Duke’s Cancer Vaccine Approach May Be More Effective
Antigen-loaded monocyte administration induces potent therapeutic anti-tumor T cell responses
Using a precursor to dendritic cells appears to be an efficient and effective way to stimulate the immune system to fight cancer tumors, said researchers at the Duke Cancer Institute.
According to a study in animal and cell models described online in the Journal of Clinical Investigation published on October 29, 2019, it offers an alternative to dendritic cell cancer vaccines, which have shown promise as a way to prompt T-cells to recognize and attack cancer cells.
But, so far, dendritic cell cancer vaccines have had limited success in improving patient survival, said these Duke researchers in a November 12, 2019, press release.
The new approach uses monocytes, a type of white blood cell that is a forerunner of dendritic cells. When the monocytes are loaded with an antigen and injected in mice, they indirectly induced a T-cell response that attacked tumors.
“This is a whole new approach,” said senior author Michael D. Gunn, M.D., a professor in the departments of Medicine and Immunology at Duke University School of Medicine.
“And it appears to offer 2 advantages relative to dendritic cell vaccination.”
“First, we see better immune responses and anti-tumor responses. And second, to make a dendritic cell vaccine, it requires starting with monocytes.”
“And then, culturing and treating the cells to differentiate into dendritic cells. This process skips all that.”
Dr. Gunn said ‘the research team predicted the monocytes would be effective transporters of antigens to dendritic cells, but they did not expect them to stimulate strong T-cell responses.’
Remarkably, after the monocytes transferred antigens to dendritic cells in the spleen using a pathway known as a gap junction that allows different cells to connect, the dendritic cells triggered T-cells to very effectively control tumor growth
“We were rather surprised when we started getting very strong immune responses,” Dr. Gunn added.
“This was a sort of wild hair experiment to see what happens. We were like everybody else and suspected you needed to inject dendritic cells to present the antigen, but it turns out you don’t.”
Dr. Gunn said additional experiments are ongoing to further illuminate the mechanisms involved in the immunological response, and a phase 1 clinical trial is slated to begin in 2020.
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In addition to Gunn, study authors include Min-Nung Huang, Lowell T. Nicholson, Kristen A. Batich, Adam M. Swartz, David Kopin, Sebastian Wellford, Vijay K. Prabhakar, Karolina Woroniecka, Smita K. Nair, Peter E. Fecci and John H. Sampson.
The work received support from a Duke Chancellor’s Program Project Accelerator Award and the Duke Specialized Program in Research Excellence (SPORE) in Brain Cancer (P50 CA 190991).
Cancer News published by Vax Before Cancer