Sarah Avery, Duke Medicine News and Communications

In the 20 years since a group of Duke University researchers pioneered the use of RNA-loaded dendritic cells as cancer vaccines, they and many others have shown that this is a safe and effective way to induce tumor-specific immune responses.

Florescence microscopy image of mouse dendritic cells with mRNA-loaded blood cells.

Florescence microscopy image of mouse dendritic cells with mRNA-loaded blood cells.

But the approach has had drawbacks – primarily in the amount of time and money it takes to develop the cells.

Now the researchers, led by Smita K. Nair, Ph.D., associate professor in the Department of Surgery, are moving the science forward with new findings that could significantly improve the utility of this promising therapy.

Appearing in the June 2014, issue of the Journal Advanced Healthcare Materials, Nair and colleagues demonstrate that a tumor vaccine can be formulated by loading RNA into whole blood cells directly after a blood draw without the need for any form of cell culture.

This overcomes the major impediments. The original approach required harvesting cells from the patient via leukapheresis – a step that relies on special equipment and highly trained technicians – to generate dendritic cells from the cellular population. Then the cells were loaded with RNA and injected back into the patient. The process took up to nine days.

Using the new method, the team can create vaccines in less than two hours.

“The therapeutic benefit in mice immunized with mRNA-loaded whole blood cells and those immunized with mRNA-loaded dendritic cells (the gold-standard for cell-based vaccines) was comparable,” Nair said. “This new approach has the potential to be an effective substitute to existing cell-based vaccinations. It could also cut costs for treatment and speed clinical translation of cell-based mRNA tumor vaccines.”

Nair said pre-clinical studies using human blood cells are continuing, with clinical trials on the near horizon.