A new approach to peripheral nerve injury? Natural killer cells in the immune system could present a target

In animal models of a totally crushed peripheral nerve, the damaged axons are broken down, allowing healthy ones to regrow. But humans rarely suffer complete axonal damage. Instead, axons tend to be partially damaged, causing neuropathic pain—a difficult-to-treat, chronic pain associated with nerve trauma, chemotherapy, and diabetes. A new study in Cell, led by Michael Costigan, Ph.D., at Boston Children's Hospital, explore the role of immune cells in breaking down damaged nerves. The findings may change our understanding of neuropathic pain and how to treat it. The study was published online on January 31.
Targeted destruction, Early in their work, Costigan's collaborators in Seoul, South Korea, noticed that immune cells called natural killer (NK) cells would strip away the axons of neurons in a petri dish. NK cells are part of our body's rapid, innate immune response to threats such as viruses and cancer. The team then started growing sensory neurons in a petri dish. They noticed these dissociated neurons began expressing large amounts of RAE1, a protein that invites NK cells to attack. When these neurons were co-cultured with activated NK cells, the NK cells began breaking down the injured nerves.