Fig. 1.

Construction and characterization of NDV/GP. (A) An EBOV GP transcription cassette was inserted into the NDV genome between the P and the M genes and under the control of a set of NDV-specific gene-end (GE) and gene-start (GS) transcriptional sequences (boxed). (B) The NDV/GP virus was purified on a sucrose gradient and analyzed by SDS-PAGE and western blot in comparison with the empty NDV vector. In the left panel, an anti-NDV polyclonal antibody was used that detected the NDV HN, NP, and the F1 cleavage product of the F protein. In the right panel, an EBOV GP-specific antibody was used for detection of the 140 kDa GP1 protein, which is generated by post-translational cleavage of the full-length GP protein [27].