Debulking SARS-CoV-2 in saliva using angiotensin converting enzyme 2 in chewing gum to decrease oral virus...

Area of Science:

• Biotechnology
• Virology
• Oral Health

Background:

• The oral cavity is a primary site for viral replication and infection.
• Current strategies for managing oral viral infections are limited.
• Developing effective methods to trap and neutralize viruses in saliva is crucial.

Purpose of the Study:

• To develop a novel chewing gum formulation incorporating virus-trapping proteins (CTB-ACE2) for oral viral debulking.
• To assess the efficacy of CTB-ACE2 chewing gum in inhibiting viral entry and reducing viral load in oral samples.
• To investigate the potential of this strategy for preventing oral virus re-infections and transmission.

Main Methods:

• Expression of CTB-ACE2 proteins in chloroplasts and development of clinical-grade plant material.
• Incorporation of CTB-ACE2 into chewing gum at high concentrations (17.2 mg ACE2/g dry weight).
• In vitro testing using pseudoviruses and SARS-CoV-2 in saliva samples, quantifying inhibition by luciferase, red fluorescence, microbubbles, and qPCR.

Main Results:

• CTB-ACE2 chewing gum demonstrated efficient (>95%) inhibition of lentivirus spike and VSV-spike pseudovirus entry into cells.
• Incubation with CTB-ACE2 microparticles reduced SARS-CoV-2 in COVID-19 saliva samples by >95%.
• COVID-19 saliva showed significantly lower ACE2 activity compared to healthy individuals, correlating with viral susceptibility.

Conclusions:

• Chewing gum containing plant-expressed CTB-ACE2 proteins is a viable and effective strategy for oral virus debulking.
• This approach significantly inhibits viral entry and reduces SARS-CoV-2 load in saliva.
• The developed chewing gum offers a general, affordable method to protect against oral virus re-infections and minimize transmission.