Journal: Vaccines
Article Title: Newcastle Disease Virus-Like Particles Displaying Prefusion-Stabilized SARS-CoV-2 Spikes Elicit Potent Neutralizing Responses
doi: 10.3390/vaccines9020073
Figure Lengend Snippet: S2P-NDVLP elicited a robust anti-SARS-CoV-2-neutralizing response with a relatively low S2P-equivalent dose in mice at Week 5. ( A ) Boost immunization elicited higher ELISA titers against the SARS-CoV-2 spike at Week 5. The titers among the S2P-NDVLP-immunized groups were not significantly different. IgG titers in the S2P-immunized groups were significantly higher than the S2P-NDVLP-immunized groups. Triangle symbols indicate the ELISA titers at assay maximum. ( B ) The S2P-NDVLP groups had robust neutralization activities at Week 5 but were not significantly different from each other. Serum neutralization titers (ID 50 ) were measured against a SARS-CoV-2 D614G variant pseudovirus. ( C ) Correlation between neutralization titers and ELISA S2P-specific IgG titers did not exist in the S2P-NDVLP-immunized groups, but a weak correlation existed in the S2P-immunized groups. ( D ) RBD-specific serum antibody titers were measured as BLI responses and calculated with Prism. BLI RBD-specific serum antibody titers in the 2 and 10 μg S2P-immunized groups were significantly higher than all other groups. ( E ) Correlation between neutralization titer and BLI RBD-specific antibody titer did not exist in the S2P-NDVLP-immunized groups, but a weak correlation existed in the S2P-immunized groups. ( F ) Quality of the immune responses elicited by immunization was calculated as the ratio of the neutralization titer to the total ELISA IgG titer, plotted as the mean and SD. In ( A , B , D ), the Kruskal–Wallis test was used to test differences between the groups, and P-values were designated as *: p < 0.05; **: p < 0.01; ***: p < 0.001; ****: p < 0.0001, and geometric mean titers were marked with a red bar. Spearman correlation was used in ( C , E ).
Article Snippet: A codon-optimized plasmid CMV/R-SARS-CoV-2-encoding D614G spike variant was constructed and cotransfected with a lentivirus backbone, luciferase reporter, and human transmembrane protease serine 2 (TMPRSS2) in HEK293T/17 cells (ATCC #CRL-11268).
Techniques: Enzyme-linked Immunosorbent Assay, Neutralization, Variant Assay