[cv]

Modular design on a DNA scaffold: a novel approach to dendritic cell-targeted vaccines.

To elicit a strong cytotoxic T lymphocyte response to a tumor antigen, a dendritic cell-targeted vaccine must be able to reach its target cell, be efficiently internalized and enter the cross-presentation pathway. We propose a novel vaccine architecture of a double-stranded DNA scaffold with antigen, targeting moieties and immunostimulatory molecules attached via zinc finger fusions. This modular design allows us to rapidly and easily test many combinations of modules to find those that are cross-presented most readily and increase T cell activation. The first specific aim is to construct a DNA-based vaccine that is roughly 100 nm in diameter for optimal delivery to the lymph node, contains a high dose of ovalbumin model antigen per particle, and targets the mannose receptor-mediated endocytosis pathway to improve cross-presentation. The second goal is to control the intracellular fate of the vaccine particle by targeting the antigen to the ER. We hypothesize that our ER-retained vaccine will exhibit virus-like kinetics, and that sustained cross-presentation will lead to more robust T cell activation. The third aim is to attach immunomodulatory molecules to our vaccine, to serve as a “danger” signal to the dendritic cell and upregulate costimulatory surface markers. We perform cross-presentation and T cell activation assays to determine vaccine potency, and correlate this data to imaging experiments to validate our rational vaccine design and suggest future improvements.