Lymph node removal enhances corneal graft survival in mice at high risk of rejection

Peer reviewedPublisher PD

Regulatory Effects of IFN-β on the Development of Experimental Autoimmune Uveoretinitis in B10RIII Mice

BACKGROUND: Experimental autoimmune uveoretinitis (EAU) serves as a model for human intraocular inflammation. IFN-β has been used in the treatment of certain autoimmune diseases. Earlier studies showed that it ameliorated EAU; however, the mechanisms involved in this inhibition are still largely unknown. METHODOLOGY/PRINCIPAL FINDINGS: B10RIII mice were immunized with interphotoreceptor retinoid-binding protein (IRBP) peptide 161-180 in Complete Freund's adjuvant. Splenocytes from different time points after immunization were used to evaluate the expression of IFN-β. An increased expression of IFN-β was observed during EAU and its highest expression was observed on day 16, 3 days after the peak of intraocular inflammation. Splenocytes and draining lymph node cells from mice immunized with IRBP(161-180) on day 13 and control mice were activated with anti-CD3/anti-CD28 antibodies or IRBP(161-180) to evaluate the production of IFN-γ and IL-17. The results showed that IFN-γ and IL-17 were significantly higher in immunized mice as compared to the control mice when exposed to anti-CD3/anti-CD28 antibodies. However, the production of IFN-γ and IL-17 was detected only in immunized mice, but not in the control mice when stimulated with IRBP(161-180). Multiple subcutaneous injections of IFN-β significantly inhibited EAU activity in association with a down-regulated expression of IFN-γ, IL-17 and an enhanced IL-10 production. In an in vitro system using cells from mice, IFN-β suppressed IFN-γ production by CD4(+)CD62L(-) T cells, IL-17 production by CD4(+)CD62L(+/-) T cells and proliferation of CD4(+)CD62L(+/-) T cells. IFN-β inhibited the secretion of IL-6, but promoted the secretion of IL-10 by monocytes. IFN-β-treated monocytes inhibited IL-17 secretion by CD4(+)CD62L(+/-) T cells, but did not influence IFN-γ expression and T cell proliferation. CONCLUSIONS/SIGNIFICANCE: IFN-β may exert its inhibitory effect on EAU by inhibiting Th1, Th17 cells and modulating relevant cytokines. IFN-β may provide a potential treatment for diseases mediated by Th1 and Th17 cells

Quantitative evaluation of the corneal endothelium in the mouse after grafting

Background/aim: Corneal graft survival depends critically on the quality of the endothelium. In this study the authors aimed to evaluate corneal endothelium in mice at different times after transplantation and to correlate endothelial integrity with corneal graft survival. Methods: Syngeneic and allogeneic corneal grafts at various times (days 0–60) after engraftment were examined in flat mount preparation by confocal microscopy, by evaluating the hexagonal pattern of the endothelial monolayer using actin staining of the cell cortex. Corneas from untreated mice and from mice, who were grafted after removal of draining lymph nodes served as controls. Results: In control corneas, more than 90% of the posterior surface was covered by endothelium. Syngeneic grafts were always covered by 54–99% of endothelium. In contrast, the posterior surface of corneal allografts showed great variation in the degree of endothelial cell coverage (0–98%). In addition, clinical opacity grading measure was not a reliable predictor of endothelial coverage. Conclusion: In corneal allografts there is progressive loss of endothelium over time, unlike with syngeneic grafts. However, in the early stages of allograft rejection, the grade of graft opacity does not accurately reflect the degree of endothelial cell coverage. Although corneal opacity grade is considered the main determinant of graft rejection, the data suggest that both the grade of corneal opacity plus a sufficient post-graft time duration (>8 weeks in the mouse) are required for the diagnosis of irreversible graft rejection

Neutralizing tumor necrosis factor activity leads to remission in patients with refractory noninfectious posterior uveitis.

OBJECTIVE: To evaluate the efficacy and safety of tumor necrosis factor (TNF) inhibition with the p55 TNF receptor fusion protein (TNFr-Ig) for severe sight-threatening noninfectious posterior segment intraocular inflammation. METHODS: Seventeen patients with refractory noninfectious posterior segment intraocular inflammation received TNFr-Ig by intravenous infusion in this nonrandomized, open-label, pilot study. The primary outcome measure was logMAR visual acuity. Secondary outcome measures were binocular indirect ophthalmoscopy score, cystoid macular edema, adverse effects, and vision-related (visual core module 1) and health-related (36-Item Short-Form Health Survey) quality of life. RESULTS: Within 1 month of TNFr-Ig therapy, 9 patients (53%) achieved at least a 2-line improvement in visual acuity, 8 (57%) of 14 patients with vitreous haze before treatment achieved an improvement in binocular indirect ophthalmoscopy score to 0, and macular edema resolved in 5 (56%) of 9 affected patients. Twelve (71%) of the patients achieved complete cessation of intraocular inflammation following TNFr-Ig therapy. A reduction in concomitant immunosuppression was possible for 11 patients (65%) following TNFr-Ig therapy. However, all but 1 patient required continuing adjuvant therapy during the response to TNFr-Ig, which had a median duration of 3 months. Adverse effects included mild infusion reactions in 3 patients and transient lymphocytopenia in 2 patients. CONCLUSION: Therapy with TNFr-Ig was safe and effective for treating patients with sight-threatening noninfectious posterior segment intraocular inflammation resistant to conventional immunotherapy, but adjuvant immunosuppression and repeat infusions would be required to maintain long-term remission