Figure 3.
In vitro characterization of the MR virus
(A) Replication kinetics of viruses on Vero/hSLAMF1 infected at an MOI of 0.03. MeV A, H1, and Δ8 denote MeVs expressing the corresponding MeV-H genes and MeV-F genotype A, whereas the MR virus encodes MeV-H Δ8 plus CDV-F. Values and error bars represent the mean and standard deviation (SD), respectively.
(B) Neutralization activity of human serum samples. Samples belonging to different cohorts are colored-coded. Mean ± SD
(C) Left panel: NT50 values of MeV-immune human sera against the MeV A and MR. Each line represents an individual sample (n = 23). The red line shows ferret serum anti-CDV, used as a control for neutralization. Statistical significance was inferred by a two-tailed paired t test. Right panel: correlation between NT50 for the vaccine virus and the MR virus. p < 0.001 for Pearson and Spearman correlation tests. The red curved line is the linear regression line, and dotted lines indicate the 95% confidence interval (CI) for the regression analysis.
(D) CHO cells expressing different MeV receptors were infected at an MOI of 1. Images were obtained 3 days after infection. Scale bar, 200 μm.
(E) Kinetics fusion assay after co-expression of MeV-F with MeV-H A or Δ8. Mean ± SD.
(F) Binding of MeV receptor-Fc to MeV-H protein, monitored by optical density (OD). The FLAG epitope in MeV-H was used as a coating control. Data are presented as mean ± SD and were fitted to a 1-site mode of total binding (R2 > 0.99). Statistical significance was determined using the Holm-Sidak multiple comparison test. ns, not significant; ∗∗∗∗p < 0.001.