Papers of the Week

Opioids are commonly used to provide analgesia for cancer pain, and functional opioid receptors have been identified on natural killer (NK) cells, the lymphocytes responsible for surveillance and elimination of cancer cells. Opioids also bind to other lymphocyte receptors, such as Toll-like receptor (TLR)-4. Here, we characterized the effects of morphine on primary human NK cell cytotoxicity and mediator release, which occur through classical opioid receptor or TLR4 signaling.