Antiviral CD8 T-cell immune responses are impaired by cigarette smoke and in COPD.

Background: Virus infections drive COPD exacerbations and progression. Antiviral immunity centres on the activation of virus-specific CD8 T-cells by viral epitopes presented on major histocompatibility complex (MHC) class I molecules of infected cells. These epitopes are generated by the immunoproteasome, a specialised intracellular protein degradation machine, which is induced by antiviral cytokines in infected cells.