Abstract
Purpose :
Cultivated allogeneic corneal endothelial cell (CEC) injection therapy for CEC dysfunction is now available. To evaluate allogeneic response post CEC injection into the anterior chamber (AC), we developed new experimental models and examined allosensitization and acquisition of transplantation tolerance.
Methods :
After detachment of the epithelial layer from the corneal eyecups of C57BL/6 mice by EDTA, mice-derived primary CECs (mpCECs) were collected by using trypsin. mpCECs (1 x 104) were then injected into the AC, subcutaneously (SC) into the neck, or intravenously (IV) into BALB/c mice. In the murine CEC injection models, a 2mm central area of the cornea was pretreated by cryoinjury to eliminate CECs. Allogeneic cell survival, allo-specific delayed-type hypersensitivity (DTH) response, and AC-associated immune deviation (ACAID) induction were evaluated at 1-week post CEC injection. Long-term transplantation tolerance was evaluated by observing the secondarily performed penetrating keratoplasty (PKP) from C57BL/6 donor mice at 8-weeks postoperative.
Results :
SC injection of mpCECs induced a DTH response, while AC and IV injection of mpCECs did not. ACAID was induced by injection of mpCECs into the AC of normal eyes. In contrast, after the eyes were inflamed by cryo-injury, the AC injection of mpCECs also did not induce DTH response in the absence of ACAID induction (N=5 each, p<0.001). Labeled mpCECs in the cryo-injured eyes survived for at least 1 week (N=5). C57BL/6 PKP allografts at 8-weeks post mpCEC injection never displayed episodes of allogeneic rejection (N=10, 100%, p<0.001), yet PKP allografts were rejected in 60% of the mice with IV injection of mpCECs and 70% of the mice with AC injection of mpCECs but without cryoinjury.
Conclusions :
Allogeneic mpCECs injected into the AC, but not SC, display low allogenicity and lack the capacity to induce DTH, and mice with surviving allogeneic mpCECs in the AC for 8 weeks acquired transplantation tolerance of the full-thickness corneal allograft. Thus, CECs injection into the AC is apart from the allogeneic rejection. Cultivated allogeneic human CEC injection therapy may be immunologically safe to maintain long-term survival post attachment at the side of Descemet’s membrane in the proposed therapy. Future studies using cultivated mCECs are necessary to further confirm the safety.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.