According to study results recently published in the European Journal of Immunology,researchers determined that when natural killer cells (NK cells) are close to lymphoma tumors, they suddenly lose their “killer” instinct—thus, finding a way to restore the power of these NK cells might lead to new therapy for lymphoma.
NK cells are white blood cells that help the immune system fight cancer and viruses. These cells send out signals that trigger the immune system’s response to fight against infections.
Lymphomas are cancers of the lymphatic system and can arise as either B cells or T cells. B cell lymphoma is difficult to treat and researchers are constantly seeking new approaches for therapy.
In the study, researchers from the Helmholtz Zentrum München in Germany placed NK cells in the vicinity of lymphoma tumors in live mice. They discovered that the NK cells lost their ability to kill the cancer cells.
The team then conducted a second experiment where they placed NK cells in a different environment—they found that their ability to kill cancer cells returns within a few hours.
From their findings, the team concluded that lymphoma tumors use two mechanisms to disable NK cells. The first mechanism is an inflammatory molecule called IL-10 that deactivates NK cells. The second mechanism is used to avoid NK cells and deactivate their NKG2D ligands. These ligands are surface molecules that NK cells attach to the infection, or cancer cells, and unleash the toxin.
From their conclusion, the team noted that NK cells are still able to send signals to activate anti-tumor immune responses by producing cytokine interferon-gamma (IFN-y). The team also believes that if they place the NK cells directly at the tumor, it can bypass the steps the tumor takes to evade the NK cells.
Source for Today’s Article:
Paddock, C. “Disarming lymphoma’s ability to escape immune response may lead to new treatments,” Medical News Today web site, July 9, 2015; http://www.medicalnewstoday.com/articles/296524.php.