The aging immune system

Published on February 28, 2023   35 min

Other Talks in the Series: The Immune System - Key Concepts and Questions

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I am Ana Maria Caetano Faria. I am a professor of immunology at the Department of Biochemistry and Immunology at the Universidade Federal de Minas Gerais in Brazil. The topic today is The Aging Immune System.
The first question that comes to our minds when discussing aging is why do we age? Not all species age. Bacteria, for instance, simply divide and give rise to new bacteria. In fact, senescence emerged with reproduction that separated the soma from the reproductive cells and from the new organism. Some theories have been proposed to explain senescence and they all take this finding into the light of evolution. Two of these theories proposed that senescence was not predicted by evolution. According to the most accepted theory, The Antagonistic Pleiotropy, aging is the result of genes that enhance fitness early in life when natural selection is stronger and become detrimental in older age when reproductive activity ceases. The Disposable Soma Theory also considers that the evolutionary value of additional life declines after the organism reaches the reproductive period. Programmed theories proposed that senescence was evolutionarily predicted since limiting the lifespans of individual members of a population increases the probability that the population will avoid extinction. It's also very interesting that not all species deteriorate with aging. Some multicellular organisms, like hydra for example, have the ability to regenerate, keep fertility, and they do not show signs of aging.