COVID-19: Zapped by Laser

Methods

Femtosecond laser irradiation

Proposed model for USP laser-induced viral capsid defect

Results

USP laser-treated virus is internalized by host cells

For all experiments, we used a GFP-expressing MCMV described in a previous report. Samples of MCMV were irradiated using a 425nm femtosecond laser. Laser-inactivated virus showed an approximate 5-log reduction in viral titers by TCID50 assay, to a level near the limit of detection. To determine whether virions were internalized by host cells, we used electron microscopy to view viral particles within murine embryonic fibroblast cells that had been infected with control (untreated) MCMV or USP laser-treated MCMV for 2 h. In both control and laser-treated groups, we observed the presence of MCMV virions within cells . To confirm these findings, we labeled control or laser-treated MCMV with a fluorescent dye, PKH26. Murine fibroblast cells were infected with PKH26-labeled control or laser-treated MCMV for 2 h before imaging by fluorescence microscopy. In both control and laser-treated groups, we found fluorescent virus particles within cells . These results were further confirmed by PCR detection of MCMV genomic DNA in cells infected with both control and laser-treated MCMV (Figure 4). Therefore, laser treatment does not alter the ability of MCMV virions to be internalized by cells.

Electron microscopy shows cellular internalization of USP laser-treated MCMV
Fluorescence microscopy shows cellular internalization of USP laser-treated MCMV

Conclusion

  • We reveal evidence supporting a functional capsid defect in viruses inactivated by ultrashort pulsed laser treatment.
  • USP laser targeting of capsids is a unique mechanism with advantages against rapidly mutating or drug-resistant pathogens.
  • USP laser treatment has applications in pathogen reduction, antiviral treatments, and vaccine development.

--

--

Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store
Aayushi Vaish

Aayushi Vaish

139 Followers

An Explorer of the Infinite Multiverse . MS - Physics , Northeastern University.