Sunao Sugita

Genome-wide association studies identify IL23R - IL12RB2 and IL10 as Behçet's disease susceptibility loci

Behçets disease is a chronic systemic inflammatory disorder characterized by four major manifestations: recurrent ocular symptoms, oral and genital ulcers and skin lesions. We conducted a genome-wide association study in a Japanese cohort including 612 individuals with Behçets disease and 740 unaffected individuals (controls). We identified two suggestive associations on chromosomes 1p31.3 (IL23R-IL12RB2, rs12119179, P = 2.7 × 10−8) and 1q32.1 (IL10, rs1554286, P = 8.0 × 10−8). A meta-analysis of these two loci with results from additional Turkish and Korean cohorts showed genome-wide significant associations (rs1495965 in IL23R-IL12RB2, P = 1.9 × 10−11, odds ratio = 1.35; rs1800871 in IL10, P = 1.0 × 10−14, odds ratio = 1.45).

Characterization of Human Induced Pluripotent Stem Cell-Derived Retinal Pigment Epithelium Cell Sheets Aiming for Clinical Application

Summary Age-related macular degeneration (AMD) causes severe visual impairment due in part to age-dependent impairment of retinal pigment epithelium (RPE). It has been suggested that autologous human induced pluripotent stem cells (hiPSCs) may represent a useful cell source for the generation of graft RPE. We generated hiPSC-derived RPE (hiPSC-RPE) cell sheets optimized to meet clinical use requirements, including quality, quantity, consistency, and safety. These cell sheets are generated as a monolayer of cells without any artificial scaffolds, express typical RPE markers, form tight junctions that exhibit polarized secretion of growth factors, and show phagocytotic ability and gene-expression patterns similar to those of native RPE. Additionally, upon transplantation, autologous nonhuman primate iPSC-RPE cell sheets showed no immune rejection or tumor formation. These results suggest that autologous hiPSC-RPE cell sheets may serve as a useful form of graft for use in tissue replacement therapy for AMD.

Autologous Induced Stem-Cell–Derived Retinal Cells for Macular Degeneration

We assessed the feasibility of transplanting a sheet of retinal pigment epithelial (RPE) cells differentiated from induced pluripotent stem cells (iPSCs) in a patient with neovascular age‐related macular degeneration. The iPSCs were generated from skin fibroblasts obtained from two patients with advanced neovascular age‐related macular degeneration and were differentiated into RPE cells. The RPE cells and the iPSCs from which they were derived were subject to extensive testing. A surgery that included the removal of the neovascular membrane and transplantation of the autologous iPSC‐derived RPE cell sheet under the retina was performed in one of the patients. At 1 year after surgery, the transplanted sheet remained intact, best corrected visual acuity had not improved or worsened, and cystoid macular edema was present. (Funded by Highway Program for Realization of Regenerative Medicine and others; University Hospital Medical Information Network Clinical Trials Registry [UMIN‐CTR] number, UMIN000011929.)

Use of multiplex PCR and real-time PCR to detect human herpes virus genome in ocular fluids of patients with uveitis

Aim: To measure the genomic DNA of human herpes viruses (HHV) in the ocular fluids and to analyse the clinical relevance of HHV in uveitis. Methods: After informed consent was obtained, a total of 111 ocular fluid samples (68 aqueous humour and 43 vitreous fluid samples) were collected from 100 patients with uveitis. The samples were assayed for HHV-DNA (HHV1–8) by using two different polymerase chain reaction (PCR) assays, qualitative PCR (multiplex PCR) and quantitative PCR (real-time PCR). Results: In all of the patients with acute retinal necrosis (n = 16) that were tested, either the HSV1 (n = 2), HSV2 (n = 3), or VZV (n = 11) genome was detected. In all patients, high copy numbers of the viral DNA were also noted, indicating the presence of viral replication. In another 10 patients with anterior uveitis with iris atrophy, the VZV genome was detected. When using multiplex PCR, EBV-DNA was detected in 19 of 111 samples (17%). However, real-time PCR analysis of EBV-DNA indicated that there were only six of the 19 samples that had significantly high copy numbers. The cytomegalovirus (CMV) genome was detected in three patients with anterior uveitis of immunocompetent patients and in one immunocompromised CMV retinitis patient. In addition, one patient with severe unilateral panuveitis had a high copy number of HHV6-DNA. There was no HHV7- or HHV8-DNA detected in any of the samples. Conclusions: A qualitative multiplex PCR is useful in the screening of viral infections. However, the clinical relevance of the virus infection needs to be evaluated by quantitative real-time PCR.

Comparison of infliximab versus ciclosporin during the initial 6-month treatment period in Behçet disease

Aim To compare the efficacy and safety of infliximab versus ciclosporin A (CsA) in refractory uveoretinitis in Behçet disease. Methods In this retrospective clinical chart review of patients with Behçet disease who were treated with CsA or infliximab, we collected information on the number of uveitis attacks, visual acuity and adverse side effects that occurred during the 6 months prior to and after the initiation of CsA (n=20) or infliximab (n=17). Results The number of acute episodes of uveitis during the 6 months before and after initiation of CsA were 3.3±2.4 and 1.2±1.2, and those of infliximab were 3.1±2.7 and 0.4±1.0, respectively (p<0.005). The number of episodes after infliximab administration was significantly lower than that seen for CsA (p<0.05). During the 6-month treatment period, there were no significant differences noted in the improvement of the visual acuity between the two therapies. After CsA administration, neurological symptoms and renal toxicity were seen in one patient each, while after the infliximab administration, an infusion reaction and leucopenia were seen in one patient each. Conclusion During the initial 6 months of treatment, infliximab proved to be more effective in reducing acute episodes of uveitis in Behçet disease.

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

IntroductionThe 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 Behçets disease (BD).MethodsTo 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-1β), 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.ResultsOcular 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.ConclusionsThese 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.

Retinal Pigment Epithelium-Derived CTLA-2α Induces TGFβ-Producing T Regulatory Cells

T cells that encounter ocular pigment epithelium in vitro are inhibited from undergoing TCR-triggered activation, and instead acquire the capacity to suppress the activation of bystander T cells. Because retinal pigment epithelial (RPE) cells suppress T cell activation by releasing soluble inhibitory factors, we studied whether soluble factors also promote the generation of T regulatory (Treg) cells. We found that RPE converted CD4+ T cells into Treg cells by producing and secreting CTLA-2α, a cathepsin L (CathL) inhibitor. Mouse rCTLA-2α converted CD4+ T cells into Treg cells in vitro, and CTLA-2α small interfering RNA-transfected RPE cells failed to induce the Treg generation. RPE CTLA-2α induced CD4+CD25+Foxp3+ Treg cells that produced TGFβ in vitro. Moreover, CTLA-2α produced by RPE cells inhibited CathL activity in the T cells, and losing CathL activity led to differentiation to Treg cells in some populations of CD4+ T cells. In addition, T cells in the presence of CathL inhibitor increased the expression of Foxp3. The CTLA-2α effect on Treg cell induction occurred through TGFβ signaling, because CTLA-2α promoted activation of TGFβ in the eye. These results show that immunosuppressive factors derived from RPE cells participate in T cell suppression. The results are compatible with the hypothesis that the eye-derived Treg cells acquire functions that participate in the establishment of immune tolerance in the posterior segment of the eye.

Induction of Regulatory T Cells by Infliximab in Behcet's Disease

PURPOSE To determine whether infliximab induces the development of Foxp3+ T regulatory (Treg) cells in patients with Behçets disease. METHODS The subjects were patients with refractory uveitis caused by Behçets disease, Vogt-Koyanagi-Harada disease, or ocular toxoplasmosis and healthy volunteers. Purified CD4+ T cells were obtained from patients with uveitis who were treated with colchicine, cyclosporine, or infliximab. Flow cytometry was used to analyze the expression of Foxp3 on CD4+ T cells. RESULTS Foxp3 was expressed in a small percentage of CD4+ T cells (<5%) from healthy subjects and from patients with active uveitis caused by Behçets disease, Vogt-Koyanagi-Harada disease, or ocular toxoplasmosis. The percentage of Foxp3+ cells among CD4+ T cells was significantly decreased in patients with active uveitis compared with patients with inactive uveitis in the remission stage. Foxp3 was expressed at a similar level in CD4+ T cells from healthy donors, colchicine-treated patients, and cyclosporine-treated patients, whereas infliximab-treated patients expressed much higher percentages of Foxp3+ cells. Patients who had a high population of Foxp3+ cells during infliximab treatment did not experience any subsequent episodes of acute uveitis. On the other hand, patients with a low population of Foxp3+ cells did experience ocular inflammatory episodes. T cells exposed to infliximab in vitro greatly expressed Foxp3 and produced TGFβ, and the Treg cells significantly suppressed the activation of bystander T cells in vitro. CONCLUSIONS Anti-TNF-α therapy may be useful for patients with ocular complications of Behçets disease who have a decreased percentage of peripheral Treg cells.

Role of ocular pigment epithelial cells in immune privilege

The ocular microenvironment is both immunosuppressive and anti-inflammatory in nature. Pigment epithelial (PE) cells isolated from the eye possess the ability to suppress the T cell receptor-dependent activation of T cells and the induction of regulatory T cells in vitro. This property is dependent on the cells’ capacity to produce cell-surface and soluble inhibitory molecules, for example CD86 (B7-2), transforming growth factor (TGF)-β, thrombospondin-1, programmed cell death 1 ligand 1 (PD-L1/B7-H1), and cytotoxic T lymphocyte-associated antigen 2α. Cultured ocular PE cells from the iris, ciliary body, and retina can individually suppress T-cell activation via mechanisms that partially overlap. Moreover, PE-derived regulatory T cells acquire functions that play a role in establishing immune regulation in the eye. Multiple strategies are employed within the eye to control immune-mediated inflammation. This phenomenon is known as immune privilege and is instrumental in helping to prevent extensive damage to bystander cells that would otherwise lead to blindness. This review focuses on the immunosuppressive property and role of ocular PE cells in immune privileged sites.The ocular microenvironment is both immunosuppressive and anti-inflammatory in nature. Pigment epithelial (PE) cells isolated from the eye possess the ability to suppress the T cell receptor-dependent activation of T cells and the induction of regulatory T cells in vitro. This property is dependent on the cells’ capacity to produce cell-surface and soluble inhibitory molecules, for example CD86 (B7-2), transforming growth factor (TGF)-β, thrombospondin-1, programmed cell death 1 ligand 1 (PD-L1/B7-H1), and cytotoxic T lymphocyte-associated antigen 2α. Cultured ocular PE cells from the iris, ciliary body, and retina can individually suppress T-cell activation via mechanisms that partially overlap. Moreover, PE-derived regulatory T cells acquire functions that play a role in establishing immune regulation in the eye. Multiple strategies are employed within the eye to control immune-mediated inflammation. This phenomenon is known as immune privilege and is instrumental in helping to prevent extensive damage to bystander cells that would otherwise lead to blindness. This review focuses on the immunosuppressive property and role of ocular PE cells in immune privileged sites.

Use of a Comprehensive Polymerase Chain Reaction System for Diagnosis of Ocular Infectious Diseases

PURPOSE To measure the genomic DNA of ocular infectious pathogens in ocular fluids and to analyze the clinical relevance of these pathogens in uveitis and endophthalmitis. DESIGN Prospective clinical case series. PARTICIPANTS A total of 500 patients with infectious uveitis and endophthalmitis were examined at Tokyo Medical and Dental University, Tokyo Medical University, Kyushu University, Osaka University, and Kyoto Prefectural University, all in Japan. METHODS Genomic DNA of bacteria, fungi, parasites, and viruses in collected intraocular samples were examined by comprehensive polymerase chain reaction (PCR). Samples were analyzed first by multiplex PCR and quantitative real-time PCR for human herpes viruses (HHVs) 1 through 8 and toxoplasma. Subsequently, samples were examined by broad-range real-time PCR for bacterial 16S and fungal 18S/28S ribosomal DNA (rDNA). MAIN OUTCOME MEASURES Infectious uveitis and endophthalmitis diagnoses were obtained when using the PCR system. Calculations of the positivity and the diagnostic parameters such as sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) also were evaluated. RESULTS In all of the tested infectious uveitis and endophthalmitis patients, either herpes simplex virus type 1 (n = 18), herpes simplex virus type 2 (n = 4), varicella-zoster virus (n = 55), Epstein-Barr virus (n = 17), cytomegalovirus (n = 68), HHV type 6 (n = 2), toxoplasma (n = 6), bacterial 16S (n = 33), or fungal 18S/28S (n = 11) genome was detected. Neither HHV type 7 nor HHV type 8 DNA was detected in any of the samples. Of the 21 false-negative results found during the PCR analyses, 12 cases were negative for patients clinically suspected of having bacterial endophthalmitis. Conversely, false-positive results for the comprehensive PCR examinations occurred in only 3 cases that subsequently were found to have bacterial 16S rDNA. Diagnostic parameters for the sensitivity, specificity, PPV, and NPV of our PCR examinations were 91.3%, 98.8%, 98.6%, and 92.4%, respectively. CONCLUSIONS Use of our comprehensive PCR assay to examine ocular samples in patients with endophthalmitis and uveitis seems to be clinically useful for detecting infectious antigen DNA. Thus, this PCR method is a reliable tool for both diagnosing ocular disorders and further screening of patients for intraocular infections. FINANCIAL DISCLOSURE(S) The author(s) have no proprietary or commercial interest in any materials discussed in this article.