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.

Framework fragments were designed to represent the sequence diversity exhibited by the first three human framework regions (FRs). Separate fragment libraries were constructed based on the human germline immunoglobulin heavy and light chain variable domains (VH and VL), and human variable domains that have been through the natural, immunological maturation process. For each FR, several fragments were designed to represent the diversity seen among natural FRs. CDR 1, 2 and 3 from the best neutralizing antibody (4049Fab14) was combined with all possible combinations of the FRs from the fragment library to generate novel VH and or VL constructs. For the kappa light chain, the total number of possible combinations of reassembled frameworks was 224 (number of unique sequences for FR1 ¼ 7, FR2 ¼ 4, FR3 ¼ 8 and FR4 ¼ 1) and for the heavy chains was 280 (number of unique sequences for FR1 ¼ 7, FR2 ¼ 5, FR3 ¼ 8 and FR4 ¼ 1).