Liposome-mediated detection of SARS-CoV-2 RNA-positive extracellular vesicles in plasma

Nat Nanotechnol. 2021 Sep;16(9):1039-1044. doi: 10.1038/s41565-021-00939-8. Epub 2021 Jul 22.

Abstract

Plasma SARS-CoV-2 RNA may represent a viable diagnostic alternative to respiratory RNA levels, which rapidly decline after infection. Quantitative PCR with reverse transcription (RT-qPCR) reference assays exhibit poor performance with plasma, probably reflecting the dilution and degradation of viral RNA released into the circulation, but these issues could be addressed by analysing viral RNA packaged into extracellular vesicles. Here we describe an assay approach in which extracellular vesicles directly captured from plasma are fused with reagent-loaded liposomes to sensitively amplify and detect a SARS-CoV-2 gene target. This approach accurately identified patients with COVID-19, including challenging cases missed by RT-qPCR. SARS-CoV-2-positive extracellular vesicles were detected at day 1 post-infection, and plateaued from day 6 to the day 28 endpoint in a non-human primate model, while signal durations for 20-60 days were observed in young children. This nanotechnology approach uses a non-infectious sample and extends virus detection windows, offering a tool to support COVID-19 diagnosis in patients without SARS-CoV-2 RNA detectable in the respiratory tract.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Biosensing Techniques
  • COVID-19 / blood
  • COVID-19 / diagnosis*
  • COVID-19 Nucleic Acid Testing
  • Chlorocebus aethiops
  • Disease Models, Animal
  • Extracellular Vesicles / metabolism*
  • HEK293 Cells
  • Humans
  • Kinetics
  • Liposomes / metabolism
  • Liposomes / therapeutic use*
  • RNA, Viral / blood*
  • RNA, Viral / genetics
  • SARS-CoV-2 / genetics
  • SARS-CoV-2 / isolation & purification*
  • Tetraspanin 28 / immunology
  • Tetraspanin 28 / metabolism

Substances

  • Liposomes
  • RNA, Viral
  • Tetraspanin 28