Seasonal influenza is associated with significant mortality worldwide, but pandemic strains that arise unexpectedly from genomic reassortment between influenza strains from diverse species can lead to pandemics and global devastation. While vaccination against influenza is effective, the science of predicting which antigenic epitopes are likely to appear in the next influenza season is an imprecise one and can be further compromised by logistical problems of manufacturing and distribution. Antiviral agents, such as neuraminidase inhibitors (NAIs), are hampered by the increasing resistance of many influenza strains to such agents and the need to be administered very soon after infection. Both of these approaches focus on targeting the virus, rather than the host response to infection. Evidence by Imai et al. (2008) suggested that acute lung injury (ALI) caused by chemical or microbial insults causes oxidative stress that results in generation of an oxidized phospholipid, OxPAPC, a potent agonist of Toll-like Receptor 4 (TLR4)-induced lung inflammation. This observation was extended in the laboratories of the PIs by experiments in which mice with a targeted mutation in TLR4 were shown to be highly refractory to infection with mouse-adapted influenza strain A/PR/8/24 (""""""""PR8""""""""). The central hypothesis to be tested is that blocking TLR4 signaling therapeutically will protect against influenza infection. We provide compelling evidence in our proposal that the synthetic TLR4 antagonist, Eritoran (E5564), produced by Eisai Inc., and shown to have an excellent safety record in humans through Phase 1-3 clinical trials, blocks influenza infection in mice when administered therapeutically, even later than required for antiviral administration. The proposed plan is a partnership between Eisai Inc. and the University of Maryland, School of Medicine, Sigmovir Biosystems, Inc., and University of Maryland, College of Veterinary Medicine to optimize treatment with Eritoran and NAIs as a therapeutic for influenza infection using mice to optimize treatment regimens and further delineate the effect of influenza infection and Eritoran on the innate immune response, cotton rats to explore efficacy against non-adapted human strains of virus and in a model of aged/immunocompromised animals, and finally, in ferrets, to confirm and extend the use of Eritoran using pandemic strains of influenza under ABSL3 conditions. A Product Development Plan is presented that delineates future plans for moving Eritoran to clinical trial as a therapeutc for influenza.

Public Health Relevance

Influenza infection kills many people yearly. Current vaccination strategies and antiviral agents have failed to protect people fully. We propose a new approach in which Eritoran (E5564), a highly safe drug that blunts the host innate immune response to influenza, will be further developed as a potential therapeutic agent.

National Institute of Health (NIH)
National Institute of Allergy and Infectious Diseases (NIAID)
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Special Emphasis Panel (ZAI1-LG-M (J3))
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Krafft, Amy
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University of Maryland Baltimore
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Patel, Mira C; Shirey, Kari Ann; Boukhvalova, Marina S et al. (2018) Serum High-Mobility-Group Box 1 as a Biomarker and a Therapeutic Target during Respiratory Virus Infections. MBio 9:
Perrin-Cocon, Laure; Aublin-Gex, Anne; Sestito, Stefania E et al. (2017) TLR4 antagonist FP7 inhibits LPS-induced cytokine production and glycolytic reprogramming in dendritic cells, and protects mice from lethal influenza infection. Sci Rep 7:40791
Perkins, Darren J; Patel, Mira C; Blanco, Jorge C G et al. (2016) Epigenetic Mechanisms Governing Innate Inflammatory Responses. J Interferon Cytokine Res 36:454-61
Keegan, Achsah D; Shirey, Kari Ann; Bagdure, Dayanand et al. (2016) Enhanced allergic responsiveness after early childhood infection with respiratory viruses: Are long-lived alternatively activated macrophages the missing link? Pathog Dis 74:
Shirey, K A; Lai, W; Patel, M C et al. (2016) Novel strategies for targeting innate immune responses to influenza. Mucosal Immunol 9:1173-82
Piao, Wenji; Shirey, Kari Ann; Ru, Lisa W et al. (2015) A Decoy Peptide that Disrupts TIRAP Recruitment to TLRs Is Protective in a Murine Model of Influenza. Cell Rep 11:1941-52
Perkins, Darren J; Vogel, Stefanie N (2015) Space and time: New considerations about the relationship between Toll-like receptors (TLRs) and type I interferons (IFNs). Cytokine 74:171-4
Patel, Mira C; Shirey, Kari Ann; Pletneva, Lioubov M et al. (2014) Novel drugs targeting Toll-like receptors for antiviral therapy. Future Virol 9:811-829
Blanco, Jorge Cg; Boukhvalova, Marina S; Perez, Daniel R et al. (2014) Modeling Human Respiratory Viral Infections in the Cotton Rat (Sigmodon hispidus). J Antivir Antiretrovir 6:40-42