Subunit vaccine design for enhanced lymphatic trafficking
Toll-like receptor (TLR) ligands are immunological danger signals and clinically-relevant vaccine adjuvants that efficiently target and activate dendritic cells (DCs). While the effects of TLR agonists on DC upregulation of costimulatory molecules and pro-inflammatory cytokines have been widely studied, the extent at which they differentially impact DC migratory phenotype and functional migration through lymphatics is underinvestigated. The overall goal of this collaborative project with the lab of Dr. Krish Roy is to determine if single and dual TLR-based adjuvant formulations (containing Poly(I:C), MPLA, R848, or CpG ODN) delivered on poly(lactic-co-glycolic) (PLGA) particles distinctly affect DC migration to the lymph node. DC expression of chemokine receptors (i.e. CCR7) and integrins (i.e. LFA-1) are measured with high-throughput flow cytometry in response to 2D culture with TLR ligand-particles and lymphatic endothelial cells. Three-dimensional migration of DCs toward lymphatic signals and their uptake of fluorescent TLR ligand-particles are tracked in microfluidic devices with time-lapse microscopy. In mice, near-infrared fluorescence microscopy can be used to monitor lymphatic transport of NIR-labeled A) PLGA particles and B) adoptively transferred DCs in response to dual TLR agonist formulations. Lymphatic transport is characterized by clearance from the injection site, appearance and velocity in collecting lymphatic vessels, and accumulation in draining lymph nodes. Understanding how to regulate DC migration to the node with particulate vaccines and multi-TLR agonist formulations provides drug developers with another means of modulating the vaccine immune response.
Contact: Alexandra Atalis