[The corneal allograft rejection features in CD4 and CD8 knock-out mice].

OBJECTIVE: To study the mechanism and the features of corneal allograft rejection using a model of CD4 and CD8 knock-out mice. METHODS: The mice were divided into three groups with 20 mice in each group. CD4 knock-out mice, CD8 knock-out mice and C57BL/6 mice were used as recipients and BALB/c mice as corneal graft donors. Postoperative evaluation included slit-lamp biomicroscopy and immunohistological studies. The rejection times were recorded and the cytokines in the eye after the surgery were measured at 1 week, 2 weeks and 4 weeks after the transplantation. Thirty mice (each group ten mice) received skin transplantation using BALB/c as donors in the second week after penetrating keratoplasty. The time of skin grafts rejection was recorded and the cornea grafts were inspected when the skin grafts were rejected. RESULTS: The rejection time varied in these three groups. The corneal grafts in CD4 knock-out mice were clear and no rejection occurred > 90 days. The corneal grafts in CD8 knock out mice were rejected at (28 +/- 3) days. The grafts in the control groups were rejected at (14 +/- 2) days (F = 2034, P < 0.01). The skin grafts rejection were recorded at (14 +/- 2), (12 +/- 1), (10 +/- 1) days in CD4 knock-out mice, CD8 knock-out mice and control groups, respectively (F = 42.54, P < 0.01). CONCLUSIONS: CD4 and CD8 knock-out mice are useful models for studying of corneal graft rejection. The cornea allograft rejection after penetrating keratoplasty is mediated primarily by CD(4)(+) T lymphocytes. The CD(8)(+) T lymphocytes also participate in the rejection processes.