S-antigen specific T cell clones from a patient with Behçet's disease

Past and Present Behçet's Disease Animal Models

Behçet's disease (BD) is presumably an autoinflammatory disease of unknown etiology for which several animal models have been described over the years. Agents and methods used for the development of these models have ranged from the herpes simplex type one virus (hsv-1) pathogen to the use of transgenic mice. Other models have also been used to investigate a possible autoimmune component. Each model possesses its own unique set of benefits and shortcomings, with no one model fully being able to recapitulate the disease phenotype. Here, we review the proposed models and provide commentary on their effectiveness and usefulness in studying the disease.

Analysis of Th Cell-related Cytokine Production in Behçet Disease Patients with Uveitis Before and After Infliximab Treatment

PURPOSE

To examine antigen-stimulated cytokine production by Behçet disease patients (BD) before and after infliximab infusion.

METHODS

PBMCs were obtained before and after infliximab infusion in BD patients with or without recurrent uveitis during at least 1 year of infliximab therapy, and from healthy subjects. PBMCs were cultured with IRBP, and Th-related cytokines in cultures were measured.

RESULTS

Levels of IL-4, IL-6, IL-10 IL-17A, IL-17F, IL-31, IFN-γ, and TNFα were higher in BD before infliximab infusion than in healthy subjects, and these levels were the highest in BD with recurrent uveitis. After infliximab infusion, these cytokine levels were reduced to a greater extent in BD without recurrent uveitis than in BD with recurrence.

CONCLUSIONS

Th-related cytokines produced by IRBP-stimulated PBMCs were elevated in BD, and infliximab infusion suppressed these cytokines to a greater extent in BD without recurrent uveitis than in those with recurrence.

Immune mechanisms in inflammatory and degenerative eye disease

It has recently been recognized that pathology of age-associated degenerative eye diseases such as adult macular degeneration (AMD), glaucoma and diabetic retinopathy, have strong immunological underpinnings. Attempts have been made to extrapolate to age-related degenerative disease insights from inflammatory processes associated with non-infectious uveitis, but these have not yet been sufficiently informative. Here we review recent findings on the immune processes underlying uveitis and those that have been shown to contribute to AMD, discussing in this context parallels and differences between overt inflammation and para-inflammation in the eye. We propose that mechanisms associated with ocular immune privilege, in combination with paucity of age-related antigen(s) within the target tissue, dampen what could otherwise be overt inflammation and result in the para-inflammation that characterizes age-associated neurodegenerative disease.

Diagnostic and prognostic biomarker discovery strategies for autoimmune disorders

Current clinical, laboratory or radiological parameters cannot accurately diagnose or predict disease outcomes in a range of autoimmune disorders. Biomarkers which can diagnose at an earlier time point, predict outcome or help guide therapeutic strategies in autoimmune diseases could improve clinical management of this broad group of debilitating disorders. Additionally, there is a growing need for a deeper understanding of multi-factorial autoimmune disorders. Proteomic platforms offering a multiplex approach are more likely to reflect the complexity of autoimmune disease processes. Findings from proteomic based studies of three distinct autoimmune diseases are presented and strategies compared. It is the authors' view that such approaches are likely to be fruitful in the movement of autoimmune disease treatment away from reactive decisions and towards a preventative stand point.

Proteomic surveillance of retinal autoantigens in endogenous uveitis: implication of esterase D and brain-type creatine kinase as novel autoantigens

PURPOSE

Various retinal proteins are newly exposed to immune system in a process of tissue destructive endogenous uveitis. Some of such proteins could be autoantigens that extend the ocular inflammation in human endogenous uveitis. In this study, we aimed to investigate the possibility of such spreading of autoantigens in endogenous uveoretinitis using a proteomic approach.

METHODS

Experimental autoimmune uveoretinitis (EAU) was induced in mice by inoculation with a peptide consisting of amino acids 1-20 (GPTHLFQPSLVLDMAKVLLP) of interphotoreceptor retinoid binding protein (IRBP). Six weeks after immunization, the presence of autoantibodies against the retinal proteins in mice with EAU were examined by two-dimensional electrophoresis followed by western blotting (2D-WB). Retinal proteins targeted by the autoantibodies were identified by mass spectrometry (MS) and their autoantigenicity in patients with endogenous uveitis, such as Behcet's disease (BD, n=36), Vogt-Koyanagi-Harada disease (VKH, n=16), and sarcoidosis (n=17) were examined by enzyme-linked immunosorbent assay.

RESULTS

Six new candidate autoantigens, which were detected in mice with EAU using 2D-WD were identified by MS as beta-actin, esterase D (EsteD), tubulin beta-2, brain-type creatine kinase (BB-CK), voltage-dependent anion-selective channel protein, and aspartate aminotransferase. Among the patients with endogenous uveitis, 25% of BD and 25% of VKH patients were positive for anti-EsteD antibody, and 25% of VKH and 38.4% of sarcoidosis patients were positive for anti-BB-CK antibody.

CONCLUSIONS

Autoantibodies to EsteD and BB-CK produced in EAU-induced mice were also detected in some endogenous uveitis patients, suggesting that these proteins might be autoantigens spreading in a process of endogenous uveoretinitis.

Proteomic surveillance of autoimmunity in Behcet's disease with uveitis: selenium binding protein is a novel autoantigen in Behcet's disease

Autoimmune response to retinal antigens is considered to be one of the pathogenesis of uveitis in Behcet's disease (BD). In the present study, we comprehensively compared retinal autoantigens recognized by sera from BD patients with uveitis or healthy donors using proteomic technique, 2-dimensional electrophoresis (2DE) followed by Western blotting (WB). Six protein spots showing high reactivity with the serum from the BD patients were detected as candidate retinal autoantigens, and three of them were identified by mass spectrometry. Two of them were previously reported BD autoantigens, S-antigen and alpha-enolase, whereas the third one was selenium binding protein (SBP), a new candidate retinal autoantigen. Autoantigenicity of SBP was examined by WB and enzyme-linked immunosorbent assay (ELISA) using a recombinant protein. We found that 20 and 16% of the BD patients with uveitis were positive for the anti-SBP antibody by WB and ELISA, respectively. Comparison of clinical parameters between anti-SBP antibody-positive and -negative patients revealed that the anti-SBP antibody-positive patient group showed more frequent ocular inflammation than the antibody-negative patient group. Autoimmunity against the retinal SBP may contribute to the pathogenesis of uveitis in BD patients.

Increased proportion of CD3+CD4-CD8- double-negative T cells in peripheral blood of children with Behcet's disease

INTRODUCTION

Behcet's disease (BD) is a multi-system inflammatory disorder of poorly understood pathogenesis, which is characterized by oral aphtosis, genital ulcers and uveitis.

OBJECTIVE

To assess the role of CD3+CD4-CD8- double negative (DN) T cells in pathogenesis of Behcet's disease.

PATIENTS

Ten BD patients (age 12.2+/-2.2 years, 7 in remission, 3 in exacerbation state) treated at the Pediatric Rheumatology unit of Soroka University Medical Center and 3 age-matched controls participated in the study.

METHODS

Peripheral blood lymphocytes of study subjects were isolated and stained with fluorescein-labeled anti-CD45, CD3, CD4, CD8 antibodies and analyzed by FACS assay.

RESULTS

Proportion of CD4-CD8- DN T cells was significantly increased in BD patients (n=10) as compared to healthy controls (6.2+/-3.4% vs. 3.2+/-1.1% of total CD3+ cells, p<0.05), this cell group was additionally enhanced in BD exacerbation, compared to patients in remission (10+/-4.1% vs. 4.7+/-1.2%, p<0.05, respectively). DN T cells were significantly increased in BD patients in remission, compared to healthy controls (4.7+1.2% vs. 3.2+1.1% of total CD3+ cells, p<0.05, respectively).

CONCLUSIONS

Behcet's disease is characterized by increased proportion of CD3+CD4-CD8- double negative T cells in peripheral blood. Further studies, that include additional immunophenotyping and analysis of gene expression, aimed at characterization of these cells are currently underway.

Eales disease--an update

Eales disease, first described by Henry Eales in 1880, remains an enigma. The disease, observed more commonly in the Indian subcontinent than in the rest of the world, occurs in young healthy adult males, initially presenting as retinal periphlebitis and later as retinal ischemia that may lead to vascular alterations and neovascularization. Recurrent vitreous hemorrhage with or without retinal detachment is the common sequelae. In recent years, immunological, molecular biological, and biochemical studies have indicated the role of human leukocyte antigen, retinal autoimmunity, mycobacterium tuberculosis genome, and free radical mediated damage in the etiopathogenesis of this disease. However, its etiology appears to be multifactorial. The management depends on the stage of the disease and consists of medical treatment with oral corticosteroids in the active inflammatory stage and laser photocoagulation in the advanced retinal ischemia and neovascularization stages. The results of vitreoretinal surgery have been found to be satisfactory in case of vitreous hemorrhage with or without retinal detachment.

Immunopathology of the noninfectious posterior and intermediate uveitides

The posterior and intermediate uveitides share an underlying immune etiology; however, they can be clinically and immunopathologically distinguished. Although the initiating stimuli for posterior and intermediate uveities are not known, it is believed that an exogenous agent (such as a bacterium or a virus) or an endogenous molecule may induce disease. In either case, T-helper lymphocytes in conjunction with human leukocyte antigens are likely to be involved. This review examines the epidemiology, histology, immunopathology, and theories of pathogenesis of several posterior and intermediate uveitides, including sympathetic ophthalmia, Vogt-Koyanagi-Harada syndrome, Behçet's disease, sarcoidosis, intermediate uveitis, white dot syndromes, and birdshot retinochoroidopathy.

Fundus changes in Behcet's disease

OBJECTIVE

To describe the fundus findings in Behcet's Disease with emphasis on characteristic small white patches of retinitis.

METHODS

Case study, utilizing review of clinical charts and fundus photographic files.

RESULTS

Search of the University of California San Francisco ophthalmic photography files revealed 6 patients coded as Behcet's Disease between 1989 and 1996. Examination of the patients and their clinical records indicated that all 6 met the International Diagnostic Criteria for Behcet's Disease. The single most common fundus finding in these cases was the presence of transient, white patches of retinitis often with a small adjacent hemorrhage. Retinal vasculitis and optic neuritis were also seen, but neither with the frequency of the white patches.

CONCLUSION

The presence of small patches of retinal whitening is the most characteristic finding in Behcet's Disease. These lesions are different from cotton wool spots, and their recognition can aid in the diagnosis of Behcet's Disease and of episodes of reactivation.

Limitations of SCID-Hu mouse model for antiretinal autoantibody responses

The transfer of human peripheral blood mononuclear cells (PBMC) to mice with severe combined immune deficiency (SCID) allows the investigation of immune function. The authors investigated the potential of SCID mice to produce anti-retinal antibodies from PBMC derived from retinal vasculitis patients, and in vivo primed with retinal antigen on days 2 and 22 following transfer. Using Western blotting they could not detect any anti-retinal humoral response in sera from reconstituted animals. Human CD(4)(+) or CD8(+) T cells in spleen or lymph nodes from reconstituted animals were not detected by histological examination. Similarly, no ocular pathology was apparent. The possible mechanisms involved in the lack of an anti-retinal specific antibody response in reconstituted SCID mice are discussed.