Fig. 4: Cellular biosensors to study measles virus receptor engagement.

a Scheme depicting measles hemagglutinin with ∆18aa cytoplasmic domain and C-terminal V5-tag modifications and the CD46-ζ chimeric receptor. b Expression of measles hemagglutinin on K562 RFP stimulator cells. c Expression of CD46 on JE6.1 TPR, JE6.1 TPR-CD46^KO and JE6.1 TPR-CD46^KO CD46-ζ. d Scheme depicting the interaction of measles hemagglutinin on stimulator cell with the CD46-ζ chimeric receptor on biosensor cells. e, f JE6.1 TPR CD46^KO, JE6.1 TPR CD46-ζ and CD46-ctrl were co-cultured with the indicated cell lines e Representative histograms showing reporter gene expression of JE6.1 TPR CD46-ζ biosensor cells stimulated with indicated stimulator cells (data presented as NFκB-eCFP FI). f One experiment was performed in triplicates. Data is presented as replicates with mean ± SD of gMFI NFκB-eCFP. g, h JE6.1 NFκB-eGFP CD46-ζ biosensor cells were co-cultured with stimulator cells as indicated. For one condition K562-hemagglutinin cells were preincubated with vaccinated donor serum at a dilution of 1:10. g Representative histograms showing reporter gene expression of JE6.1 NFκB-eGFP CD46-ζ biosensor cells stimulated with indicated stimulator cells (data presented as NFκB-eGFP FI). h Graph shows pooled data from independent experiments (n = 3, each performed in triplicates). The triplicate means of NFκB-eGFP gMFI values were normalized to unstimulated cells. Data is presented as mean fold induction values of the three experiments with mean ± SD. For statistical analysis ordinary one-way ANOVA with Dunnett’s multiple comparisons test for unpaired, normally distributed data was performed (***p = 0.0004; ns p > 0.05). i JE6.1 TPR CD46-ζ biosensor cells were co-cultured with K562 hemagglutinin stimulator cells. The stimulators were preincubated with IVIG preparations at the indicated concentrations (n = 1 experiment, performed in triplicates). Data is presented as individual values with mean ± SD of gMFI NFκB-eCFP. Source data for this figure are provided as a Source Data file.