Analysis of dendritic cell activation by differential filovirus GP concentration in virus-like particle vaccines

Abstract

Abstract Filoviruses, specifically ebola- and marburgviruses, can cause severe hemorrhagic fever in humans. Currently, there are no US licensed vaccines available against filoviruses. An important filovirus protein required for cellular entry is glycoprotein (GP). GPs are also used as vaccine antigens that can trigger antibody production, which makes them an important factor in vaccine development. Distinct vaccine platforms are made in different cell types, such as mammalian and insect cells. Different glycosylation patterns and GP distribution in virus-like particles (VLPs) were observed by our lab in GPs expressed in mammalian cell lines, but comparative data is needed to determine how differential filovirus GP concentration in the VLP platform affects the immune response in vaccination. We hypothesize that differential filovirus GP concentration will yield diverse results in immunogenicity and will provide insight into specifically how we can utilize GP concentration to improve vaccine development. We are using ebolavirus GPs to develop VLPs by transfecting 293T (mammalian) cells with VP40, a structural protein, and GP DNA from the different filoviruses. Preliminary results show that changing the amount of GP in transfection appears to affect the amount of VLPs generated and the relative amount of GP compared to VP40. We are currently adding the VLPs to dendritic cells (DCs), a key subset of innate immune cells, to measure activation by flow cytometry. We expect to measure how differential filovirus GP concentration in VLPs affects DC activation. This will result in broad significance in development of filovirus vaccine platforms.