Long Lived Humans Resistant to Cytomegalovirus
Cytomegalovirus is one of the important contributions to immune system failure with aging: most people are infected, and it causes an ever-greater fraction of available T cells to be uselessly specialized to fight it, leaving too few naive T cells left for other jobs. Intriguingly, it seems that long-lived people have some resistance to this consequence of infection: "we analyzed long-lived families in the Leiden Longevity Study (LLS) in which offspring enjoy a 30% reduced standardized mortality rate, possibly owing to genetic enrichment. We [determined] the capacity of T cells to respond [against] CMV in a smaller group of LLS subjects and controls. CMV infection was strongly associated with an age-related reduction in the frequency of naive T cells and an accumulation [of] late-differentiated effector memory T cells in the general population, but not in members of long-lived families. The latter also had significantly lower C-reactive protein levels, indicating a lower proinflammatory status compared with CMV-infected controls. ... Our data suggest that these rare individuals genetically enriched for longevity are less susceptible to the characteristic CMV-associated age-driven immune alterations commonly considered to be hallmarks of immunosenescence, which might reflect better immunological control of the virus and contribute to their decreased mortality rate." Hopefully the basis for this resistance can be uncovered and made into a therapy.