ovalbumin and Retinitis

To investigate the effect of systemic or local TNF-α inhibition with etanercept on experimental autoimmune uveoretinitis (EAU).. EAU was induced by immunizing B10.RIII mice with IRBPp161-180 or by adoptively transferring uveitogenic splenocytes. Mice received systemic or local treatment with etanercept in the afferent or efferent phase. For systemic treatment, mice were injected intraperitoneally. For local treatment, etanercept was injected intravitreally or subconjunctivally. Control mice received PBS. EAU scores were determined histologically. Splenic cells were assessed for [(3)H]thymidine incorporation. ELISA was performed to measure levels of cytokines produced by splenocytes. Vitreous cavity-associated immune deviation (VCAID) was induced by intravitreally injecting ovalbumin and evaluated by measuring DTH reaction.. After systemic treatment with etanercept in the afferent phase, EAU disease scores, IRBP-specific cell proliferation, and production of Th1, Th2, and Th17 cytokines were reduced. EAU also improved after intravitreal etanercept treatment in the afferent phase, with unaltered IRBP-specific proliferation, reduced IFN-γ, but increased IL-6 and IL-10 secretion. VCAID induction was impaired after intravitreal etanercept treatment. No amelioration of EAU or reduction in IRBP-specific cell response was found after systemic or intravitreal treatment in the efferent phase or after subconjunctival treatment. After adoptive transfer, etanercept- and PBS-treated recipients showed similar disease severity and antigen-specific proliferation of splenocytes.. It can be concluded that TNF-α participates mainly in the immunopathology in the induction phase of EAU. The mechanism of action underlying EAU improvement may be different for local and systemic etanercept treatment.

Topics: Adoptive Transfer; Animals; Autoimmune Diseases; Cell Proliferation; Cytokines; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Etanercept; Eye Proteins; Immunoglobulin G; Immunosuppressive Agents; Injections, Intraperitoneal; Intravitreal Injections; Mice; Ovalbumin; Receptors, Tumor Necrosis Factor; Retinitis; Retinol-Binding Proteins; T-Lymphocytes, Helper-Inducer; Tumor Necrosis Factor-alpha; Uveitis, Posterior; Vitreous Body

To investigate the efficacy of the B subunit of Escherichia coli heat-labile enterotoxin (EtxB) in the treatment of ocular autoimmune disease. Murine experimental autoimmune uveoretinitis (EAU) is an animal model of autoimmune posterior uveitis initiated by retinal antigen-specific Th1 and Th17 CD4(+) T cells, which activate myeloid cells, inducing retinal damage. EtxB is a potent immune modulator that ameliorates other Th1-mediated autoimmune diseases, enhancing regulatory T-cell activity.. EAU was induced in B10.RIII mice by immunization with peptide hIRBP(161-180). Disease severity was measured by clinical and histologic assessment, and functional responses of macrophages (Mphis) and T cells were assessed, both in vivo and in cocultures in vitro. EtxB was administered intranasally daily for 4 days, starting either 3 days before or 3 days after EAU induction.. Preimmunization treatment with EtxB protected mice from EAU, limiting both the number and the activation status of retinal infiltrating immune cells. Treatment after EAU induction did not alter the disease course, despite suppression of IFN-gamma. Although EtxB treatment of in vitro cocultures of T cells and Mphis increased IL-10 production, EtxB treatment in vivo increased the proportion and number of IL-17-producing CD4(+) cells infiltrating the eye.. EtxB preimmunization protects mice from EAU induction by inhibiting Th1 responses, but the resultant reduction in IFN-gamma responses by EtxB does not effect infiltration or structural damage in established EAU, where Th17 responses predominate. These data highlight the critical importance of the dynamics of T-cell phenotype and infiltration during EAU when considering immunomodulatory therapy.

Topics: Amino Acid Sequence; Animals; Autoimmune Diseases; Bacterial Toxins; Bone Marrow Cells; Cell Division; Disease Models, Animal; Enterotoxins; Escherichia coli Proteins; Macrophages; Mice; Mice, Inbred C57BL; Ovalbumin; Peptide Fragments; Retinitis; Retinol-Binding Proteins; T-Lymphocytes; T-Lymphocytes, Helper-Inducer; Th1 Cells; Uveitis

To determine whether the inflammation of endotoxin-induced uveitis (EIU) and experimental autoimmune uveoretinitis (EAU) alters key in vivo and in vitro parameters of ocular immune privilege.. For EIU induction, C3H/HeN mice received 200 microg lipopolysaccharide (LPS). For EAU induction, B10.A mice were immunized with 50 microg interphotoreceptor retinoid-binding protein (IRBP) mixed with complete Freund's adjuvant. Aqueous humor (AqH) was collected at periodic intervals and assayed for leukocyte content and the ability to suppress or enhance T-cell proliferation. Eyes with EAU were assessed for the capacity to support anterior chamber (AC)-associated immune deviation (ACAID) induction after injection of ovalbumin (OVA).. Inflammation within the anterior segment in EIU peaked at 12 to 24 hours and was detected from 10 days onward in EAU. In AqH of EIU, protein content rose within 4 hours, followed by infiltrating leukocytes. EIU AqH promptly lost its capacity to suppress T-cell proliferation and became mitogenic for T cells. In AqH of EAU, protein and leukocyte content rose at 11 days and continued to remain elevated thereafter. Whereas 11-day EAU AqH failed to suppress T-cell proliferation, AqH at later time points reacquired immunosuppressive properties. Injection of OVA into the AC of eyes of mice with EAU failed to induce ACAID.. The intraocular inflammation of EIU and EAU disrupted important parameters of immune privilege, ranging from breakdown of the blood- ocular barrier, to loss of an immunosuppressive microenvironment, to abrogation of ACAID. Because AqH from inflamed EAU reacquired the ability to suppress T-cell proliferation, the authors conclude that the capacity to regulate immune expression and inflammation can be a property even of inflamed eyes.

Topics: Animals; Anterior Eye Segment; Aqueous Humor; Autoimmune Diseases; Blood-Aqueous Barrier; Eye Proteins; Hypersensitivity, Delayed; Inflammation; Leukocyte Count; Lipopolysaccharides; Lymphocyte Activation; Mice; Mice, Inbred BALB C; Mice, Inbred C3H; Ovalbumin; Retinitis; Retinol-Binding Proteins; Salmonella typhimurium; T-Lymphocytes; Uveitis

The purpose of this study was to determine whether adoptive transfer of murine cytomegalovirus (MCMV)-immune lymph node cells prevents retinitis in immunosuppressed mice.. Adult BALB/c mice were thymectomized and T-cell depleted using rat monoclonal antibodies specific for mouse CD4+ and CD8+ T-cells. The level of rat immunoglobulin G in the treated mice was monitored by enzyme-linked immunosorbent assay. Immune cells were labeled with PKH26-GH immediately before adoptive transfer, and flow cytometry was used to determine the percentage of adoptively transferred T-cells (PKH+, fluorescein isothiocyanate [FITC+]) in the spleens of the recipient mice 3 days after transfer. The ability of adoptively transferred cells to protect from retinitis was studied in T-cell-depleted mice injected with MCMV through the supraciliary route. Mice received 4 x 10(7) in vitro-restimulated MCMV-immune cells, 4 x 10(7) freshly isolated MCMV-immune cells, 4 x 10(7) freshly isolated ovalbumin-immune cells, or no cells (control group).. The best time to balance depletion of endogenous T-cells with persistence of transferred cells was 3 weeks after T-cell depletion. Both restimulated and freshly isolated MCMV-immune cells conferred protection from retinitis. Freshly isolated ovalbumin-immune lymph node cells did not prevent retinitis, indicating that protection was virus-specific and merely was not because of transfer of antigen-activated lymph node cells.. Adoptive immunotherapy has been used to prevent cytomegalovirus (CMV) infection in patients who have undergone transplantation, and, by extrapolation, the results of these studies suggest that adoptive immunotherapy with human CMV-specific immune cells might be used to prevent or ameliorate CMV retinitis in immunocompromised patients.

Topics: Animals; Antibodies, Monoclonal; CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; Enzyme-Linked Immunosorbent Assay; Eye Infections, Viral; Female; Flow Cytometry; Herpesviridae Infections; Immune Tolerance; Immunotherapy, Adoptive; Lymph Nodes; Lymphocyte Depletion; Mice; Mice, Inbred BALB C; Muromegalovirus; Ovalbumin; Retinitis; T-Lymphocytes; Time Factors

Oral administration of retinal soluble antigen (S-Ag) suppresses the induction of S-Ag-mediated experimental autoimmune uveitis (EAU) in Lewis rats. EAU induced with interphotoreceptor retinoid-binding protein (IRBP), another retinal autoantigen, can also be suppressed by oral administration of IRBP. It has been speculated that feeding with one retinal autoantigen could suppress induction of uveitis with the other retinal protein by means of bystander suppression. Both uveitogenic effector and suppressor cells should find their antigens within the retina, where the suppressor cells would be expected to act on the effector cells. However, reciprocal combinations of antigens used for induction and suppression of uveitis failed to prevent onset of disease, demonstrating that bystander suppression obviously does not occur in the eye. To investigate further the localization of suppressor mechanisms, we fed Lewis rats either with retinal S-Ag or with ovalbumin (OVA) and then immunized the animals either with a mixture of S-Ag and OVA or with each antigen separately, injected into contralateral hind legs. Feeding of S-Ag prior to immunization led to suppression of uveitis, whereas feeding of OVA had no tolerizing effect when S-Ag and OVA were injected into different legs. Nevertheless, immunizing rats with a mixture of S-Ag and OVA after OVA feeding suppressed uveitis to a high degree. These findings suggest that orally induced bystander suppression might not occur in the target organ, but rather peripherally at the site of induction of the autoimmune T cells.

Topics: Administration, Oral; Animals; Anterior Chamber; Antigens; Arrestin; Autoimmune Diseases; Cells, Cultured; Desensitization, Immunologic; Eye; Eye Proteins; Hindlimb; Immune Tolerance; Immunization; Injections, Subcutaneous; Lymph Nodes; Lymphocyte Activation; Ovalbumin; Rats; Rats, Inbred Lew; Retinitis; Retinol-Binding Proteins; T-Lymphocytes, Cytotoxic; T-Lymphocytes, Regulatory; Tail; Uveitis

We compared the time course of changes in serum levels of circulating immune complexes (CICs) and of IgG antibody after sensitization of albino Lewis and pigmented Lister strain rats with uveitogenic (retinal S-antigen) and non-uveitogenic (ovalbumin) protein antigens of comparable molecular weight. Normal levels of CICs were far lower in Lewis rats in which experimental autoimmune uveoretinitis (EAU) takes the form of a severe panuveitis, than in Lister rats, in which the disease is mild, focal, confined to the posterior segment, and of lower incidence. After sensitization with either S-antigen or ovalbumin, polyethylene-glycol-precipitable CIC (PEG-CIC) peaked and fell as IgG antibody levels rose in both rat strains. However, peak levels of PEG-CIC were lower and subsequent IgG antibody levels were higher in the Lewis strain than in the less susceptible Lister strain. In both strains of rat these linked PEG-CIC/IgG antibody responses occurred earlier after sensitization with uveitogenic (S-) antigen than with ovalbumin, whether or not individual S-antigen-sensitized Lister rats developed EAU. In contrast, complement-binding CIC rose substantially only in those rats of both strains displaying EAU in response to S-antigen and not in response to ovalbumin. We suggest that immune complex (idiotypic) regulation of IgG antibody responses may be more readily perturbed by a pathogenic autoantigen (S-antigen) than by a bland antigen (ovalbumin). We also suggest that differences between the balance of regulatory and pathogenic CIC responses to uveitogenic retinal antigen may underlie or reflect strain differences in susceptibility to and severity of EAU.

Topics: Animals; Antigen-Antibody Complex; Antigens; Arrestin; Autoimmune Diseases; Enzyme-Linked Immunosorbent Assay; Eye Proteins; Freund's Adjuvant; Immunoglobulin G; Male; Ovalbumin; Rats; Rats, Inbred Lew; Retinitis; Species Specificity; Uveitis