Pancreatic Cancer :: Analysis of immunological response to a MUC-1 loaded DC vaccine for pancreatic cancer

Results from a Phase I study of a pancreatic cancer vaccine may offer clues toward promoting long-term survival from the disease, according to researchers from the University of Pittsburgh Cancer Institute.

The researchers gave a dendritic cell vaccine to 12 pancreatic cancer patients. Four of the subjects have shown no signs of recurrence in the three years since the study began.

“The trial was a look at the toxicity and feasibility of using a dendritic cell-based vaccine against pancreatic cancer,” said Andrew Lepisto, Ph.D, post-doctoral researcher in the University of Pittsburgh?s Department of Immunology. “While we are unlikely to run large-scale trials with this particular form of the vaccine due to difficulty in its manufacturing, we have learned a tremendous amount from the subjects that benefited from the trial, which may translate well into more practical vaccine formulations.”

The dendritic cell vaccination strategy combines a cancer protein with the patient?s own dendritic immune cells. These cells are antigen presenting cells that, in effect, advertise the presence of the antigen molecule to the rest of the immune system. The antigen, MUC-1, is a protein that is over-produced by pancreatic cancer cells. By presenting patients with MUC-1 on dendritic cells, the researchers expected that they could influence the white blood cells to attack pancreatic cancer cells.

The study data suggests that the key to the effectiveness of the vaccine could be in controlling the regulatory T cells, which suppress the immune system, says Lepisto. Prior to vaccination, the pancreatic cancer patients had significantly more regulatory T cells than normal, which then increased following each injection. Likewise, the patients also experienced an increase in effector T cells, white blood cells that respond against antigen.

“Our next step is to create a strategy that allows us to downplay the regulatory T cells while still benefiting from the increase of effector T cells,” Lepisto said.

Each year, pancreatic cancer kills approximately 32,000 people in the United States alone. Pancreatic cancer is notoriously resistant to conventional cancer therapies and has one of the lowest five year survival rates of all cancers.


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