proteins; Rhodopsin; Uveitis

To investigate the retinal neural damage that occurs during inflammation and the therapeutic effects of the angiotensin II type 1 receptor (AT1R) blocker, telmisartan, using a model of endotoxin-induced uveitis (EIU).. The localization of AT1R and AT2R was shown by immunohistochemistry. EIU was induced by intraperitoneal injection of lipopolysaccharide (LPS). Animals were treated with telmisartan for 2 days and were evaluated 24 hours later. Expression levels of angiotensin II, STAT3 activation induced by inflammatory cytokines, and retinal proteins essential for neural activities (e.g., synaptophysin, rhodopsin) were analyzed by immunoblot. An AT2R antagonist was administered to evaluate the contribution of AT2R signaling in this therapy. Dark-adapted full-field electroretinography (ERG) was also performed.. AT1R and AT2R were expressed in presynaptic terminals in most of the retinal neurons. AT1R was also expressed in Müller glial cells. During inflammation, angiotensin II expression was elevated, STAT3 was activated, and synaptophysin and rhodopsin expression were reduced. The expression of glial fibrillary acidic protein (GFAP), downstream of STAT3 activation, was induced in Müller glial cells. However, treatment with telmisartan successfully avoided all these changes. An AT2R antagonist lowered synaptophysin expression despite the treatment. STAT3 activity was negatively correlated with rhodopsin expression. Furthermore, ERG responses, which were mostly prevented by telmisartan, were disturbed during inflammation.. Retinal protein expression and visual function are both disturbed by inflammation. Treatment with the AT1R blocker telmisartan efficiently prevented these signs of retinal neural damage through the reduction of local angiotensin II expression, the blockade of AT1R, and the relative upregulation of AT2R function.

Topics: Angiotensin II Type 1 Receptor Blockers; Animals; Benzimidazoles; Benzoates; Dark Adaptation; Disease Models, Animal; Electroretinography; Fluorescent Antibody Technique, Indirect; Glial Fibrillary Acidic Protein; Immunoblotting; Lipopolysaccharides; Mice; Mice, Inbred C57BL; Neuroglia; Neuroprotective Agents; Receptor, Angiotensin, Type 1; Receptor, Angiotensin, Type 2; Retina; Rhodopsin; STAT3 Transcription Factor; Synaptophysin; Telmisartan; Uveitis

To develop a conceptual model of using catalytic autoantibodies as diagnostic and monitoring tools in organ-specific autoimmune disorders.. A total of 99 patients (56 males and 43 females aged 21-52 years) with autoimmune myocarditis (AM) and 198 patients (77 males and 121 females aged 8-79 years) with autoimmune uveitis (A U) participated in the study. AM patients were examined for anticardiomyosin and anti-DNA autoantibodies (ACM, ADNAab), AU patients - for autoantibodies to S-antigen, IRBP, redopsin, phosphocine, autoDNA.. AM patients had double level of DNA-binding autoantibodies. In 1/3 of them there was hydrolysing DNA and cytotoxic activity. In AU patients maximal titers were in Behcet's disease, sympathic ophthalmia, generalized uveitis and viral uveitis.. Autoantibodies with different specificity and function including DNA-abzymes can be additional diagnostic and prognostic markers.

Topics: Adolescent; Adult; Aged; Antibodies, Antinuclear; Antibodies, Catalytic; Arrestin; Autoantibodies; Autoimmune Diseases; Biomarkers; Child; DNA; Eye Proteins; Female; Humans; Male; Middle Aged; Myocarditis; Myosins; Prognosis; Retinol-Binding Proteins; Rhodopsin; Uveitis

Rhodopsin, a membrane protein of rod photoreceptor cells, induces an experimental autoimmune uveitis (EAU) in Lewis rats. Synthetic peptides derived from rhodopsin sequences that cover hydrophilic, exposed regions of the protein were tested for their capacity of eliciting in vitro T cell proliferation and their ability for inducing EAU in Lewis rats. Rats were injected with rhodopsin's peptides mixed in complete Freund's adjuvant containing M. tuberculosis H37Ra (5 mg/ml) three days after pretreatment with cyclophosphamide (20 mg/kg). ELISA results indicate that all peptides induce antibody responses; however antibody titers differ among sera tested. Immunization with four peptides--the amino-terminus (2-32), loop I-II (61-75), loop V-VI (230-251), and the carboxyl-terminus (324-348 and 331-342) induced both antibody and T cell responses. In all cases, the proliferative responses of cells derived from peptide-injected rats were stronger against the immunizing peptide than against native protein. Three distinct uveitogenic epitopes were identified on rhodopsin's cytoplasmic surface--within the rhodopsin carboxyl-terminus (324-348), loop I-II (61-75), and loop V-VI (230-250). Histopathologically, at the immunized doses, total destruction of the photoreceptor cell layer was observed as compared to the control group. Loop V-VI caused severe inflammation of the retina while the other pathogenic peptides produced less severe destruction with few inflammatory cells present. Our study indicates that the major immunodominant T cell epitope (331-342) is also involved in EAU induction but is not the primary uveitogenic site.

Topics: Amino Acid Sequence; Animals; Autoimmune Diseases; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Female; Immunodominant Epitopes; Injections; Lymphocyte Activation; Molecular Sequence Data; Peptides; Rats; Rats, Inbred Lew; Rhodopsin; T-Lymphocytes; Uveitis

Rhodopsin, an integral membrane protein of rod photoreceptor cells, induces an experimental autoimmune uveitis (EAU) when injected into Lewis rats. This disease is characterized by a mononuclear and polymorphonuclear cellular infiltrate of the retina resulting in destruction of the photoreceptor cells. In this study the B and T cell specificities of the response to bovine rhodopsin by Lewis rats were determined. Antibodies induced by injection of rhodopsin were directed almost exclusively to the IV-V loop (residues 174-202). Later in the response, antibody to the N-terminus was also detected. At the T cell level, most activity was directed to the C-terminus as measured by in vitro lymphocyte proliferation. Other minor T cell epitopes were found in the II-III (96-114) and IV-V (174-202) loops. Further dissection of the amino acid sequence responsible for the activity isolated to the C-terminus indicated that a 12-amino acid-long sequence (331-342) elicited the strongest proliferative response.

Topics: Amino Acid Sequence; Animals; Autoimmune Diseases; B-Lymphocytes; Cattle; Female; Lymphocyte Activation; Molecular Sequence Data; Rats; Rats, Inbred Lew; Rhodopsin; T-Lymphocytes; Uveitis

The rod visual pigment, rhodopsin, and its illuminated form, opsin, were used to induce experimental autoimmune uveoretinitis in rats. Rhodopsin appears to be more pathogenic than opsin. A dose of 250 micrograms rhodopsin injected in Freund's complete adjuvant and pertussis adjuvant induces nongranulomatous inflammation with higher frequency, which starts earlier and is more severe than that induced by opsin. Two weeks postinjection, the mean score of rhodopsin-injected animals is more than twice as high as that of opsin-injected animals. The high pathogenicity of rhodopsin appears to be related to the biochemical integrity of the protein and depends on its state of illumination. The levels of the immune responses (both cellular and humoral) measured at day 10 postinjection do not account for the pronounced difference in pathogenicity between rhodopsin and opsin. The developmental patterns of severe uveoretinitis induced by rhodopsin or opsin were histologically evaluated and appear to be similar. In both cases we observed dense mononuclear and polymorphonuclear cell infiltrations in the retina and anterior uvea. Only in the severe stages does the choroid become involved. However, rhodopsin causes more pronounced involvement of the ciliary body, pars plana, and anterior chamber. The inflammation finally results in total elimination of the photoreceptor cell layer.

Topics: Animals; Autoimmune Diseases; Cattle; Eye Proteins; Female; Photoreceptor Cells; Rats; Rats, Inbred Lew; Retinal Pigments; Retinitis; Rhodopsin; Rod Opsins; Uveitis

We have studied the clinicopathological features of experimental autoimmune uveoretinitis (EAU) induced in Lewis rats by injection of different doses of rhodopsin and its illuminated form opsin. Rhodopsin consistently appears to be more pathogenic than opsin. Injected in Freund's complete adjuvant and pertussis adjuvant 50 micrograms of rhodopsin induces a frequency of severe EAU similar to 250 micrograms of opsin. Intensity, frequency and location of ocular inflammation are markedly dose dependent. At high dose (100-250 micrograms), rhodopsin induces severe bilateral uveoretinitis in all animals, which starts with acute inflammation of the anterior eye segment at day 10-12 followed by chorioretinitis (predominantly retinitis) which results in complete elimination of the photoreceptor cells. At low dose (20 micrograms), rhodopsin induces mild transient inflammation in 60% of the animals, mainly consisting of mild posterior retinitis which starts at day 20 and leads to a typical multiple focal destruction of the photoreceptor cells. Intermediate doses cause an intermediate type of disease. Omission of pertussis adjuvant lowers the frequency of severe disease at low doses of rhodopsin, delays its onset and changes its features. The last characteristic has been observed in particular at intermediate doses (50-100 micrograms). In these cases, EAU usually starts by cell infiltration of the vitreous, while the anterior segment is only mildly affected. Without pertussis adjuvant the pathogenicity of opsin is low. Even in both adjuvants severe EAU can only be evoked by a high dose of opsin. Although there exists a marked difference in uveitogenicity between rhodopsin and opsin, the immunogenicity is similar and seems not to be correlated with their pathogenicity.

Topics: Animals; Autoimmune Diseases; Dose-Response Relationship, Immunologic; Eye Proteins; Female; Rats; Rats, Inbred Lew; Retinal Pigments; Retinitis; Rhodopsin; Rod Opsins; Time Factors; Uveitis

In Vertebrate retinal rod outer segments, a soluble "48 K" protein binds to disk membranes upon illumination in presence of ATP or GTP (H. Kühn, Biochemistry, 17, 1978, p. 4389). Its binding to photoexcited rhodopsin implies a probable role of the "48 K" protein in the ATP dependent regulation of the photoinduced enzymatic cascade which controls the hydrolysis of cGMP. The "retinal S antigen" is also a soluble protein located in photoreceptor cells which is known to be an organ-specific auto-antigen inducing experimental autoimmune uveoretinitis. Using extracts of purified cattle and frog rod outer segments, purified bovine S antigen, and monoclonal antibodies against S antigen, we found that both proteins exhibit identical characteristics with respect to: their migration in SD S-gel electrophoresis; their binding to rod disc membranes upon illumination in presence of ATP or GTP; their immunological reactivity with monoclonal antibodies.

Topics: Animals; Antigens; Anura; Arrestin; Autoimmune Diseases; Cattle; Eye Proteins; Photic Stimulation; Photoreceptor Cells; Protein Binding; Retinal Pigments; Retinitis; Rhodopsin; Uveitis

Sera from guinea pigs and rabbits with and without experimental autoimmune uveitis (EAU) induced by immunization with retina, choroid, optic nerve, retinal rod outer segments (ROS) and purified bovine S-antigen were tested for the ability to immunoprecipitate 125I-labeled, detergent-solubilized bovine retinal proteins. The results demonstrate that three major protein antigens with m.w. of 50,000 (p50), 35,000 (p35) and 27,000 (p27) and several minor activities between 30,000 and 60,000 m.w. are recognized by antibodies from these animals. The p50 component was immunoprecipitated by sera from animals immunized with whole retina homogenate, the high speed supernatant of whole retina homogenate, ROS, and S-antigen, and has been identified as S-antigen in competition experiments. The p35 band appeared when sera were used that were raised against antigen preparations containing membrane-bound retinal protein, i.e., whole retina homogenate, ROS, and washed ROS, and thus appears to be an ROS membrane protein. The p27 band was found when sera raised against ROS, washed ROS, optic nerve and whole retina homogenate were used, suggesting it is a membrane-bound antigen common to ROS and optic nerve. Serum from animals immunized with homologous choroid did not immunoprecipitate a detectable product. S-antigen and p35 were also precipitated by some uveitis patient sera. Because S-antigen is also an ROS protein as is rhodopsin, a putative uveitogenic retinal antigen, ROS appear to be an unusually rich source of autoantigenic proteins. S-antigen was also shown to be synthesized in the retina, and the primary translation product was indistinguishable from purified S-antigen by SDS-PAGE, thus eliminating the possibility that it is derived from or is cross-reactive with the 67,000 m.w. rhodopsin kinase.

Topics: Animals; Antigen-Antibody Reactions; Antigens; Arrestin; Autoimmune Diseases; Binding Sites, Antibody; Electrophoresis, Polyacrylamide Gel; Eye Proteins; Guinea Pigs; Heterotrimeric GTP-Binding Proteins; Humans; Rabbits; Retina; Rhodopsin; Transducin; Uveitis

Topics: Cyclosporins; Eye Proteins; G-Protein-Coupled Receptor Kinase 1; Humans; Protein Kinases; Rhodopsin; Uveitis

Topics: Animals; Antigens; Autoimmune Diseases; Guinea Pigs; Lymphocyte Activation; Lymphokines; Retinal Pigments; Rhodopsin; Uveitis

The retinal S-antigen (S-Ag) has been shown to induce uveitis effectively in subhuman primates, and lymphocytes from patients with certain uveitic conditions show cell-mediated responses to this antigen. Rhodopsin kinase (RK), an enzyme probably unique to the mammalian eye, is reported here to resemble the retinal S-Ag in its capacity to induce uveitis in experimental animals. A histological comparison of rat eyes taken 2 and 3 weeks after immunisation with either RK or S-Ag reveals essentially identical pathological alterations. Ocular inflammation is seen in both the anterior and posterior portion of the globe. Areas of focal degeneration of the photo-receptor layer, from which both the S-Ag and RK are extracted, could be seen in both RK and S-Ag immunised animals. Cells from draining lymph nodes of both groups responded by increased thymidine incorporation when cultured in the presence of either RK or S-Ag. In addition antibodies directed against the S-Ag were detected in both groups. These findings, in addition to the biochemical similarities of these preparations, reported elsewhere, would strongly suggest that RK and S-Ag are one and the same. The identification of potentially uveitogenic ocular antigens could help to reclassify uveitic entities that at present have clinically similar courses.

Topics: Animals; Antigens; Arrestin; Cross Reactions; Eye; Eye Proteins; Female; G-Protein-Coupled Receptor Kinase 1; Immunization; Lymphocytes; Mitosis; Protein Kinases; Rats; Rats, Inbred Lew; Retina; Rhodopsin; Uveitis

24 different antigenic preparations from bovine or guinea pig retina and 3 from bovine uvea were tested for their ability to induce uveo-retinitis in guinea pigs. Each animal received one injection into the hind foot pads of 0.1 ml og the tissue preparation mixed with an equal volume of complete Freund's adjuvant. The intensity of the disease was assessed by clinical and histological criteria. Homogenates and extracts from whole guinea pig retina are more active than the same preparations from bovine retina. Autologous retinal extract is slightly more active than homologous in low doses. In bovine retina, the autoantigen(s) is localized in the photoreceptor structures and the pigment epithelium. Bovine uveal preparations seem to be inactive when the epithelium has been removed. Purified outer segments are very active, as well as soluble extracts of outer segments. Highly purified bovine rhodopsin has no immunopathogenic activity. A soluble autoantigen (autoantigen S) has been isolated by preparative isoelectrofocusing from retinas of several species. Autoantigen S from guinea pig induces the disease in guinea pigs at a dose of a few micrograms.

Topics: Animals; Antigens; Autoantigens; Autoimmune Diseases; Cattle; Disease Models, Animal; Eye Proteins; Freund's Adjuvant; Guinea Pigs; Isoelectric Focusing; Phosphoric Diester Hydrolases; Photoreceptor Cells; Pigment Epithelium of Eye; Retina; Retinitis; Rhodopsin; Solubility; Species Specificity; Uvea; Uveitis

Systemic immunization with purified homologous rhodopsin from retinal outer segments induced blindness in primates (Macaca mulatta). Inflammation and characteristic retinal changes were the earliest clinical signs of the disease. Perivasculitis, subretinal exudations and bullous detachments of the retina were progressive and unrelenting pathological processes leading to rapid and irreversible visual deterioration. Electroretinographic responses (ERG) at this stage of the disorder became abolished. Antibodies and delayed hypersensitivity to rhodopsin were demonstrated only in the experimental diseased animals. Homologous visual purple appears to be organ and immunopathologically specific. Histological confirmation of these findings showed a pathological spectrum of destructive alterations confirmed specifically to the outer segments of the entire retina. The pathologic reaction was supported by a distinct and pronounced granulomatous inflammatory response.

Topics: Animals; Blindness; Electroretinography; Female; Haplorhini; Immunization; Macaca mulatta; Male; Pigment Epithelium of Eye; Retinal Diseases; Retinal Pigments; Rhodopsin; Uveitis

Chorio-retinal lesions induced in guinea pigs after one inoculation of bovine rod outer segments (ROS) with complete Freund's adjuvant are described with light and electron microscopy. The auto-antigenic activity of different preparations from bovine retina and uvea is compared for their efficacy to induce the disease. ROS are much more active than total retina homogenate. Pigment epithelium is active, and the effect of choroid is impaired after removal of pigment epithelium from the surface of the choroid. Purification of ROS by several sucrose flotations does not reduce their activity. Almost complete extraction of soluble antigens from pure ROS by buffer washings, controlled with isoelectrofocusing and immunodiffusion, decreases only slightly their pathogenicity. Rhodopsin, extracted using cetyltrimethylammonium bromide from pure washed ROS, induced prominent chorio-retinal damage at the dose of 500 mug. It seems likely that besides soluble retinal auto-antigens, outer segments contain a pathogenic insoluble antigen which seems to be linked to rhodopsin or to be rhodopsin itself.

Topics: Animals; Autoantigens; Autoimmune Diseases; Cattle; Choroiditis; Epitopes; Guinea Pigs; Photoreceptor Cells; Retina; Retinitis; Rhodopsin; Solubility; Uveitis

Topics: Animals; Antigens; Guinea Pigs; Photoreceptor Cells; Rhodopsin; Uveitis