Fig. 1.

Schematic representation of pembrolizumab therapeutic protocol. Eight-to-10 week old male C57B6/J mice were randomly assigned in the following groups: (1) saline, (2) saline + high dose pembrolizumab, (3) bleomycin, (4) bleomycin + low dose pembrolizumab, (5) bleomycin + high dose pembrolizumab (Fig. 1). Pembrolizumab (A2005, Selleckchem) was diluted in saline as recommended by the supplier at a final concentration of 1.5 mg/mL and was injected intraperitoneally on days 8, 10 and 12 following bleomycin administration (Day 0). High dose pembrolizumab stands for 10 mg/kg, 5 mg/kg and 5 mg/kg on days 8, 10 and 12, respectively. Low dose pembrolizumab stands for 5 mg/kg, 2.5 mg/kg and 2.5 mg/kg on days 8, 10 and 12, respectively. On day 14, Ashcroft score, body weight, total protein, cellularity and respiratory mechanics were compared among the aforementioned groups. Nine mice were initially used for each arm (total: 9 mice for 5 arms-45 mice)