A critical role for IL-15 in TLR-mediated innate antiviral immunity against genital HSV-2 infection

作者：Thatte Amit; DeWitte Orr Stephanie J; Lichty Brian; Mossman Karen L; Ashkar Ali A^*

来源：Immunology and Cell Biology, 2011, 89(6): 663-669.

DOI：10.1038/icb.2011.7

• toll-like receptors
• type I interferons
• interleukin-15
• innate antiviral activity

Innate antiviral immunity, particularly at mucosal surfaces, has a critical role in early control of viral infections. Both type I interferons (IFNs) and interleukin-15 (IL-15) are essential components of innate antiviral immunity. It has been shown that toll-like receptor (TLR) ligand-induced innate antiviral immunity requires IFN-alpha/beta and -lambda receptor signaling. However, it is not known if IL-15 has a role in TLR ligand-mediated antiviral responses. Here, we report that ligands for TLR-3 and TLR-9 cannot confer protection against genital herpes simplex virus-2 (HSV-2) in the absence of IL-15 in vivo. Interestingly, wild-type mice depleted of natural killer (NK) cells and treated with TLR ligands are protected upon HSV-2 challenge, suggesting that the critical role of IL-15 is independent of NK cell-mediated activity. To examine the cytokine response in the absence of IL-15, we investigated TLR ligand-induced IFN-beta and -lambda production in the vaginal washes, but found no impairment in IL-15(-/-) mice. Finally, we report no impairment in the expression of the IFN-stimulated genes in IL-15(-/-) mice. Collectively, the data suggest that TLR ligands induce an IFN-mediated response in the vaginal tract of both wild-type and IL-15(-/-) mice, but its induction is insufficient for providing protection against HSV-2 in the absence of IL-15. Immunology and Cell Biology (2011) 89, 663-669; doi:10.1038/icb.2011.7; published online 22 February 2011

• 出版日期2011-9