CD8 T cell responses to influenza virus infection in aged mice.

Influenza is one of the most common infectious diseases afflicting humans, particularly the elderly. The murine model has been widely employed for investigation of immunity to influenza virus infection. In this paper, we review the recent advances in understanding the diminished CD8 T cell immune response to influenza virus infection in aged mice. Possible mechanisms of impaired CD8 T cell responses with aging are addressed, including: (1) the role of dendritic cells (DCs); (2) the effect of age-associated changes in the T cell repertoire; and (3) the interactions with CD4 T cells, including T regulatory (Treg) cells and CD4 T helper cells. The aged murine model of the CD8 T cell response to influenza virus is helping to elucidate the mechanisms of immunosenescence which can lead to therapeutic improvements in the primary CD8 T cell response to new infections, as well as the development of new strategies for immunization to prevent influenza in the elderly.