Figure 4.

Sympathetic loss of immune privilege is the result of an axis involving ocular surface CD11c⁺ DCs, corneal nerves, and the elaboration of substance P (SP). (A, B) MHC class II⁺ DCs (including CD11c⁺ DCs) reside at the interface between the corneal allograft and the graft bed. (C) Severing corneal nerves with a trephine elicits the release of SP that converts resident CD11c⁺ DCs to contrasuppressor (CS) cells that disable CD4⁺CD25⁺ Tregs. Reproduced from Niederkorn (39) with permission from Invest Ophthalmol Vis Sci.