The novel llama‐human chimeric antibody has potent effect in lowering LDL‐c levels in hPCSK9 transgenic rats

Abstract

publisher‐imprint‐name Springer volume‐issue‐count 1 issue‐article‐count 16 issue‐toc‐levels 0 issue‐pricelist‐year 2020 issue‐copyright‐holder The Author(s) issue‐copyright‐year 2020 article‐contains‐esm Yes article‐numbering‐style Unnumbered article‐registration‐date‐year 2020 article‐registration‐date‐month 1 article‐registration‐date‐day 21 article‐toc‐levels 0 toc‐levels 0 volume‐type Regular journal‐product ArchiveJournal numbering‐style Unnumbered article‐grants‐type OpenChoice metadata‐grant OpenAccess abstract‐grant OpenAccess bodypdf‐grant OpenAccess bodyhtml‐grant OpenAccess bibliography‐grant OpenAccess esm‐grant OpenAccess online‐first false pdf‐file‐reference BodyRef/PDF/40169_2020_Article_265.pdf pdf‐type Typeset target‐type OnlinePDF issue‐type Regular article‐type OriginalPaper journal‐subject‐primary Medicine & Public Health journal‐subject‐secondary Medicine/Public Health, general journal‐subject‐collection Medicine open‐access true --> Background: The advent of proprotein convertase subtilisin/kexin type 9 (PCSK9)–inhibiting drugs have provided an effective, but extremely expensive treatment for the management of low density lipoprotein (LDL). Our aim was to explore a cost‐effective application of camelid anti‐PCSK9 single domain antibodies (sdAbs), which are high variable regions of the camelid heavy chain antibodies (VHHs), as a human PCSK9 (hPCSK9) inhibitor. One female llama was immunized with hPCSK9. Screening of high affinity anti‐PCSK9 VHHs was carried out based on surface plasmon resonance (SPR) technology. We reported a lysate kinetic analysis method improving the screening efficiency. To increase the serum half‐life and targeting properties, the constant region fragment of the human immunoglobulin gamma sub‐type 4 (IgG4 Fc) was incorporated to form a novel llama‐human chimeric molecule (VHH‐hFc). Results: The PCSK9 inhibiting effects of the VHH proteins were analyzed in two human liver hepatocellular cells (HepG2 and Huh7) and in the hPCSK9 transgenic Sprague–Dawley (SD) rat model. The hPCSK9 antagonistic potency of the bivalent VHH‐hFc exceeded the monovalent VHH (P < 0.001) in hepatocarcinoma cells. Furthermore, the llama‐human chimeric VHH‐Fc protein had a similar reduction (~ 40%) of the LDL‐c and total cholesterol when compared to the approved evolocumab in transgenic SD rat model, but with low cost. More surprisingly, the chimeric heavy chain antibodies could be persevered for 3 months at room temperature with little loss of the affinity. Conclusions: Due to the high yield and low cost of Pichia pastoris, lipid‐lowering effect and strong stability, the llama‐human chimeric antibody (VHH‐Fc) offers a potent therapeutic candidate for the control of the serum lipid level. [ABSTRACT FROM AUTHOR]