concanavalin-a and Uveitis--Anterior

To investigate the interaction and adherence of inflammatory cells to a heparin-surface-modified intraocular lens (HSM IOL).. Department of Ophthalmology, Tokyo Medical University Hospital, Tokyo, Japan.. Splenic mononuclear leukocytes from rats with experimental autoimmune uveitis were cultured with the optic of an HSM IOL for 96 hours. The number of adherent cells on the HSM IOL surface was measured with and without the addition of interphotoreceptor retinoid-binding protein and concanavalin A (ConA) to the culture medium. The adherent cells were observed under a light microscope or a scanning electron microscope.. Interphotoreceptor retinoid-binding protein and ConA increased the number of adherent cells on the HSM IOL relative to the control. Adherent cells on the HSM IOL were small and round, considered to be mainly lymphocytes.. Activated lymphocytes tended to adhere to the surface of the HSM IOL.

Topics: Animals; Autoimmune Diseases; Cell Adhesion; Cells, Cultured; Coated Materials, Biocompatible; Concanavalin A; Disease Models, Animal; Eye Proteins; Fibrinolytic Agents; Heparin; Lenses, Intraocular; Polymethyl Methacrylate; Rats; Rats, Inbred Lew; Retinol-Binding Proteins; Spleen; Surface Properties; Uvea; Uveitis, Anterior

To quantify S-antigen-specific (S-Ag) T cells in the retina after adoptive transfer, and to evaluate their role in the initiation and progress of destructive ocular inflammation in experimental autoimmune uveoretinitis (EAU).. Lewis rats were administered 10 x 10(6) S-Ag-specific T cells from the SP35 cell line or 10 x 10(6) concanavalin A-stimulated syngeneic spleen cell lymphoblasts labeled with lipophilic PKH26 fluorescent dye immediately before intravenous inoculation. Labeled cells in each retina were counted at various times from 4 to 120 hours after cell transfer by fluorescence microscopic analysis of each dissociated retina. Recipient eyes were examined within the same period by light and confocal microscope.. SP35 T cells showed a biphasic distribution in the retina. The first peak of 160 cells/retina was noted at 24 hours. A steady decline of labeled cells at 48 and 72 hours was followed by a rapid increase at 96 and 120 hours. Concanavalin A-stimulated, control-labeled cell populations showed an identical peak at 24 hours but a persistent decline thereafter; only two or three T cells were present in each retina at 120 hours. Concurrent inoculation of SP35 cells and nonspecific T cell blasts did not produce more SP35 cells than control cells in the retina at any time. Microscopic analysis showed mononuclear cell infiltration of the iris, ciliary body, and aqueous humor at 48 hours, which intensified rapidly and persisted through 120 hours. Retinal inflammation did not begin until 80 hours. Mononuclear cell adherence to vascular endothelium and perivascular macrophage infiltration of the innermost layers progressed to edema, and profound destructive inflammation and loss of retinal stratification were observed at 120 hours.. There is no evidence of a blood-ocular or blood-retinal barrier to activated T cell blasts. Autologous S-Ag does not provoke a more rapid entry of specific T cells at that site. The data confirm that anterior segment inflammation precedes retinal inflammation, even though S-Ag-specific T cells were present in the retina within a few hours after cell transfer. Because S-Ag is clearly present in the retina, delay in antigen presentation at that site may account for the temporal difference between retinal and anterior segment inflammation.

Topics: Adoptive Transfer; Animals; Arrestin; Autoimmune Diseases; Concanavalin A; Cytokines; Disease Models, Animal; Fluorescent Dyes; Lymphocyte Activation; Lymphocyte Count; Male; Organic Chemicals; Rats; Rats, Inbred Lew; Retina; Retinitis; T-Lymphocytes; Uveitis, Anterior; Uveitis, Posterior

To evaluate the effect of Concanavalin A (Con A) on cataract formation in New Zealand Albino rabbits. Uveitis is a chronic inflammatory condition of the eye involving the anterior and/or posterior segments. It may be acute or chronic and is associated with the development of posterior subscapular cataract over time. Con A is a nonspecific inflammatory agent and mitogen for T cells and some B cells. Used extensively in immunogenic studies Con A has been shown to induce uveitis after intravitreal injection in New Zealand Albino rabbits.. In two separate studies, Con A was injected intracamerally or intravitreally into one eye of 12 New Zealand Albino rabbits and an equal volume of balanced salt solution was injected into the opposite eye as a control. In a third study, the effect of topical steroids after intravitreal injection of Con A was evaluated. In all studies, anterior and posterior inflammation and the development of cataract was monitored by slit lamp biomicroscopy and photography. Cataract formation was also studied histopathologically.. Initially, all eyes treated with Con A demonstrated moderate anterior chamber inflammation while eyes treated with balanced salt solution showed no inflammation. Three months after treatment, posterior subcapsular cataracts were present in all rabbit eyes treated with intravitreal Con A. In the third study, topical steroid treatment of Con A-induced inflammation significantly reduced anterior chamber inflammation but had no effect on vitreous humor and posterior subcapsular cataract formation.. This experimental model was the first to demonstrate the development of posterior subcapsular cataracts after Con-A induced inflammation. The cataract was clinically and histologically similar to human posterior subscapular cataracts.

Topics: Administration, Topical; Animals; Anterior Chamber; Cataract; Concanavalin A; Disease Models, Animal; Female; Injections; Lens Capsule, Crystalline; Lens, Crystalline; Prednisone; Rabbits; Uveitis, Anterior; Uveitis, Posterior; Vitreous Body