Immune cells turn back the clock to provide long-term protection

White blood cells called memory T cells are the rapid reaction force of the disease-fighting immune system. These cells recognize and respond when previously vanquished viruses, cancer or other threats try to stage a return.

But where do these smart soldiers come from? Scientists have long debated the origin of memory T cells. The answer might help researchers develop better vaccines or expand cancer immunotherapies.

Researchers from St. Jude Children’s Research Hospital and Emory University have the best evidence yet about the answer.

The scientists showed that certain memory T cells develop from T cells originally made by the body for another role. These T cells, called effector T cells, are created to fight viral infections and other threats. Usually, these cells complete their job and then die.

However, researchers found that a small percentage of effector T cells turn back the developmental clock and live on as memory T cells. The memory T cells move throughout the body. They are always ready to recognize an attack and quickly mount a defense.

“These results have provided new insights into memory T cell differentiation and may help researchers generate more effective vaccines or cancer immunotherapies,” said Ben Youngblood, PhD, of the St. Jude Department of Immunology.

The research appeared in the journal Nature.

Read the news release.