Pilot Scale Production and Testing of a Recombinant Staphylococcal Enterotoxin (SEB) Triple Mutant

The use of chemically or thermally inactivated biothreat toxins in detection methodologies can prove problematic when the resulting toxoids become attenuated or altered to the point that they are no longer recognizable by the antibody-based test methods for which they were intended. Recombinant technology was used to assess whether a nontoxic surrogate could be developed that retains the relative epitopes for antibody-based detection platforms. Here, three small batches of staphylococcal enterotoxin B triple mutant (L45R, Y89A, and Y94A) were prepared for the Defense Biological Products Assurance Office (DBPAO) to demonstrate the reproducibility of recombinant antigen production. Yields of starting material and final purified product were determined. Post-production testing for these batches was performed to identify purity, homogeneity, and activity as determined by the DBPAO using a Meso Scale Discovery SEB SinglePlex PR2 electrochemiluminescence assay (Meso Scale Diagnostics; Rockville, MD). Test results revealed that this product demonstrates high levels of reproducibility and consistency in yield, purity, homogeneity, and antigenicity.