Fig. 2
Blockage of IDO enhances resistance to JE and reduces viral burden. a Levels of l-kynurenine in the sera and brain of BL/6 and IDO KO mice. Following JEV infection, levels of l-kynurenine in the sera and brain homogenates were estimated by HPLC at different time points. b Susceptibility of IDO-ablated mice to JE. BL/6 and IDO KO mice (4 to 5 weeks old, n = 25–30) were inoculated i.p. with JEV (3.0 × 107 PFU) and examined over 15 days for their survival. c Enhanced resistance to JE by IDO inhibition. BL/6 mice were infected i.p. with JEV and administered an IDO inhibitor (1-MT, 1 and 2 mg per mouse) every day. Left graph, curve showing survival rates; middle graph, proportion of mice showing neurological disorders during JE progression every 6 h from 4 to 11 dpi; right graph, changes in body weight. Changes in body weight were expressed as the mean percentage ± SD of body weight relative to the time of challenge. d Viral burden in lymphoid and inflammatory tissues during JE. Viral burden in the spleen and brain of infected mice was assessed by real-time qRT-PCR at the indicated time points post-infection. The viral RNA load was expressed as viral RNA copy number per microgram of total RNA (n = 5–7). *p < 0.05; **p < 0.01; ***p < 0.001 compared with levels in the indicated groups or in BL/6 control mice