Sicilian semi- and supercentenarians: age-related Tæ cell immunophenotype contributes to longevity trait definition

The immune system of semi- (from >= 105 to <110 years old) and supercentenarians (>= 110 years old), i.e. oldest centenarians, is thought to have characteristics that allow them to reach extreme longevity in relatively healthy status. Thus, we investigated variations of the two principal subsets of T gamma delta, V delta 1, and V delta 2, and their functional subsets using the markers defining T alpha beta cells, i.e. CD27, CD45RA, in a cohort of 28 women and 26 men (age range 19-110 years), including 11 long-living individuals (from >90 years old to<105 years old), and eight oldest centenarians (>= 105 years old), all of them were previously analysed for T alpha beta and NK cell immunophenotypes on the same blood sample collected on recruitment day. Na & iuml;ve V delta 1 and V delta 2 cells showed an inverse relationship with age, particularly significant for V delta 1 cells. Terminally differentiated T subsets (T-EMRA) were significantly increased in V delta 1 but not in V delta 2, with higher values observed in the oldest centenarians, although a great heterogeneity was observed. Both na & iuml;ve and T-EMRA V delta 1 and CD8+ T alpha beta cell values from our previous study correlated highly significantly, which was not the case for CD4+ and V delta 2. Our findings on gamma delta T-EMRA suggest that these changes are not unfavourable for centenarians, including the oldest ones, supporting the hypothesis that immune ageing should be considered as a differential adaptation rather than a general immune alteration. The increase in T-EMRA V delta 1 and CD8+, as well as in NK, would represent immune mechanisms by which the oldest centenarians successfully adapt to a history of insults and achieve longevity.