Proliferation cues ‘natural killer’ cells for job change
PROVIDENCE, R.I. [Brown University] —The immune system maintains a rich abundance of “natural killer” cells to confront microbial invaders, but as the body gains the upper hand in various infections it sometimes starts to produce even more of the cells. For three decades, scientists haven’t understood what purpose that serves. In a new paper, Brown University researchers show one: proliferation helps change the NK cells’ function from stimulating the immune response to calming it down, lest it get out of hand.
In a series of experiments now published online in the Journal of Immunology, the researchers show that the process of proliferation unlocks expression of the gene in NK cells for producing Interleukin-10(IL-10), a protein that moderates other immune system cells.
"It’s really important for regulating potentially dangerous CD8 T cell responses," said Margarite Tarrio, co-lead author of the paper and a graduate student in the lab of Brown immunology Professor Christine Biron. "If you get CD8 T cells that are hyperactivated they can cause a tremendous amount of damage."
Human Lymphocyte, 2011, by David Scharf, Los Angeles. A human “Natural Killer” lymphocyte, a type of cell that mediates the immune system. This image is from a scanning electron micrograph, with the colours taken from multiple secondary detectors in a technique invented by the photographer.