Abstract
Purpose :
Pathologic insults like chemical burn, transplant rejection or trauma lead to blindness and to a so called “high risk situation” with increased rejection rates after subsequent corneal transplantation.
All these insults cause different immunological tissue responses. Aim of this study was to evaluate the impact of different types of corneal injuries on immune cell recruitment in the cornea.
Methods :
We used 5 kinds of corneal injury models and naïve cornea as the control (n=5). The suture model is the corneal intrastromal placement of three nylon sutures. Alkali burn was induced by 1 M NaOH placed on the central corneal. Incision injury was induced in the central cornea with a linear perforating incision with 1 mm length. Corneal grafts were placed either into an avascular recipient bed as the normal-risk keratoplasty (NR-KPL) or a prevascularized recipient as the high-risk keratoplasty (HR-KPL). 1 week after incision and 2 weeks after other different injuries, corneas were excised and stained with F4/80, CD11c, Ly6G, MHC class II, CD3, CD4 and CD8. Furthermore, the draining lymph nodes (dLN) were analyzed by flow cytometry.
Results :
HR-KPL and NR-KPL initiated significantly higher recruitment of F4/80+ macrophages (Mφ), CD11c+ dendritic cells (DCs), Ly6G+ neutrophils as well as MHC II expression compared to all other groups. Suture placement and alkali burn induced only a significant increased recruitment of macrophages compared to incision and naïve eyes. The incision model did not induce a significant increase of any immune cells. Regarding T cell recruitment , only HR-KPL and NR- KPL provoked a significant higher invasion of CD3+CD4+ and CD3+CD8+ T cells, whereas in HR-KPL compared to NR-KPL significantly more CD3+CD4+ T cells were recruited. Interestingly, in the dLNs significantly less DC and Mφ could be detected in all groups compared to control. In contrast, MHC II expression was increased in HR-KPL and NR-KPL on DCs and Mφ. Only in NR-KPL CD8+ T cells were significantly increased compared to all groups.
Conclusions :
In this study we established for the first time a comparative corneal immune cell profile of different clinically relevant types of corneal injuries. This immune cell profiles will allow the establishment of a more personalized treatment regimen of high risk patients according to their individual preexisting pathologies.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.