Hacking Commensal Bacteria to Consolidate the Adaptive Mucosal Immune Response in the Gut-Lung Axis: Future...

Area of Science:

• Immunology and Microbiology
• Vaccine Development
• Respiratory Pathogen Research

Background:

• Mucosal pathogens cause significant mortality and morbidity, necessitating strategies to target entry points for protective immunity.
• SARS-CoV-2 primarily affects the upper respiratory mucosa, with gut-lung axis microbiome dysregulation impacting disease severity.
• Understanding mucosal and adaptive immune responses is key to designing effective bacterial mucosal vaccine vectors.

Purpose of the Study:

• To review mucosal vaccine vectors developed from 2015 to the present.
• To explore the potential of resident bacteria as vaccine carriers.
• To investigate the use of alpha streptococci in the upper respiratory tract as a novel vaccine carrier.

Main Methods:

• Literature review of mucosal vaccine vectors from 2015 to present.
• Analysis of bacterial candidates (e.g., Salmonella, lactic acid bacteria) used as vaccine carriers.
• Evaluation of strategies for displaying antigens (e.g., SARS-CoV-2 Spike proteins) to enhance immunogenicity.

Main Results:

• Some studies utilize Salmonella and lactic acid bacteria to display SARS-CoV-2 Spike proteins or fragments.
• Research on these vectors shows promising results, despite limited studies beyond in vitro or in vivo efficiency.
• The gut-lung axis microbiome's role in mucosal immunity is discussed.

Conclusions:

• Bacterial mucosal vaccine vectors offer a promising approach to target mucosal pathogens.
• Further research is needed to fully establish the efficacy of current vectors.
• Alpha streptococci present a novel potential carrier for upper respiratory tract mucosal vaccines.