Chemicals and reagents:
All bacterial toxins were purchased from List Biological Laboratories (Campbell, CA). …
Human B-lymphocytes sensitivity to Pseudomonas toxin-mediated lethality:
Human B lymphocytes were treated with serial dilutions of P. aeruginosa exotoxin A for 48hours.
Cellular drug screens:
RAW264.7 cells (10,000 per well) were seeded in 96-well plates 24hours before the assay. Cells were treated with compounds for 1hour, and then challenged with either 2g/ml PE or 4g/ml cholera toxin for 12hours. As rodent cells are insensitive to diphtheria toxin, C32 cells were treated with 2g/ml of diphtheria toxins for 24hours. …
Toxins treatments and cell viability assays:
Cells (10,000 per well) were seeded in 96-well plates 24hours before the assay. Cells were treated with Bithionol for 1hour. RAW264.7 cells were challenged with anthrax toxins that include LF or FP59 and PA83 or PA63 (for 6hours), PE (for 12hours), or cholera toxin (for 12hours) at 0.5, 2, and 4g/ml respectively. C32 cells were treated with 2g/ml of diphtheria toxin for 24hours. Determination of cells viability was performed by MTT assay….
MAPKK2 cleavage assay:
… Following pre-treatment, the cells were exposed to 0.5g/ml of PA and LF at 37C for up to three hours in the presence of 33M of Bithionol. …
Cellular cathepsin B and caspase-1 activity assays:
…Caspase-1 activities were induced by 1hour pretreatment of cells with 0.5g/ml of LF+PA, and was compared to cells un-induced by the toxin. …
BoNT/A light chain FRET assay:
The reaction volume was 250l per well in 96 wells plate, containing 50mM HEPES pH 7.4 containing 0.05% TWEEN 20, 5M SNAPtide (BoNT/A substrate peptide) conjugated with DABCYL and FITC (List Biological Laboratories, Inc), and 33M of Bithionol. …