Table I.

PD-L1 on islets protects against self-reactive T cells in diabetic mice

Group (islet donor→
 diabetic recipient)Days to
 rejectionaInfiltrate
 scorebIslet
 scorec
PD-L1/PD-L2−/−→WT740
540
740
240
140
PD-L1/PD-L2−/−110
PD-L1/PD-L2−/−210
110
210
810
WT→PD-L1/PD-L2−/−1240
1141
>5713
1441
840
WT→WT232
331
841
132
2632
1540
  • a Days to rejection signifies the first day at which a mouse had a blood glucose reading of ≥300 mg/dL.

  • b Graft infiltration was scored on a scale of 0–4: 0, no infiltration; 1, scattered infiltrate; 2, some infiltrate; 3, scattered islet cells with heavy infiltrate; 4, very heavy infiltration.

  • c Islet engraftment was scored on a scale of 0–4: 0, scar formation and no evidence of any islet tissue; 1, scattered islet cells with heavy infiltrate; 2, obvious foci of differentiated islet cells despite a heavy infiltrate; 3, well-differentiated graft with scattered infiltrate; 4, large differentiated graft with no infiltrate.