Cytotoxic T cells in influenza immunity

A key role for CD8⁺CTL in influenza virus clearance has been defined in the mouse model. This is supported by the demonstration of linkage of CTL kinetics to viral clearance and disease modulation, by direct lysis of cells infected with non-neutralizable subtypes, and by adoptive transfer and deletion of CTLs. Further, immunization with DNA encoding influenza nucleoprotein protects in the absence of antibody. While the documentation of a parallel role in human infection is limited, the mouse model provides a conceptually valid surrogate for human infection and immunity. Rapid memory CTL recall should be of most value in the presence of infection where antibody is inadequate, such as in the elderly and those with chronic disease.