Both type I and type III interferons are required to restrict measles virus growth in lung epithelial cells.

Measles virus (MeV) first infects immune cells in the respiratory tract of a human host, spreads to lymphoid organs throughout the body, and finally enters and grows in respiratory epithelial cells before being released and transmitted to the next host. Thus, efficient growth in respiratory epithelial cells is important for the person-to-person transmission of MeV. Upon viral entry, host cells detect viral nucleic acids and produce interferons (IFNs) to control viral growth. Type I (IFN-α/β) and type III (IFN-λ) IFNs have largely common induction and signaling mechanisms and stimulate expression of similar target genes but utilize distinct receptors. To determine the relative contributions of type I and type III IFNs to the control of MeV growth in epithelial cells, we examined the growth of MeV and that of its mutants lacking either type I or type III IFN receptor in the human lung epithelial cell line H358. Our results revealed that both type I and type III IFNs are required to restrict MeV growth in H358 cells and that the induction of type III as well as type I IFNs was increased in the absence of the MeV nonstructural V protein.