Fig 4. Innate immune signal transduction pathways in keratinocytes.

An example of an immune signaling cascade downstream of pattern recognition receptors is shown. Stimulus from pathogen infection is sensed by PRRs, communicated through the adaptor protein TRIF, and further communicated through complexes formed by signaling proteins shown. These result in translocation of the transcription factors IRF-3 or NFkB to induce expression of interferon-stimulated genes, or proinflammatory cytokines and other mediators.