Self-Assembled Ligands Targeting TLR7: A Molecular Level Investigation

Area of Science:

• Immunology
• Biochemistry
• Materials Science

Background:

• Toll-like receptors (TLRs) are crucial transmembrane proteins in innate immunity.
• TLR7 specifically recognizes viral and bacterial nucleic acids, making it a target for various pathologies.
• Developing potent yet low-toxicity TLR7 agonists is an active area of research.

Purpose of the Study:

• To investigate the impact of phospholipid versus polyethylene glycol (PEG) conjugation on TLR7 agonist properties.
• To evaluate self-assembly, stability, and interaction with TLR7 for different conjugation strategies.
• To establish a framework for studying aggregated ligand-protein receptor interactions.

Main Methods:

• Molecular Dynamics (MD) simulations to analyze compound behavior.
• Dynamic Light Scattering (DLS) for aggregate size and stability assessment.
• Electron Paramagnetic Resonance (EPR) and cytotoxicity assays to study TLR7 interaction and cellular effects.

Main Results:

• Phospholipid conjugation facilitated orderly self-assembly with maximal pharmacophore exposure.
• Phospholipid compounds formed stable aggregates that effectively interacted with TLR7.
• PEGylated compounds exhibited poorly stable aggregates on cell surfaces, with less effective TLR7 interaction.

Conclusions:

• Phospholipid conjugation is a superior strategy for developing effective TLR7 agonists compared to PEGylation.
• The self-assembly and stability of drug conjugates significantly influence their interaction with target receptors.
• The study presents a robust methodological framework for evaluating drug delivery systems at a molecular level.