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. 2022 Apr 6;8(1):e12283. doi: 10.1002/trc2.12283

FIGURE 3.

FIGURE 3

Antibacterial and antiviral functionality of amyloid beta (Aβ). (A) Fluorescence microscopy of Vero cells infected with Vesicular Stomatitis Virus tagged with green fluorescent protein (VSV‐GFP) pretreated overnight with varying Aβ1‐42 concentrations. Control (CTL) samples were diluted and infected immediately, without overnight treatment; cells imaged 24 hours post‐infection and reveal a dose‐dependent antiviral response. (B) Typhoon scans of culture plates, where plaques are visible as dark‐gray spots, show the same. (C) Dose‐response curve of Aβ against herpes simplex virus 1 (HSV‐1), derived from fluorescence experiments, demonstrating clear antiviral functionality. Calculated EC50 = 1 μg/ml or 0.2 μM. (D) Toxicity/antimicrobial peptides (AMP) activity of Aβ1‐42 against E.coli, in the presence of cholesterol and metal ions (Cu2+ and Zn2+), as determined by relative 12‐hour optical density (OD12H); and calculated IC50 of Aβ1‐42 with/out cholesterol and metal ions from fitted nonlinear regressions (sigmoidal) to data. Cholesterol and Zn2+ enhance Aβ1‐42 toxicity against bacteria. (E) Aβ production in lysate and supernatant of SK‐N‐AS incubated with liopopolysaccharide (LPS), lipoteichoic acid, and bacterial fragments. Aβ production quantified by enzyme‐linked immunosorbent assay; significant increases observed in cell lysates only, exposed to E.coli (*P = 0.03), K. pneumoniae (**P < 0.01), Methicillin‐susceptible S. aureus (MSSA, *** P = 0.02), LPS (100 ng/ml, **** P < 0.01). MRSA denotes Methicillin‐resistant S. aureus. (F) Time‐dependent production of Aβ in lysates of SK‐N‐AS showing upregulation within 1 hour of initial exposure, suggesting innate (as opposed to adaptive) immune response; P < 0.01 (compared to control) in all cases. (G) Relative neurotoxicity of Aβ (1‐40 and 1‐42) and AMPs (Ceropin and LL‐37) against SK‐N‐AS cells, assayed by 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT). (H) Relative neurotoxicity of Aβ and AMPs against primary cultured rat neurons, assayed by MTT