Table 2.

Factors that abolish immune privilege of corneal allografts

Factor	Mode of action	Effect on alloimmune response
Lymph vessels in graft bed	Provide conduits for APC trafficking to regional lymph nodes	Promotes induction of alloimmune response
Blood vessels in graft	Elevation of chemokine expression	Promotes recruitment and activation of primed immune T cells into the corneal allograft
Mucosal allergic diseases	Unknown	Activates both Th1 and Th2 alloimmunity
Splenectomy	Prevents induction of ACAID	Prevents generation of ACAID Tregs
Depletion of γδ T cells	Prevents induction of ACAID	Prevents generation of ACAID Tregs

ACAID, anterior chamber-associated immune deviation; APC, antigen-presenting cell; Tregs, T regulatory cells.