title: Type I interferon mimetics bypass vaccinia virus decoy receptor virulence factor for protection of mice against lethal infection.
abstract: The canonical model of interferon (IFN) signaling focuses solely on the activation of STAT transcription factors which, according to the model, are initiated by the singular event of cross-linkage of the receptor extracellular domain by the IFN. The IFN has no further function beyond this. The model thus provides no approach to circumventing poxviruses decoy receptors that compete with the IFN receptors for IFNs. This simple event has allowed smallpox virus to decimate human populations throughout the ages. We have developed a noncanonical model of IFN signaling that has resulted in the development of small peptide mimetics to both types I and II IFNs. In this report, we focus on a type I IFN mimetic at positions 152 to 189, IFN-α1(152-189), which corresponds to the C terminus of human IFN-α1. This mimetic functions intracellularly and is thus not recognized by the B18R vaccinia virus decoy receptor. Mimetic synthesized with an attached palmitate (lipo-) for cell penetration protects mice from a lethal dose of vaccinia virus, while the parent IFN-α1 is ineffective. Unlike IFN-α1, the mimetic does not bind to the B18R decoy receptor. It further differs from the parent IFN in that it lacks the toxicity of weight loss and bone marrow suppression in mice while at the same time possessing a strong adjuvant effect on the immune system. The mimetic is thus an innate and adaptive immune regulator that is evidence of the dynamic nature of the noncanonical model of IFN signaling, in stark contrast to the canonical or classical model of signaling.
authors: University of Florida, Department of Microbiology and Cell Science, Gainesville, Florida, USA.
authors: Chulbul M
authors: CM
authors: Ahmed
authors: University of Florida, Department of Microbiology and Cell Science, Gainesville, Florida, USA johnsonh@ufl.edu.
authors: Howard M
authors: HM
authors: Johnson
mesh_terms: D000818:Animals; D000998:Antiviral Agents; D005260:Female; D016898:Interferon-alpha / Q000235:genetics / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D053633:Receptor, Interferon alpha-beta / Q000235:genetics / Q000378:metabolism*; D011991:Receptors, Virus / Q000378:metabolism*; D014615:Vaccinia / Q000276:immunology* / Q000517:prevention & control; D014616:Vaccinia virus / Q000276:immunology* / Q000472:pathogenicity; D014764:Viral Proteins / Q000378:metabolism; D037521:Virulence Factors; D014779:Virus Replication / Q000235:genetics
chemical_list: D000998:Antiviral Agents; D016898:Interferon-alpha; D011991:Receptors, Virus; D014764:Viral Proteins; D037521:Virulence Factors; D053633:Receptor, Interferon alpha-beta