Preclinical development of the TLR4 antagonist FP12 as a drug lead targeting the HMGB1/MD-2/TLR4 axis in lethal influenza infection

Shirey, K. A., Romerio, A., Shaik, M. M., Leake, D. S. ORCID: https://orcid.org/0000-0002-1742-6134, Palmer, C., Skupinska, N., Paton, J. ORCID: https://orcid.org/0009-0000-2242-251X, Pirianov, G., Blanco, J. C. G., Vogel, S. N. and Peri, F. ORCID: https://orcid.org/0000-0002-3417-8224 (2025) Preclinical development of the TLR4 antagonist FP12 as a drug lead targeting the HMGB1/MD-2/TLR4 axis in lethal influenza infection. Innate Immunity, 31. pp. 1-11. ISSN 1753-4267 doi: 10.1177/17534259241313201

Abstract/Summary

Background Acute Lung Injuries (ALI) are a severe consequence of influenza-induced cytokine storm that can cause respiratory failure and death. It has been demonstrated that Toll-like Receptor 4 (TLR4) is involved in cytokine storm and that TLR4−/− mice are protected against ALI. Therefore, TLR4 is a prime target for protection against ALI. FP12 is a known TLR4 antagonist that reduces TLR4-dependent immune activation and it is a promising lead compound for the treatment of innate immunity related pathologies. Objectives We present here the preclinical development of FP12 as an anti-inflammatory lead compound acting on influenza-induced ALI. Methods In vitro: We pre-treated THP-1 cells with FP12 (10 μM) for 0.5 h, then exposed to LPS (100 ng/ml) for 0 to 16 h. In some experiments, cells were simultaneously incubated with FP12 and LPS, or FP12 was added 30 min after LPS. Cytokine levels were measured by Western blot and ELISA assays. In vivo: WT C57BL/6J mice were infected with mouse-adapted influenza virus (PR8). Two days after infection, mice received either vehicle, FP7 (200 µg/mouse), or FP12 (200 µg/mouse) once daily (Day 2 to Day 6). Mice were monitored daily for survival for 14 days. Data were collected through histological staining, qRT-PCR, and ELISA assay. Results FP12 treatment inhibited both LPS- and HMGB1-induced TLR4 intracellular pathways (MyD88 and TRIF) leading to significantly reduced levels of a variety of proinflammatory cytokines including Type I interferon (IFN-β), highlighting its effectiveness in controlling proinflammatory protein production and reducing inflammation. FP12 protected mice therapeutically from influenza virus-induced lethality and reduced both cytokine gene expression and High Mobility Group Box 1 (HMGB1) levels in the lungs as well as ALI. Conclusion FP12 can antagonize TLR4 activation in vitro and protects mice from severe influenza infection, most likely by reducing the TLR4-dependent cytokine storm mediated by danger-associated molecular patterns (DAMPs).

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/121985
Item Type	Article
Refereed	Yes
Divisions	Life Sciences > School of Biological Sciences > Biomedical Sciences
Publisher	SAGE Publications
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