NaLi-H1: A universal synthetic library of humanized nanobodies providing highly functional antibodies and intrabodies

摘要

In vitro selection of antibodies allows to obtain highly functional binders, rapidly and atlower cost. Here, we describe the first fully synthetic phage display library of humanized llamasingle domain antibody (NaLi-H1: Nanobody Library Humanized 1). Based on a humanized syntheticsingle domain antibody (hs2dAb) scaffold optimized for intracellular stability, the highly diverselibrary provides high affinity binders without animal immunization. NaLi-H1 was screened followingseveral selection schemes against various targets (Fluorescent proteins, actin, tubulin, p53, HP1).Conformation antibodies against active RHO GTPase were also obtained. Selected hs2dAb wereused in various immunoassays and were often found to be functional intrabodies, enabling trackingor inhibition of endogenous targets. Functionalization of intrabodies allowed specific proteinknockdown in living cells. Finally, direct selection against the surface of tumor cells producedhs2dAb directed against tumor-specific antigens further highlighting the potential use of thislibrary for therapeutic applications.