OR11H1 Missense Variant Confers the Susceptibility to Vogt-Koyanagi-Harada Disease by Mediating Gadd45g Expression.

Vogt-Koyanagi-Harada (VKH) disease is a severe autoimmune disease. Herein, whole-exome sequencing (WES) study are performed on 2,573 controls and 229 VKH patients with follow-up next-generation sequencing (NGS) in a collection of 2,380 controls and 2,278 VKH patients. A rare c.188T>C (p Val63Ala) variant in the olfactory receptor 11H1 (OR11H1) gene is found to be significantly associated with VKH disease (rs71235604, Pcombined = 7.83 × 10-30 , odds ratio = 3.12). Functional study showes that OR11H1-A63 significantly increased inflammatory factors production and exacerbated barrier function damage. Further studies using RNA-sequencing find that OR11H1-A63 markedly increased growth arrest and DNA-damage-inducible gamma (GADD45G) expression. Moreover, OR11H1-A63 activates the MAPK and NF-κB pathways, and accelerates inflammatory cascades. In addition, inhibiting GADD45G alleviates inflammatory factor secretion, likely due to the regulatory effect of GADD45G on the MAPK and NF-κB pathways. Collectively, this study suggests that the OR11H1-A63 missense mutation may increase susceptibility to VKH disease in a GADD45G-dependent manner.

A de novo missense mutation in MPP2 confers an increased risk of Vogt-Koyanagi-Harada disease as shown by trio-based whole-exome sequencing.

Vogt-Koyanagi-Harada (VKH) disease is a leading cause of blindness in young and middle-aged people. However, the etiology of VKH disease remains unclear. Here, we performed the first trio-based whole-exome sequencing study, which enrolled 25 VKH patients and 50 controls, followed by a study of 2081 VKH patients from a Han Chinese population to uncover detrimental mutations. A total of 15 de novo mutations in VKH patients were identified, with one of the most important being the membrane palmitoylated protein 2 (MPP2) p.K315N (MPP2-N315) mutation. The MPP2-N315 mutation was highly deleterious according to bioinformatic predictions. Additionally, this mutation appears rare, being absent from the 1000 Genome Project and Genome Aggregation Database, and it is highly conserved in 10 species, including humans and mice. Subsequent studies showed that pathological phenotypes and retinal vascular leakage were aggravated in MPP2-N315 mutation knock-in or MPP2-N315 adeno-associated virus-treated mice with experimental autoimmune uveitis (EAU). In vitro, we used clustered regularly interspaced short palindromic repeats (CRISPR‒Cas9) gene editing technology to delete intrinsic MPP2 before overexpressing wild-type MPP2 or MPP2-N315. Levels of cytokines, such as IL-1ß, IL-17E, and vascular endothelial growth factor A, were increased, and barrier function was destroyed in the MPP2-N315 mutant ARPE19 cells. Mechanistically, the MPP2-N315 mutation had a stronger ability to directly bind to ANXA2 than MPP2-K315, as shown by LC‒MS/MS and Co-IP, and resulted in activation of the ERK3/IL-17E pathway. Overall, our results demonstrated that the MPP2-K315N mutation may increase susceptibility to VKH disease.

Identification of FCER1G as a cyclosporin A plus corticosteroid sensitization gene in female patients with Vogt-Koyanagi-Harada disease.

The resistance development of the combination regimen of corticosteroids (CS) with cyclosporin A (CsA) leads to therapeutic failure of some patients with autoimmune diseases. In the male patients with Vogt-Koyanagi-Harada (VKH) disease, we have identified RPS4Y1 as an important resistance gene of the regimen and a functional mediator of chlorambucil (CLB). However, it remains unclear what is responsible for the resistance in female patients. In the present study, we performed RNA sequencing, tandem mass tag (TMT) proteomics, gain- and loss-of-function assays and rescue assays to screen and validate potential resistant mediators. The results showed that only Fc epsilon receptor Ig (FCER1G) exhibited significantly differential expression in CD4+ T cells among female CsA & CS resistant, sensitive and CLB & CsA & CS treated patients at transcription and protein levels. Inhibition of FCER1G was demonstrated to modulate CD4+ T cell resistance to CsA & CS in female patients. Importantly, the inhibition was mediated by elevated DNA methylation in the promoter region of the FCER1G gene. Moreover, we found that the salvage effect of CLB on CsA & CS resistance was mediated by an increased FCER1G expression via DNA demethylation in female patients. Taken together, the downregulation of FCER1G due to DNA hypermethylation is responsible for the resistance to CsA & CS and CLB reverses this resistance by inducing FCER1G expression via DNA demethylation in female patients. Modulation of FCER1G would be a promising sensitization strategy in female patients with resistance to CsA & CS.

HLA-DRB1*04:05 is involved in the development of Vogt-Koyanagi-Harada disease-like immune-related adverse events in patients receiving immune checkpoint inhibitors.

Immune checkpoint inhibitors (ICIs) activate anti-tumor activity by inhibiting immune checkpoint molecules that suppress inflammatory T-cell activity. However, ICIs can initiate excessive immune responses, thereby causing immune-related adverse events (irAEs). ICI-associated uveitis (ICIU) is an irAE that affects the eyes. Although Vogt-Koyanagi-Harada disease (VKH)-like uveitis is a common form of ICIU, it is unclear which factors determine the ICIU form. We retrospectively reviewed the medical records of nine ICIU cases treated with ICIs for malignancies. We also performed HLA typing in seven cases to investigate the association between HLA and disease type. Fisher's exact test was used for the statistical analysis. Five of the ICIU cases were VKH-like ICIUs, and four were non-VKH-like ICIUs. No association was found between mean age, sex, primary disease, ICI, time to onset, and disease type. Four patients with VKH-like uveitis underwent HLA genotyping and were all positive for HLA-DRB1*04:05. All 3 patients with non-VKH-like uveitis were negative for HLA-DRB1*04:05. Statistical analysis showed that HLA-DRB1*04:05 was significantly associated with developing VKH-like ICIU (P = 0.029). In ICIU, HLA-DRB1*04:05 was associated with the pathogenesis of VKH-like uveitis, suggesting that ICI-associated VKH-like uveitis has a similar pathogenesis to VKH.

Epigenome-wide association study identifies Vogt-Koyanagi-Harada disease-associated DNA methylation loci in Chinese.

DNA methylation is one of the important epigenetic mechanisms for modulating gene expression. By performing a genome-wide methylation association analysis of whole peripheral blood from 60 Vogt-Koyanagi-Harada disease (VKH) patients and 60 healthy controls, we depicted the global DNA methylation status of VKH disease. Further pyrosequencing validation in 160 patients and 159 controls identified 3 aberrant CpG sites in HLA gene regions including cg04026937 and cg18052547 (located in HLA-DRB1 region), and cg13778567 (HLA-DQA1). We also identified 9 aberrant CpG sites in non-HLA gene regions including cg13979407, cg21075643, cg24290586, cg10135747 and cg22707857 (BTNL2), cg22155039 (NOTCH4), cg02605387 (TNXB), cg06255004 (AGPAT2) and cg18855195 (RIBC2). Increased mRNA levels of BTNL2, NOTCH4 and TNXB were identified in VKH patients when compared with healthy controls, consistent with the hypomethylated CpG status in these gene regions. Moreover, seven aberrantly methylated CpG sites may serve as a diagnostic marker for VKH disease (AUC = 84.95%, 95%CI: 79.49%-90.41%).

Genetic association of PRKCD and CARD9 polymorphisms with Vogt-Koyanagi-Harada disease in the Chinese Han population.

BACKGROUND: Protein kinase C delta (PRKCD) and caspase recruitment domain family member 9 (CARD9) are genes involved in B and T cell activation, and cytokine production, which are vital mechanisms underlying autoimmune disease development. This study aimed to explore the association of the PRKCD and CARD9 genes with Vogt-Koyanagi-Harada disease (VKH) disease. The case-control study was performed to in 912 patients with VKH and 878 normal controls. MassARRAY system, SHEsis online platform, real-time PCR, and enzyme-linked immunosorbent assay were used to detect genotyping, haplotyping, mRNA expression, and cytokine levels, respectively. RESULTS: We found that rs74437127 C allele of PRKCD, rs3812555 CC genotype, and C allele of CARD9 were associated with increased susceptibility of VKH (Pc = 0.020, OR = 1.624; Pc = 2.04 × 10-5, OR = 1.810; Pc = 2.76 × 10-5, OR = 1.698, respectively). However, the rs74437127 T allele, and rs3812555 TC genotype and T allele were linked with decreased susceptibility to VKH (Pc = 0.020, OR = 0.616; Pc = 7.85 × 10-5, OR = 0.559; Pc = 2.76 × 10-5, OR = 0.589, respectively). PRKCD ATG and CARD9 GCTTA haplotypes decreased susceptibility to VKH (Pc = 3.11 × 10-3, OR = 0.594; Pc = 5.00 × 10-3, OR = 0.639, respectively). Functional studies on rs3812555 genotyped individuals revealed that CC carriers had significantly higher CARD9 mRNA expression and tumour necrosis factor-α production than TC/TT carriers (P = 1.00 × 10-4; P = 2.00 × 10-3, respectively). CONCLUSIONS: We found an association between PRKCD rs74437127 and CARD9 rs3812555 polymorphisms and VKH susceptibility and revealed that the increased susceptibility of rs3812555 for VKH may be mediated by regulating CARD9 gene expression and the production of pro-inflammatory cytokines, such as TNF-α.

Identification of immune hub genes participating in the pathogenesis and progression of Vogt-Koyanagi-Harada disease.

Background: Vogt-Koyanagi-Harada (VKH) disease is an autoimmune inflammatory disorder characterized by bilateral granulomatous uveitis. The objective of this study was to identify immune hub genes involved in the pathogenesis and progression of VKH disease. Methods: High throughput sequencing data were downloaded from the Gene Expression Omnibus (GEO) and an immune dataset was downloaded from ImmPort. Immune differentially expressed genes (DEGs) were obtained from their intersection in the GEO and ImmPort datasets. Immune hub genes for VKH disease were selected through differential expression analyses, including Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), Disease Ontology (DO), protein-protein interaction (PPI) network, and clustering analyses. Confidence in the immune hub genes was subsequently validated using box plots and receiver operating characteristic (ROC) curves. Results: A total of 254 DEGs were screened and after the intersection with ImmPort, 20 genes were obtained as immune DEGs. Functional enrichment analysis indicated that the key genes were mainly involved in several types of immune pathways (such as the lymphocyte mediated and leukocyte mediated immune responses, natural killer cell mediated cytotoxicity, and antigen binding) and immunodeficiency diseases. Following PPI network analysis, the top seven genes in cluster 1 were selected as potential immune hub genes in VKH. After evaluating the accuracy of the hub genes, one gene (GNLY) was excluded because its expression level was statistically similar in VKH patients and healthy controls. Finally, six immune hub genes, namely KLRC2, KLRC3 SH2D1B, GZMB, KIR2DL3, and KIR3DL2 were identified as playing important roles in the occurrence and development of VKH disease. Conclusion: Six immune hub genes (KLRC2, KLRC3 SH2D1B, GZMB, KIR2DL3, and KIR3DL2) identified by our bioinformatics analyses may provide new diagnostic and therapeutic targets for VKH disease.

Different MicroRNA profiles in Peripheral Blood mononuclear cells from patients with initial-onset and recurrent vogt-Koyanagi-Harada Disease.

BACKGROUND: Vogt-Koyanagi-Harada (VKH) disease is a common type of uveitis that leads to blindness. The clinical manifestations and treatment solutions are different between initial-onset and recurrent VKH. Therefore, identifying the microRNA (miRNA) profiles from initial-onset and recurrent VKH patients may shed light on the molecular mechanisms underlying the pathogenesis of VKH disease. METHODS AND RESULTS: RNAs isolated from peripheral blood mononuclear cells (PBMCs) from patients with initial-onset VKH, recurrent VKH, and healthy individuals were subjected to high-throughput miRNA sequencing. Pairwise analysis of miRNA sequencing data between groups was conducted to identify differentially expressed miRNAs (DEMs), which were verified using real-time quantitative polymerase chain reaction. After receiver operating characteristic analyses, we found that hsa-miR-4664-3p, hsa-miR-7704, hsa-miR-4504, and hsa-miR-206 may serve as biomarkers of different VKH stages. DEMs were classified into three groups based on their differential expression: DEMs in initial-onset stage, DEMs in recurrent stage, and DEMs common between both VKH stages (shared DEMs). Pathway enrichment analysis using the Kyoto Encyclopedia of Genes and Genomes identified the mitogen-activated protein kinase, tumor necrosis factor, and mechanistic target of rapamycin kinase pathways as significantly enriched among the target genes of recurrent stage and shared DEMs. Furthermore, we mapped a network of competing endogenous RNAs for hsa-miR-206, which we used to identify putative targets for VKH treatment. CONCLUSION: Hsa-miR-4664-3p, hsa-miR-7704, hsa-miR-4504, and hsa-miR-206 may serve as biomarkers for different stages of VKH. Additionally, our competing endogenous RNA network of hsa-miR-206 provides a new direction for VKH treatment.

Chromatin accessibility analysis reveals regulatory dynamics and therapeutic relevance of Vogt-Koyanagi-Harada disease.

The barrier to curing Vogt-Koyanagi-Harada disease (VKH) is thought to reside in a lack of understanding in the roles and regulations of peripheral inflammatory immune cells. Here we perform a single-cell multi-omic study of 166,149 cells in peripheral blood mononuclear cells from patients with VKH, profile the chromatin accessibility and gene expression in the same blood samples, and uncover prominent cellular heterogeneity. Immune cells in VKH blood are highly activated and pro-inflammatory. Notably, we describe an enrichment of transcription targets for nuclear factor kappa B in conventional dendritic cells (cDCs) that governed inflammation. Integrative analysis of transcriptomic and chromatin maps shows that the RELA in cDCs is related to disease complications and poor prognosis. Ligand-receptor interaction pairs also identify cDC as an important predictor that regulated multiple immune subsets. Our results reveal epigenetic and transcriptional dynamics in auto-inflammation, especially the cDC subtype that might lead to therapeutic strategies in VKH.

The emerging role of epigenetics and gut microbiota in Vogt-Koyanagi-Harada syndrome.

Vogt-Koyanagi-Harada (VKH) syndrome is an autoimmune disorder characterized often by acute diffuse uveitis, also known as idiopathic uveoencephalitis. The associated complications can potentially affect multiple systems throughout the body, including eyes, ears, skin and nervous system. Although the pathogenesis of VKH syndrome remains unclear, it has been established that the various genetic factors, epigenetic factors and the imbalance in immune regulation can significantly contribute to the development of this disease. In addition, the experimental autoimmune uveitis (EAU) has been commonly used to further explore the pathogenesis of the disease. Herein, in this review article, we discuss about the major research advances made in understanding of the different epigenetic factors and gut microbes involved in the pathogenesis of VKH syndrome as well as EAU. The information discussed can help to better understand the pathogenesis of VKH syndrome, and thereby might provide a basis for finding novel molecular targets and innovative treatment strategies in the future.

Peripheral Blood Transcriptome in Patients with Sarcoidosis-Associated Uveitis.

PURPOSE: To identify peripheral blood transcriptome differences in uveitis patients with sarcoidosis compared to those with Vogt-Koyanagi-Harada (VKH) syndrome and controls. METHODS: Ten patients with uveitis compatible with sarcoidosis (eight with pulmonary sarcoidosis, one with central nervous system sarcoidosis, and one with conjunctival sarcoidosis), nine patients with VKH, and nine healthy controls were prospectively enrolled. RESULTS: Ten genes exhibited a four-fold difference in expression in sarcoidosis patients compared to controls, many being involved in regulating inflammatory processes or cellular responses to microbes. CONCLUSIONS: This research suggests that the transcriptome in sarcoidosis is robust enough to be detected in the peripheral blood and that sarcoidosis can be distinguished from healthy controls. Differentially expressed genes may serve as candidates warranting further investigation with respect to disease pathophysiology and may provide additional information, such as ability to stratify patients based on associated disease severity and anatomical location of inflammation within the eye.

miRNAs: una nueva mirada de la enfermedad de Vogt-Koyanagi-Harada / miRNAs: a new look at Vogt-Koyanagi-Harada disease

Vogt-Koyanagi-Harada disease (VKH) is an autoimmune multisystemic syndrome that includes bilateral intraocular inflammation, associated with exudative retinal detachments, and systemic manifestations in the auditory, integumentary, and central nervous systems. The frequency of VKH disease in the world is variable, but in Santiago, Chile, it causes approximately 17% of non-infectious uveitis, an incidence 2 to 3-fold greater than in the USA or European countries. The evidence shows that the pathogenesis of VKH would be caused by cell-mediated autoimmunity directed against melanocytes present in the uveal tissue. CD4+ T lymphocytes (especially hyperactivity of Th17 and Th1 cells), B lymphocytes, cytokines (e.g., TGF-ß, IL-2, IL-6, IL-23 and INF-γ) and chemokines appear to play an important role in the development of VKH. Several lines of evidence support that the pathogenesis of uveitis observed in VKH involves an altered pattern of micro-ribonucleic acids (miRNA) expression, driving the loss of immunological tolerance. In this review, we discuss the evidence related to regulation and altered expression of miRNA associated with Vogt-Koyanagi-Harada and other autoimmune diseases. (AU)

Visual outcomes and choroidal thickness associated with human leukocyte antigen DRB1*04 in unclassifiable uveitis in Japanese patients.

PURPOSE: Human leukocyte antigen (HLA) and immunity are related. Uveitis is also closely related to immunity. For example, the common presence of human leukocyte antigen (HLA)-DRB1*04 in the immune response is well known. The aim of this study was to investigate the relationship between visual prognosis and various HLA alleles before and after therapy in patients with unclassifiable uveitis, excluding those with Vogt-Koyanagi-Harada (VKH) disease. METHODS: This retrospective case series included 42 eyes from 22 consecutive patients with unclassifiable uveitis, excluding those with VKH disease. Visual acuity (VA), sex, refractive error, central retinal thickness (CRT), central choroidal thickness (CCT), and duration from onset to treatment were measured at initial and 6-month visits. Mean values of parameters were compared at each visit. Genotyping was performed by polymerase chain reaction amplification with sequence-specific primers. RESULTS: DRB1*04 showed a dominant change. No significant difference was observed in the other alleles. In DRB1*04, The mean differences in initial CCT, 6-month CCT, and 6-month VA showed statistically significant difference was found in best-corrected visual acuity (BCVA) between DRB1*04+ and DRB1*04- at the first visit. BCVA values at baseline and at the final visit were 0.13 ± 0.29 and 0.20 ± 0.36 in the DRB1*04+ and 0.00045 ± 0.20 and - 0.058 ± 0.11 in the DRB1*04- groups(p = 0.00465). Central Choroidal Thickness (CCT) values pretreatment and at the final visit after treatment were (pretreatment:361.00 ± 361.0 µm,after treatment: 286.00 ± 106.53 µm, p = 0.0174) in the DRB1*04+ group, and (pretreatment:281.3 ± 139.68 µm,after treatment:223.85 ± 99.034 µm, p = 0.0426) in the DRB1*04- group, respectively, indicating changes between baseline and the final visit. CCT was significantly greater in the DRB1*04+ group at both the initial visit and at 6 months. Multivariate analysis showed a significant difference between the presence or absence of DRB1*04 and sex. CONCLUSION: HLA-DRB1*04 allele may affect visual prognosis and CCT in unclassifiable uveitis.

Analyses of circRNA and mRNA Profiles in Vogt-Koyanagi-Harada Disease.

Recent studies revealed that circular RNAs (circRNAs) are important in numerous biological process and involved in autoimmune diseases. However, their role in Vogt-Koyanagi-Harada (VKH) disease, a classical autoimmune disease, is not yet known. This research aimed to study the expression profile of mRNAs, microRNAs (miRNAs) and circRNAs and investigate the influence of circRNAs on the pathogenesis of VKH disease. We identified circRNAs, miRNAs, and mRNAs expression profiles in CD4+ T cells between 4 VKH patients and 3 healthy controls using the whole-transcriptome sequencing (RNA-seq) technique. We discovered that a total of 5088 mRNAs, 451 circRNAs and 433 miRNAs were differently expressed. The GO and KEGG pathway enrichment analyses were performed for significantly differentially expressed circRNAs and mRNAs. GSEA was conducted for all mRNAs. The functional enrichment suggested that the inflammatory response, the adaptive immune response, NF-kappa B signaling pathway, Th17 cell differentiation, Th1 and Th2 cell differentiation and T cell receptor signaling pathway were associated with VKH disease. In addition, based on the immune-related genes we screened, the circRNA-miRNA-mRNA ceRNA network was analyzed and constructed. Ten differently expressed mRNAs (LAT, ZAP70, ITK, ICOS, RASGRP1, PAG1, PLCG1, PRKCQ, LCK, CARD11) and 5 differently expressed circRNAs (hsa_circ_0033144, hsa_circ_0000233, hsa_circ_0000396, hsa_circ_0001924, hsa_circ_0001320) were selected to be validated by Real-time qPCR (RT-qPCR). The results of RT-qPCR turned out to be consistent with RNA-seq data. Further analysis showed that hsa_circ_0001320 and hsa_circ_0001924 may serve as crucial candidate marker genes of VKH disease. These results reveal that circRNAs may have a crucial immunomodulatory function in the pathophysiological process of VKH disease.

The Rs12569232 SNP Association with Vogt-Koyanagi-Harada Disease and Behcet's Disease is Probably Mediated by Regulation of Linc00467 Expression.

Purpose: To investigate whether the rs12569232 SNP association with Vogt-Koyanagi-Harada disease and Behcet's disease is mediated by regulation of Linc00467 expression.Methods: The expression of linc00467 was detected by real-time PCR. Adenovirus carrying the linc00467 was transduced into CD4+T cells and the effect on cell viability was measured by the CCK-8 test. Human proteome microarray and starBase 2.0 were used to identify the binding proteins of linc00467 and RNA Immunoprecipitation (RIP) was used to confirm the identity of bound proteins.Results: The rs12569232 was associated with the expression of linc00467. The expression of linc00467 was up-regulated in PBMCs and CD4+T cells from VKH disease and BD patients. Over-expression of linc00467 increased cell viability of CD4+T cells. HUR was the common binding protein identified by the two methods and confirmed by RIP.Conclusions: The rs12569232 association with VKH disease and BD may be mediated via regulating the expression of linc00467.

HLA-DRB1*04:05 and HLA-DQB1*04:01: Alleles Potentially Associated with Vogt-Koyanagi-Harada in Northern Thai Patients.

PURPOSE: To determine the frequency and association of alleles at human leukocyte antigen (HLA)-DRB1 and HLA-DQB1 loci in VKH disease patients from Northern Thailand. METHODS: A case-control study was conducted with three subject groups: 23 VKH patients, 20 patients with other uveitis entities, and 40 healthy blood donors. HLA-DRB1 and HLA-DQB1 loci were analyzed and the frequency of HLA-DRB1 and HLA-DQB1 alleles was calculated by direct counting. The measure of association was calculated by odds ratio (OR) and 95% confidence interval. RESULTS: In VKH patients, the most prevalent allele was HLA-DRB1*04:05, found in 35% of patients and with the highest OR (42.13). HLA-DQB1*04:01 was the next most prevalent, found in 23.91% of VKH patients. HLA-DQB1*05:02 was also detected in 23.91% of patients; however, a higher prevalence was observed in non-VKH and healthy controls (30% and 35%, respectively). CONCLUSION: HLA-DRB1*04:05 and HLA-DQB1*04:01 could be potential genetic markers for VKH.

Genetic landscape and autoimmunity of monocytes in developing Vogt-Koyanagi-Harada disease.

Vogt-Koyanagi-Harada (VKH) disease is a systemic autoimmune disorder affecting multiple organs, including eyes, skin, and central nervous system. It is known that monocytes significantly contribute to the development of autoimmune disease. However, the subset heterogeneity with unique functions and signatures in human circulating monocytes and the identity of disease-specific monocytic populations remain largely unknown. Here, we employed an advanced single-cell RNA sequencing technology to systematically analyze 11,259 human circulating monocytes and genetically defined their subpopulations. We constructed a precise atlas of human blood monocytes, identified six subpopulations-including S100A12, HLA, CD16, proinflammatory, megakaryocyte-like, and NK-like monocyte subsets-and uncovered two previously unidentified subsets: HLA and megakaryocyte-like monocyte subsets. Relative to healthy individuals, cellular composition, gene expression signatures, and activation states were markedly alternated in VKH patients utilizing cell type-specific programs, especially the CD16 and proinflammatory monocyte subpopulations. Notably, we discovered a disease-relevant subgroup, proinflammatory monocytes, which showed a discriminative gene expression signature indicative of inflammation, antiviral activity, and pathologic activation, and converted into a pathologic activation state implicating the active inflammation during VKH disease. Additionally, we found the cell type-specific transcriptional signature of proinflammatory monocytes, ISG15, whose production might reflect the treatment response. Taken together, in this study, we present discoveries on accurate classification, molecular markers, and signaling pathways for VKH disease-associated monocytes. Therapeutically targeting this proinflammatory monocyte subpopulation would provide an attractive approach for treating VKH, as well as other autoimmune diseases.

Increased Expression of Indoleamine 2,3-Dioxygenase (IDO) in Vogt-Koyanagi-Harada (VKH) Disease May Lead to a Shift of T Cell Responses Toward a Treg Population.

Previous studies have pointed out that indoleamine 2,3-dioxygenase (IDO), the rate-limiting enzyme initiating tryptophan metabolism, plays a role in the regulation of the immune system. This project was designed to investigate the potential role of IDO in monocyte-derived dendritic cells (moDCs) obtained from active Vogt-Koyanagi-Harada (VKH) disease patients. In this study, we found that the IDO mRNA expression and enzyme activity were increased in active VKH patients as compared with healthy controls and patients in remission. To investigate the role of IDO in immune regulation, an effective inhibitor 1-methyl-L-tryptophan (1-MT) was used to suppress its activity in DCs. The results showed that inhibition of IDO with 1-MT significantly decreased the expression of DC marker CD86. IDO inhibition did not affect the cytokine production of IL-6, IL-1ß, TNF-α, IL-10, and TGF-ß in DCs. Downregulation of IDO in DCs also led to the reduction of regulatory T (Treg) cells and an increased CD4+ T cell proliferation. Treatment with 1-MT did not affect the phosphorylation of the MAPK pathway in DCs. In general, our study suggests that IDO may play an important role in the pathogenesis of VKH disease by regulating DC and CD4+ T cell function. Tryptophan deficiency and kynurenine accumulation may account for the complicated effects of IDO. Further research is needed to study the precise tryptophan metabolites that may limit immune responses in VKH disease.

Variants in IL23R-C1orf141 and ADO-ZNF365-EGR2 are associated with susceptibility to Vogt-Koyanagi-Harada disease in Japanese population.

Vogt-Koyanagi-Harada (VKH) disease is a systemic inflammatory disorder that affects pigment cell-containing organs such as the eye (e.g., chronic and/or recurrent granulomatous panuveitis). While the exact etiology and pathogenic mechanism of VKH disease are unclear, HLA-DR4 alleles have been documented to be strongly associated with VKH disease in various ethnic groups. Recently, a genome-wide association study (GWAS) found two new genetic risk factors (IL23R-C1orf141 and ADO-ZNF365-EGR2) in a non-HLA region from a Han Chinese population. In this study, we replicated these GWAS findings in a Japanese population. A total of 1,643 Japanese samples (380 cases with VKH disease and 1,263 healthy controls) were recruited. We assessed four single nucleotide polymorphisms (SNPs) shown in previous GWAS: rs78377598 and rs117633859 in IL23R-C1orf141, and rs442309 and rs224058 in ADO-ZNF365-EGR2. A significant allelic association with VKH disease was observed for all of the four SNPs (rs78377598: pc = 0.0057; rs117633859: pc = 0.0017; rs442309: pc = 0.021; rs224058: pc = 0.035). In genotypic association analysis, the minor alleles of IL23R-C1orf141 rs78377598 and rs117633859 had the strongest association with disease susceptibility under the additive model (pc = 0.0075 and pc = 0.0026, respectively). The minor alleles of ADO-ZNF365-EGR2 rs442309 and rs224058 were most strongly associated with disease susceptibility under the dominant model (pc = 0.00099 and pc = 0.0023, respectively). The meta-analysis of the current and previous studies found that all of the four SNPs exhibited a significantly strong association with VKH disease (meta-p < 0.00001: rs78377598, meta-odds ratio (OR) = 1.69; rs1176338, meta-OR = 1.82; rs442309, meta-OR = 1.34; rs224058, meta-OR = 1.33). In summary, our study replicated significant associations with VKH disease susceptibility reported in a previous GWAS. Thus, the IL23R-C1orf141 and ADO-ZNF365-EGR2 loci may play important roles in the development of VKH disease through genetic polymorphisms.

Identification of Ribosomal Protein S4, Y-Linked 1 as a cyclosporin A plus corticosteroid resistance gene.

Combination of corticosteroids (CS) with cyclosporin A (CsA) is widely used in the treatment of autoimmune diseases, autoinflammatory diseases and transplantation rejection. However, some patients fail to respond or develop resistance to the combination regimen. In Vogt-Koyanagi-Harada (VKH) disease model, we performed RNA sequencing (RNA-seq) based transcriptomics, isobaric tags for relative and absolute quantification (iTRAQ) based proteomics and assays in vitro to screen and validate potential resistant molecules. We found that a total of 1697 differentially expressed genes (DEGs) and 21 differentially expressed proteins (DEPs) in CD4+ T cells between CsA & CS-resistant and -sensitive VKH patients. Ribosomal Protein S4, Y-Linked 1 (RPS4Y1) was verified to regulate the resistance of CD4+ T cells from male VKH patients to CsA & CS. Importantly, we showed that chlorambucil (CLB) could reverse the resistance by RPS4Y1 suppression. Taken together, we identify RPS4Y1 as an important CsA & CS resistance gene in VKH disease. Researchers should consider validating the resistant effect of RPS4Y1 in other autoimmune diseases or organ transplantation.