Engineering T3 and T7 host range to target protein receptors and guide bacterial evolution

Area of Science:

• Microbiology
• Molecular Biology
• Biotechnology

Background:

• Phage therapy faces challenges limiting its effectiveness, including narrow host range.
• Engineering phage host range and guiding bacterial evolution (evolutionary steering) are promising strategies.
• The impact of balancing phage-bacterial binding interactions on host range and evolutionary trajectories is not well understood.

Purpose of the Study:

• To investigate how phage engineering affects host range expansion and bacterial evolutionary trajectories.
• To explore methods for programming protein-protein interactions between phages and bacteria.
• To assess the role of the phage capsid in host range.

Main Methods:

• Engineered T3 and T7 phages, which normally target lipopolysaccharide (LPS), to target a novel proteinaceous nanobody receptor.
• Measured host range expansion and observed evolutionary trajectories of bacteria post-infection.
• Surveyed various phage engineering techniques to modify phage-bacterial interactions.

Main Results:

• Successfully engineered T3 and T7 phages to target a new receptor, expanding their host range.
• Demonstrated that phage capsid modifications can influence host range.
• Observed distinct evolutionary trajectories in bacteria influenced by engineered phages.

Conclusions:

• Phage engineering, particularly targeting receptor binding and capsid structure, enhances the therapeutic potential of T3 and T7 phages.
• This work provides insights into evolutionary steering and broadens the applicability of LPS-targeting phages.
• The findings support the development of engineered phages for targeted antibacterial therapies.