The Battle Between Influenza and the Innate Immune Response in the Human Respiratory Tract

Nicholls, John M

Similar to neutrophils these cells do not constitute a major population of inflammatory cells within normal alveoli. They do Electron micrograph of human ex vivo tissues infected with avian influenza virus showing egress of viral particles from type 2 pneumocytes. The viral RNA binds to RIG-I and is then ubiquitinated by TRIM25 allowing binding to MAVS followed by activation of TBK-1, IKK pathways and transcription of interferon. The release of interferon leads to increased cytokine production, recruitment of neutrophils and activation of macrophages. The interferon will act as an autocrine and paracrine function leading to more cytokine and antiviral proteins. however appear to be closely involved in later stages of the inflammatory response, either through direct activation using the interferon receptor pathway (see below) or through type I IFNmediated trans-presentation of IL-15 by dendritic cells (reviewed by Hwang and colleagues [47] ).