Rapid discovery and optimization of therapeutic antibodies against emerging infectious diseases

Rogers, J.; Schoepp, R.J.; Schröder, O.; Clements, T.L.; Holland, T.F.; Li, J.Q.; Li, J.; Lewis, L.M.; Dirmeier, R.P.; Frey, G.J.; Tan, X.; Wong, K.; Woodnutt, G.; Keller, M.; Reed, D.S.; Kimmel, B.E.; Tozer, E.C.

These screens resulted in hundreds of potential candidates to the three different antigen preparations. Confirmation and prioritization of the potential hits was performed by a sandwich ELISA using the spike protein as the capture antigen. Relative antibody expression levels were measured in a second ELISA and subsequently, used to determine 'specific activity' (i.e. functional ELISA/quantitative ELISA) of the various anti-SARS Fabs. Seventy-eight Fab candidates exhibited confirmed binding activity to the spike protein. Figure 2 is data from one ELISA plate and demonstrates the recovery rate of SARS-reactive antibodies from the screen was $10-15%. Twenty-eight of these antibodies bound to the spike protein with 3-fold or greater activity than background.