Abstract
Recently, invertebrate models have been widely used for the study of innate immunity. Nematodes are novel potential candidates because of the experimental advantages of Caenorhabditis elegans. However, whether nematodes have active immune responses is still ambiguous. Previously, we reported ASABF (Ascaris suum antibacterial factor)-type antimicrobial peptides in the parasitic nematode Ascaris suum and the genetic model nematode C. elegans. Further screening of a cDNA library and an expressed-sequence-tag database search detected five novel members of ASABF (ASABF-β, -γ, -δ, -ε and -ζ) in A. suum. The transcripts for ASABF-α, -β, -γ, and -δ clearly increased in the body wall, and also in the intestine for ASABF-δ, 4 h after injection of heat-killed bacteria into the pseudocoelom (body cavity), suggesting that these peptides are inducible in the acute phase of immune response. These results also suggest that the nematodes can recognize bacteria in the pseudocoelomic fluid and evoke an active immune response.
- defensin
- innate immunity
- nematode
- parasite
- Toll
Footnotes
↵1 These authors contributed equally to this work.
The nucleotide sequences reported in this paper have been submitted to the EMBL, DDBJ, GenBank® and GSDB Nucleotide Sequence Databases and the EBI (European Bioinformatics Institute) Data Bank under the accession numbers D87123, D87124, D87125, AB086058, AB091202, AB029812, AB029813, AB029814, AB029815, AB090347, AB090348, AB090349, and AB090350.
Abbreviations used: ASABF, Ascaris suum antibacterial factor; RACE, rapid amplification of cDNA ends; UTR, untranslated region; EST, expressed sequence tag; RT, reverse transcription; EF1α, elongation factor 1α; cybS, the small subunit of cytochrome b558; SL1, nematode splice leader sequence 1; MAP kinase, mitogen-activated protein kinase.
- The Biochemical Society, London ©2003
May 2003
Volume: 371 Issue: 3
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