Enhanced immunostimulatory activity of in silico discovered agonists of Toll-like receptor 2 (TLR2)
| Autor: | Sandra Santos-Sierra, Gerhard Wolber, Christin Rakers, P. Hörtnagl, Manuela S. Murgueitio, Philipp Henneke, Ramona S Bruckner, S. Ebner |
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| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Biophysics Biology Ligands Biochemistry Cancer Vaccines Small Molecule Libraries 03 medical and health sciences chemistry.chemical_compound Mice User-Computer Interface Immune system Downregulation and upregulation Adjuvants Immunologic Neoplasms Animals Humans Molecular Biology CD86 Toll-like receptor Virtual screening Lipopeptide Dendritic cell Dendritic Cells Toll-Like Receptor 2 Molecular Docking Simulation TLR2 030104 developmental biology HEK293 Cells chemistry Immunology Cancer research Leukocytes Mononuclear Cytokines |
| Zdroj: | Biochimica et biophysica acta. General subjects. 1861(11 Pt) |
| ISSN: | 0304-4165 |
| Popis: | Background Emergent therapies in anticancer vaccination use Toll-like receptors (TLRs) agonists as dendritic cell (DC) vaccine adjuvants. DCs from the patient are isolated, stimulated with TLR agonists and tumor antigens ex vivo and then infused back into the patient. Although some TLR ligands have been tested in clinical trials, novel TLR agonists with improved immunomodulatory properties are essential to optimize treatment success. We report on the discovery of small-molecule TLR2 agonists, with favorable properties as synthetic adjuvants. Methods We performed a shape- and featured-based similarity virtual screening against a commercially available compound library. The selected virtual hits were experimentally tested in TLR2-reporter cells and their activity in phagocytes and DCs was characterized. A binding model of the compounds to TLR2 (docking studies) was proposed. Results Through a virtual screening approach against a library of three million compounds four virtual hits (AG1, AG2, AG3, AG4) were found to synergistically augment the NF-kB activation induced by the lipopeptide ligand Pam 3 CSK 4 in luciferase reporter assays using HEK293-TLR2 cells. Biacore experiments indicated that AG1–AG4 are ago-allosteric modulators of TLR2 and AG2 bound TLR2 with high affinity (K D 0.8 μM). The compounds induced TNF-α production in human peripheral blood mononuclear cells (PBMCs) and they activated DCs as indicated by IL-12 production and upregulation of CD83/CD86. Conclusions Following a combined in silico / in vitro approach we have discovered TLR2-agonists (AG1–AG4) that activate human and mouse immune cells. General significance We introduce four novel TLR2 ago-allosteric modulators that stimulate myeloid cell activity and constitute promising candidates as synthetic adjuvants. |
| Databáze: | OpenAIRE |
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