Tumor Cell Marker PVRL4 (Nectin 4) Is an Epithelial Cell Receptor for Measles Virus
Figure 2
PVRL4 (Nectin 4) can function as an entry factor for IC323-EGFP wtMV.
COS-1 cells were transfected with expression plasmids containing the coding sequences for candidate membrane protein receptors. After 36 hrs the cells were infected with IC323-EGFP wtMV. Virus specific fluorescence was observed between 24–48 hrs infection at 100x magnification using a Leica inverted microscope. Both PVRL4 (Nectin 4) and the positive control CD150/SLAM were capable of converting the non-susceptible COS-1 cells to a virus susceptible phenotype that produced syncytia. Other candidate receptor proteins including SLC6A14, STEAP4, TMPRSS11E, MUC1, ERBB3, and MUC20 were ineffective in producing infections, and yielded only isolated background single-cell infections that did not produce syncytia. Whole cell protein lysates were separated by SDS-PAGE followed by Western Immunoblot using Flag (IB: DDK) and V5 (IB: V5) antibodies to detect expression of these candidate receptors. GAPDH was used as a loading control. Scale bar = 100 µm. See also Figures S2 and S3 in Text S1.