title: Tribolium castaneum immune defense genes are differentially expressed in response to Bacillus thuringiensis toxins sharing common receptor molecules and exhibiting disparate toxicity.
abstract: In Tribolium castaneum larvae we have demonstrated by RNA interference knockdown that the Bacillus thuringiensis Cry3Ba toxin receptors Cadherin-like and Sodium solute symporter proteins are also functional receptors of the less active Cry3Aa toxin. Differences in susceptibility to B. thuringiensis infection might not only rely on toxin-receptor interaction but also on host defense mechanisms. We compared the expression of the immune related genes encoding Apolipophorin-III and two antimicrobial peptides, Defensin3 and Defensin2 after B. thuringiensis challenge. All three genes were up-regulated following Cry3Ba spore-crystal intoxication whereas only Defensins gene expression was induced upon Cry3Aa spore-crystal treatment, evidencing a possible association between host immune response and larval susceptibility to B. thuringiensis. We assessed the antimicrobial activity spectra of T. castaneum defensins peptide fragments and found that a peptide fragment of Defensin3 was effective against the human microbial pathogens, Escherichia coli, Staphylococcus aureus and Candida albicans, being S. aureus the most susceptible one.
authors: Departamento de Genética, Facultad de Ciencias Biológicas, Universidad de Valencia, Burjassot, Valencia, Spain.
authors: Estefanía
authors: E
authors: Contreras
authors: Departamento de Genética, Facultad de Ciencias Biológicas, Universidad de Valencia, Burjassot, Valencia, Spain.
authors: María
authors: M
authors: Benito-Jardón
authors: Departamento de Genética, Facultad de Ciencias Biológicas, Universidad de Valencia, Burjassot, Valencia, Spain.
authors: M José
authors: MJ
authors: López-Galiano
authors: Departamento de Genética, Facultad de Ciencias Biológicas, Universidad de Valencia, Burjassot, Valencia, Spain.
authors: M Dolores
authors: MD
authors: Real
authors: Departamento de Genética, Facultad de Ciencias Biológicas, Universidad de Valencia, Burjassot, Valencia, Spain. Electronic address: carolina.rausell@uv.es.
authors: Carolina
authors: C
authors: Rausell
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001053:Apolipoproteins / Q000235:genetics / Q000276:immunology; D001413:Bacillus thuringiensis / Q000276:immunology*; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D001427:Bacterial Toxins / Q000235:genetics / Q000276:immunology*; D002176:Candida albicans / Q000187:drug effects; D023082:Defensins / Q000235:genetics / Q000276:immunology / Q000494:pharmacology*; D004731:Endotoxins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D004926:Escherichia coli / Q000187:drug effects; D006460:Hemolysin Proteins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D019476:Insect Proteins / Q000235:genetics / Q000276:immunology / Q000494:pharmacology; D007814:Larva / Q000235:genetics / Q000276:immunology; D008969:Molecular Sequence Data; D034622:RNA Interference; D034741:RNA, Small Interfering; D013211:Staphylococcus aureus / Q000187:drug effects; D027981:Symporters / Q000235:genetics; D014231:Tribolium / Q000235:genetics / Q000276:immunology*
chemical_list: D000900:Anti-Bacterial Agents; D001053:Apolipoproteins; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D023082:Defensins; D004731:Endotoxins; D006460:Hemolysin Proteins; D019476:Insect Proteins; D034741:RNA, Small Interfering; D027981:Symporters; C042470:apolipophorin III; C030956:insecticidal crystal protein, Bacillus Thuringiensis
keywords: Apolipophorin III; Bacillus thuringiensis; Cry toxin receptors; Defensin; Innate immunity; Tribolium castaneum