Enhancement of vaccine-mediated antitumor immunity in cancer patients after depletion of regulatory T cells

Duke University researchers have now shown that selectively killing the population of regulatory T cells in cancer patients - cells that normally function to restrain the activity of the immune response - improves the ability of a cancer vaccine to stimulate tumor-specific T cells.

The results suggest that this approach holds great promise for augmenting the potency of current cancer vaccination protocols.

In their study appearing online on November 23 in advance of print publication in the December issue of the Journal of Clinical Investigation, Johannes Vieweg and colleagues show that the immunotoxin DAB389IL-2 selectively eliminates CD25-expressing regulatory T cells in cancer patients, without any toxic effects. This strategy significantly improved the stimulation of tumor-specific T cell responses in these cancer patients, compared to vaccination alone. Researchers had previously suggested that eliminating this population of T cells could enhance the efficacy of cancer vaccines, and this study represents what is believed to be the first time this concept had been tested and shown to be successful in humans.