[Preparation and identification of monoclonal antibodies against SARS-CoV putative protein X4].

Luo, Xin; Zhang, Ting; Ma, Da-long; Chen, Ying-yu

OBJECTIVE To obtain monoclonal antibodies against putative protein X4 of SARS-CoV for further study of the structure and function of protein X4. METHODS Balb/c mice were immunized with recombinant Protein X4, hybridoma cell lines secreting monoclonal antibodies against protein X4 were screened by regular cell fusion and subcloning approach. The specificities of these monoclonal antibodies were determined by Western blotting and Immunofluorescence assay. RESULTS Three hybridoma cell lines (8A5, 8H6 and 4A2) stable in secreting specific monoclonal antibodies were successfully obtained. They could bind specifically to protein X4 proved by Western blotting. All of them belonged to the IgG2a isotype proved by antigen mediated ELISA. Indirect Immunofluorescence assay indicated that they could specifically bind to protein X4 expressed in SARS-CoV infected Vero E6 cells. CONCLUSION Monoclonal antibodies of high specificity against protein X4 have been successfully prepared, which laid the foundation for the further study of protein X4.