New research says ‘super’ enzyme may boost tumor vaccines

The key to boosting the vaccines is by extending the lives of dendritic cells, the immune-system master switches that promote the response of T-cells, which attack tumors.

“By keeping the dendritic cells alive longer, you extend the window of activation, promoting the desirable immune response, which in the case of cancer, is the expansion of T-cells,” said Dr David Spencer, associate professor of immunology at Baylor College of Medicine.

The scientists found that Akt1 “was in fact essential for dendritic cell survival,” he said. Then they sought to develop a more potent form of Akt1 that would enable the dendritic cells to live longer, boosting immune response.

They altered the enzyme so that it targeted a particular domain on the plasma membrane of the cell where signaling occurred, making the action of Akt1 more specific. They then eliminated a small part of the Akt1 molecule that had a negative or inhibitory effect.

Using specially designed adenoviruses, he and his colleagues put the modified “super” Akt1 molecule into the dendritic cells.

“As predicted, these dendritic cells lived longer and were more potent, both in the laboratory and in mice,” said Dr David Spencer. “It led to the elimination of some very aggressive tumors in the mice.”

In the laboratory, they found that the “super” Akt1 also has a potent effect on human dendritic cells as well, although it has not been used to treat people yet.