PD-1 deficiency renders resistance to listeriosis. (A) WT B6 (n = 10) or B6 PD-1KO (n = 10) mice were infected with 105 LM by intravenous injection. Their survival was monitored daily. A total of 50% of PD-1KO mice survived more than 90 days. P < .01 between the 2 groups. With the same infection procedure as in panel A, liver (B), and spleen (C) LM count (CFU per gram tissue) was measured daily for 3 days after infection. Data shown are the average of 5 mice. (D) B6 Rag-1KO (n = 10) or B6 Rag-1 PD-1 DKO (n = 10) mice were infected with 105 LM by intravenous injection, and their survival was monitored for 15 days. P < .01 between the 2 groups. With the same infection procedure as in panel D, liver (E) and spleen (F) LM count (CFU per gram tissue) was measured daily for 3 days after infection. Data shown are the average of 4 mice. *P < .05.
