Scientists have uncovered a new way the immune system may fight cancers and viral infections. The finding could aid efforts to use immune cells to treat illness.
The research, in mice, suggests that some organs have the immunological equivalent of "neighborhood police" specialized squads of defenders that patrol only one area, a single organ, instead of an entire city, the body.
Scientists at Washington University School of Medicine in St. Louis have shown that the liver, skin and uterus each has dedicated immune cells, which they call tissue-resident natural killer cells. Other organs may have similar arrangements.
Their study, published in eLife, disproves the long-held assumption that all natural killer cells roam the body to provide the first line of defense against cancers and viruses.
"If, for example, we can use specialized medications to activate only these organ-specific cells, they could provide powerful and selective weapons against infections and tumors in the organs where they reside," said senior investigator Wayne M. Yokoyama, MD, the Sam and Audrey Loew Levin Professor of Medicine. "Cells that only defend one organ may be much better equipped than the roaming immune cells to mount an attack and limit collateral damage to healthy tissue."
Scientists have thought that mature natural killer cells circulate through the body looking for viruses and cancers. When these immune cells identify a threat, they attack. Scientists also thought that natural killer cells that stayed in the liver instead of circulating were immature or inactive and eventually would become like other natural killer cells, leaving the liver and moving through the body.
In the new study, lead author Dorothy K. Sojka, PhD, a postdoctoral research fellow in Yokoyama's laboratory, showed that some natural killer cells never leave the liver. She identified additional tissue-resident natural killer cells in the skin and uter
|Contact: Michael C. Purdy|
Washington University School of Medicine