Pore worms: using Caenorhabditis elegans to study how bacterial toxins interact with their target host.
The interaction of pathogenic bacteria with a target host is regulated both by bacterial virulence factors and by host components that either protect the host or that promote pathogenesis. The soil nematode Caenorhabditis elegans is a host for a number of bacterial pathogens, as briefly reviewed here. Bacillus thuringiensis (Bt) is a pathogenic bacteria that C. elegans is likely to encounter naturally in the soil. The pore-forming Crystal (Cry) toxins made by Bt are recognized as the dominant virulence factor in this host-pathogen interaction. Forward genetic screens for C. elegans mutants resistant to the Cry toxin, Cry5B, have identified a host carbohydrate structure that promotes pathogenesis. Data suggest this structure is likely to be a Cry5B receptor expressed in the host intestine. This finding is discussed in light of other carbohydrate receptors for bacterial toxins. To investigate host-toxin interactions on a global level, the response of C. elegans to the pore-forming Cry5B is also being investigated by gene transcription profiling (microarrays). These data are beginning to reveal a diverse intracellular response to toxin exposure. To put these investigations in perspective, host responses to other pore-forming toxins are discussed. Investigations with Cry5B in C. elegans show a promising beginning in helping to elucidate host-toxin and host-pathogen interactions.
Huffman
Danielle L
DL
Section of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA 92093-0349, USA.
Bischof
Larry J
LJ
Griffitts
Joel S
JS
Aroian
Raffi V
RV
D000818:Animals; D001413:Bacillus thuringiensis / Q000276:immunology / Q000378:metabolism*; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000276:immunology / Q000378:metabolism*; D001427:Bacterial Toxins; D017173:Caenorhabditis elegans / Q000276:immunology / Q000378:metabolism / Q000382:microbiology*; D029742:Caenorhabditis elegans Proteins / Q000276:immunology / Q000378:metabolism; D050260:Carbohydrate Metabolism; D002241:Carbohydrates / Q000276:immunology; D004731:Endotoxins / Q000276:immunology / Q000378:metabolism*; D006460:Hemolysin Proteins; D008565:Membrane Proteins / Q000276:immunology / Q000378:metabolism
D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D029742:Caenorhabditis elegans Proteins; D002241:Carbohydrates; D004731:Endotoxins; D006460:Hemolysin Proteins; D008565:Membrane Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis