Project description:The response of the nematode C. elegans to Y. pestis infection was evaluated by gene expression profiling. A synchronized population of nematodes were exposed to Y. pestis KIM5 for 24h. Transcript levels from Y. pestis-treated animals were compared with animals maintained on relatively nonpathogenic E. coli OP50 for 24h.
Project description:Young adult fer-15;fem-1 Caenorhabditis elegans were infected with Staphylococcus aureus for 8 h to determine the transcriptional host response to Staphylococcus aureus. Analysis of differential gene expression in C. elegans young adults exposed to two different bacteria: E. coli strain OP50 (control), wild-type Staphylococcus aureus RN6390. Samples were analyzed at 8 hours after exposure to the different bacteria. These studies identified C. elegans genes induced by pathogen infection. Keywords: response to pathogen infection, innate immunity, host-pathogen interactions
Project description:The response of the nematode C. elegans to Y. pestis infection was evaluated by gene expression profiling. A synchronized population of nematodes were exposed to Y. pestis KIM5 for 24h. Transcript levels from Y. pestis-treated animals were compared with animals maintained on relatively nonpathogenic E. coli OP50 for 24h. Three independent RNA isolations were performed following exposure to either Y. pestis KIM5 or E. coli OP50. Exposures to the different pathogens were performed in parallel for each replicate isolation.
Project description:C-type lectin-like domain (CTLD) encoding genes are highly diverse in C. elegans, comprising a clec gene family of 283 members. Since vertebrate CTLD proteins have characterized functions in defense responses against pathogens and since expression of C. elegans clec genes is pathogen-dependent, it is generally assumed that clec genes function in C. elegans immune defenses. In this study we challenged this assumption and focused on the C. elegans clec gene clec-4, whose expression is highly upregulated upon infection with various pathogens. We tested the involvement of clec-4 in the defense response to infection with Pseudomonas aeruginosa PA14, Bacillus thuringiensis BT18247, and the natural pathogen Serratia rubidaea MYb237. Contrary to our expectation clec-4(ok2050) mutant worms were not more susceptible to pathogen infection than wildtype worms. To explore potential redundant function between different C. elegans clec genes, we investigated expression of several clec-4 paralogs, finding that clec-4, clec-41, and clec-42 expression shows similar infection-dependent changes and co-localizes to the intestine. We found that only clec-42 is required for the C. elegans defense response to BT18247 infection and that clec-4 genetically interacts with clec-41 and clec-42. The exact role of clec-4 in pathogen defense responses however remains enigmatic. Our results further indicate that a complex interplay between different clec genes regulates C. elegans defense responses.
Project description:Young adult N2 Caenorhabditis elegans were infected with Enterococcus faecalis or Enterococcus faecium for 8 h to determine the transcriptional host response to each enterococcal species. Analysis of differential gene expression in C. elegans young adults exposed to four different bacteria: heat-killed Escherichia coli strain OP50 (control), wild-type E. faecalis MMH594, wild-type E. faecium E007, or Bacillus subtilis PY79 (sigF::kan). Samples were analyzed at 8 hours after exposure to the different bacteria. These studies identified C. elegans genes induced by pathogen infection. Brain-heart infusion agar plates (10 ug/ml kanamycin) were used.
Project description:The Caenorhabditis elegans bus (bacterial unswollen) mutants were isolated by their altered response to the nematode pathogen Microbacterium nematophilum. The bus-2, bus-4 and bus-17 mutants are resistant to infection by this bacterium and to infection by human pathogens Yersinia pestis and Yersinia pseudotuberculosis. Here we extend that list to Staphylococcus aureus. The bus-2, bus-4 and bus-17 mutants each harbors a defect in a different glycosyltransferase involved in O-glycosylation. Glycomics analysis of these strains reveals significant O-glycosylation defects. We further investigated the nature of bus mutant phenotypes in bus-2, bus-4 and bus-17 by gene expression analysis. Three distinct areas of altered expression were identified: 1) N- and O-glycosylation; 2) innate immune response; 3) protein folding and editing control. As expected N- and O-glycosylation gene expression was altered at key enzymatic steps. Innate immune system expression patterns were altered in a way that significantly overlapped with expression patterns seen in wild-type upon exposure to Staphylococuss aureus. Upon infection with S. aureus markers of innate immune activity increased significantly compared to wild-type. The abu/pqn genes, active in the non-canonical unfolded protein response (UPR) pathway were dramatically upregulated in bus when these mutants were exposed to the pathogen. This work demonstrates a genetic link between O-glycosylation and expression of key components of the innate immune response.