Figure 7From: A novel platform for virus-like particle-display of flaviviral envelope domain III: induction of Dengue and West Nile virus neutralizing antibodiesImmuno-EM analysis of DIII-pseudotyped VLPs. Extracellular VLPs released from Sf9 cells co-expressing Pr55GagHIV and DIII-RIgE fusion protein, were isolated by ultracentrifugation through sucrose cushion. Aliquots of VLP samples were adsorbed on EM grids and reacted with monoclonal anti-His6 tag antibody, and secondary 10-nm colloidal gold-labeled anti-mouse IgG. (a), Control VLPs devoid of DIII (VLP-0); (b-d), VLP-displayed DIII-DENV1-RIgE; (e, f), VLP-displayed DIII-WNVKun-RIgE. Specimens were negatively stained with sodium phosphotungstate. BV, baculovirus vector. Note that all visible gold grains are found to be associated with membrane-enveloped VLPs of 120-130Â nm in diameter [12]. Scale bar represents 100Â nm in (a-c) and (e-f), and 20Â nm in (d).Back to article page