# In Silico Prediction of Potential pTLR7/pSTING Dual-Targeting Ligands via Virtual Screening and Molecular Dynamics Simulation

## TL;DR

This paper uses computer simulations to identify two compounds that may activate immune receptors in pigs, offering potential for developing animal immune enhancers.

## Contribution

The study introduces a computational approach to identify dual-target ligands for pTLR7 and pSTING in pigs, with predicted stability and favorable properties.

## Key findings

- Two compounds (compound 2 and compound 7) showed strong binding to pTLR7 and pSTING with binding free energies comparable to positive controls.
- Molecular dynamics simulations confirmed the stability of ligand-target complexes.
- Structure–activity relationship analysis was conducted to guide future design of immune modulators.

## Abstract

Toll-like receptor 7 (TLR7) and Stimulator of Interferon Genes (STING) ligands possess a series of immunomodulatory effects such as anti-infection, anti-tumor, and autoimmune-disease-alleviating effects. In this study, porcine TLR7 (pTLR7) and porcine STING (pSTING) were selected as targets, and molecular docking and virtual screening methods were used for screening of dual-target livestock immunomodulators. Finally, two compounds were screened with molecular docking scores higher than the positive control compounds. They have good binding ability with pTLR7 and pSTING proteins, as well as satisfactory predictive safety and pharmacokinetic properties. Molecular dynamics (MD) simulation results also indicated that the above ligands can form stable complexes with two target proteins. The average binding free energies of compound 2 with pTLR7 and pSTING were −28.65 kcal/mol and −30.12 kcal/mol, respectively, and of compound 7 with pTLR7 and pSTING were −35.93 kcal/mol and −31.70 kcal/mol, respectively, which were comparable to that of positive control ligands. The similarity of target proteins between pigs, humans, and mice, as well as the interactions between ligands and TLR7 and STING in different species, were analyzed. And analysis of predicted structure–activity relationship (SAR) was conducted. Briefly, compound 2 and compound 7 were predicted to form stable complexes with pTLR7 and pSTING, with satisfactory predicted physicochemical properties and pharmacokinetic characteristics, and represented candidates for experimental validation. This study supplies a research basis for the development, design, and structural modification of immune enhancers for animals.