Centenarians may possess a unique immune system that remains functional in extreme old age, helping them achieve exceptional longevity, a new study suggests.
This rare population of individuals who reach 100 years or more have a distinct composition of immune cells that provides them with highly functional immune systems, said researchers, including those from the Boston University School of Medicine.
Previous studies have shown that one of the defining characteristics of ageing is a decline in the proper functioning of the immune system.
Immune cells are behind important mechanisms to recover from disease, promoting longevity.
In the new study, published recently in the journal EBioMedicine, researchers performed single cell sequencing to assess the molecules in peripheral blood mononuclear cells (PBMCs) – a broad category of immune cells circulating in the blood – taken from seven centenarians.
The centenarians were part of the New England Centenarian Study, one of the largest studies of individuals in North America who have lived longer.
Researchers then used advanced computational techniques to analyse how the proportion of different cell types and their internal activities change with age.
They identified cell type-specific composition and function changes that are unique to centenarians, reflecting normal immune response with age.
“We assembled and analyzed what is, to our knowledge, the largest single-cell dataset of centenarian subjects that allowed us to define unique features of this population that support the identification of molecular and lifestyle factors contributing to their longevity,” explained study senior author Stefano Monti.
“Our data support the hypothesis that centenarians have protective factors that enable to recover from disease and reach extreme old ages,” said Tanya Karagiannis, another author of the study.
Scientists said that as people are exposed to infections and recover from them over their lifetime, their immune systems learn to adapt. This ability, however, usually declines with age.
“The immune profiles that we observed in the centenarians confirms a long history of exposure to infections and capacity to recover from them and provide support to the hypothesis that centenarians are enriched for protective factors that increase their ability to recover from infections,” said senior author Paola Sebastiani.
Researchers believe the findings provide a foundation to better understand the mechanisms driving immune resilience with age – a factor that likely contributes to extreme longevity.
“Centenarians, and their exceptional longevity, provide a ‘blueprint’ for how we might live more productive, healthful lives. We hope to continue to learn everything we can about resilience against disease and the extension of one’s health span,” study senior author George J Murphy said.
