Posterior Uveitis Associated with Cemiplimab.

PURPOSE: The immune checkpoint inhibitors (ICPIs) comprise a class of oncologic immunotherapies. The most recent US Food and Drug Administration-approved ICPI is cemiplimab (Libtayo®). Cemiplimab, like the other ICPIs, blocks checkpoint receptors in order to disinhibit T-cells so that they may detect and eliminate tumor cells. Consequently, treatment with ICPIs is associated with immune-related adverse events including uveitis. METHODS: Case report. RESULTS: A 63-year-old man with a history of metastatic squamous cell carcinoma developed blurry vision 3 months after starting treatment with cemiplimab. The patient was found to have posterior uveitis with retinal vasculitis that was successfully controlled with discontinuation of the medication as well as treatment with local and systemic steroids. CONCLUSION: Similar to other ICPIs, uveitis may be associated with cemiplimab. In the setting of posterior uveitis, treatment may require cessation of cemiplimab and intensive steroid treatment.

Use of fluocinolone acetonide intravitreal implant to manage chronic panuveitis for long-term inflammatory control without interfering with systemic immunity.

We report 2 patients with chronic panuveitis who were treated with fluocinolone acetonide intravitreal implant (Yutiq, EyePoint Pharmaceuticals Inc, Watertown, MA) intended to control ocular inflammation long term without interfering with systemic immunity. The first case was a man in his 50s referred for ocular complaints in the setting of ongoing immunotherapy for the treatment of metastatic melanoma. He was diagnosed with bilateral drug-induced panuveitis. Treatment objectives were outlined as reduction of inflammation, prevention of uveitis recurrence, and continuation of systemic immunomodulatory therapy in order to maintain malignancy remission; the patient was treated with fluocinolone acetonide intravitreal implant bilaterally and at 18 months' follow-up had 20/20 bilateral visual acuity and no inflammation. In case 2, a woman in her 70s, presented with a 2-month history of worsening floaters and blurry vision. She was phakic, with bilateral nuclear sclerotic cataracts, 1+ vitreous cells and 2+ haze, diffuse vasculitis, and central leakage around the optic nerve and posterior pole. She was diagnosed with bilateral idiopathic panuveitis with retinal vasculitis. The patient continued to do well at 1 year following intravitreal implantation with fluocinolone acetonide.

Vision loss with pembrolizumab treatment: A report of two cases.

BACKGROUND: Vision loss and other ocular toxicities are rare, but detrimental, side effects of immune checkpoint inhibitors. Herein, we report two patients who developed vision loss while on pembrolizumab treatment. CASES PRESENTATION: Case 1 - A 58-year-old man was started on pembrolizumab for advanced melanoma. He was tolerating the treatment well. After receiving 14 cycles of pembrolizumab, he developed acute bilateral vision loss and occipital headaches. An emergent ophthalmologic evaluation revealed bilateral shallow choroidal effusion with bilateral focal exudative retinal detachment. After excluding other possible etiologies, inflammatory process secondary to pembrolizumab was suspected. Pembrolizumab was stopped, and the patient was started on a course of systemic and topical steroids. His vision improved within days and he recovered completely within two months. Calculated Naranjo Nomogram score was 7 indicating a "probable" correlation; Case 2 - A 57-year-old man with stage IIIC melanoma was started on adjuvant pembrolizumab. After a few weeks of treatments, he reported minor bilateral vision changes that progressively worsened over a period of six months. An ophthalmologic evaluation revealed bilateral posterior uveitis with right optic disc edema. Pembrolizumab-related inflammatory changes were suspected, and he was started on systemic and topical steroids. His symptoms improved within a few weeks and steroids were tapered. He was re-challenged with pembrolizumab and his symptoms quickly re-occurred. Pembrolizumab was stopped indefinitely and the patient again treated with systemic and topical steroids. His symptoms resolved and his vision returned to baseline within two months. The Naranjo Nomogram score was 9 indicating a "definite" correlation. CONCLUSIONS: Vision loss is a serious complication that may occur at any point during treatment with PD-1 inhibitors. Vision loss is very distressing to the patients and their families. It is prudent for practitioners to recognize early vision abnormalities in patients receiving PD-1 antagonists to prevent permanent vision loss.

Association of Ledipasvir-Sofosbuvir Treatment With Uveitis in Patients Treated for Hepatitis C.

Importance: Ledipasvir-sofosbuvir has become the current standard of care for hepatitis C since its release in 2014. Therefore, potential adverse effects are important to identify. Objective: To report findings of uveitis after treatment with ledipasvir-sofosbuvir for hepatitis C. Design, Setting, and Participants: This case series includes patients treated in an urban academic setting with ledipasvir-sofosbuvir for hepatitis C from June 2015 to June 2017 who are known to have developed signs and symptoms of posterior uveitis. Exposures: All patients had been treated with ledipasvir-sofosbuvir for hepatitis C for a total of 12 weeks. All patients but 1 had finished treatment prior to presentation. Main Outcomes and Measures: Signs of posterior uveitis on ophthalmic testing. Results: Data were collected from 6 patients (median age, 64.5 [range, 54-72] years). Five patients were male; 4 were white, and 2 were African American. The mean (SD) time between beginning of treatment and presentation was 8.8 (5.5) months. Both eyes were affected in 3 of the 6 patients (total, 9 eyes). The median presenting visual acuity in affected eyes was 20/40 (range, 20/20-20/70). All patients had a negative systemic uveitis workup. Five patients presented with blurred vision, and 1 had a paracentral scotoma. The main ocular findings were peripheral vasculitis (in 8 of 9 eyes), papillitis (in 7 of 9 eyes), and cystoid macular edema (in 6 of 9 eyes). The median follow-up was 8 (range, 4-13) months. The median final visual acuity was 20/40 (range, 20/20-20/200). Conclusions and Relevance: In these patients, it appears that treatment with ledipasvir-sofosbuvir for hepatitis C was associated with a mild posterior uveitis different than interferon retinopathy. Given the large number of patients treated with ledipasvir-sofosbuvir, these findings cannot be considered causative, and an association cannot be quantified at this time.

PEMBROLIZUMAB ADMINISTRATION ASSOCIATED WITH POSTERIOR UVEITIS.

PURPOSE: To describe the development of uveitis and retinal vasculitis in association with pembrolizumab treatment for metastatic uveal melanoma. METHODS: A case report and a brief review of the literature are presented. Information collected and reported include the patient's clinical course, physical examination findings, fluorescein angiogram images, retinal photographs, and her response to treatment. RESULTS: A 54-year-old woman was diagnosed with a large choroidal malignant melanoma and had the affected eye enucleated. Pathology confirmed a mixed cell choroidal melanoma, and gene expression profiling was Class 2. Seventeen months after enucleation, the patient was diagnosed with metastatic uveal melanoma to the liver. Disease progression was observed during ipilimumab treatment. Pembrolizumab treatment was initiated, and after four infusions, she presented to clinic complaining of floaters and blurred vision. Examination revealed a nongranulomatous panuveitis characterized by perivascular retinal pigment epithelium pigmentary changes, retinal venous sheathing, 1+ anterior chamber and vitreous cellular reaction, 2+ vitreous haze, and optic disk edema. A dexamethasone sustained-release implant was administered and the uveitis regressed. A relapse in symptoms occurred but quickly subsided with a repeat injection. CONCLUSION: Pembrolizumab may induce a uveitic reaction. There is mounting evidence that patients using prembrolizumab should be educated and monitored for signs of uveitis.

Laser-induced intrachoroidal dexamethasone drug delivery system to posterior eye segment.

PURPOSE: To investigate the feasibility of laser-induced intrachoroidal dexamethasone (DEX) delivery as a potentially useful therapy for adjusting the most effective drug level to the posterior segment eye diseases. METHODS: An implant was prepared by dissolving poly(DL-lactide) and DEX. In vitro release of DEX was evaluated at 7, 14, and 28 days by ELISA. In vivo, a DEX implant was inserted into a rabbit choroid, and 10, 50, or 200 burns of photocoagulation were applied at the implant lesion. After treatment, the vitreous humor was immediately aspirated and the DEX level was measured by liquid chromatography/mass spectrometry/mass spectrometry. Furthermore, the vitreous DEX level was measured at 1, 7, 14, and 28 days after implantation and 50 burns of photocoagulation. The toxicity of the laser-induced DEX implant was evaluated by ophthalmoscopy and light microscopy. Endotoxin-induced uveitis (EIU) was induced after DEX implantation and photocoagulation, and anti-inflammatory activities were evaluated by grading clinical signs, protein concentrations, and histopathologic studies. RESULTS: Photocoagulation significantly increased the DEX release from the implant at 7 days in vitro. In vivo, the DEX implant exposed to 10, 50, and 200 burns of photocoagulation increased the vitreous DEX levels in a dose-dependent manner. The vitreous DEX level in the DEX implant applied to 50 burns of photocoagulation peaked 1 day after treatment. The laser-induced DEX implant showed no retinal abnormalities except the implantation site, and significantly inhibited the EIU. CONCLUSIONS: Laser-induced intrachoroidal DEX delivery controls the DEX level in the vitreous humor and effectively prevents the experimental uveitis.

Sarcoid-related uveitis occurring during adalimumab therapy.

PURPOSE: To report the first case of sarcoid-related uveitis in a patient receiving adalimumab. DESIGN: Case report. METHODS: A 61-year-old woman with rheumatoid arthritis treated with adalimumab for 4 years presented with a 1-year history of bilateral panuveitis with venous vasculitis and peripheral multifocal choroiditis. A small papular lesion was found on her forehead, which upon biopsy showed noncaseating granulomas. No systemic involvement was observed. RESULTS: An ophtalmological and clinical improvement was seen after (TNF) antagonist withdrawal plus a course of prednisone. CONCLUSIONS: Ophthalmologists should know that a sarcoid-like granulomatosis can develop during TNFα blockade therapy.

The monocyte chemokine receptor CX3CR1 does not play a significant role in the pathogenesis of experimental autoimmune uveoretinitis.

PURPOSE: To examine the role of the monocyte chemokine receptor CX(3)CR1 in experimental autoimmune uveoretinitis (EAU). METHODS: EAU was induced in naive WT, Cx(3)cr1(gfp/+), and Cx(3)cr1(gfp/gfp) C57Bl/6 mice or chimeric mice. Ocular disease severity was graded by histologic analysis of resin sections. In addition, immunohistochemistry and confocal microscopy were performed on retinal whole mounts to characterize the monocytic infiltrate and changes in retinal microglia. To determine the relative roles of resident and blood-borne monocyte-derived cells in the active phase of uveoretinitis, EAU was induced 4 weeks after transplantation in chimeric mice (Cx(3)cr1(gfp/gfp)→WT and Cx(3)cr1(gfp/+)→WT), and analysis was performed at days 14, 16, 21, and 28 after immunization. RESULTS: After EAU induction, disease scores were not significantly different in WT, Cx(3)cr1(gfp/+), and Cx(3)cr1(gfp/gfp) mice. Chimeric studies revealed both donor- and host-derived monocyte-derived cells in the inner retinal layers during early EAU; however, it was donor monocytic cells that infiltrated the photoreceptors, the site of the target antigen. The absence of CX(3)CR1 did not impede the ability of monocyte-derived cells from Cx(3)cr1(gfp/gfp) donor mice to infiltrate during the peak of EAU. CONCLUSIONS: The lack of CX(3)CR1 on monocyte-derived cells does not significantly influence the onset or severity of EAU. In addition, chimeric studies revealed that it is primarily blood-derived monocytes that mediate photoreceptor damage in the effector phase of EAU, and this process is not CX(3)CR1 dependent.

Neuroprotective effect of an antioxidant, lutein, during retinal inflammation.

PURPOSE: Lutein has been the focus of recent study as a possible therapeutic approach for retinal diseases, but the molecular mechanism of its neuroprotective effect remains to be elucidated. The aim of this study was to investigate, with the use of a mouse endotoxin-induced uveitis (EIU) model, the neuroprotective effects of lutein against retinal neural damage caused by inflammation. METHODS: EIU was induced by intraperitoneal injection of lipopolysaccharide (LPS). Each animal was given a subcutaneous injection of lutein or vehicle three times: concurrently with and 3 hours before and after the LPS injection. Analysis was carried out 24 hours after EIU induction. Levels of rhodopsin protein and STAT3 activation were analyzed by immunoblotting. Lengths of the outer segments of the photoreceptor cells were measured. Dark-adapted full-field electroretinograms were recorded. Oxidative stress in the retina was analyzed by dihydroethidium and fluorescent probe. Expression of glial fibrillary acidic protein (GFAP) was shown immunohistochemically. RESULTS: The EIU-induced decrease in rhodopsin expression followed by shortening of the outer segments and reduction in a-wave amplitude were prevented by lutein treatment. Levels of STAT3 activation, downstream of inflammatory cytokine signals, and reactive oxygen species (ROS), which are both upregulated during EIU, were reduced by lutein. Pathologic change of Müller glial cells, represented by GFAP expression, was also prevented by lutein. CONCLUSIONS: The present data revealed that the antioxidant lutein was neuroprotective during EIU, suggesting a potential approach for suppressing retinal neural damage during inflammation.

The clinical time-course of experimental autoimmune uveoretinitis using topical endoscopic fundal imaging with histologic and cellular infiltrate correlation.

PURPOSE: EAU is an established preclinical model for assessment of immunotherapeutic efficacy toward translation of therapy for posterior uveitis. Reliable screening of clinical features that correlate with underlying retinal changes and damage has not been possible to date. This study was undertaken to describe, validate, and correlate topical endoscopic fundus imaging (TEFI) with histologic features of murine experimental autoimmune uveoretinitis (EAU), with the intent of generating a rapid noninvasive panretinal assessment of ocular inflammation. METHODS: EAU was induced in B10.RIII mice by immunization with the peptide RBP-3(161-180). The clinical disease course (days 0-63) was monitored and documented using TEFI. Disease severity and pathology were confirmed at various time points by histologic assessment. The composition of the cell infiltrate was also examined and enumerated by flow cytometry. RESULTS: TEFI demonstrated the hallmark features of EAU, paralleling many of the clinical features of human uveitis, and closely aligned with underlying histologic changes, the severity of which correlated significantly with the number of infiltrating retinal leukocytes. Leukocytic infiltration occurred before manifestation of clinical disease and clinically fulminant disease, as well as cell infiltrate, resolved faster than histologic scores. During the resolution phase, neither the clinical appearance nor number of infiltrating retinal leukocytes returned to predisease levels. CONCLUSIONS: In EAU, there is a strong correlation between histologic severity and the number of infiltrating leukocytes into the retina. TEFI enhances the monitoring of clinical disease in a rapid and noninvasive fashion. Full assessment of preclinical immunotherapeutic efficacy requires the use of all three parameters: TEFI, histologic assessment, and flow cytometric analysis of retinal infiltrate.

Identification of novel dendritic cell populations in normal mouse retina.

PURPOSE: Whether tissue resident or infiltrating antigen-presenting cells (APCs) are involved in modulating immune responses in the retina and initiating inflammation is controversial. In this histologic study, the authors examine the retinas of mice strains with different susceptibility to experimental autoimmune uveoretinitis (EAU) for tissue resident APC. METHODS: Retinal wholemounts from normal and inflamed eyes of B10R III, C57BL/6, BALB/c, and ABH Biozii mice were immunostained for APC markers (33D1, CD11c, CD11b, major histocompatibility complex [MHC] class II, F4/80, CD80, CD86, CD205, mPDCA, B220, and GR1) and analyzed by confocal fluorescence microscopy using emission fingerprinting and three-dimensional reconstruction techniques. Hematoxylin and eosin-stained histologic sections were used to evaluate EAU disease scores and to assess outer blood retina barrier (retinal pigment epithelium [RPE]) structures. RESULTS: A population of 33D1(+) cells was identified exclusively in the peripheral margins and juxtapapillary areas of the retina in normal, nonimmunized C57BL/6 adult mice. These cells were also MHC class II(high), and their location corresponded to sites of earliest inflammation in EAU. Numbers in the papillary area were very low (less than 10), but this region marked the predominant anatomic site for initiation of inflammation in this moderately susceptible strain. The distribution and phenotype of these cells within the retinas differed between mouse strains exhibiting different disease susceptibility. In EAU-resistant BALB/c mice, many more 33D1(+) dendritic cells were present in the normal retina but were MHC class II(low/-). Conversely, no 33D1(+) or MHC class II (+) dendriform cells could be found in the normal retinas of highly EAU-susceptible B10.RIII mice. CONCLUSIONS: A novel population of 33D1(+) DCs was identified in normal mouse retina. The function of these cells remains to be defined, but increased numbers correlate positively with structural abnormalities in the RPE and increased resistance of the strain to EAU.

Immunological effects of allopurinol in the treatment of experimental autoimmune uveitis (EAU) after onset of the disease.

PURPOSE: Allopurinol reduces oxidative tissue damage and exerts immunomodulating effects in the treatment of experimental autoimmune uveitis (EAU). However, the mechanism of the immunologic pathway remains unclear. In previous studies, treatment was started at the time of immunization. Therefore, whether allopurinol prevents the onset of the disease (i.e., acts in a protective manner) is not known. METHODS: Sixteen male Lewis rats were used: 6 EAU without therapy [control]; 4 EAU with allopurinol treatment starting 7 days after immunization [AL7]; and 6 EAU with allopurinol treatment starting 11 days after immunization [AL11]. Their sera were tested against Western blots of sodium dodecyl sulfate-polyacrylamide gel electrophoresis of retinal proteins. Based on digital image analysis, analysis of discriminance was done. RESULTS: There were significant immunomodulating effects in both therapy groups (Wilks' lambda 0.001, P < 0.008) compared to controls. However, the effects were more pronounced in the AL7 group, where peak intensities and the number of peaks were markedly more reduced. CONCLUSIONS: Immunomodulating effects of allopurinol can be detected even if the therapy starts after the onset of the disease. Thus allopurinol strongly influences the immunologic mechanism in this model of autoimmune disease. In view of its minimal side effects, the drug could be a promising alternative for the therapy and prophylaxis of uveitis and other autoimmune diseases.

Contribution of TNF-alpha to leukocyte adhesion, vascular leakage, and apoptotic cell death in endotoxin-induced uveitis in vivo.

PURPOSE: To investigate the effect of TNF-alpha on leukocyte adhesion, vascular leakage, and apoptotic cell death in endotoxin-induced uveitis (EIU) in the rat. METHODS: EIU was induced in Long-Evans rats by a single footpad injection of lipopolysaccharide (LPS; 350 microg/kg) from Salmonella typhimurium. A single injection of recombinant TNF receptor P75 (etanercept) was given subcutaneously 24 hours before the administration of LPS. Twenty-four hours after administration of LPS, leukocyte adhesion was evaluated in vivo with SLO-acridine orange angiography and ex vivo with concanavalin A lectin staining of retinal flatmounts. Neutrophil activation was quantified by a myeloperoxidase activity assay. Vascular leakage was assessed by Evans blue extravasation. Retinal cell death was assessed with TUNEL staining and quantified with a modified ELISA protocol. Involvement of caspase-3 and -8 was determined by M30 antibody staining, Western blot analysis, and a test for enzymatic activity. RESULTS: Twenty-four hours after the LPS injection, significant increases in leukocyte rolling, adhesion, and activation were observed. In addition, increased levels of apoptosis in the vascular endothelium and the ganglion cell and inner nuclear layers and activation of caspase-8 and -3 were observed. After administration of the TNF-alpha inhibitor, significant reduction in the leukocyte rolling, adhesion, activation, and apoptosis in all the affected layers was observed. The quantitative analysis of vascular leakage revealed a significant decrease after treatment with etanercept. Retinal cell death quantification showed a significant decrease after treatment with the TNF-alpha inhibitor. CONCLUSIONS: Anti-TNF-alpha treatment reduces the LPS-induced increases in leukocyte rolling, adhesion, and vascular leakage in this rat model of inflammatory uveitis. These results suggest the involvement of TNF-alpha in inflammatory uveitis and its potential use as a therapeutic agent in the reduction of ocular inflammation.

Chemokine and chemokine receptor expression during experimental autoimmune uveoretinitis in mice.

BACKGROUND: Chemokines act as chemoattractants and activators of specific leukocytes at the site of inflammation. In this study, we investigated serial expression of chemokines and chemokine receptors in the eye with experimental autoimmune uveoretinitis (EAU) using RNAse protection assay, and confirmed their expression by immunohistochemical staining. METHODS: B10.A mice were immunized with 50 micro g of interphotoreceptor retinoid binding protein (IRBP) emulsified in complete Freund's adjuvant in order to induce EAU. The eyes were enucleated 0, 7, 14 and 21 days after IRBP immunization to analyze mRNA expression of chemokines and chemokine receptors in the posterior segment. In addition, expression of IP-10 and CXCR3 was analyzed by immunohistochemistry. RESULTS: The gene expression of RANTES, IP-10, and MCP-1 was upregulated on day 14 after immunization (early stage of EAU). The expression of chemokine receptors (CCR2 and CCR5) associated with Th1-type T cells correlated with their appropriate ligands. Furthermore, immunohistochemical study showed that IP-10 and CXCR3, the receptor for IP-10, were strongly expressed in the posterior segment of the eyes from mice with EAU. CONCLUSION: These results suggest that RANTES, IP-10 and MCP-1 may contribute to the recruitment of Th1-type T cells into the eye during the development of EAU in mice.

Posterior uveitis: an under-recognized adverse effect of pamidronate: 2 case reports.

Ocular adverse effects of pamidronic acid are rare but well documented. Pamidronate, an inhibitor of bone resorption used primarily in the management of tumor-induced hypercalcemia and Paget's disease, is reported to cause conjunctivitis, anterior uveitis, and infrequently episcleritis and scleritis. It is hypothesized that an allergic or immunologic phenomenon caused by drug-indued immune complex formation is at fault. The reason why the uvea is a target organ is unclear. The acute inflammatory response seems unrelated to the dose of the drug, the way of administration, or the activity of Paget's disease or malignancy. We report two cases of pamidronate-induced posterior uveitis, following the WHO Causality Assessment Guide of Suspected Adverse Reactions. Uveitis and scleritis have been reported in association with a variety of topical, intraocular, periocular, and systemic medications. Seven criteria were proposed to establish causality of adverse events by drugs. Only systemically administered biphosphonates meet all seven criteria. Where pamidronate is currently considered as the drug of choice in diverse strategies, the adverse ocular effects should be well known to physicians in order to make rapid diagnosis and stop the drug causing adverse reaction.

Systemic toxicity of topical and periocular corticosteroid therapy in an 11-year-old male with posterior uveitis.

PURPOSE: To report a case of systemic corticosteroid toxicity resulting from topical and periocular therapy. METHODS: Treatment and follow-up of an 11-year-old male with uveitis are illustrated. Initial presentation of the patient was bilateral iridocyclitis, for which he was treated with prednisolone acetate 1% every 2 hours for 6 months. Subsequently, posterior uveitis developed, necessitating posterior subtenon injections. RESULTS: After initial topical corticosteroid therapy, the patient developed a cushingoid habitus accompanied by increased lanugo hair, acanthosis nigricans, posterior subcapsular lens opacities, and increased intraocular pressure. Cushingoid stigmata worsened after administration of posterior subtenon injection of corticosteroids. The patient's truncal obesity worsened, and his linear growth stopped. CONCLUSIONS: Systemic toxic effects may develop as a result of topical and local use of ophthalmic corticosteroid preparations in susceptible patients.

Immune recovery uveitis in patients with AIDS and cytomegalovirus retinitis after highly active antiretroviral therapy.

PURPOSE: To estimate the incidence and describe the characteristics of immune recovery uveitis in patients with acquired immunodeficiency syndrome (AIDS) and cytomegalovirus retinitis treated with highly active antiretroviral therapy. METHODS: The records of all patients with AIDS and cytomegalovirus retinitis from 1995 to 1998 seen at the AIDS Ophthalmology Service of the Johns Hopkins Medical Institutions were reviewed. Eighty-two patients with cytomegalovirus retinitis treated with highly active antiretroviral therapy were identified. Thirty-three patients (40.2%) were classified as responders to highly active antiretroviral therapy, defined as an increase in CD4+ T-cell count by 50 cells/microL or more to a level of 100 cells/microL or more. RESULTS: Immune recovery uveitis occurred in six patients. Among the 33 patients with an immunologic response to highly active antiretroviral therapy, the incidence rate of immune recovery uveitis was 0.109/person-year. Ocular complications associated with immune recovery uveitis included cystoid macular edema (four patients), epiretinal membranes (two patients), and optic disk neovascularization (one patient). CONCLUSIONS: Immune recovery uveitis was uncommon in our population but may have vision-impairing complications.

The role of costimulatory molecules B7-1 and B7-2 in mice with experimental autoimmune uveoretinitis.

BACKGROUND: Onset of experimental autoimmune uveoretinitis (EAU) is believed to involve a CD4-positive type 1 T helper cell (Th1) immune response, with inhibition involving a Th2 immune response. Development of Th1 and Th2 responses involves the participation of the costimulatory molecules B7-1 and B7-2, respectively. The purpose of this study was to investigate the role of B7-1 and B7-2 in the EAU model in mice. METHODS: B10.A mice were immunized with interphotoreceptor retinoid-binding protein (IRBP) and given daily intraperitoneal injections of either phosphate-buffered saline (control), mouse monoclonal antibody (mAb) to B7-1, mAb to B7-2, or mAb to both B7-1 and B7-2. Eyes were evaluated by histopathological criteria and cytokines were assayed in culture medium of IRBP-stimulated lymphocytes. Cellular immune responses were measured by cell proliferation assay under IRBP stimulation. RESULTS: Rates of EAU onset were 5/10 (50%) for control mice, 1/9 (11%) for mice treated with anti-B7-1 mAb, 5/6 (83%) for mice treated with anti-B7-2 mAb, and 2/6 (33%) for mice treated with both anti-B7-1 and anti-B7-2 mAb. Mean histopathological severity scores were 2. 4+/-0.8, 1.0+/-0, 2.6+/-1.0, and 1.0+/-0, respectively. Production of IL-5 was significantly increased in mice treated with anti-B7-1 mAb, while IFN-gamma was increased in mice treated with anti-B7-2 mAb. Spleen cell proliferation was significantly reduced in mice treated with anti-B7-1 mAb. CONCLUSIONS: These results suggest that the costimulatory molecules B7-1 and B7-2, via their influence on generating Th1 and Th2 immune responses, play an important role in the clinical outcome of EAU in mice immunized with IRBP.

Macrophages and dendritic cells in IRBP-induced experimental autoimmune uveoretinitis in B10RIII mice.

PURPOSE: To investigate the characteristics of the mononuclear cell infiltrate in murine experimental autoimmune uveoretinitis (EAU). METHODS: EAU was induced by immunization with bovine interphotoreceptor retinal binding protein (IRBP) in Freund's complete adjuvant (subcutaneous injection) and pertussis toxin (intraperitoneal injection) in B10RIII mouse. Then animals were killed on days 7, 9, 12, 15, 20, 26, and 39 after immunization. Eyes were processed for hematoxylin and eosin staining to characterize the disease and to assess the severity and extent of the EAU. Single and dual immunohistochemical staining in various combinations with monoclonal antibodies against CD45, CD4, CD8, major histocompatibility complex (MHC) class II, CD11c, NLDC-145, and a variety of macrophage markers was performed. RESULTS: The authors' results showed that vitritis, vasculitis and perivasculitis, retinal detachment, and granuloma formation in retina and choroid were the predominant features of IRBP-induced B10RIII mice EAU. Immunohistologic results showed that CD4+ T cells and macrophages were the main infiltrating cells in retina and choroid throughout the entire course of the disease. MHC class II negative macrophages expressing antigens reacting with MOMA-2, F4/80, sialoadhesin, and CD11b were prominent during the peak phase of tissue damage in the retina and choroid. Dendritic cells (DCs) characterized by dual positivity for MHC class II and CD11c and negative for sialoadhesin appeared at time of disease onset and continued to be recruited during the inflammatory process. DCs at the site of inflammation were NLDC-145 weak and CD8 negative, indicating that they were of the myeloid rather than the lymphoid lineage. CONCLUSIONS: The results suggest that EAU in B10RIII mice is initiated by local-infiltrating, dendritic antigen-presenting cells, whereas tissue damage is associated with sialoadhesin-positive, phagocytic nonantigen-presenting macrophages during the effector stage.