Researchers at the Gladstone Institutes have found that a protein that is commonly known for being activated by red wine could help rejuvenate cells in the immune system. The work was published yesterday in the Journal of Experimental Medicine.
The study focuses on SIRT1, which is a known anti-aging protein that has been shown to protect against a number of diseases. The group wanted to find out how SIRT1 affects cytotoxic T cells, which are cells of the immune system known to kill infected cells.
"Over the course of a person's life, with repeated exposure to bacteria and viruses, these T cells mature and eventually lose a protein called CD28," said Melanie Ott, senior author of the study. "And as these cells get older, they become more toxic to their environment." Due to viral infections, such as HIV or CMV, the aging process is accelerated.
"A higher number of mature cytotoxic T cells in the body has been associated with age-related, autoimmune, and inflammatory diseases," added Ott. "We wanted to come up with a way to counteract this phenomenon."
"We studied human T cells, isolated from blood donors of all ages, to compare mature cytotoxic T cells with naive ones," said Philip Ansumana Hull, one of the first authors of the study. The naive cells showed a higher expression of CD28 and a higher concentration of SIRT1. When the cells aged, they lost SIRT1, rapidly shifting into glycolysis and production of more toxic proteins that lead to inflammatory diseases.
Based on the new findings, the researchers believe that there could be two potential drug targets. First, new drugs could be developed to strengthen SIRT1 to rejuvenate mature cytotoxic T cells or keep them from progressing too quickly into a highly toxic state. "This could postpone the development of age-related diseases," said Mark Y. Jeng, the study's other first author. "It could also help people with a weaker immune system fight infections or better respond to immune vaccination, such as seniors or chronically-infected patients."
Alternatively, drugs could be used to encourage the T cells to be more toxic by temporarily making naive T cells fight more aggressively against tumors.
Image: In a new study, Melanie Ott (back) and Philip Ansumana Hull (front) reveal what happens when the immune system ages. Image courtesy of the Gladstone Institutes.