Figure 1.

Modulation of immune cells and inflammatory cells by MSCs in corneal surface diseases. Cornea is the avascular and transparent front part of the eye, maintained by immune and angiogenesis privilege. In the occurrence of injury and transplantation, ingrowth of blood and lymph vessels into the cornea leads to infiltration of inflammatory cells and Th1 cells, which strengthen the inflammation and damage the cornea structure. MSCs have several protective functions by (1) inhibition of the inflammatory cell infiltration and inflammatory cytokine release, (2) activation of Treg cells for immune tolerance, (3) tuning the transition from Th1 cells toward Th2 cells, and (4) improving epithelium regeneration (not shown).