Then, the group tracked the cells to the main messenger center of the immune system - the lymph nodes. Here, they found approximately 35 percent of the original group of IKDCs now secreting communication molecules signaling a switch to messenger-mode.

Simultaneously, Housseau's colleagues in France, led by Laurence Zitvogel at the Institut Gustave Roussy, tested whether IKDCs are culprits in killing cancer by injecting mice with a cancer drug called Gleevec, which blocks an abnormal protein produced by cancer cells, and a growth factor for NK cells. The drug-growth factor combo served as a lure, leading the IKDCs to tumors implanted in the mice. The results were that tumors shrunk in mice, which received injections of IKDCs, but not in those receiving conventional NK cells only. Evidence from the shrunken tumors revealed certain "cell-killing" proteins that could be traced to IKDCs. These results are published separately in Nature Medicine.

Housseau's group is conducting further studies to verify the role of IKDC cells in infection and cancer. Meanwhile, the group is profiling IKDC genes to find a specific marker that could help them identify a human counterpart.

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Contact: Vanessa Wasta
wastava@jhmi.edu
410-955-1287
Johns Hopkins Medical Institutions
3-Mar-2006