Aim: To prepare the monoclonal antibodies (mAbs) against listeriolysin O (LLO), which is the major virulence factor of Listeria monocytogenes.
Methods: The BALB/c mice were immunized with the SDS-PAGE product of BL21(pGEX-6p-1-hly). The purified LLO-GST protein was used as antigen for detection. mAbs against LLO were prepared by using the lymphocyte hybridoma technique. The specificity of mAbs was characterized by Dot-ELISA and Western blot.
Results: Three hybridoma cell lines named 3B6, 4D1 and 5D10 secreting mAbs against LLO were obtained. The immunoglobulin subclasses of the mAbs were IgG1. The ELISA titer of the ascitic fluids of 3B6, 4D1 and 5D10 was 1:200,000, 1:200,000 and 1:100,000, respectively. Western blot analysis confirmed the three mAbs reacted on fusion protein LLO-GST but didn't react on protein GST. Dot-ELISA proved the three mAbs only react on the bacteria expressing LLO.
Conclusion: The successful preparation of three mAbs specific to protein LLO lays a foundation for further study of the biological characteristics of LLO and the pathogenesis of Listeria monocytogenes.