NIPI-3 regulates the expression of C. elegans immune genes. Caenorhabditis elegans

Many pathogens secrete toxins that target key host processes resulting in the activation of immune pathways. The secreted Pseudomonas aeruginosa toxin Exotoxin A (ToxA) disrupts intestinal protein synthesis which triggers the induction of a subset of P. aeruginosa-response genes in the nematode Caenorhabditis elegans. We found that losing one ToxA-induced C. elegans gene, the Tribbles pseudokinase ortholog nipi-3, results in hypersusceptibility to both P. aeruginosa and ToxA. We determined that NIPI-3 mediates the post-developmental expression of intestinal immune genes and proteins and primarily functions in parallel to known immune pathways, including p38 PMK-1 MAPK signaling. Here we present the microarray data that was used to determine that (1) nipi-3 regulates immune gene expression and that (2) nipi-3 and pmk-1 regulate non-overlapping gene sets consistent with them functioning in parallel. We used microarray analysis to identify the genes regulated by nipi-3 and pmk-1 at the L4 stage. Overall design: There are nine samples total that comprise three biological replicates of L4 C. elegans animals grown at 20C on OP50. The following genotypes were compared: wild type (N2), nipi-3(fr4), pmk-1(km25).

许多病原体分泌靶向宿主关键生理过程的毒素，进而激活免疫通路。分泌的铜绿假单胞菌（Pseudomonas aeruginosa）外毒素A（Exotoxin A, ToxA）可破坏肠道蛋白质合成，从而触发秀丽隐杆线虫（Caenorhabditis elegans）中一组铜绿假单胞菌应答基因的表达。我们发现，ToxA诱导的秀丽隐杆线虫基因——Tribbles假激酶同源基因nipi-3发生功能缺失后，线虫对铜绿假单胞菌和ToxA均表现出超敏易感表型。研究表明，NIPI-3介导肠道免疫基因及蛋白的发育后表达，且主要与已知免疫通路（包括p38 PMK-1丝裂原活化蛋白激酶（MAPK）信号通路）平行发挥功能。本文呈现的微阵列芯片数据可用于验证两项核心结论：(1) nipi-3调控免疫基因表达；(2) nipi-3与pmk-1调控互不重叠的基因集，这与二者平行发挥功能的推论一致。我们通过微阵列芯片分析鉴定了L4期秀丽隐杆线虫中受nipi-3和pmk-1调控的基因。整体实验设计：本研究共包含9个样本，均为在20℃条件下以OP50大肠杆菌培养的L4期秀丽隐杆线虫，设置3次生物学重复。本次研究比较了三种基因型的线虫：野生型（N2）、nipi-3(fr4)突变体、pmk-1(km25)突变体。