Cellular immune response to Ia induction by intraocular gamma-interferon

Cytokines in immunotherapy of experimental uveitis

A better understanding of the basic mechanisms of uveitis and of the role of cytokines in experimental ocular inflammation autoimmune diseases should allow us to define new approaches for therapy. Modulation of the cytokine network by either blocking cytokine activity or administration of regulatory Th2 cytokines has shown its efficacy in several experimental autoimmune diseases including uveitis. However, cytokines present pleiotropic activities and thus may exert different effects depending on the autoimmune diseases, making interventions on their production complex. Anti-cytokine therapy or a combination of anti-cytokine drugs, antibodies, and cytokine gene therapy to synergize the therapeutical effects of other treatments appear to be of interest. Improvements in drug delivery and in biotechnology will also allow us to elaborate new and safe immunomodulatory strategies.

Ocular surface upregulation of intercellular adhesive molecule-1 (ICAM-1) by local interferon-gamma (IFN-gamma) in the rat

Inflammatory mediators such as interferon-gamma (IFN-gamma) are known to induce the expression of class II HLA (HLA-DR) and intercellular adhesion molecule 1 (ICAM-1) in a variety of cell types including epithelial cells. The coexpression of ICAM-1 and HLA-DR has been implicated in the pathogenesis of immune mediated ocular disease. We investigated the expression of ICAM-1 on the ocular surface of the rat eye following subconjunctival administration of IFN-gamma. A dose response study was performed using 100, 1,000 and 10,000 IU IFN-gamma/dose. The presence of ICAM-1 was determined using a standard immuno-peroxidase staining technique. The cornea, limbus, and conjunctiva were evaluated. The degree of reaction product in each area was graded by a masked observer. We found constitutive expression of ICAM-1 on the conjunctiva but not on the cornea. There was a significant relationship between the dose of IFN-gamma and the intensity of ICAM-1 staining on the conjunctiva (p < or = 0.05) and on the limbus (p < or = 0.04). Subconjunctival IFN-gamma had no effect on the expression of ICAM-1 in the cornea.