Expression of
the Newcastle Disease Virus Fusion Glycoprotein in Vero Cells Using Attenuated Salmonella
typhimurium as Transgenic Carrier
FANG Wei-Huan*, LIANG Xue-Ya
( Institute of Preventive Veterinary Medicine, Zhejiang University, Hangzhou
310029, China )
Abstract The
full-length cDNA of fusion protein (F) gene of newcastle disease virus
(NDV)strain F48E9 was amplified by RT-PCR and inserted into pcDNA3 under the
control of human cytomegalovirus (hCMV) immediate early enhancer and promoter.
The resulting recombinant plasmid pcDNA3-F was transformed by
electroporation into attenuated Salmonella typhimurium strain ZJ111 (dam– and phoP–),
which was then used to transfect the Vero cells. The DNA and RNA dot blotting
revealed that the F gene was transcribed into mRNA in the Vero
cells. There was expression of the F protein as shown by indirect
immunofluorescent assay. The expression began at 48 h post-infection and
increased thereafter, as indicated by ELISA. A 55 kD band of the F protein was
identified by SDS-PAGE and Western blotting. These results clearly show that
the expressed fusion protein was immuno-reactive with chicken anti-NDV serum.
Key words newcastle disease virus; fusion
glycoprotein; attenuated Salmonella typhimurium; DNA vaccine vector
*Corresponding author: Tel,
86-571-86971242; Fax, 86-571–86971242;
e–mail, [email protected]