Evaluation of Measles Vaccine Virus as a Vector to Deliver Respiratory Syncytial Virus Fusion Protein or Epstein-Barr Virus Glycoprotein gp350

Mok, Hoyin; Cheng, Xing; Xu, Qi; Zengel, James R; Parhy, Bandita; Zhao, Jackie; Wang, C. Kathy; Jin, Hong

The reverse genetics system for measles Edmonston-Zagreb (EZ) vaccine virus was established by transfecting MV antigenomic plasmid pEZ together with pP, pN and pL into MVA-T7 infected HEp-2 cells to recover infectious EZ virus. To generate rEZ expressing RSV F or EBV gp350, the F ectodomain of RSV and EBV gp350 were cloned into the MV antigenomic cDNA (Fig. 1A) . The F was cloned at the two positions of the viral genome: one proximal to the N gene (1 st position) and the other between the P and M genes (3 rd position). EBV gp350 ectodomain and its N-terminal half of the gp350 (amino acid 1-470, gp350tr) that encoded the receptor binding site to CD21 [39] were also cloned into the EZ genome at the 1 st and 3 rd positions. Recombinant EZ with RSV F, EBV gp350 and EBV gp350tr inserted at the 1 st or 3 rd position were generated. However, viruses with gp350 and gp350tr inserted at the 1 st position replicated poorly in vitro and were not evaluated further. The rescued recombinant viruses expressing RSV F or EBV gp350 or gp350tr were designed as sF1 (F at the 1 st position), sF3 (F at the 3 rd position), gp350 and gp350tr (both at the 3 rd position), respectively.