A Decoy Peptide that Disrupts TIRAP Recruitment to TLRs Is Protective in a Murine Model of Influenza
Wenji Piao,
Kari Ann Shirey,
Lisa W. Ru,
Wendy Lai,
Henryk Szmacinski,
Greg A. Snyder,
Eric J. Sundberg,
Joseph R. Lakowicz,
Stefanie N. Vogel,
Vladimir Y. Toshchakov
Affiliations
Wenji Piao
Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
Kari Ann Shirey
Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
Lisa W. Ru
Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
Wendy Lai
Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
Henryk Szmacinski
Department of Biochemistry and Molecular Biology and Center for Fluorescence Spectroscopy, University of Maryland School of Medicine, Baltimore, MD 21201, USA
Greg A. Snyder
Institute of Human Virology and Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
Eric J. Sundberg
Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
Joseph R. Lakowicz
Department of Biochemistry and Molecular Biology and Center for Fluorescence Spectroscopy, University of Maryland School of Medicine, Baltimore, MD 21201, USA
Stefanie N. Vogel
Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
Vladimir Y. Toshchakov
Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
Toll-like receptors (TLRs) activate distinct, yet overlapping sets of signaling molecules, leading to inflammatory responses to pathogens. Toll/interleukin-1 receptor (TIR) domains, present in all TLRs and TLR adapters, mediate protein interactions downstream of activated TLRs. A peptide library derived from TLR2 TIR was screened for inhibition of TLR2 signaling. Cell-permeable peptides derived from the D helix and the segment immediately N-terminal to the TLR2 TIR domain potently inhibited TLR2-mediated cytokine production. The D-helix peptide, 2R9, also potently inhibited TLR4, TLR7, and TLR9, but not TLR3 or TNF-α signaling. Cell imaging, co-immunoprecipitation, and in vitro studies demonstrated that 2R9 preferentially targets TIRAP. 2R9 diminished systemic cytokine responses elicited in vivo by synthetic TLR2 and TLR7 agonists; it inhibited the activation of macrophages infected with influenza strain A/PR/8/34 (PR8) and significantly improved the survival of PR8-infected mice. Thus, 2R9 represents a TLR-targeting agent that blocks protein interactions downstream of activated TLRs.
