Journal: mBio
Article Title: Cathepsin B hyperactivation facilitates exosome release of CVB3 particles and exacerbation of acute pancreatitis by impairing lysosomal integrity and acidification
doi: 10.1128/mbio.03111-25
Figure Lengend Snippet: Inhibition of CTSB blocks exosomal release of virus. 266-6 cells were infected with CVB3 (MOI = 1) for 1 h, maintained in the presence of CA074me (20 µM) for 12 h. ( A ) BCA assay analysis of exosomes harvested from CVB3-infected 266-6 cells at indicated times. ( B ) Immunoblotting analysis of exosomal markers (CD9, CD63, and Alix) expression in exosomes purified from supernatant of 266-6 cells infected with CVB3 for 1 h and treated with bafilomycin A1 (20 nM) for 12 h. ( C ) Relative fluorescence units (RFU) detection of GFP + virus in exosomes from 266 to 6 cells infected with GFP-CVB3 (MOI = 1). ( D ) BCA assay of exosomal protein levels harvested from culture supernatant of infected 266-6 cells. ( E ) Western blot detection of exosomal markers CD9, CD63, and Alix expression in exosome lysates. ( F ) Relative fluorescence units (RFU) detection of eGFP-CVB3 progeny in 266-6 cells after CVB3 infection (MOI = 1) for 24 h. ( G ) Viral titers of 266-6 or SW1990 cells infected with 0.1 µg purified exosomes (from infected 266-6 cells treated with CA074Me). ( H, J ) Plaque assay determination of viral titers of exosome lysate from 1 mL supernatant of 266-6 cells treated with CA074Me ( H ), or from cells transfected with con-siRNA or CTSB-siRNA 36 h before CVB3 (MOI = 1) infection ( J ). Total viral titer: viral titer in whole cell culture supernatant; exosome viral titer: free viral titer in the exosome-removed supernatant. ( I ) Western blot analysis of CTSB and VP1 levels in 266-6-exosome and whole cell lysate (WCL). Data from panels A, C, D, F, G, H, and J were shown as mean ± SEM of averages from three independent experiments. * P < 0.05, ** P < 0.01, *** P < 0.001.
Article Snippet: Cells with 85% confluency were infected with CVB3 at a multiplicity of infection (MOI) of 1, 5, or 10 for 1 h. After washing with PBS, cells were maintained for 12 ~ 24 h. In experiments where CA074Me (Cathepsin B Inhibitor) (TargetMol T3420) was used, cells were treated with 10 μM CA074-Me dissolved in DMSO (Sigma) for 12 h after CVB3 infection (MOI of 1).
Techniques: Inhibition, Virus, Infection, BIA-KA, Western Blot, Expressing, Purification, Fluorescence, Plaque Assay, Transfection, Cell Culture