A team of researchers from Russia, the Czech Republic and Israel has found that the reason some blind mole rats live longer than other small creatures is because they have short immune memory With age, they do not accumulate large populations of long-lived memory cells; this allows to preserve the diversity of naive T cells and avoid senile autoimmune diseases.
The longer and brighter is immune memory, the stronger the defense of the organism will be, but only in theory. Mole rats demonstrated short immune memory. It allows them to avoid age-related autoimmune conditions and maintain a rich arsenal of naive immune T cells susceptible to new pathogens for the rest of their lives. In the long run, a strong immune memory is not always beneficial: an excessive or misdirected immune response can lead to allergies or autoimmune diseases. Scientists believe that senile diseases are largely the result of the accumulation of such wrong decisions.
Distinct organization of adaptive immunity in the long-lived rodent Spalax galili
A balanced immune response is a cornerstone of healthy aging. Here, we uncover distinctive features of the long-lived blind mole-rat ( Spalax spp.) adaptive immune system, relative to humans and mice. The T-cell repertoire remains diverse throughout the Spalax lifespan, suggesting a paucity of large long-lived clones of effector-memory T cells. Expression of master transcription factors of T-cell differentiation, as well as checkpoint and cytotoxicity genes, remains low as Spalax ages. The thymus shrinks as in mice and humans, while interleukin-7 and interleukin-7 receptor expression remains high, potentially reflecting the sustained homeostasis of naive T cells. With aging, immunoglobulin hypermutation level does not increase and the immunoglobulin-M repertoire remains diverse, suggesting shorter B-cell memory and sustained homeostasis of innate-like B cells. The Spalax adaptive immune system thus appears biased towards sustained functional and receptor diversity over specialized, long-lived effector-memory clones—a unique organizational strategy that potentially underlies this animal’s extraordinary longevity and healthy aging.