Pseudomonas aeruginosa Suppresses Host Immunity by Activating the DAF-2 Insulin-Like Signaling Pathway in Caenorhabditis elegans
Figure 2
The downregulation of host defense genes is specifically attenuated in daf-2 insulin-like signaling mutants.
(A–B) The transcriptional response to PA14 infection in wildtype N2 versus (A) daf-2(e1370) and (B) sma-6(wk7) worms is plotted based on whole-genome microarray analysis. Values are log2 scale transformations of the response to infection. The subset of genes that were differentially regulated in N2 worms is shown (p<0.05 and absolute difference >2 fold). Linear regressions are plotted for induced (red) and repressed (green) genes independently. (A) In daf-2(e1370), the response to induced genes to PA14 infection was largely intact (r2 = 0.4280, p<0.0001), but the response to repressed genes was strongly attenuated (r2 = 0.0009, p = 0.8306). (B) In sma-6(wk7), the response of both induced and repressed genes was largely intact (p<0.0001). (C–E) The transcriptional response to PA14 infection in wildtype N2 and (A) daf-2(e1370), (B) sek-1(km4), and (C) sma-6(wk7) animals is plotted for a set of 146 candidate immune and stress response genes based on qRT-PCR measurement. Linear regressions were calculated for induced (red) and repressed (green) genes independently. The associated correlation coefficients (r2) and p-values are indicated. (C) In daf-2(e1370), the response to induced genes to PA14 infection was largely intact (r2 = 0.62, p<0.0001), but the response to repressed genes was strongly attenuated (r2 = 0.061, p = 0.1103). (D) In sek-1(km4) the response of both induced and repressed genes was largely intact (p<0.0001 and p = 0.0026, respectively). (E) In sma-6(wk7) the response of both induced and repressed genes was largely intact (p<0.0001 each).