Subtle differences in chemical pattern between human toll-like receptor 8 agonists and antagonists: Emerging chemical...

Area of Science:

• Medicinal Chemistry
• Immunology
• Computational Chemistry

Background:

• Human toll-like receptor 8 (hTLR8) modulators are crucial for treating cancer, infectious, and autoimmune diseases.
• Agonists and antagonists exhibit opposite biological effects despite structural similarities, necessitating investigation into subtle differences.

Purpose of the Study:

• To identify key structural differences between hTLR8 agonists and antagonists.
• To establish a predictive model for classifying hTLR8 modulators based on structural patterns.

Main Methods:

• Emerging chemical pattern (ECP) analysis was employed to extract distinguishing structural features.
• A Classification and Regression Training (CART) algorithm (CAEP classifier) was used to build a predictive model.
• Hierarchical cluster analysis and molecular docking were performed to elucidate structure-activity relationships.

Main Results:

• An optimal ECP model with three descriptors achieved over 90% prediction accuracy for hTLR8 agonists and antagonists.
• Agonists exhibit stronger specific hydrogen-bond properties compared to antagonists.
• Antagonists display stronger non-specific hydrophobic properties than agonists.

Conclusions:

• Subtle differences in H-bond and hydrophobic properties are critical determinants of hTLR8 agonist versus antagonist activity.
• These structural distinctions provide insights into the activation/inhibition mechanisms of hTLR8.
• The developed ECP model offers a valuable tool for predicting the function of novel hTLR8 modulators.