Side-effects of anti-inflammatory therapy in uveitis

Beneficial mechanisms of dimethyl fumarate in autoimmune uveitis: insights from single-cell RNA sequencing

BACKGROUND

Dimethyl fumarate (DMF) is a fumaric acid ester that exhibits immunoregulatory and anti-inflammatory properties. However, the function of DMF in autoimmune uveitis (AU) is incompletely understood, and studies comprehensively exploring the impact of DMF on immune cells are still lacking.

METHODS

To explore the function of DMF in uveitis and its underlying mechanisms, we conducted single-cell RNA sequencing (scRNA-seq) on the cervical draining lymph node (CDLN) cells of normal, experimental autoimmune uveitis (EAU), and DMF-treated EAU mice. Additionally, we integrated scRNA-seq data of the retina and CDLNs to identify the potential impact of DMF on ocular immune cell infiltration. Flow cytometry was conducted to verify the potential target molecules of DMF.

RESULTS

Our study showed that DMF treatment effectively ameliorated EAU symptoms. The proportional and transcriptional alterations in each immune cell type during EAU were reversed by DMF treatment. Bioinformatics analysis in our study indicated that the enhanced expression of Pim1 and Cxcr4 in EAU was reversed by DMF treatment. Further experiments demonstrated that DMF restored the balance between effector T (Teff) /regulatory T (Treg) cells through inhibiting the pathway of PIM1-protein kinase B (AKT)-Forkhead box O1 (FOXO1). By incorporating the scRNA-seq data of the retina from EAU mice into analysis, our study identified that T cells highly expressing Pim1 and Cxcr4 were enriched in the retina. DMF repressed the ocular infiltration of Teff cells, and this effect might depend on its inhibition of PIM1 and CXCR4 expression. Additionally, our study indicated that DMF might reduce the proportion of plasma cells by inhibiting PIM1 expression in B cells.

CONCLUSIONS

DMF effectively attenuated EAU symptoms. During EAU, DMF reversed the Teff/Treg cell imbalance and suppressed the ocular infiltration of Teff cells by inhibiting PIM1 and CXCR4 expression. Thus, DMF may act as a new drug option for the treatment of AU.

INJECTABLE FLUOCINOLONE IMPLANT FOR THE MANAGEMENT OF CHRONIC POSTSURGICAL CYSTOID MACULAR EDEMA IN VITRECTOMIZED EYES

PURPOSE

Long-acting injectable steroids are changing the treatment paradigm for patients with chronic intraocular inflammation and cystoid macular edema (CME). We report the use of the fluocinolone implant 0.18 mg in patients with chronic postsurgical CME after pars plana vitrectomy.

METHODS

This is a retrospective case series of 24 vitrectomized eyes which received fluocinolone implant for the management postsurgical CME. Clinical outcomes and requirement for rescue therapy were studied.

RESULTS

Median length of follow-up was 19.3 months (range 8.3-23.2 months). There was an improvement in median central subfield thickness from 412 µ m (range 167-806 µ m) to 311 µ m (range 157-686 µ m) after fluocinolone implant ( P < 0.001). The injection burden decreased significantly after study treatment ( P < 0.001); however, there was no significant change in visual acuity ( P = 0.334). Eighteen eyes had control of CME that did not require additional intravitreal therapy. Four eyes had initially controlled but recurrent CME requiring intravitreal steroid therapy at median of 7.8 months (range 7.6-15.4 months). One eye never attained sufficient inflammatory control despite rescue therapy.

CONCLUSION

Fluocinolone implant can be an effective treatment in vitrectomized patients with chronic postsurgical CME and can help decrease the overall injection burden.

Pathogenesis and current therapies for non-infectious uveitis

Non-infectious uveitis (NIU) is a disorder with various etiologies and is characterized by eye inflammation, mainly affecting people of working age. An accurate diagnosis of NIU is crucial for appropriate therapy. The aim of therapy is to improve vision, relieve ocular inflammation, prevent relapse, and avoid treatment side effects. At present, corticosteroids are the mainstay of topical or systemic therapy. However, repeated injections are required for the treatment of chronic NIU. Recently, new drug delivery systems that may ensure intraocular delivery of therapeutic drug levels have been highlighted. Furthermore, with the development of immunosuppressants and biologics, specific therapies can be selected based on the needs of each patient. Immunosuppressants used in the treatment of NIU include calcineurin inhibitors and antimetabolites. However, systemic immunosuppressive therapy itself is associated with adverse effects due to the inhibition of immune function. In patients with refractory NIU or those who cannot tolerate corticosteroids and immunosuppressors, biologics have emerged as alternative treatments. Thus, to improve the prognosis of patients with NIU, NIU should be managed with different drugs according to the response to treatment and possible side effects.

Local and Systemic Injections of Human Cord Blood Myeloid-Derived Suppressor Cells to Prevent Graft Rejection in Corneal Transplantation

Myeloid-derived suppressor cells (MDSCs) are therapeutic agents to prevent graft rejection in organ transplants by modulating inflammation. Herein, the immunosuppressive effect of human cord blood MDSCs on corneal allograft models was confirmed. CB-MDSCs were locally (subconjuctival, 5 × 10⁵) or systemically (intravenous, 1 × 10⁶) injected twice on days 0 and 7. A corneal transplantation model was established using C57BL/6 and BALB/c mice, and corneal graft opacity was measured to evaluate graft rejection up to 6 weeks. Results showed that graft survival in the MDSCs groups increased compared to vehicle groups after 42 days. Systemic and local MDSC administration inhibited the maturation (MHC-II^hi CD11c+) of dendritic cells (DCs) and the differentiation of interferon γ+ CD4+ Th1 in draining lymph nodes (LNs). However, vehicle groups increased the infiltration of CD3+ T cells and F4/80+ macrophages and produced prominent neovascular and lymphatic vessels into the graft site with increased mRNA expression of VEGF-A/C and VEGFR-1/R-3. Local MDSCs administration showed prominent anti-angiogenic/anti-lymphangiogenic effects even at lower MDSCs doses. Thus, CB-MDSCs could relatively suppress the infiltration of pathological T cells/macrophages into the corneas and the migration of mature DCs into draining LNs Therefore, ocular and systemic MDSCs administration showed therapeutic potential for preventing corneal allograft rejection.

Efficacy of Tacrolimus in Uveitis, and the Usefulness of Serum Tacrolimus Levels in Predicting Disease Control. Results from a Single Large Center

AIMS

To evaluate the efficacy of tacrolimus in patients with noninfectious uveitis, as well as the usefulness of serum tacrolimus concentration measurements in predicting disease control.

METHODS

A retrospective review was carried out on 71 eligible patients from a single specialist uveitis center for minimum 1-year follow-up. Analysis was carried out on disease activity, visual acuity, and trough serum tacrolimus concentrations (STC).

RESULTS

At 1-year follow-up, disease control was achieved in 49 patients (69.0%), this was significantly more likely in patients with trough STC levels above 5 ng/mL (88% vs 53%, p = .002). There was a significant reduction in oral prednisolone (dose ≥7.5 mg, 86% vs 54%, p < .0001). Tacrolimus was discontinued in 12 patients (17%) due to side effects.

DISCUSSION

In this study cohort, oral tacrolimus was effective and well tolerated in the treatment of noninfectious uveitis. Trough STC between 5 ng/mL and 10 ng/ml was associated with better disease control at 1-year follow-up.

Management and Treatment Outcomes of High-Risk Corneal Transplantations

Corneal transplantation is the most effective treatment for corneal blindness. Standard planned keratoplasties have a high success rate. Conditions such as active inflammation at the time of surgery, the presence of ocular surface disease, previous graft disease, or neovascularization make them more susceptible to rejection. These are so-called high-risk corneal transplantations. In our study, we selected 52 patients with a higher risk of graft rejection. A total of 78 procedures were performed. The main indications for the first keratoplasty were infections (59.6%) and traumas (21.2%). Visual acuity (VA) significantly improved from 2.05 logMAR on the day of keratoplasty to 1.66 logMAR in the latest examination (p = 0.003). An analysis of the graft survival showed a 1-year survival of 54% and a 5-year survival of 19.8% of grafts. The mean observation time without complications after the first, second, and third surgery was 23, 13, and 14 months, respectively. The best results were noted among patients with infectious indications for keratoplasty (p = 0.001). Among them, those with bacterial infection had the best visual outcomes (p = 0.047).

Anti-Inflammatory Effects of GM1 Ganglioside on Endotoxin-Induced Uveitis in Rats

Exogenous ganglioside GM1 has been reported to exert an immunomodulatory effect. We investigated the anti-inflammatory effect of GM1 ganglioside on endotoxin-induced uveitis (EIU) in rats and RAW 264.7 macrophages. Methods: EIU was induced in Lewis rats by administering a subcutaneous injection of lipopolysaccharide (LPS). GM1 was injected intraperitoneally for three consecutive days prior to the LPS injection. Twenty-four hours after the LPS injection, the integrity of the blood-aqueous barrier was evaluated by determining the protein concentration and number of infiltrating cells in the aqueous humor (AqH). Immunohistochemical and Western blot analyses of the iris-ciliary body (ICB) were performed to evaluate the effect of GM1 on the LPS-induced expression of cyclooxygenase-2 (COX-2) and intercellular adhesion molecule-1 (ICAM-1). The effect of GM1 on proinflammatory mediators and signaling cascades was examined in LPS-stimulated RAW 264.7 cells using Western blotting and immunofluorescence staining to further clarify the underlying anti-inflammatory mechanism. Results: GM1 significantly reduced the protein concentration and number of infiltrating cells in the AqH of rats with EIU. GM1 also decreased the LPS-induced expression of the ICAM-1 and COX-2 proteins in the ICB. In RAW 264.7 cells, GM1 inhibited the proinflammatory mediators induced by LPS, including inducible nitric oxide synthase (iNOS), COX-2, tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6), and this inhibitory effect was potentially mediated by suppressing transforming growth factor-β-activated kinase 1 (TAK1) and reactive oxygen species (ROS)-mediated activation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinases (MAPKs). Conclusions: Based on this study, GM1 may be a potential anti-inflammatory agent for ocular inflammatory diseases.

Efficacy and safety of intravitreal and periocular injection of corticosteroids in non-infectious uveitis: a systematic review

Uveitis is among the leading causes of visual loss in the working age population. In non-infectious uveitis, corticosteroids are the first line therapy. We sought to review systematically the evidence regarding the regional corticosteroid delivery modalities in the treatment of non-infectious uveitis. A five-database search (Pubmed, ISI Web of Science, Cochrane, ClinicalTrials.gov, and Scopus) was performed from inception to February, 2021. Nineteen studies with a total of 1935 eyes of 1753 patients were selected from 8922 abstracts retrieved by the initial search. The most frequently compared regimens were intravitreal triamcinolone acetonide injection and orbital floor triamcinolone acetonide injection (2 studies), intravitreal triamcinolone acetonide injection and posterior sub-Tenon triamcinolone acetonide injection (2 studies), and posterior sub-Tenon triamcinolone acetonide injection with the intravitreal dexamethasone implant (2 studies). Our results show that the intravitreal injection of corticosteroids is more effective, but is associated with more adverse events, than periocular injection. Some evidence supports the use of subconjunctival triamcinolone acetonide over intravitreal/periocular triamcinolone acetonide. Moreover, the overall results of 0.59 mg dosage of the intravitreal fluocinolone acetonide implant were superior to those from the 2.1 mg dose. The evidence, however, is not robust and further studies with standardized outcomes are warranted.

Blocking the inflammasome: A novel approach to treat uveitis

Uveitis is a complex ocular inflammatory disease often accompanied by bacterial or viral infections (infectious uveitis) or underlying autoimmune diseases (non-infectious uveitis). Treatment of the underlying infection along with corticosteroid-mediated suppression of acute inflammation usually resolves infectious uveitis. However, to develop more effective therapies for non-infectious uveitis and to better address acute inflammation in infectious disease, an improved understanding of the underlying inflammatory pathways is needed. In this review, we discuss the disease aetiology, preclinical in vitro and in vivo uveitis models, the role of inflammatory pathways, as well as current and future therapies. In particular, we highlight the involvement of the inflammasome in the development of non-infectious uveitis and how it could be a future target for effective treatment of the disease.

Topical Corticosteroid Use Associated With Increased Degree of Ptosis and Rate of Ptosis Repair Failure

PURPOSE

To compare the degree of ptosis and the risk of ptosis repair failure among patients with and without a history of topical corticosteroid use.

METHODS

Retrospective, case-controlled study examining topical corticosteroid use among adults with ptosis who underwent external levator advancement/resection (ELR) or Müller muscle conjunctival resection with at least 3 months postoperative follow-up. Comparative statistical analyses of surgical outcomes were performed amongst patients with and without history of topical corticosteroid use.

RESULTS

A total of 240 patients (406 eyelids) met study criteria, of which 36 patients (44 eyelids) had history of topical corticosteroid use. Mean preoperative margin reflex distance was 0.20 mm and 0.58 mm for topical corticosteroid and non-corticosteroids users (p = 0.01). Mean preoperative levator function was 9.78 mm and 10.38 mm for topical corticosteroid and non-corticosteroid users (p = 0.02). The rate of ptosis repair failure was 30% and 16% in patients with and without a history of topical corticosteroid use (odds ratio 2.25, 95% confidence interval 1.10-4.55; p = 0.03). The rate of recurrence per surgical type in eyelids with and without history of topical corticosteroid use was: external levator advancement/resection 11/27 (41%) and 48/266 (18%) (odds ratio = 3.12, confidence interval 1.36-7.15 0; p = 0.01); Müller muscle conjunctival resection 2/17 (12%) and 9/96 (9%) (odds ratio 1.29, confidence interval 0.25-6.56; p = 0.76).

CONCLUSIONS

Topical corticosteroid use is associated with more severe presenting ptosis and increased rates of ptosis repair failure. Compared to Müller muscle conjunctival resection, there is a significantly higher rate of ptosis repair failure in patients undergoing external levator advancement/resection.

Role of ASM/Cer/TXNIP signaling module in the NLRP3 inflammasome activation

BACKGROUND

This study aimed to explore the effects of ceramide (Cer) on NLRP3 inflammasome activation and their underlying mechanisms.

METHODS

Lipopolysaccharide (LPS)/adenosine triphosphate (ATP)-induced NLRP3 inflammasome activation in J774A.1 cells and THP-1 macrophages was used as an in vitro model of inflammation. Western blotting and real-time PCR (RT-PCR) were used to detect the protein and mRNA levels, respectively. IL-1β and IL-18 levels were measured by ELISA. ASM assay kit and immunofluorescence were used to detect ASM activity and Cer content.

RESULTS

Imipramine, a well-known inhibitor of ASM, significantly inhibited LPS/ATP-induced activity of ASM and the consequent accumulation of Cer. Additionally, imipramine suppressed the LPS/ATP-induced expression of thioredoxin interacting protein (TXNIP), NLRP3, caspase-1, IL-1β, and IL-18 at the protein and mRNA level. Interestingly verapamil, a TXNIP inhibitor, suppressed LPS/ATP-induced activation of TXNIP/NLRP3 inflammasome but did not affect LPS/ATP-induced ASM activation and Cer formation. TXNIP siRNA and verapamil inhibited C2-Cer-induced upregulation of TXNIP and activation of the NLRP3 inflammasome. In addition, the pretreatment of cells with sulfo-N-succinimidyl oleate (SSO), an irreversible inhibitor of the scavenger receptor CD36, blocked Cer-induced upregulation of nuclear factor-κB (NF-κB) activity, TXNIP expression, and NLRP3 inflammasome activation. Inhibition of NF-κB activation by SN50 prevented Cer-induced upregulation of TXNIP and activation of the NLRP3 inflammasome but did not affect CD36 expression.

CONCLUSION

This study demonstrated that the ASM/Cer/TXNIP signaling pathway is involved in NLRP3 inflammasome activation. The results documented that the CD36-dependent NF-κB-TXNIP signaling pathway plays an essential role in the Cer-induced activation of NLRP3 inflammasomes in macrophages.

Efficacy and Safety of Corticosteroid Implants in Non-infectious Uveitis: A Systematic Review with Network Meta-analysis

BACKGROUND/AIMS

To compare different existent implants for noninfectious uveitis.

METHODS

We performed a systematic review of randomized clinical trials (RCTs), searching in five electronic databases and screening reference lists of included studies and relevant reviews. We performed network meta-analysis to compare 0.18 mg fluocinolone acetonide implants, 0.70 mg and 0.35 mg dexamethasone implants, and sham procedures.

RESULTS

Eight RCTs were included in this systematic review, of which three articles from two studies (n = 358 patients) were included in network meta-analysis. The 0.70 mg dexamethasone implant (at 1.5 months) was associated with better results than the 0.18 mg fluocinolone acetonide implant (at 1 month) at improving vitreous haze grading (RR = 2.96; 95%CI = 1.23-7.07), and with less frequently development of cataracts at 12 (RR = 0.36; 95%CI = 0.17; 0.79) and 36 months (RR = 0.37; 95%CI = 0.20; 0.71).

CONCLUSIONS

In the short term, the 0.70 mg dexamethasone implant is superior at improving vitreous haze, and shows lower risk of cataracts. However, additional RCTs with standardized outcomes are needed.

Effectiveness of pharmacological agents for the treatment of non-infectious scleritis: a systematic review protocol

BACKGROUND

Non-infectious scleritis is a potentially sight-threatening condition in which the sclera, the white outer layer of the eye, becomes inflamed. Whilst scleritis can be infective, the majority of cases are due to non-infectious causes, often occurring in association with an underlying systemic autoimmune or auto-inflammatory condition. Thorough systemic work-up is crucial to identify disease aetiology and exclude infection; however, a significant proportion of disease remains idiopathic with the underlying cause unknown. Non-infectious scleritis is normally managed with systemic corticosteroid and immunosuppression, yet there is no widely agreed consensus on the most appropriate therapy, and no national or international guidelines exist for treatment of non-infectious scleritis.

METHODS

Standard systematic review methodology will be used to identify, select and extract data from comparative studies of pharmacological interventions used to treat patients with non-infectious scleritis. Searches of bibliographic databases (Cochrane Library, MEDLINE, CINAHL and EMBASE) and clinical trial registers will be employed. No restrictions will be placed on language or date of publication. Non-English articles will be translated where necessary. The primary outcome of interest will be disease activity measured by reduction in scleritis grading according to standardised grading systems. Secondary outcomes will include change in best corrected visual acuity, reduction in concurrent dose of systemic corticosteroid, time to treatment failure, adverse events and health-related quality of life. Risk of bias assessment will be conducted appropriate to each study design. Study selection, data extraction and risk of bias assessment will be completed by two reviewers independently. Data will be presented in a table and a narrative synthesis will be undertaken. Meta-analysis will be performed where methodological and clinical homogeneity exists. Subgroup and sensitivity analysis will be undertaken if appropriate.

DISCUSSION

Many studies have investigated the effectiveness of pharmacological agents used in the management of non-infectious scleritis. A systematic review is needed to collate and analyse this evidence. Findings of this systematic review will help guide ophthalmologists managing patients with non-infectious scleritis and may form the basis for evidence-based recommendations for future clinical practice and encourage standardisation of treatment protocols.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42019125198.

Variable Responses to Corneal Grafts: Insights from Immunology and Systems Biology

Corneal grafts interact with their hosts via complex immunobiological processes that sometimes lead to graft failure. Prediction of graft failure is often a tedious task due to the genetic and nongenetic heterogeneity of patients. As in other areas of medicine, a reliable prediction method would impact therapeutic decision-making in corneal transplantation. Valuable insights into the clinically observed heterogeneity of host responses to corneal grafts have emerged from multidisciplinary approaches, including genomics analyses, mechanical studies, immunobiology, and theoretical modeling. Here, we review the emerging concepts, tools, and new biomarkers that may allow for the prediction of graft survival.

MicroRNA-146a Alleviates Experimental Autoimmune Anterior Uveitis in the Eyes of Lewis Rats

Purpose

This study aimed to determine the effect and roles of microRNA (miRNA, miR) treatment in experimental autoimmune anterior uveitis (EAAU).

Materials and Methods

Uveitis was induced in Lewis rats by simultaneous injections of bovine melanin-associated antigen into the hind footpad and the intraperitoneal cavity. The animals were injected intravitreally with low-dose (0.5 μg) or high-dose (1.5 μg) miR-146a. The clinical scores, leukocyte count in the aqueous humor, and histology were assessed. Cytokine changes were evaluated by relative mRNA expression and enzyme-linked immunosorbent assay (ELISA). The expression of nuclear factor kappa B (NF-κB) was assessed by immunofluorescence and Western blotting. Evaluation of the DNA-binding activity of NF-κB was performed by electrophoretic mobility shift assay (EMSA).

Results

Treatment with miR-146a significantly attenuated clinical scores and leukocyte infiltration in a dose-dependent manner, a result that was compatible with histological findings. Following miR-146a injections, downregulation of interleukin- (IL-) 1β, IL-6, and IL-12 and interferon- (IFN-) γ and upregulation of IL-10 and IL-17 were noted. The decreased NF-κB expression on immunofluorescence and Western blotting and reduced DNA-binding activity on EMSA were demonstrated following miR-146a treatment.

Conclusions

miR-146a effectively reduced intraocular inflammation in EAAU through the inhibition of NF-κB. miR-146a might be a new treatment choice for uveitis.

Ptosis induced by topical steroid eye drops: Two cases reports

RATIONALE

Ptosis is a rare complication of periocular steroid use. Studies report that local injections of steroids produce ptosis. We describe the first 2 cases of ptosis because of long-term treatment with topical steroid eye drops.

PATIENT CONCERNS

Two cases admitted to our hospital because of ptosis of their right eye after long-term treatment with topical steroid eye drops. Both of them had uncontrolled Posner-Schlossman syndrome.

DIAGNOSIS

Two cases were diagnosed as steroid-related ptosis.

INTERVENTIONS

Regulatory anti-inflammation therapy was prescribed for case 1, and after inflammation control, phacoemulsification was done for her. Six months after steroid withdrawal, the levator resection of the right eye was performed. Case 2 refused our advice of steroid reduction and ptosis surgery.

OUTCOMES

After surgery, case 1 retained a symmetrical appearance during a 1-year follow-up. In the surgery, we found thin levator muscles and slack levator palpebrae superioris aponeurosis (LPSA) in the affected eye. Postoperative transmission electron microscopy revealed typical signs of apoptosis in levator muscle cells.

LESSONS

We suggest topical application of steroids induces levator muscle apoptosis and LPSA weakness, and results in ptosis.

Clinical Outcomes of Adjunctive Sustained-Release Intravitreal Dexamethasone Implants in Tuberculosis-Associated Multifocal Serpigenoid Choroiditis

PURPOSE

To analyze the safety and efficacy of sustained-release intravitreal dexamethasone implant (Ozurdex) in management of TB-associated multifocal serpiginoid choroiditis (MSC).

METHODS

Retrospective review of TB-associated MSC patients, treated with anti-TB therapy (ATT) and adjunctive intravitreal Ozurdex.

RESULTS

Nine eyes of six patients were included. Four patients required Ozurdex implant for progressive or new lesions following ATT and two for additional systemic contraindications to corticosteroids - hyperglycemia and uncontrolled hypertension, respectively. The mean time to resolution was 9.17 ± 7.71 weeks. The mean follow-up post-injection was 13.11 ± 6.05 months (median 12 months [range 6-24.5 months]). Only one of nine eyes developed recurrent MSC lesions and this was attributed to possible autoimmune etiology. Two eyes (22.2%) developed steroid-induced glaucoma - one required implant removal.

CONCLUSIONS

Sustained-release intravitreal dexamethasone is a safe and efficacious adjunctive anti-inflammatory therapy for TB-associated MSC patients with contraindication for systemic corticosteroids or requiring supplemental anti-inflammatory therapy.

Systemic administration of an anti-tumor necrosis factor-alpha monoclonal antibody protects against endotoxin-induced uveitis in rats

OBJECTIVE

This study was to evaluate the effect of systemic injection of an anti-tumor necrosis factor alpha (TNF-α) monoclonal antibody (mAb) on endotoxin-induced uveitis (EIU).

MATERIALS AND METHODS

Fifty-six male Wistar rats (6-8 weeks old) were randomly divided into three groups: EIU, anti-TNF-α mAb + EIU, and control. EIU was induced by injecting Escherichia coli O55:B5 lipopolysaccharide (LPS) into the hind footpad of the rats (150 μg/rat). The anti-TNF-α mAb (1 μg/kg) was administrated 30 min before LPS injection through one-time intravenous injection. The onset time and peak time of EIU were recorded. The serum and aqueous humor (AH) TNF-α, interleukin (IL)-6, and IL-10 levels were measured by ELISA at 4, 24, and 72 h post-LPS injection. Clinical manifestations of EIU and eye histopathology were scored.

RESULTS

Compared with the EIU rats, anti-TNF-α mAb + EIU rats showed significantly delayed onset of uveitis (t = 7.41, P< 0.001), lower clinical scores and histopathological grades (t = 3.18/2.22, P< 0.001), reduced levels of TNF-α (F = 15.06/59.43, P< 0.001) and IL-6 (F = 99.63/14.92, P< 0.001), and increased levels of IL-10 (F = 24.94/8.99, P< 0.001) in the serum and AH. AH TNF-α, serum IL-6, and AH IL-6 levels are positively correlated, whereas serum IL-10 levels were negatively correlated with EIU activity.

CONCLUSION

Antagonizing TNF-α by system injection of the anti-TNF-α mAb protects against EIU in rats. Blocking TNF-α signaling could be a useful strategy for managing uveitis.

A novel bispecific molecule delivered by recombinant AAV2 suppresses ocular inflammation and choroidal neovascularization

Elevated vascular endothelial growth factor (VEGF) and complement activation are implicated in the pathogenesis of different ocular diseases. The objective of this study was to investigate the hypothesis that dual inhibition of both VEGF and complement activation would confer better protection against ocular inflammation and neovascularization. In this study, we engineered a secreted chimeric VEGF inhibitor domain (VID), a complement inhibitor domain (CID) and a dual inhibitor (ACVP1). Vectors expressing these three inhibitors were constructed and packaged into AAV2 (sextY-F) particles. The expression and secretion of the proteins were validated by Western blot. The effects of these inhibitors expressed from AAV2 vectors were examined in endotoxin-induced uveitis (EIU), experimental autoimmune uveoretinitis (EAU) and choroidal neovascularization (CNV) mouse models. The AAV2 vectors expressing the CID- and ACVP1-attenuated inflammation in EIU and EAU model, whereas the vector expressing VID showed improved retinal structure damaged by EAU, but not affect the infiltration of inflammatory cells in EAU or EIU eyes. Both VID and CID vectors improved laser-induced retinal and choroid/RPE injuries and CNV, whereas ACVP1 vector provided significantly better protection. Our results suggest that gene therapy targeting VEGF and complement components could provide an innovative and long-term strategy for ocular inflammatory and neovascular diseases.

Systemic Immunomodulatory Strategies in High-risk Corneal Transplantation

The cornea is the most commonly transplanted tissue in the body. Although corneal grafts generally have high success rates, transplantation onto inflamed and vascularized host beds, or so-called high-risk corneal transplantation, has a high rate of graft rejection. The management of this high-risk corneal transplantation is challenging and involves numerous measures. One of the key measures to prevent graft rejection in these cases is the use of systemic immunosuppressive agents. In this article, we will review the systemic immunosuppressive agents most commonly used for high-risk corneal transplantation, which include corticosteroids, cysclosporine A, tacrolimus, mycophenolate mofetil, and rapamycin. Benefits, risks, and published data on the use of these medications for high-risk corneal transplantation will be detailed. We will also summarize novel immunoregulatory approaches that may be used to prevent graft rejection in high-risk corneal transplantation.

Sirolimus for the treatment of noninfectious uveitis

INTRODUCTION

Noninfectious posterior uveitis (NIPU) remains a significant burden of legal blindness. Because of its immune mediated and chronic recurrent nature, common therapy includes (systemic) corticosteroids and immune modulatory agents. Most treatments bear the risk of significant adverse effects. Therefore efforts are made to administer therapeutic agents directly into the vitreous cavity. The purpose of this article is to identify the role of intravitreally applied sirolimus as a recently approved therapeutic option in NIPU.

AREAS COVERED

A MEDLINE database search was conducted through August 2015 using the terms: intravitreal injection, pharmacology, sirolimus, treatment and uveitis. To provide ongoing and future perspectives in treatment options, also clinical trials as registered at ClinicalTrials.gov were included. Sirolimus (Opsiria) was in licensed from SANTEN in 2015 and approved in Phase III registration trials in the US, Europe and other countries for NIPU. Current information results mainly from registration and Phase III trials.

EXPERT OPINION

Intravitreal sirolimus appears to be an interesting option in the treatment algorithms of NIPU because of its highly targeted molecular effects, nonsteroidal nature and good safety profile. It has the advantage to avoid systemic side effects, but this has to be balanced against the fact that treatment covers one eye only and bears the risks of any intraocular procedure. Nevertheless a careful evaluation of this agent has to be made, as current experience is almost exclusively based on registration trials and long-term effects still have to be explored.

Pathogenic Function of Herpesvirus Entry Mediator in Experimental Autoimmune Uveitis by Induction of Th1- and Th17-Type T Cell Responses

Herpesvirus entry mediator (HVEM), a member of the TNFR superfamily, serves as a unique molecular switch to mediate both stimulatory and inhibitory cosignals, depending on its functions as a receptor or ligand interacting with multiple binding partners. In this study, we explored the cosignaling functions of HVEM in experimental autoimmune uveitis (EAU), a mouse model resembling human autoimmune uveitis conditions such as ocular sarcoidosis and Behcet disease. Our studies revealed that EAU severity significantly decreased in HVEM-knockout mice compared with wild-type mice, suggesting that stimulatory cosignals from the HVEM receptor are predominant in EAU. Further studies elucidated that the HVEM cosignal plays an important role in the induction of both Th1- and Th17-type pathogenic T cells in EAU, including differentiation of IL-17-producing αβ(+)γδ(-) conventional CD4(+) T cells. Mice lacking lymphotoxin-like, inducible expression, competes with herpes simplex virus glycoprotein D for HVEM, a receptor expressed by T lymphocytes : LIGHT), B- and T-lymphocyte attenuator (BTLA) or both LIGHT and BTLA are also less susceptible to EAU, indicating that LIGHT-HVEM and BTLA-HVEM interactions, two major molecular pathways mediating HVEM functions, are both important in determining EAU pathogenesis. Finally, blocking HVEM cosignals by antagonistic anti-HVEM Abs ameliorated EAU. Taken together, our studies revealed a novel function of the HVEM cosignaling molecule and its ligands in EAU pathogenesis through the induction of Th1- and Th17-type T cell responses and suggested that HVEM-related molecular pathways can be therapeutic targets in autoimmune uveitis.