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Updated: Jan 14, 2026
A "Plug-And-Display" Nanoparticle Vaccine Platform Based on Outer Membrane Vesicles Displaying SARS-CoV-2 Receptor-Binding Domain
Published on: July 25, 2022
Outer membrane vesicles from Escherichia coli as a presentation platform for AR-23 antiviral peptide
Francesca Mensitieri1,2, Federica Dell'Annunziata1, Giulia Gaudino1
1Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, Baronissi, Italy.
Introduction:
Anti-microbial peptides (AMPs) are a well-established alternative among antiviral and antibacterial agents, having considerable advantages over traditional antimicrobials in terms of biocompatibility and limited resistance development. However, a general poor bioavailability and short half-life limit their large-scale implementation. In this framework, different strategies are being explored, such as AMPs encapsulation or their functionalization on antigen-presenting platforms. In this work the evaluation of Escherichia coli (E. coli) derived Outer Membrane Vesicles (OMVs) as antiviral presenting platforms is described.
Methods:
OMVs were engineered through the recombinant overexpression of an outer membrane chimeric protein, ClyA-AR23, obtained by combining Cytolysin A (ClyA) with the AR-23 antiviral peptide, derived from frog skin and active against herpes simplex viruses. LC-MS/MS was used to screen the presence of the recombinant protein in cells and OMVs. Plaque reduction assay after pre-incubation treatment and qPCR on viral transcript were used to evaluate ClyA-AR23 OMVs antiviral activity of the engineered vesicles.
Results:
The expression of ClyA-AR23 protein was verified in recombinant E. coli cells and OMVs and the surface exposure of ClyA C-terminus was confirmed. Engineered ClyA-AR23 OMVs negligible cytotoxicity effect was assessed on VERO-76 cells. Both control and functionalized OMVs were used in pre-incubation treatment with HSV-1, HSV-2, SARS-COV2 and PV-1. Results highlighted that ClyA-AR23 OMVs did effectively impair HSV-1 and HSV-2 replication cycle in a dose dependent manner.
Discussion:
In this work we provided a first evidence of AMPs functionalization on membrane vesicles of bacterial origin. The systems demonstrated to be active towards HSV-1 and HSV-2 viruses with negligible cytotoxicity on VERO-76 cells.
Insights
Engineered bacterial outer membrane vesicles (OMVs) carrying antiviral peptides show promise for treating herpes simplex virus infections. These novel platforms demonstrate effective antiviral activity with minimal toxicity, offering a potential alternative to traditional antimicrobials.
Area of Science:
- Biotechnology
- Antimicrobial Research
- Virology
Background:
- Antimicrobial peptides (AMPs) offer advantages like biocompatibility and reduced resistance but suffer from poor bioavailability.
- Strategies to improve AMP delivery include encapsulation and functionalization on antigen-presenting platforms.
Purpose of the Study:
- To evaluate Escherichia coli (E. coli) derived Outer Membrane Vesicles (OMVs) as platforms for presenting antiviral peptides.
- To engineer OMVs with a chimeric protein combining Cytolysin A (ClyA) and an antiviral peptide (AR-23).
Main Methods:
- Engineered OMVs by overexpressing a ClyA-AR23 chimeric protein in E. coli.
- Verified protein expression and surface localization using LC-MS/MS.
- Assessed antiviral activity against HSV-1, HSV-2, SARS-CoV2, and PV-1 using plaque reduction assays and qPCR.
- Evaluated cytotoxicity on VERO-76 cells.
Main Results:
- Confirmed expression and surface exposure of ClyA-AR23 in engineered OMVs.
- Demonstrated negligible cytotoxicity of engineered OMVs on VERO-76 cells.
- Showed that ClyA-AR23 OMVs effectively inhibited HSV-1 and HSV-2 replication in a dose-dependent manner.
Conclusions:
- First evidence of AMP functionalization on bacterial outer membrane vesicles.
- Engineered OMVs are active against HSV-1 and HSV-2 with minimal cytotoxicity.
- OMVs represent a promising platform for developing novel antiviral therapies.
