Researchers designed DLnano-vaccines displaying 60 copies of protein parts derived from the melanoma-specific antigens Trp2 and Gp100 and tested these in mouse models of melanoma, observing prolonged survival that depended on CD8 T cell activation both in therapeutic and prophylactic settings.

"One of the advantages of synthetic DNA technologies over other methods is the versatility of the platforms," said Ziyang Xu, Ph.D., a recent doctoral graduate working at Wistar and the first author of the study. "DLnano-vaccines may be designed for various cancer targets and our study shows this is a promising strategy for cancer immunotherapy that may warrant further testing."

To elucidate the mechanism through which DLnano-vaccines activate CD8 T cells, the team studied the effects of the DNA-launched version of a previously described HIV nanoparticle vaccine (eOD-GT8-60mer). They observed that DLnano-vaccines administered via electroporation resulted in transient muscle cell apoptosis that attracted macrophage infiltration at the injection site, which in turn was instrumental to activate CD8 T cells.

DLnano-vaccines were developed using synthetic DNA technology in collaboration with the lab of David B. Weiner, Ph.D., Wistar executive vice president, director of the Vaccine & Immunotherapy Center, and the W.W. Smith Charitable Trust Professor in Cancer Research and also a co-senior author on the study.