Enhanced allosensitization following corneal allograft transplantation in dry eye disease recipients

Abstract

Purpose: Results from our previous studies have confirmed dry eye disease (DED) as a risk factor for corneal allograft rejection. Allosensitization mediated through antigen-presenting cells (APC) in the draining lymph nodes (DLN) plays a large role in determining corneal allograft survival. In this study, we investigated APC trafficking in DED recipients and the subsequent immune sensitization against alloantigens

Methods: DED was induced in female Balb/c mice using the controlled environment chamber and subcutaneous scopolamine injections over two weeks. CD45.1 ⁺ congenic transgenic donor corneas on a C57Bl/6 background were grafted onto DED Balb/c mice. Normal Balb/c mice residing in room air underwent corneal transplantation and served as controls. DLNs were isolated 24 hours after transplantation for flow cytometric analysis: CD45.1 staining was used to detect donor-derived APCs and YAe antibody was used to identify alloantigen-bearing recipient APCs. Furthermore, delayed-type hypersensitivity (DTH) assay was performed on postoperative day 8

Results: Flow cytometry analysis demonstrated increased frequencies of both CD45.1⁺ and YAe⁺ cells in the DLNs of DED recipients 24 hours after allograft transplantation compared with control mice (CD45.1⁺: 0.53% vs. 0.35%; YAe⁺: 0.94% vs. 0.62%). Among CD11c⁺ APCs in the DLNs, DED recipients displayed more donor-derived cells (CD45.1⁺: 56.6% vs. 19.56%) and the APCs were more mature (MHCII⁺: 61.91% vs. 23.16%). DED recipients also had a greater CD45.1⁺ MHCII⁺ population (56% vs.19.2%). APC maturation was confirmed by higher frequencies of CD80 and CD86 on CD45.1⁺ cells in DLNs of DED recipients. Ear swelling in DTH assay was significantly higher in DED vs. control mice (3.4 µm vs. 1.7 µm, n=5, p=0.0023)

Conclusions: Our data demonstrate that increased APC maturation and trafficking in DED recipients may contribute to the enhanced allosensitization and furthermore a higher rejection rate

Keywords: 480 cornea: basic science • 741 transplantation • 555 immunomodulation/immunoregulation