title: Antisera-mediated in vivo reduction of Cry1Ac toxicity in Helicoverpa armigera.
abstract: A functional assessment of Bacillus thuringiensis (Bt) toxin receptors in the midgut of lepidopteran insects will facilitate understanding of the toxin mode of action and provide effective strategies to counter the development of resistance. In this study, we produced anti-aminopeptidase (APN) and anti-cadherin sera with purified Cry1Ac toxin-binding APN or cadherin fragments from Heliocoverpa armigera. Antisera were evaluated for their effects on Cry1Ac toxicity through bioassays. Our results indicated that both the anti-APN and anti-cadherin sera reduced Cry1Ac toxicity in vivo, although cadherin antiserum reduced toxicity more than APN antiserum. These results suggest that both APN and cadherin are involved in Cry1Ac intoxication of H. armigera, evidence that the pore formation model may be representative of Cry1Ac toxin mode of action in this insect.
authors.affiliation: State Key Laboratory of Plant Disease and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Science, West Yuanmingyuan Road, Beijing 100193, China.
authors.forename: Chenxi
authors.initials: C
authors.lastname: Liu
authors.forename: Yulin
authors.initials: Y
authors.lastname: Gao
authors.forename: Changming
authors.initials: C
authors.lastname: Ning
authors.forename: Kongming
authors.initials: K
authors.lastname: Wu
authors.forename: Brenda
authors.initials: B
authors.lastname: Oppert
authors.forename: Yuyuan
authors.initials: Y
authors.lastname: Guo
mesh_terms: D000626:Aminopeptidases / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D000818:Animals; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000633:toxicity*; D015820:Cadherins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D004731:Endotoxins / Q000633:toxicity*; D006460:Hemolysin Proteins / Q000633:toxicity*; D007106:Immune Sera / Q000302:isolation & purification / Q000494:pharmacology*; D019476:Insect Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D009036:Moths / Q000187:drug effects* / Q000201:enzymology* / Q000235:genetics / Q000276:immunology; D011485:Protein Binding / Q000187:drug effects; D011817:Rabbits
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D015820:Cadherins; D004731:Endotoxins; D006460:Hemolysin Proteins; D007106:Immune Sera; D019476:Insect Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis; D000626:Aminopeptidases