Generation of human
Described and claimed herein are combinatorial synthetic Fab libraries displayed on a phage pIX protein. The libraries were built on scaffolds representing the most frequently used genes in human antibodies, which were diversified to mirror the variability of natural antibodies. After selection using a diverse panel of proteins, numerous specific and high-affinity Fabs were isolated. By a process called in-line maturation the affinity of some antibodies was improved up to one hundred-fold yielding low pM binders suitable for in vivo use. This work thus demonstrates the feasibility of displaying complex Fab libraries as pIX-fusion proteins for antibody discovery and lays the foundations for studies on the structure-function relationship of antibodies.
1. A method for screening a phage library for Fab antibody fragments having a desired biological activity, comprising (a) expressing Fab antibody fragments in said phage library wherein said fragments are expressed in bacterial host cells, and where said host cells comprise a recombinant nucleic acid phage vector comprising the sequence of SEQ ID NO:79, and nucleic acid sequences encoding a phage pIX protein fused to a Fab amino acid sequence, wherein said Fab amino acid sequence binds to an antigen and (b) selecting bacterial cells expressing said Fab antibody fragments having said desired biological activity.