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2014 Agenda and Abstracts | < Previous | Next > 2014 OMIG Abstract 19 The Contribution of T cells to Corneal Angiogenic Privilege in Transplantation Purpose: To investigate the effect of T effector cells (Teffs) and/or regulatory T cells (Tregs) from high-risk (HR) or low-risk (LR) transplanted mice on vascular endothelial cell (VEC) proliferation. Methods: Ipsilateral lymph nodes were collected from Balb/c mice 14 days after low-risk and high-risk corneal transplantation. CD4+CD25-effector T cells and CD4+CD25+ Tregs, sorted by magnetic beads and stimulated with anti-CD3, were cocultured in a 96-well plate with MILE SVEN 1 cells, a vascular endothelial cell line, in DMEM/FBS10%. VEC proliferation was measured using the BrdU incorporation assay 19 hours after coculturing. Results: CD4+CD25- Teffs from high-risk and low-risk transplanted mice significantly promoted VEC proliferation compared to positive (VEGF-A 20ng/ml) and negative controls. VEC proliferation was significantly higher when cocultured with Teffs from HR than Teffs from LR and naïve mice (Teff HR 0.9 ± 0.03;Teff LR 0.7234 ± 0.1; VEGF-A 0.6 ± 0.03; Negative Control: 0.5± 0.02 p<0.0001). After culturing Teffs and VECs with CD4+CD25+ Tregs from transplanted mice VEC proliferation was significantly decreased compared to VECs cultured with Teffs alone (Teff 0.9 ± 0.03; Teff+Treg 0.6 ± 0.06; p<0.0005). Tregs alone had no effect on VEC proliferation. Conclusions: Our data showed a direct induction of VEC proliferation mediated by CD4+CD25- effector T cells isolated from high-risk and low risk transplanted mice. Further, Tregs indirectly inhibited Teff cell-mediated VEC proliferation. Our results suggest that a balance between pro-aniogenic Teffs and anti-angiogeneic Tregs is essential to sustain angiogenic privilege in HR corneal transplantation. Disclosure: N 2014 Agenda and Abstracts | < Previous | Next >
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