Tim-3 Is Necessary for Corneal Allograft Survival

Abstract

Purpose: : T cell immunoglobulin and mucin domain (Tim)-3 is a helper T (Th) 1 cell-specific antigen that was implicated to play a role in the maintenance of peripheral tolerance. The purpose of the present study was to determine the role of Tim-3 in immune privilege of corneal allografts.

Methods: : Normal corneas of C57BL/6 were transplanted orthotopically into normal eyes of BALB/c mice. Recipients were administrated with 0.2 mg of anti-Tim-3 monoclonal antibodies or control rat IgG intraperitoneally, three times a week for 8 weeks after grafting. Graft survival was assessed clinically and was compared with control. Expression of Tim-3 in normal corneas and in allografts was examined immunohistochemically by confocal microscopy.

Results: : Allografts survival in anti-Tim-3 group was significantly shorter than that in the control group (p<0.05). Tim-3 expression was found on CD4-positive T cells in the posterior surface of allografts.

Conclusions: : Tim-3 plays a role on the acceptance of corneal allografts. Tim-3 positive CD4 positive T cells infiltrating in the corneal grafts may have a role in the maintenance of allografts survival within the cornea.

Keywords: immune tolerance/privilege • transplantation • cornea: basic science