Involvement of SKN-1 in immunosenescence.

<p>(<b>A</b>) Representative epifluorescence images showing the decreased induction of the <i>gcs-1</i> promoter. L3 larvae, 4 d/9 d adult <i>Pgcs-1::gfp</i> worms were exposed to PA14 for 24 h. (<b>B</b>) Quantification of the epifluorescence images of panel (A). Epifluorescence images are representatives of two independent experiments. EV: empty vector RNAi. (<b>C</b>) Pathogen resistance of young adult (1 day-old), 4 day-old and 9 day-old adult N2 and <i>skn-1(zu135)</i> mutant animals. <i>skn-1(zu135)</i> mutant worms exhibited significantly increased susceptibility to PA14 compared to N2 wild-type animals at all ages (p<0.0001). 1 day-old adult <i>skn-1(zu135)</i> worms show similar pathogen resistance to 4 day-old N2 worms (p = 0.1429) (middle graph). Killing assays were performed with 3 parallel plates in each condition in 2 independent trials. (<b>D</b>) Venn diagram showing the distribution of age-regulated SKN-1 target genes. Data were analyzed by finding the overlaps between micro-array databases containing the genes down-regulated at least 10-fold in 15 d adult compared to 6 d adult wild-type animals <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1002673#ppat.1002673-Youngman1" target="_blank">[27]</a> and SKN-1 dependent genes under non-stress <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1002673#ppat.1002673-Oliveira1" target="_blank">[29]</a> or oxidative stress conditions <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1002673#ppat.1002673-Park1" target="_blank">[30]</a> using expression data from Wormbase <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1002673#ppat.1002673-Yook1" target="_blank">[31]</a>. Please note that the majority of genes belong to those regulated by PA14 infection. 10 of 46 genes could be assigned to none of the groups. For the detailed gene list please refer to <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1002673#ppat.1002673.s006" target="_blank">Table S2</a>.