To study the expression and possible implication of programmed death 1 (PD-1) and its ligands in the iris-ciliary body from mice with anterior chamber-associated immune deviation (ACAID).This was an experimental study. Twenty-four BALB/c mice were divided into ACAID group, negative controls, positive controls and phosphate-buffer saline controls. ACAID was evaluated by delayed-type hypersensitivity response. Expressions of PD-1 and its ligands (PD-L1, PD-L2) in the iris-ciliary body from ACAID mice were determined by real-time polymerase chain reaction and immunohistochemical studies.Delayed-type hypersensitivity was not detected in ACAID group, indicating that ACAID was induced successfully. The expression of PD-1 mRNA in ACAID group was higher than that in all other groups (F = 248. 109, P0.05). The positive controls showed a high expression of PD-L1 mRNA (F = 179. 033, P0.05). PD-1 and PD-L1 positive cells with round or oval shapes were found in whole iris-ciliary body, especially in the iris base and pupil margin. Expression of PD-1 and PD-L1 proteins were similar to their expression at mRNA levels. Neither mRNA nor protein of PD-L2 was detected in the iris-ciliary body in all groups.An increased expression of PD-1 in the iris-ciliary body of ACAID mice indicates that this is involved in the induction of ACAID.
