FIG 1.

Antiprion activities of insect extracts. (A) Immunoblot data for PrPres in ScN2a cells treated with each insect extract. Lanes 1 to 9 correspond to the extracts from the adult body of Chalcosoma chiron, the larval shell of Graptopsaltria nigrofuscata, the adult body of Halyomorpha halys, the adult body of Agrus convolvuli, the adult body of Papilio protenor, the adult body of Allomyrina dichotoma, the adult body of Graptopsaltria nigrofuscata, the larval head of Dorcus hopei binodulosus, and the remaining parts of the larva of Dorcus hopei binodulosus, respectively. Cells were treated with 0.5% insect extracts, which were equivalent to 0.5 mg of the initial insect materials per milliliter of culture medium. Signals for β-actin are shown as controls for the integrity of samples used for PrPres detection. PrP signals were detected with the anti-PrP monoclonal antibody SAF83 in this analysis and the following analyses, unless otherwise specified. Molecular size markers on the right indicate sizes in kilodaltons. The bar graph shows averages and standard deviations for triplicate experiments (**, P < 0.01). Samples in lanes 1 and 6 were used for subsequent analyses. (B) Immunoblot data for PrPres in three distinct prion strain-infected cell lines treated with two representative insect extracts from C. chiron and A. dichotoma. The bar graph shows averages and standard deviations for triplicate experiments (**, P < 0.01). The 50% effective concentration value (EC₅₀) of each extract is also shown. (C) Immunoblot data for PrPc in N2a cells treated with extracts from C. chiron and A. dichotoma. (D) Flow cytometry of cell surface PrPc in N2a cells treated with 0.5% (vol/vol) extracts from C. chiron and A. dichotoma. Blue and black lines indicate insect extract-treated and untreated cells, respectively. The broken-line peaks on the left show their respective isotype controls. (E) Immunoblot data of PrPc fractionated by the flotation assay in N2a cells treated with 0.5% (vol/vol) extracts from C. chiron and A. dichotoma. The fraction numbers are indicated from the top to the bottom.