Reiko Kinouchi

Tyrosinase epitope recognized by an HLA-DR-restricted T-cell line from a Vogt-Koyanagi-Harada disease patient

Abstract Human T-cell-mediated autoimmune diseases are often genetically linked to particular alleles of HLA class II genes. Vogt-Koyanagi-Harada’s (VKH) disease, which is regarded as an autoimmune disorder in multiple organs containing melanocytes, has been found to be associated with HLA-DR4 (DRB1*0405) and HLA-DR53 (DRB4*0101). Tyrosinase is a melanoma antigen (Ag) expressed by normal melanocytes as well as melanoma cells against which responses by autologous T cells have been detected. We established a T-cell line from the peripheral blood of a patient with VKH disease which responded to synthetic peptides corresponding to tyrosinase. The T-cell line was generated which recognized the tyrosinase p188 – 208 peptide when presented by the HLA-DR4 (DRB1*0405) molecule on the surface of HLA class II-expressing L-cell transfectants. The minimal antigenic peptide which induced T-cell responses was an 11-amino-acid sequence and located at tyrosinase p193 – 203 (E-I-W-R-D-I-D-F-A-H-E). This peptide contained the DRB1*0405-binding peptide motif (hydrophobic residues (Y, F, W) at position 1 as an anchor residue, and negatively charged residues (D, E) at position 9), which corresponded to the W at p195 and the D at p203. These observations demonstrate that tyrosinase peptides are immunogenic, and may be a candidate for an autoantigen in VKH disease, suggesting that probing the T-cell responses against synthetic peptides is a productive approach for identifying the autoantigenic peptides associated with autoimmune diseases including VKH disease.

Peptide motifs of HLA-DR4/DR53 (DRB1*0405/DRB4*0101) molecules

HLA-DR4(DRBI*0405) is frequently observed among Japanese, Koreans, Singapore Chinese, Sardinians, and Highlanders in Papua New Guinea. It has been shown that HLA-DR4(DRBI*0405) is positively associated with rheumatoid arthritis (Tsuchiya et al. 1991) and VogtKoyanagi-Haradas syndrome (Ohno 1992). The elucidation of the characteristics of naturally processed peptides bound to HLA-DR4(DRBl*0405) molecules may help in understanding the pathogenesis of these diseases. Peptides were isolated and sequenced from HLA-DR4/ DR53 (DRBI*0405/DRB4*0101) molecules according to the method used by Van Bleek and Natbenson (1990), with minor modifications. Briefly, HLA-DR molecules were solubilized by Nonidet-P40 from 3 x 1010 cells of EBVWa cell line (homozygous for DR4(DRBI*0405) and DR53(DRB4*0101); Katagiri et al. 1979) and immunopurified by L243 antibody specific for HLA-DR (Deboreh et al. 1981). The isolated HLA-DR molecules were treated with 10% acetic acid at 70 ° C for 15 min and the released peptides were separated from HLA-DR molecules by filtration through Centricon 10 (Amicon, Danvers, MA). They were fractionated by reverse phase high pressure liquid chromatography (RP-HPLC), using C2/C18 RPC column (Pharmacia, Uppsala, Sweden). The amino acid sequence of each peptide peak was determined by automated Edman microsequencing (477A; Applied Biosysterns, Foster City, CA). The source proteins of peptides were identified by searching the PRF-SEQDB and the GenBank databases, using the JOIS-F sequence search system. Nineteen peptides were identified, and their amino acid sequences and source proteins were determined (Table 1). Table 2 summarizes the core sequences of eluted peptides. The sequences contain conserved Tyr, which has been shown to be an anchor residue of DR binding peptides

Retinal changes in juvenile X linked retinoschisis using three dimensional optical coherence tomography.

Juvenile X linked retinoschisis is a congenital X linked recessive retinal disorder, the characteristic funduscopic findings of which are a silver-grey retinal reflex, foveal retinoschisis, and peripheral retinoschisis. Electroretinograms (ERGs) typically record a reduced b-wave amplitude with relative preservation of the a-wave amplitude. Visual acuity (VA) usually deteriorates slowly until the patient is about 20 years of age, stabilises around 0.2∼0.5, and sometimes deteriorates further because of macular degeneration.1–4 Podoleanu and associates developed a novel integration of scanning laser ophthalmoscopy (SLO) and optic coherence tomography (OCT)—three dimensional optical coherence tomography (3-D OCT).5 Using transverse scanning, typical for SLO, the instrument simultaneously produces SLO and interferometric OCT images.6 We can obtain both cross sectional scans (B-scans) as with conventional OCT and transverse scans (C-scans) using 3-D OCT. This is the first report of 3-D OCT findings in juvenile X linked retinoschisis. A 7 year old boy presented with VA of 0.5 …

Hypertensive choroidopathy with eclampsia viewed on spectral-domain optical coherence tomography

PurposeWe report a case of hypertensive choroidopathy with detailed retinal images obtained using spectral-domain optical coherence tomography (SD-OCT).CaseA 19-year-old pregnant woman with no history of high blood pressure had an eclamptic seizure at the 39th week of pregnancy; the baby was delivered by emergency Caesarean section. Six days later, she presented with bilateral blurred vision (best-corrected visual acuity [VA], 0.5, right eye; 0.3, left eye). Bilateral extensive, punctate, pale-yellow Elschnig’s spots were present in the posterior fundus. SD-OCT showed a serous retinal detachment (SRD) and retinal pigment epithelium detachment (PED) representing a waveform retinal pigment epithelium (RPE) layer in each eye. The reflective intensity decreased partly at the waveform RPE. A wavy structure suggestive of fibrin was present in both foveas between the photoreceptor ellipsoid zone and the RPE-outer segment line. Four weeks after delivery and oral antihypertensive treatment, the SRDs, PEDs and wavy structure resolved and the VA recovered.ConclusionSD-OCT visualized SRDs, PEDs, wavy structures under the photoreceptor ellipsoid zone, and areas of low intensity RPE layer in hypertensive choroidopathy.

Immunohistochemical Study of Idiopathic and Secondary Epiretinal Membrane

PURPOSE We investigated the immunohistochemical features of surgically resected idiopathic epiretinal membranes(ERMs) and secondary ERMs with regard to posterior vitreous detachment(PVD). METHODS Six specimens of idiopathic epiretinal membranes(3 eyes with complete PVD, 2 eyes with partial PVD, and one eye with no PVD) and 3 specimens of secondary ERMs(all eyes with complete PVD) were immunohistochemically studied. We used type I, II, III, IV collagen and fibronectin to study extracellular components, and glial fibrillary acidic protein(GFAP), S 100 protein, vimentin, and so forth to study cellular components. RESULTS All the specimens of idiopathic ERMs had the major components of the lamellar stained by type II collagen antibody, and one out of 3 specimens of secondary ERMs had a minor component stained by type II collagen antibody. Compared with idiopathic ERMs with complete PVD, 2 out of 3 specimens of idiopathic ERMs with partial PVD or no PVD contained rather thick collagen lamellar. CONCLUSION There was difference between specimens of idiopathic ERMs and specimens of secondary ERMs in staining by type II collagen antibody, supposed by vitreous, in this study. Idiopathic ERM with attached posterior vitreous membrane may cause growth of collagen.

A low meat diet increases the risk of open-angle glaucoma in women—The results of population-based, cross-sectional study in Japan

Background Studies identifying modifiable lifestyle risk factors related to open-angle glaucoma (OAG) are limited, especially from Asian countries. This study aimed to identify lifestyle risk factors for OAG in a Japanese population. Methods and findings This population-based, cross-sectional study recruited Japanese participants aged 40 years or older from January 2013 to March 2015. We took fundus photographs for OAG screening, determined lifestyle and health characteristics through a questionnaire and performed physical examinations. The participants who had suspect findings in the fundus photographs were sent for a detailed ophthalmic examination to diagnose OAG. Lifestyle and heath characteristics were statistically compared between the OAG and non-OAG participants. A total of 1583 participants were included in the study, of which 42 had OAG and 1541 did not have OAG. The number of days per week that the female participants consumed meat (mean±SD; OAG: 1.7±1.2 days, non-OAG: 2.7±1.5 days) was negatively associated with OAG (OR = 0.61; 95% CI: 0.43–0.88; p = 0.007). Higher intraocular pressure was positively associated with OAG in men (OR = 1.20; 95% CI: 1.05–1.38, p = 0.009). No significant difference between participants with and without OAG was observed for a range of other lifestyle factors and health criteria including self-report of diabetes, number of family living together, body mass index, blood pressure, pulse rate, coffee drinking, tea drinking, alcohol drinking, number of fruits consumed per day and days of fish consumption per week. Conclusions A higher weekly consumption of meat appears to be negatively associated with OAG in Japanese women. Increasing the dietary intake of meat can contribute to reducing the risk of developing OAG.

Reperfusion of the choriocapillaris observed using optical coherence tomography angiography in hypertensive choroidopathy

PurposeOptical coherence tomography angiography (OCTA) can visualize the vascular status of the choriocapillaris noninvasively and separately from the other vascular beds. We describe focal ischemia in the choriocapillaris and reperfusion of the area in hypertensive choroidopathy using en-face OCTA.CaseA 32-year-old woman diagnosed with pregnancy-induced hypertension presented with acute anorthopia in the right eye after delivery via Caesarian section. Fundus examination showed an Elschnig’s spot and serous retinal detachment (SRD) in the inferior perifoveal region. Early-phase fluorescein angiography and indocyanine green angiography images showed focally delayed choroidal perfusion, i.e., regional absence of choroidal flush. OCTA also showed a focal dark area in a slab of the choriocapillaris corresponding to the angiographic observation. After oral antihypertensive treatment, the dark area on the OCTA image of the choriocapillaris resolved over time in association with the resolving SRD.ConclusionEn-face OCTA is a useful technology to follow noninvasively the circulatory status of the choriocapillaris in hypertensive choroidopathy.