Background.  Telomeres provide a key mechanism for protecting the integrity of chromosomes and their attrition after cell division and during aging are evident in lymphocytes. However, the significance of telomere shortening in age-associated decline of immune function is unknown.

Methods.  We selected 22 HLA-A2–positive healthy older adults who have relatively short or long telomere lengths to compare their antibody response against the influenza vaccine, and their CD8⁺ T-cell response against an influenza antigen.

Results.  B cells from individuals with a robust antibody response to the influenza vaccine had significantly longer telomeres than those with a poor antibody response. Monocyte-derived antigen-presenting cells of both short and long telomere groups induced similar expansions of influenza M1–specific CD8⁺ T cells. Vaccination did not increase M1-specific CD8⁺ T cells in blood, but M1-specific CD8⁺ T cells from the long telomere group exhibited significantly greater expansion in vitro than those from the short telomere group. Finally, M1-specific CD8⁺ T cells that underwent more expansions had significantly longer telomeres than cells with fewer divisions.

Conclusions.  Telomere length is positively associated with a robust lymphocyte response, and telomere attrition may contribute to the age-associated decline of adaptive immunity.