| First Author | Ma J | Year | 2013 |
| Journal | Sci Signal | Volume | 6 |
| Issue | 295 | Pages | ra87 |
| PubMed ID | 24084649 | Mgi Jnum | J:244497 |
| Mgi Id | MGI:5913276 | Doi | 10.1126/scisignal.2004431 |
| Citation | Ma J, et al. (2013) The TNF family member 4-1BBL sustains inflammation by interacting with TLR signaling components during late-phase activation. Sci Signal 6(295):ra87 |
| abstractText | Activation of Toll-like receptor (TLR)-dependent signaling leads to the expression of genes encoding proinflammatory factors, such as tumor necrosis factor-alpha (TNF-alpha), and this proinflammatory gene expression is sustained for the duration of the inflammatory response. TLR4-mediated inflammation, which occurs in two phases, depends on the TNF family member 4-1BB ligand (4-1BBL) to sustain TNF-alpha production during late-phase signaling. We showed that Toll-interleukin-1 receptor (TIR) domain-containing adaptor protein (TIRAP) and the kinase IRAK2 interacted with 4-1BBL to mediate late-phase TLR4 signaling. Expression of 4-1bbl depended on early TLR4 signaling that also induced Tnf expression, and 4-1BBL translocated to the plasma membrane, where it interacted with TLR4 to mediate late-phase signaling. TLR4-4-1BBL-mediated signaling depended on TIRAP and IRAK2, as well as a complex consisting of the E3 ubiquitin ligase TRAF6 (TNF receptor-associated factor 6), the kinase TAK1 (transforming growth factor-beta-activated kinase 1), and the adaptor protein TAB1 (TAK-binding protein 1). Inhibition of this late-phase pathway reduced the extent of TNF-alpha production by mouse macrophages exposed to the TLR4 ligand lipopolysaccharide (LPS) and ameliorated LPS-induced sepsis in mice. Together, these data suggest that TIRAP and IRAK2 are critical for the sustained inflammatory response that is mediated by late-phase signaling by the TLR-4-1BBL complex. |
