Construction of an A549 cell line expressing the surface protein of Jaagsiekte retrovirus

The surface protein (SU) of Jaagsiekte retrovirus (JSRV) is considered closely related to the formation of sheep pulmonary adenomatosis induced with JSRV. To facilitate investigations on SU for its role in transformating target cells, an A549 cell line that stably expresses the JSRV SU was developed in this study. The coding region of the su gene was amplified by PCR and cloned into the eukaryotic expression vector pcDNA3.1(+). The resulting recombinant plasmid was transfected into the A549 cells, and a transfected cells stably expressing SU, named as A549-SU, was screened and colony-purified under the drug selection of G418. The expression of SU was confirmed by indirect immunofluorescence assay and western blot. Results indicated that the recombinant SU was correctly and effectively expressed in A549-SU and was mostly located in the cytoplasm. This SU-expressing cell line provides a useful in vitro platform for studying biological functions of the JSRV SU.