Fig 2: Treatment with LRP1 binding chaperone protein RAP reduces RVFV but not ZIKV titres in trophoblast cell lines. (a) Pre-treatment of JEG-3, JAR and HTR-8 cells with 5 µg ml−1 WT mRAPD3 prior to infection with RVFV (MOI 0.1) reduced RVFV vRNA in JEG-3, JAR and to a lesser extent HTR-8 cells compared to no treatment (no Tx). Dashed lines represent the LOD. **P<0.01, ***P<0.001. P-values were determined by two-way ANOVAs. vRNA data from three separate experimental replicates, each with three technical replicates. (b) Treatment of trophoblast cells with 5 μg ml−1 WT mRAPD3 prior to infection with ZIKV (MOI 0.1) did not have any impact on ZIKV vRNA levels measured from supernatant via qRT-PCR in JEG-3, JAR or HTR-8 cells 48 hpi. (c) Detectable RVFV viral antigen is reduced following 5 µg ml−1 mRAP pre-treatment in each of the tested cell lines 24 hpi. Images obtained at 20×. Scale bar=100 µm. Blue=DAPI, red=RVFV nucleoprotein, green=LRP1.

Fig 3: Human trophoblast cell lines support RVFV infection and express LRP1. Growth curves of RVFV ZH501 in JEG-3, JAR and HTR-8 cells at various MOIs. (a) Infectious titres were quantified via viral plaque assay and (b) vRNA was quantified via quantitative reverse transcription polymerase chain reaction (qRT-PCR) (n=3 replicates per dose and timepoint). Dashed lines represent the limit of detection. (c) Cells were stained with an anti-RVFV or separately with an (d) anti-LRP1 antibody. Blue=DAPI, red=RVFV nucleoprotein antigen, green=LRP1. Images obtained at 20× magnification, scale bar=100 µm. (e) Protein lysates were generated from JEG-3, JAR and HTR-8 cells and analysed via western blot for LRP1 and Beta-actin expression. Gel was loaded by increasing passage age (lower passage to higher passage left to right, respectively).