While T cells are the body’s warriors against infection, without rest and maintenance T cells can die, leaving their hosts more susceptible to pathogens, researchers reported in the journal Science.
“We may have to change how we teach T cell biology,” said Professor Lieping Chen, who is the senior author of the study.
T cells remain in a quiescent state until pathogens are detected, but the molecular mechanisms of this state were previously unknown.
In the new study, researchers showed that a protein known as CD8a – which is found in a subset of T cells called CD8 cells – is crucial to keeping the cells in this dormant state. When scientists deleted this protein in mice, the protective CD8 cells were unable to enter a quiescent state and died, leaving the host vulnerable to infections.
Further, they identified another protein, PILRa, that provides a biochemical signal to CD8a. By disrupting this protein pair, both “memory” CD8 cells – previously been exposed to pathogens – and naïve cells died because they lacked the ability to stay in a quiescent state.
The researchers hope that understanding why this resting state is crucial to maintenance and survival of T cells can lead to improved immune system function.
Chen noted that as people age they tend to lose both naïve and memory T cells, making older individuals more susceptible to infections. It is possible that the inability of T cells to remain in a quiescent state could lead to people becoming more susceptible to infections and cancer, the authors suggest.
Source: Yale University
