A Self-Assembling Cross-Protective Antigen Against Multiple Gram-Positive Nosocomial Pathogens.

Area of Science:

• Microbiology
• Immunology
• Biomaterials Science

Background:

• ESKAPE pathogens cause difficult-to-treat nosocomial infections globally.
• Antibiotic resistance in pathogens like vancomycin-resistant Enterococcus faecium and methicillin-resistant Staphylococcus aureus necessitates alternative treatments.
• Previous work identified a protective epitope from E. faecium's AdcA protein.

Purpose of the Study:

• To develop a novel vaccine antigen using a self-assembling peptide strategy.
• To evaluate the efficacy of a new epitope presentation method (Q11-EH) for cross-protective vaccines.
• To assess the potential of Q11-EH in combating Gram-positive nosocomial infections.

Main Methods:

• Designed a multipresenting peptide (Q11-EH) based on a self-assembling peptide scaffold.
• Characterized the nanostructure of the Q11-EH peptide fibers.
• Generated antibodies against Q11-EH and tested their efficacy in opsonic killing assays against Gram-positive pathogens.

Main Results:

• Q11-EH self-assembles into stable, nanometric fibers.
• Antibodies generated against Q11-EH demonstrated opsonic killing activity.
• Effective killing was observed against a broad range of Gram-positive bacteria, including E. faecium, S. aureus, and E. faecalis.

Conclusions:

• Self-assembling peptides offer a potent strategy for improving vaccine antigen presentation.
• Q11-EH is a promising candidate antigen for developing novel, cross-protective vaccines against Gram-positive pathogens.
• This approach addresses the urgent need for alternative treatments against antibiotic-resistant nosocomial infections.