Measles virus enhances the expression of cellular immediate-early genes and DNA-binding of transcription factor AP-1 in lung epithelial A549 cells

In this work we investigated the effect of measles virus (MV) infection on the expression of immediate-early genes junB, c-jun and c-fos mRNA as well as AP-1 DNA-binding activity in the lung epithelial-like adenocarcinoma cell line A549. The transcription factor AP-1, which is a group of dimeric complexes of the Fos and Jun family proteins, is an important regulator in many cellular responses to different extracellular stimuli. Membrane cofactor protein CD46, which acts as a receptor for laboratory-adapted and vaccine strains of MV, has been reported to associate with beta1 integrin molecules, which are known to trigger signaling events and activate immediate-early genes. The expression of junB and c-jun mRNA was rapidly induced by MV. It was observed already at 1 h postinfection. and detected again at the later phase of infection. Moreover, the expression of c-fos mRNA seemed to be weak and transient. The early induction was apparently associated with MV binding and CD46 clustering, whereas the later induction coincided with virus replication. MV infection also enhanced the activation of AP-1 DNA-binding. Our results suggest that changes in the expression of immediate-early genes and in the activation of AP-1 DNA-binding may have an important role in many cellular events detected in MV-infected cells.