Sarcoidosis and uveitis

Overexpression of IL-17RC associated with ocular sarcoidosis

Background

Sarcoidosis is a chronic inflammatory disease with a systemic granulomatous disorder affecting multiple organs including the eye. Both CD4⁺ T cell and macrophage have been linked to the pathogenesis of the disease.

Methods

The expression of IL-17RC was measured using FACS,immunohistochemistry and real-time PCR. Serum level of IL-17 was detected using ELISA.

Results

An elevated expression of IL-17RC on CD8⁺ T cells in peripheral blood was found in patients with ocular sarcoidosis as compared to healthy controls. Interestingly, we found a significant increase in the serum level of IL-17 in patients with ocular sarcoidosis as compared to healthy controls, which may be responsible for the induction of IL-17RC on CD8⁺ cells. In addition, IL-17RC appeared only in the retinal tissue of the patient with clinically active sarcoidosis.

Conclusions

Our results suggested a potential involvement of IL-17RC⁺CD8⁺ T cells in pathogenesis of ocular sarcoidosis.

Immunotherapeutic strategies in autoimmune uveitis

Autoimmune uveitis is an organ-specific disorder characterized by irreversible lesions to the eye that predominantly affect people in their most productive years and is among the leading causes of visual deficit and blindness. Currently available therapies are effective in the treatment of a wide spectrum of uveitis, but are often associated with severe side effects. Here, we review ongoing research with promising immunomodulatory therapeutic strategies, describing their specific features, interactions and the responses triggered by the targeted immune molecules that aim to minimize clinical complications and the likelihood of disease relapse. We first review the main features of the disease, diagnostic tools, and traditional forms of therapy, as well as the animal models predominantly used to understand the pathogenesis and test the novel intervention approaches aiming to control the acute immune and inflammatory responses and to dampen chronic responses. Both exploratory research and clinical trials have targeted either the blockade of effector pathways or of their companion co-stimulatory molecules. Examples of targets are T cell receptors (CD3), their co-stimulatory receptors (CD28, CTLA-4) and corresponding ligands (B7-1 and B7-2, also known as CD80 and CD86), and cytokines like IL-2 and their receptors. Here, we summarize the available evidence on effectiveness of these treatments in human and experimental uveitis and highlight a novel CD28 antagonist monovalent Fab′ antibody, FR104, which has shown preclinical efficacy suppressing effector T cells while enhancing regulatory T cell function and immune tolerance in a humanized graft-versus-host disease (GVHD) mice model and is currently being tested in a mouse autoimmune uveitis model with encouraging results.