Figure 3

Single-hit and two-hit Candida infection induce increased PD-1 on T cells. Mice were injected via tail vein with 50 μl of the 0.5A₆₀₀Candida suspension and spleens harvested on days 0, 3, 5 and 7 post-infections.(A and B) Expression of PD-1 on CD4 and CD8 T cells was determined by immunostaining and flow cytometry.There was an increase in PD-1 expression on CD4 T cells on all three time points (P <0.05); PD-1 expression on CD8 T cells was increased at days 3 and 5 post-infection (P <0.05).(C andD) Mice underwent CLP followed three days later by i.v. injection of Candida.Cohorts of mice were killed and spleens harvested on days 3, 5, 9 and 12 post-CLP.PD-1 expression was increased on CD4 and CD8 T cells at Day 3 post-CLP (prior to Candida injection) and at days 9 and 12 post-CLP (days 6 and 9 post-Candida infection) in CD4 T cells and at Day 5 post-CLP (two days post Candida infection) in CD8 T cells (P <0.05). CD, cluster of differentiation; CLP, cecal ligation and puncture; PD-1, programmed cell death 1.