Induction of innate immunity against herpes simplex virus type 2 infection via local delivery of Toll-like receptor ligands correlates with beta interferon production.
Toll-like receptors (TLRs) constitute a family of innate receptors that recognize and respond to a wide spectrum of microorganisms, including fungi, bacteria, viruses, and protozoa. Previous studies have demonstrated that ligands for TLR3 and TLR9 induce potent innate antiviral responses against herpes simplex virus type 2 (HSV-2). However, the factor(s) involved in this innate protection is not well-defined. Here we report that production of beta interferon (IFN-beta) but not production of IFN-alpha, IFN-gamma, or tumor necrosis factor alpha (TNF-alpha) strongly correlates with innate protection against HSV-2. Local delivery of poly(I:C) and CpG oligodeoxynucleotides induced significant production of IFN-beta in the genital tract and provided complete protection against intravaginal (IVAG) HSV-2 challenge. There was no detectable IFN-beta in mice treated with ligands for TLR4 or TLR2, and these mice were not protected against subsequent IVAG HSV-2 challenge. There was no correlation between levels of TNF-alpha or IFN-gamma in the genital tract and protection against IVAG HSV-2 challenge following TLR ligand delivery. Both TNF-alpha(-/-) and IFN-gamma(-/-) mice were protected against IVAG HSV-2 challenge following local delivery of poly(I:C). To confirm that type I interferon, particularly IFN-beta, mediates innate protection, mice unresponsive to type I interferons (IFN-alpha/betaR(-/-) mice) and mice lacking IFN regulatory factor-3 (IRF-3(-/-) mice) were treated with poly(I:C) and then challenged with IVAG HSV-2. There was no protection against HSV-2 infection following poly(I:C) treatment of IFN-alpha/betaR(-/-) or IRF-3(-/-) mice. Local delivery of murine recombinant IFN-beta protected C57BL/6 and IRF-3(-/-) mice against IVAG HSV-2 challenge. Results from these in vivo studies clearly suggest a strong correlation between IFN-beta production and innate antiviral immunity against HSV-2.
Gill
Navkiran
N
Centre for Gene Therapeutics, Department of Pathology and Molecular Medicine, McMaster University Health Sciences Centre, Hamilton L8N 3Z5, Ontario, Canada.
Deacon
Philip M
PM
Lichty
Brian
B
Mossman
Karen L
KL
Ashkar
Ali A
AA
D000818:Animals; D004195:Disease Models, Animal; D005260:Female; D006558:Herpes Genitalis / Q000276:immunology* / Q000517:prevention & control; D018258:Herpesvirus 2, Human / Q000276:immunology*; D007113:Immunity, Innate; D016899:Interferon-beta / Q000096:biosynthesis*; D007371:Interferon-gamma / Q000032:analysis / Q000235:genetics; D008024:Ligands; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009092:Mucous Membrane / Q000473:pathology; D009838:Oligodeoxyribonucleotides / Q000494:pharmacology*; D011070:Poly I-C / Q000494:pharmacology*; D013223:Statistics as Topic; D016019:Survival Analysis; D051193:Toll-Like Receptors / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis / Q000235:genetics
C408982:CPG-oligonucleotide; D008024:Ligands; D009838:Oligodeoxyribonucleotides; D051193:Toll-Like Receptors; D014409:Tumor Necrosis Factor-alpha; D016899:Interferon-beta; D007371:Interferon-gamma; D011070:Poly I-C