Researchers say they can shorten manufacturing time for dendritic cell vaccines in patients who have recurring cancers in the ovaries, primary peritoneum, or fallopian tubes.

A benefits of the reduced time includes cost savings, according to a study by University of Pennsylvania researchers published in the December issue of PLoS ONE.

“Our work proves that these dendritic cells can be manufactured with a reasonable cost and retain their potency after being loaded with patients’ tumor extract. This is a very personalized approach to immunotherapy, which can be easily prepared for most patients with ovarian cancer undergoing surgery to remove their tumors,” says senior author George Coukos.

Coukos is director of Ovarian Cancer Research Center at the University of Pennsylvania’s Abramson Cancer Center.

Previously experts have predicted that vaccines could stimulate a patient’s own immune system to attack tumors and control the disease. Dendritic cells are a particularly promising path towards immune therapy, especially for patients with small tumors or patients in remission.

These dendritic cells contain a tumor antigen that when properly activated could activate the immune system to attack the cancer and restrain tumor progression, the study authors said.

Past studies have shown that dendritic cell vaccines containing a single protein antigen were capable of shrinking pre-invasive breast cancers in just two days, and it was thought that these antigens required seven days of maturation before they could be used.

However, Coukos and his team determined that these dendritic cells could be matured in culture for just four days and are just as effective as cells matured for seven days.

The research team isolated peripheral blood monocytes, a kind of white blood cell, from health volunteers and ovarian cancer patients, and using clinical-grade protocols, the team induced the cells to separate into immature dendritic cells that were exposed to whole tumor lysate for two, four or seven days.

When researchers compared protein markers on cells’ surfaces, than found that although the majority of dendritic cells were still immature at two days, a majority of cells were mature on the fourth day.

Researchers found that the day-four dendritic cells induced T-cell responses from both cancer patients and healthy donors in test tube experiments, and that those responses were comparable to say-seven dendritic cells.

"Given the overall superior performance of whole-tumor lysate preparations over molecularly defined antigens for cancer vaccines and the overall superiority of dendritic cell-based vaccines, our results provide important preclinical data for the rapid development of potent, highly immunogenic vaccines for treating many tumor types," says author Cheryl Lai-Lai Chiang, a post-doctoral researcher at the Center.