Production and Epitope Studying of Monoclonal Antibody Against IMPDH in SS2

Abstract:

Fusion protein Thioredoxin (Trx A)–IMPDH of Streptococcu suis type 2 (SS2) was purified with affinity chromatograph. Spleen cells from BALB/c mice which were immunized with purified fusion protein were fused with SP2/0 myeloma cells in order to product monoclonal antibody against IMPDH. Four hybridoma cell strains against IMPDH (named 1A8, 1F2, 2D2 and 2D12 respectively) were developed after four times of limiting dilution assay. The indirect ELISA titers of their ascites were 100×211, 100×211, 100×210, 100×28. The results of Western-blot indicated that the four McAbs only reacted with Trx A–IMPDH but not reacted with Trx A, that showed their good specificity. Meanwhile, the difference of their recognizing epitopes was analysed by means of four proteins which were respectively producted by deleting specific genes. The results showed that 1A8, 1F2 and 2D2’s corresponding epitopes are in 627 bp~790 bp sites of IMPDH gene and 2D12’s is in 411 bp~790 bp sites. The successful preparation of monoclonal antibodies against IMPDH of SS2 and the analysis of epitopes would facilitate the further research on the biological and immunological activity of IMPDH.

Key words:Streptococcus suis type 2, IMPDH, Monoclonal antibody, Epitope