Identifying one of the processes that plays a role in naïve and memory T-cells' growth and production could one day lead to better vaccines and possibly more effective cancer immunotherapy, said researchers at Baylor College of Medicine and Texas Children's Hospital in a report that appears in the current edition of Nature Immunology.
In previous work, Dr. Daniel Lacorazza, assistant professor of pathology at BCM, along with his research team, identified a transcription factor, ELF4, which regulates blood stem cells. A transcription factor is a protein that regulates how genes are translated into a form that leads to the making of the proteins associated with them.
"We knew ELF4 played a role in maintaining T cells," said Lacorazza, who is the principal investigator of the current study. "What we discovered was that ELF4 activates an inhibitor that leads to cell arrest, stopping naive T cells from proliferation."
A population of naïve CD8 T-cell is always circulating in the body and maintained at a constant level. Memory T cells are created when naïve CD8 T cells are activated to fight intracellular pathogens such as viruses or bacteria. The fight against infections prompts creation of memory T cells that then "remember" antigens or proteins found on cells infected with viruses or bacteria. In the future when same infections arise, memory T-cell enhances the body's ability to fight them.
Lacorazza and his research team focused on how ELF4 affected the process of inhibiting proliferation of CD8 T cells. Using mice generated to lack ELF4, researchers found that CD8 T-cells grew over time and acquired a "memory phenotype" without being exposed to any type of infections. At the same time, they determined that expression of the tumor suppressor gene called KLF4 was reduced in these mice.