Attenuation of G954 strain is not linked to type IIFN induction. (A-D): Cytopathic effects of MV infection on pDCs. Cells were infected at a MOI of 0,1. Photographs were taken when the maximum of cytopathic effects was observed (2–4 days pi). (A): non infected pDCs; (B): Infection by G954 PBL; (C): G954 V13; (D): Edmonston Zagreb strain induces syncytia formation. Magnification ×400. (E): pDCs are the main producers of type I IFN following MV infection. Haematopoietic cells were infected at a MOI of 0,1 with G954 and Ed-Zagreb viruses. Type I IFN amounts were determined by biological assays on UV-inactivated supernatants harvested 3 days pi.