Retraining immune cells to kill tumors

Retraining immune cells to kill tumors

(Note: In cells, IKK-beta is the enzyme that frees the transcription factor,
NF-kappaB, from its inhibitor, IKB (inhibitor kappa-B), allowing NF-kappaB
to travel from the cytosol (the non-nucleus portion of the cell) to the
nucleus where it turns on something like 100 genes in the DNA. In cancer
cells, the activation of NF-kappaB (via the destruction of IKB by IKK-beta)
makes the cancer cell much more agressive. But in the study below, the
IKK-beta is in the immune cells, not cancer cells.)


Public release date: 19-May-2008
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Contact: Hema Bashyam
hbashyam@rockefeller.edu
212-327-7053
Journal of Experimental Medicine

Retraining immune cells to kill tumors

Immune cells called macrophages can destroy tumor cells by producing
inflammatory proteins that are toxic to the tumor. But the environment
inside the tumor somehow halts this production and instead causes the cells
to make proteins that promote tumor growth.

The new study identifies a protein, called IKK(beta), that drives this
pro-tumor switch. This protein normally stimulates protective inflammation.
But in the context of tumors, the study shows, IKK(beta) also blocked the
activity of a protein that turns on anti-tumor genes.

When the scientists inactivated IKK(beta) in macrophages from mouse tumors,
the tumor-friendly cells went on the attack. These cells also secreted
proteins that attracted professional tumor-killing cells that helped to
shrink the tumors. The researchers are now conducting clinical trials to
determine whether macrophages from cancer patients can be similarly
reprogrammed into tumor killers.