Project description:Across metazoans, innate immunity is vital in defending organisms against viral infection. In mammals, antiviral innate immunity is orchestrated by interferon signaling, activating the STAT transcription factors downstream of the JAK kinases to induce expression of antiviral effector genes. In the nematode C. elegans, which lacks the interferon system, the major antiviral response so far described is RNA interference but whether additional gene expression responses are employed is not known. Here we show that, despite the absence of both interferon and JAK, the C. elegans STAT homologue STA-1 orchestrates antiviral immunity. Intriguingly, mutants lacking STA-1 show increased resistance to antiviral infection. Using gene expression analysis and chromatin immunoprecipitation we show that, in contrast to the mammalian pathway, STA-1 acts as a transcriptional repressor. Thus STA-1 might act to suppress a constitutive antiviral response in the absence of infection. Using a reverse genetic screen we identify the SID-3 as a kinase upstream of STA-1 in the response to infection. Together, our work identifies a novel STAT regulatory cascade controlling its activity in antiviral resistance, illustrating the complex evolutionary trajectory displayed by innate immune signaling pathways across metazoan organisms.
Project description:Across metazoans, innate immunity is vital in defending organisms against viral infection. In mammals, antiviral innate immunity is orchestrated by interferon signaling, activating the STAT transcription factors downstream of the JAK kinases to induce expression of antiviral effector genes. In the nematode C. elegans, which lacks the interferon system, the major antiviral response so far described is RNA interference but whether additional gene expression responses are employed is not known. Here we show that, despite the absence of both interferon and JAK, the C. elegans STAT homologue STA-1 orchestrates antiviral immunity. Intriguingly, mutants lacking STA-1 show increased resistance to antiviral infection. Using gene expression analysis and chromatin immunoprecipitation we show that, in contrast to the mammalian pathway, STA-1 acts as a transcriptional repressor. Thus STA-1 might act to suppress a constitutive antiviral response in the absence of infection. Using a reverse genetic screen we identify the SID-3 as a kinase upstream of STA-1 in the response to infection. Together, our work identifies a novel STAT regulatory cascade controlling its activity in antiviral resistance, illustrating the complex evolutionary trajectory displayed by innate immune signaling pathways across metazoan organisms.
Project description:This experiment investigates the gene expression differences upon Orsay virus infection in the Caenorhabdits elegans strains N2 and CB4856. Assays measuring viral load found that the N2 strain displays higher viral loads upon infection than the CB4856 strain. The goal of the experiment was to identify gene-expression differences that could explain the differences in viral load. We (mock-)infected 26h-old C. elegans populations with Orsay virus and took samples after 30h of infection. For each treatment-strain combination 8 samples were collected. Thereafter RNA was isolated, labelled, and hybridized on microarray.
Project description:This experiment investigates the temporal dynamics in gene expression upon Orsay virus infection in the nematode Ceanorhabditis elegans. Three different strains were infected: JU1580, N2, and CB4856. Of these, JU1580 is highly susceptible, N2 moderately susceptible, and CB4856 the most resistant strain. The goal of the experiment was to identify genes that show different expression dynamics over the time-course of the infection. We (mock-)infected 40h-old C. elegans populations with Orsay virus and took samples over a 32-hour spanning time-course. For each treatment-strain combination 12 samples were collected. Thereafter RNA was isolated, labelled, and hybridized on microarray. The gene-expression dynamics of previously identified genes (e.g. from literature and from a highly replicated N2 versus CB4856 experiment) were analyzed.
Project description:This experiment investigates changes in gene expression upon Orsay virus infection and between males and hermaphrodites in the nematode Ceanorhabditis elegans. The laboratory reference strain N2 was used. For this strain, males are less susceptible to Orsay virus infection than hermaphrodites. The goal of the experiment was to identify genes that show different expression patterns for both sexes upon Orsay virus infection. We mock-treated or infected 48h-old C. elegans populations with Orsay virus and took samples 30-hours after infection. For each treatment-sex combination 8 samples were collected. Thereafter RNA was isolated, labelled, and hybridized on microarray. The gene-expression dynamics of previously identified genes (e.g. from literature and from a highly replicated N2 versus CB4856 experiment) were analyzed.
Project description:We used RNA-seq to identify gene expression changes in C. elegans ectopically expressing Orsay virus RNA1(wt) or RNA1(RDRP defective mutant), in both wt and drh-1 mutant backgrounds
Project description:This explorative study investigated the transcriptional response of C. elegans wild types N2 and CB4856 after Orsay virus infection and Heat shock (n=1). Each strain had a sample that was heat-shocked and infected, one that was heat-shocked and mock-infected, one that was only infected and one that only underwent a mock infection. Age synchronized worms were treated separately according to different treatments mentioned before. After flash freezing, RNA was isolated, labeled and hybridized on oligo microarray (Agilent) slides.