Blue Wavelength of Scanning Laser Ophthalmoscope Potentially Detects Arteriosclerotic Lesions in Diabetic Retinopathy.

(1) Background: The fundus examination is one of the best and popular methods in the assessment of vascular status in the human body. Direct viewing of retinal vessels by ophthalmoscopy has been utilized in judging hypertensive change or arteriosclerosis. Recently, fundus imaging with the non-mydriatic scanning laser ophthalmoscope (SLO) has been widely used in ophthalmological clinics since it has multimodal functions for optical coherence tomography or angiography with contrast agent dye. The purpose of this study was to examine the utility in detecting arteriosclerosis of retinal vessels in SLO images; (2) Methods: Both color and blue standard field SLO images of eyes with diabetic retinopathy (DR) were examined retrospectively. Retinal arteriosclerosis in color SLO images was graded according to the Scheie classification. Additionally, characteristics of retinal arterioles in blue SLO images were identified and examined for their relevance to arteriosclerosis grades, stages of DR or general complications; (3) Results: Relative to color fundus images, blue SLO images showed distinct hyper-reflective retinal arterioles against a monotone background. Irregularities of retinal arterioles identified in blue SLO images were frequently observed in the eyes of patients with severe arteriosclerosis (Grade 3: 79.0% and Grade 4: 81.8%). Furthermore, the findings on arterioles were more frequently associated with the eyes of DR patients with renal dysfunction (p < 0.05); (4) Conclusions: While color SLO images are equally as useful in assessing retinal arteriosclerosis as photography or ophthalmoscopy, the corresponding blue SLO images show arteriosclerotic lesions with high contrast in a monotone background. Retinal arteriosclerosis in eyes of advanced grades or advanced DR frequently show irregularities of retinal arterioles in the blue images. The findings of low, uneven, or discontinuous attenuation were easier to find in blue than in color SLO images. Consequently, blue SLO images can show pathological micro-sclerosis in retinal arterioles and are potentially one of the safe and practical methods for the vascular assessment of diabetic patients.

Characteristics of physical activity during beginner-level group tennis lessons and the effect daily activity.

Tennis is a popular leisure sport, and studies have indicated that playing tennis regularly provides many health benefits. We aimed to clarify the characteristics of physical activity during beginner-level group tennis lessons and daily physical activity of the participants. Physical activity was measured using an accelerometer sensor device for four weeks, including the 80-min duration tennis lessons held twice a week. Valid data were categorized for tennis and non-tennis days. The mean physical activity intensity during the tennis lesson was 3.37 METs. The mean ratio of short-bout rest periods to the tennis lesson time in 90 and 120 s was 7% and 4%, respectively. The mean physical activity intensity was significantly higher (p < 0.0001) and the duration of vigorous-intensity physical activity (VPA) was increased in 76% of participants on days with tennis lessons compared to without tennis lessons. Beginner-level tennis lesson has characteristics of less short-bout rest physical activity than previously reported competitive tennis match and increased the duration of VPA in daily activity compared to without tennis lessons, suggesting that beginner-level tennis lessons contribute physical activity of health benefits.

Outcomes of standalone ab interno trabeculotomy in the treatment of open-angle glaucoma in eyes with high myopia.

BACKGROUND: We retrospectively evaluate the long-term efficacy and safety of trabeculotomy glaucoma surgery in treating open-angle glaucoma (OAG) in eyes with high myopia (HM). METHODS: This study included 20 eyes with HM (axial length ≥ 26.5 mm) and OAG; age, preoperative IOP (intraocular pressure), and sex-matched 20 non-HM eyes (axial length < 26.5 mm) served as controls. Each eye underwent standalone ab interno trabeculotomy using a Kahook dual blade. A follow-up examination was performed 36 months after surgery. The main outcome measure was the operative success rate (i.e., a ≥ 20% pre- to post-operative reduction in IOP with or without IOP-lowering medication). Kaplan-Meier analysis was employed as a measure of surgical success. The secondary outcome measures were postoperative IOP, the number of glaucoma medications, and postoperative complications. RESULTS: IOP and the number of glaucoma medications were statistically significantly reduced at all postoperative follow-up examinations. The Kaplan-Meier analysis demonstrated that the probability of postoperative success at 36 months was 45% and 65% for HM and non-HM eyes, respectively. In the HM group, the presence of pathological myopia was statistically significant risk factor for surgical failure. No critical postoperative complications were detected. CONCLUSIONS: In our study, the long-term efficacy of ab interno trabeculotomy in HM eyes with OAG was inferior to that in non-HM eyes with OAG. Our findings suggest that surgical indications for trabeculotomy in HM should be determined based on the presence of pathological myopia.

Microperimetry in Retinal Diseases.

Retinal microperimetry (MP) is a procedure that assesses the retinal sensitivity while the fundus is directly observed, and an eye tracker system is active to compensate for involuntary eye movements during testing. With this system, the sensitivity of a small locus can be accurately determined, and it has become an established ophthalmic test for retinal specialists. Macular diseases are characterized by chorioretinal changes; therefore, the condition of the retina and choroid requires careful and detailed evaluations to perform effective therapy. Age-related macular degeneration is a representative retinal disease in which the macular function has been evaluated by the visual acuity throughout the course of the disease process. However, the visual acuity represents the physiological function of only the central fovea, and the function of the surrounding macular area has not been sufficiently evaluated throughout the different stages of the macula disease process. The new technique of MP can compensate for such limitations by being able to test the same sites of the macular area repeatedly. This is especially useful in the recent management of age-related macular degeneration or diabetic macular edema during anti-vascular endothelial growth factor treatments because MP can assess the effectiveness of the treatment. MP examinations are also valuable in diagnosing Stargardt disease as they can detect visual impairments before any abnormalities are found in the retinal images. The visual function needs to be carefully assessed along with morphologic observations by optical coherence tomography. In addition, the assessment of retinal sensitivity is useful in the presurgical or postsurgical evaluations.

Progress of Imaging in Diabetic Retinopathy-From the Past to the Present.

Advancement of imaging technology in retinal diseases provides us more precise understanding and new insights into the diseases' pathologies. Diabetic retinopathy (DR) is one of the leading causes of sight-threatening retinal diseases worldwide. Colour fundus photography and fluorescein angiography have long been golden standard methods in detecting retinal vascular pathology in this disease. One of the major advancements is macular observation given by optical coherence tomography (OCT). OCT dramatically improves the diagnostic quality in macular edema in DR. The technology of OCT is also applied to angiography (OCT angiograph: OCTA), which enables retinal vascular imaging without venous dye injection. Similar to OCTA, in terms of their low invasiveness, single blue color SLO image could be an alternative method in detecting non-perfused areas. Conventional optical photography has been gradually replaced to scanning laser ophthalmoscopy (SLO), which also make it possible to produce spectacular ultra-widefield (UWF) images. Since retinal vascular changes of DR are found in the whole retina up to periphery, it would be one of the best targets in UWF imaging. Additionally, evolvement of artificial intelligence (AI) has been applied to automated diagnosis of DR, and AI-based DR management is one of the major topics in this field. This review is trying to look back on the progress of imaging of DR comprehensively from the past to the present.

Sympathetic ophthalmia in eye with pathologic myopia.

PURPOSE: To present our findings in a case of SO that developed in an eye with pathologic myopia. OBSERVATIONS: The patient was an 83-year-old woman who was examined one month after an ocular trauma to the right eye. She was found to have signs of uveitis with multiple serous retinal detachments in the non-injured contralateral left eye. In addition, she had hearing loss and mononuclear pleocytosis of the spinal fluids. Swept-source OCT images showed focal and choroidal thickening in areas with abrupt edges that was restricted to the regions with more normal appearing choroid. Bruch's membrane was damaged at the edge of the focal choroidal thickening. The ocular and systemic findings were rapidly resolved after systemic corticosteroid therapy. CONCLUSIONS AND IMPORTANCE: The pathobiological and clinical course of SO is nearly identical to Vogt-Koyanagi Harada disease (VKH) although its pathogenesis of autoimmunity had not been definitively established. In eyes with pathologic myopia, the choroid is extremely thin and sometimes completely absent. The findings in this rare case indicate that in eyes with thin choroid, the OCT findings typical of SO might be different from those seen in non-highly myopic eyes. Thus, the pre-status of the choroid may affect the choroidal thickening in pathological conditions. This case gives us a valuable insight in understanding the pathology of SO and characteristic of pathologic myopia.

Blue Widefield Images of Scanning Laser Ophthalmoscope Can Detect Retinal Ischemic Areas in Eyes With Diabetic Retinopathy.

PURPOSE: To determine whether the hyporeflective areas in the blue images obtained by widefield scanning laser ophthalmoscopy (SLO) correspond to the non-perfused areas (NPAs) in the fluorescein angiograms (FA) in eyes with diabetic retinopathy (DR). DESIGN: Retrospective observational case series. METHODS: Ninety patients with diabetes mellitus (DM) were studied. All had undergone multicolor widefield SLO imaging. The NPAs in the FA images and hyporeflective areas in the blue widefield SLO images were examined. The morphology of the retina was determined by optical coherence tomography. RESULTS: Hyporeflective areas in the blue SLO images were found with a rate of 76.6% in eyes with proliferative DR eyes. In a comparison of the hyporeflective areas of the blue SLO images to the non-perfused areas in the FA images, the appearance and the correspondence in the locations of these two types of images were found, and the rate was highly concordant with a Cohen's kappa value of 0.675. CONCLUSIONS: The high concordance between the hyporeflective areas in the widefield blue SLO and the NPAs in the FA indicates that widefield blue SLO can be used to identify ischemic retinal areas in eyes with DR without the intravenous injection of any dye.

A 10-year follow-up of infliximab monotherapy for refractory uveitis in Behçet's syndrome.

Infliximab (IFX) was the first biologic introduced for refractory uveitis treatment in Behçet's syndrome (BS). However, there have been few reports on the safety and efficacy of IFX monotherapy over follow-up periods of more than 10 years. This retrospective study evaluated the 10-year safety and efficacy of IFX monotherapy compared to IFX combination therapies with colchicine or corticosteroid for refractory uveitis in BS patients. Monotherapy was performed in 30 eyes of 16 patients while combination therapies were performed in 20 eyes of 11 patients. Continuation of IFX occurred in 70.3% of enrolled patients for 10 years without any significant difference noted in the retention rate between the monotherapy and combination therapies (p = 0.86). Reduction of ocular inflammatory attacks and improvement of best corrected visual acuity occurred in the monotherapy group after 10 years, which was equivalent to that for the combination therapies. Although adverse events (AEs) or therapy discontinuation occurred during the initial 5 years in both therapies, no AEs were observed for either therapy after 6 years. Our results suggested that IFX monotherapy proved to be effective and not inferior to combination therapies over a 10-year follow-up. Although loss of response and AEs may be noticed during the initial 5-year period, a safe and effective continuation can be expected thereafter.

Posterior staphylomas and scleral curvature in highly myopic children and adolescents investigated by ultra-widefield optical coherence tomography.

PURPOSE: To determine the early signs of posterior staphylomas in highly myopic eyes of younger subjects by swept-source ultra-widefield optical coherence tomography (WF-OCT). METHODS: This was an observational case series study. Highly myopic subjects younger than 20 years old who were examined consecutively by prototype WF-OCT were studied. High myopia was defined according to the Ministry of Health and Welfare, Japan classification. A posterior displacement of the sclera and two OCT features indicating the staphyloma edges were used as markers of a staphyloma. RESULTS: Fifty-five eyes of 30 patients with the mean age of 12.3 years, and the mean axial length of 27.9 mm were studied. Seven of the 55 eyes (12.7%) had a posterior displacement of the sclera and were diagnosed as having a staphyloma. Among the two OCT features of the staphyloma edges, a gradual thinning of the choroid toward the staphyloma edge and gradual re-thickening of choroid from the staphyloma edge toward the posterior pole were found in these 7 eyes. However, the other feature of an inward protrusion of the sclera at the staphyloma edge, was obvious in only 2 eyes. The subfoveal choroid and choroid nasal to the optic disc were significantly thinner in eyes with a staphyloma than those without it. CONCLUSIONS: The changes of the choroidal thickness toward the staphyloma edge with the posterior displacement of the sclera were considered an early sign which precedes an inward protrusion of sclera at the staphyloma edge.

CORRELATIONS BETWEEN EXPERIMENTAL MYOPIA MODELS AND HUMAN PATHOLOGIC MYOPIA.

PURPOSE: To analyze the hallmark features of pathologic myopia developed in animal models and compare them with those seen in patients. METHODS: A literature review was performed to identify animal models that exhibited key features of pathologic myopia, namely posterior staphyloma, myopic maculopathy, lacquer cracks, and choroidal neovascularization, either spontaneously or induced by monocular deprivation. Using imaging modalities, such as optical coherence tomography, confocal scanning laser ophthalmoscopy, fluorescein angiography, and electron microscopy, these features were compared with those found in myopic maculopathy of patients. RESULTS: Three types of animals were identified. The LRP2 knockout mice exhibited posterior staphylomas and chorioretinal atrophy at 21 and 60 days after birth, respectively. Retinopathy globe enlarged (rge) chicks and normal lid-sutured chicks developed lacquer cracks and chorioretinal atrophy. Lacquer cracks detected in rge chicks subsequently progressed to patchy chorioretinal atrophy, which is also commonly seen in patients with pathologic myopia. CONCLUSION: The LRP2 knockout mice, retinopathy globe enlarged (rge) chicks, and normal lid-sutured chicks exhibit features typical for myopic maculopathy in patients and could serve to further elucidate the pathogenesis of myopic maculopathy.

Immune Privilege and Eye-Derived T-Regulatory Cells.

Certain cellular components of the eye, such as neural retina, are unable to regenerate and replicate after destructive inflammation. Ocular immune privilege provides the eye with immune protection against intraocular inflammation in order to minimize the risk to vision integrity. The eye and immune system use strategies to maintain the ocular immune privilege by regulating the innate and adaptive immune response, which includes immunological ignorance, peripheral tolerance to eye-derived antigens, and intraocular immunosuppressive microenvironment. In this review, we summarize current knowledge regarding the molecular mechanism responsible for the development and maintenance of ocular immune privilege via regulatory T cells (Tregs), which are generated by the anterior chamber-associated immune deviation (ACAID), and ocular resident cells including corneal endothelial (CE) cells, ocular pigment epithelial (PE) cells, and aqueous humor. Furthermore, we examined the therapeutic potential of Tregs generated by RPE cells that express transforming growth factor beta (TGF-ß), cytotoxic T lymphocyte-associated antigen-2 alpha (CTLA-2α), and retinoic acid for autoimmune uveoretinitis and evaluated a new strategy using human RPE-induced Tregs for clinical application in inflammatory ocular disease. We believe that a better understanding of the ocular immune privilege associated with Tregs might offer a new approach with regard to therapeutic interventions for ocular autoimmunity.

Bilateral hearing impairment as the initial symptom of sympathetic ophthalmia.

IMPORTANCE: Sympathetic ophthalmia (SO), a rare bilateral panuveitis following penetrating ocular trauma or ocular surgery to one eye, shares a strikingly similar ocular pathology to that of Vogt-Koyanagi-Harada disease (VKH). Audiovestibular dysfunction is a major extraocular manifestation of VKH; however, to date, only a few cases of sympathetic ophthalmia associated with hearing loss have been reported from ophthalmologists, but not otolaryngologists. Accordingly, little is known about the audiovestibular findings in patients with SO. We herein present two cases of SO with preceding bilateral hearing loss. OBSERVATIONS: The patient in Case 1, an 80-year-old female, experienced acute bilateral hearing loss. Five days after the onset of hearing loss, she presented with sudden bilateral blurred vision. In Case 2, a 32-year-old female noticed acute bilateral hearing loss and also experienced acute bilateral blurred vision the subsequent day. Patient 1 had a history of a penetrating injury to the right eye 25 days before the onset of hearing loss, while patient 2 had previously undergone right vitreous surgery twice for the treatment of a myopic macular hole and retinal detachment 36 and 43 days prior to the current symptom onset. Both cases were diagnosed as SO based on ocular findings of bilateral panuveitis and the history of ocular insult. Patient 1 carried HLA-DR4, HLA-DR15, HLA-A33, HLA-A24, HLA-B44 and HLA-B52, and patient 2 carried HLA-DR4. Audiograms showed bilateral mild to moderate sensorineural hearing loss in both cases, with normal auditory brainstem responses and deteriorated distortion product otoacoustic emission amplitudes. In addition, the significant recruitment phenomenon observed in case 1 suggested a cochlear origin of the hearing loss. Both patients received corticosteroid therapy, and the cochlear signs and symptoms recovered within one month. CONCLUSIONS AND RELEVANCE: This is the first report to describe the comprehensive audiovestibular findings in patients with SO. In the present study, acute bilateral hearing loss developed a couple of days prior to the onset of bilateral visual loss and auditory examinations suggested a cochlear etiology in both cases.

CD200R signaling inhibits pro-angiogenic gene expression by macrophages and suppresses choroidal neovascularization.

Macrophages are rapidly conditioned by cognate and soluble signals to acquire phenotypes that deliver specific functions during inflammation, wound healing and angiogenesis. Whether inhibitory CD200R signaling regulates pro-angiogenic macrophage phenotypes with the potential to suppress ocular neovascularization is unknown. CD200R-deficient bone marrow derived macrophages (BMMΦ) were used to demonstrate that macrophages lacking this inhibitory receptor exhibit enhanced levels of Vegfa, Arg-1 and Il-1ß when stimulated with PGE2 or RPE-conditioned (PGE2-enriched) media. Endothelial tube formation in HUVECs was increased when co-cultured with PGE2-conditioned CD200R(-/-) BMMΦ, and laser-induced choroidal neovascularization was enhanced in CD200R-deficient mice. In corroboration, signaling through CD200R results in the down-regulation of BMMΦ angiogenic and pro-inflammatory phenotypes. Translational potential of this pathway was investigated in the laser-induced model of choroidal neovascularization. Local delivery of a CD200R agonist mAb to target myeloid infiltrate alters macrophage phenotype and inhibits pro-angiogenic gene expression, which suppresses pathological angiogenesis and CNV development.

Myeloid cells expressing VEGF and arginase-1 following uptake of damaged retinal pigment epithelium suggests potential mechanism that drives the onset of choroidal angiogenesis in mice.

Whilst data recognise both myeloid cell accumulation during choroidal neovascularisation (CNV) as well as complement activation, none of the data has presented a clear explanation for the angiogenic drive that promotes pathological angiogenesis. One possibility that is a pre-eminent drive is a specific and early conditioning and activation of the myeloid cell infiltrate. Using a laser-induced CNV murine model, we have identified that disruption of retinal pigment epithelium (RPE) and Bruch's membrane resulted in an early recruitment of macrophages derived from monocytes and microglia, prior to angiogenesis and contemporaneous with lesional complement activation. Early recruited CD11b(+) cells expressed a definitive gene signature of selective inflammatory mediators particularly a pronounced Arg-1 expression. Accumulating macrophages from retina and peripheral blood were activated at the site of injury, displaying enhanced VEGF expression, and notably prior to exaggerated VEGF expression from RPE, or earliest stages of angiogenesis. All of these initial events, including distinct VEGF (+) Arg-1(+) myeloid cells, subsided when CNV was established and at the time RPE-VEGF expression was maximal. Depletion of inflammatory CCR2-positive monocytes confirmed origin of infiltrating monocyte Arg-1 expression, as following depletion Arg-1 signal was lost and CNV suppressed. Furthermore, our in vitro data supported a myeloid cell uptake of damaged RPE or its derivatives as a mechanism generating VEGF (+) Arg-1(+) phenotype in vivo. Our results reveal a potential early driver initiating angiogenesis via myeloid-derived VEGF drive following uptake of damaged RPE and deliver an explanation of why CNV develops during any of the stages of macular degeneration and can be explored further for therapeutic gain.

Role of IL-22- and TNF-α-producing Th22 cells in uveitis patients with Behcet's disease.

Behçet's disease is a systemic inflammatory disorder with recurrent episodes of oral ulceration, skin lesions, genital ulceration, and intraocular inflammation (uveitis). The intraocular inflammation is strictly associated with Th effector cells. IL-22 is a member of the IL-10 cytokine family that is involved in inflammatory processes. Recently, Th22 cells were identified as a Th cell population that produces IL-22 and TNF-α and are distinct from Th1, Th2, and Th17 cells. In this study, we established Th22-type T cell clones from ocular samples taken from Behçet's disease patients with active uveitis. These clones produced large amounts of IL-22 and TNF-α but not the Th1 cytokine IFN-γ and the Th17 cytokine IL-17. CD4(+) T cells from the peripheral blood of Behçet's disease patients differentiated into Th22 cells in the presence of IL-6 and TNF-α in vitro. The polarized Th22 cell lines produced large amounts of IL-22, and the polarized Th1 and Th17 cells also produced IL-22. In the presence of anti-TNF-α- and anti-IL-6-blocking Abs, Behçet's disease Th22-type T cells failed to produce IL-22. In addition, infliximab-pretreated Th22 cells and Th22-type ocular T cells produced less IL-22 and TNF-α. Moreover, IL-22-producing T cells were isolated from mice with experimental autoimmune uveitis, an animal model of Behçet's disease, and the intraocular T cells from uveitis models produced large amounts of IL-22 in the presence of retinal Ags. Our results suggest that inflammatory cytokines IL-22 and TNF-α may play a key role in the ocular immune response in Behçet's disease.

Immunosuppressive properties of regulatory T cells generated by incubation of peripheral blood mononuclear cells with supernatants of human RPE cells.

PURPOSE: To determine whether supernatants of human retinal pigment epithelium (RPE) cells can convert CD4⁺ T cells into regulatory T cells (Tregs) under Treg-induction conditions in vitro and in vivo. METHODS: Peripheral blood mononuclear cells were cocultured with supernatants from TGFß2-pretreated human RPE lines on anti-CD3-coated plates. Cells were then separated with a CD4⁺CD25⁺ Treg isolation kit and cultured with supernatants from RPE, anti-CD3/CD28 antibodies, high-dose IL-2, and TGFß2. By flow cytometry sorting, CD25⁺CD45RA⁻ Tregs were separated. Expressions of CD25(high), Foxp3, CD152, and TNFRSF 18 on Tregs were analyzed by flow cytometry. Cytokine production by Tregs was measured by ELISA. Proliferation of target T cells was assessed by [³H]thymidine incorporation or CFSE incorporation. In addition, mouse RPE-induced Tregs were used for the in vitro assay and in vivo experimental autoimmune uveitis (EAU) models. RESULTS: Human RPE-induced Tregs expressed higher levels of the Treg markers CD25(high), Foxp3, CD152, and TNFRSF 18. In addition, RPE-induced Tregs included significant numbers of CD4⁺CD25(high)Foxp3(high)CD45RA⁻ active effector Tregs that significantly suppressed the activation of Th1/Th17 cell lines, indicating that they have immunosuppressive properties. Furthermore, CD4⁺CD25(low)Foxp3(low)CD45RA⁻ nonsuppressing cytokine-secreting T cells were removed from the in vitro-manipulated Treg population. Administration of mouse RPE-induced Tregs significantly suppressed ocular inflammation in mice with EAU. In addition, the Tregs suppressed retinal antigen-specific T cells in vitro. CONCLUSIONS: It is hoped that through the data provided in this study that Tregs might become useful as individualized therapeutic agents for ocular autoimmune diseases.

Inhibition of Th17 differentiation by anti-TNF-alpha therapy in uveitis patients with Behçet's disease.

INTRODUCTION: The purpose of this study was to determine whether anti-tumour necrosis factor alpha (anti-TNF-α) antibody, infliximab, can inhibit T helper 17 (Th17) differentiation in uveitis patients who have Behçet's disease (BD). METHODS: To measure inflammatory cytokines, ocular fluid samples from BD patients being treated with infliximab were collected. Cluster of differentiation 4 (CD4)+ T cells from BD patients with active uveitis were co-cultured with anti-cluster of differentiation 3/cluster of differentiation 28 (CD3/CD28) antibodies in the presence of infliximab. For the induction of Th17 cells, CD4+ T cells from BD patients were co-cultured with anti-CD3/CD28, anti-interferon-gamma (anti-IFN-γ), anti-interleukin-4 (anti-IL-4), and recombinant proteins such as interleukin-1 beta (IL-1ß), interleukin-6 (IL-6), interleukin-23 (IL-23), and TNF-α. The BD T cells were co-cultured with infliximab, and the production of interleukin-17 (IL-17) was evaluated by ELISA and flow cytometry, and the expression of retinoid-acid receptor-related orphan receptor gamma t (RORγt) was also evaluated by flow cytometry. In addition, intraocular cells collected from mice with experimental autoimmune uveitis (EAU) were used for the assay with anti-TNF-α blocking antibody. RESULTS: Ocular fluids from active uveitis patients who have BD contained significant amounts of inflammatory cytokines such as IFN-γ, IL-2, TNF-α, IL-6, and IL-17, while ocular fluids from infliximab patients did not contain any inflammatory cytokines. Activated CD4+ T cells from BD patients produced large amounts of TNF-α and IL-17, whereas T cells in the presence of infliximab failed to produce these cytokines. Polarized Th17 cell lines from BD patients produced large amounts of IL-17, and Th17 cells exposed to infliximab had significantly reduced IL-17 production. Polarized BD Th17 cells expressed large amounts of transcription factor RORγt. In contrast, in vitro-treated infliximab Th17 cells expressed less RORγt. Moreover, intraocular T cells from EAU mice had a high population of IL-17+ cells, and retinal antigen-specific T cells from EAU mice produced large amounts of IL-17 in the presence of retinal peptide. However, the EAU T cells produced less IL-17 if the T cells were treated with anti-TNF-α antibody. CONCLUSIONS: These results indicate that anti-TNF-α therapy suppresses effector T-cell differentiation in BD patients with uveitis. Thus, suppression of effector T-cell differentiation by anti-TNF-α therapy may provide protection from severe ocular inflammation in BD.

Inhibitory effect of corneal endothelial cells on IL-17-producing Th17 cells.

AIM: To determine whether cultured corneal endothelial (CE) cells suppress interleukin 17 (IL-17)-producing effector T cells in vitro. METHODS: CE cell lines established from a normal mouse were used. Target bystander T cells were established from normal splenic T cells with anti-CD3 antibodies. Production of IL-17 by target T cells was evaluated by ELISA, flow cytometry and quantitative PCR. To abolish the CE-inhibitory function, transforming growth factor ß (TGFß)-small interfering RNA-transfected CE cells or transwell membrane inserts, which block cell-to-cell contact, were used. RESULTS: Cultured CE cells greatly suppressed the activation of bystander target cells (pan-T, CD4 T, CD8 T, and B cells) in vitro, particularly inflammatory cytokine production by CD4 cells. Cultured CE cells significantly suppressed IL-17-producing T cells and fully suppressed polarised T helper 17 (Th17) cell lines that are induced by Th17-associated differentiation factors. However, CE cells failed to suppress Th17 cells if the CE cell lines were pretreated with TGFß small interfering RNA or if direct contact with T cells was blocked with transwell membrane inserts. CONCLUSION: CE cells impair the effector functions and activation of IL-17-producing helper T cells in a cell-contact-dependent mechanism. Thus, corneal endothelium may contribute to the maintenance of the privileged immune status in the eye by inducing peripheral immune tolerance.

Retinoic acid from retinal pigment epithelium induces T regulatory cells.

Primary cultured retinal pigment epithelial (RPE) cells can convert T cells into T regulatory cells (Tregs) through inhibitory factor(s) including transforming growth factor ß (TGFß) in vitro. Retinoic acid (RA) enhances induction of CD4(+) Tregs in the presence of TGFß. We investigated whether RA produced by RPE cells can promote generation of Tregs. We found that in vitro, RA-treated T cells expressed high levels of Foxp3 in the presence of recombinant TGFß. In GeneChip analysis, cultured RPE cells constitutively expressed RA-associated molecules such as RA-binding proteins, enzymes, and receptors. RPE from normal mice, but not vitamin A-deficient mice, contained significant levels of TGFß. RPE-induced Tregs from vitamin A-deficient mice failed to suppress activation of target T cells. Only a few Foxp3(+) T cells were found in intraocular cells from vitamin A-deficient experimental autoimmune uveitis (EAU) mice, whereas expression was higher in cells from normal EAU mice. RA receptor antagonist-pretreated or RA-binding protein-siRNA-transfected RPE cells failed to convert CD4(+) T cells into Tregs. Our data support the hypothesis that RPE cells produce RA, thereby enabling bystander T cells to be converted into Tregs through TGFß promotion, which can then participate in the establishment of immune tolerance in the eye.

Suppression of interleukin-17-producing T-helper 17 cells by retinal pigment epithelial cells.

PURPOSE: To determine whether retinal pigment epithelial (RPE) cells can inhibit cytokine production by activated T helper (Th) cells. METHODS: Primary RPE cells were cultured from normal C57BL/6 mice. Target bystander T cells were established from normal splenic T cells with anti-CD3 antibodies. T-cell activation was assessed for production of cytokines, determined by ELISA. Production of IL-17 on target T cells was evaluated using oligonucleotide microarray, RT-PCR and flow cytometry. TGFß small interfering RNA was used to inhibit the RPE cells' inhibitory function. RESULTS: The cultured RPE cells greatly suppressed the activation of bystander CD4(+) T cells in vitro, especially cytokine production by target T helper cells (Th1 cells, Th2 cells and Th17 cells, but not Th3 cells). The cultured RPE cells and RPE supernatants significantly suppressed the IL-17-producing CD4(+) T cells and fully suppressed the polarized Th17 cell lines that were induced by recombinant proteins IL-6 and TGFß2. However, the RPE cells failed to suppress the IL-17-producing T cells in the presence of rIL-6. In addition, the TGFß produced by the RPE cells suppressed the Th17 cells. CONCLUSIONS: These results indicate that RPE cells have an immunosuppressive effect on Th17-type effector T cells, which highlights a role for ocular resident cells in establishing immune regulation in the eye.