Reconstruction of a robust glycodiagnostic agent supported by multiple lectin‐assisted glycan profiling

Abstract

Wisteria floribunda agglutinin positive human Mac-2-binding protein (WFA(+)-hM2BP) was recently validated as a liver fibrosis glycobiomarker with a fully automated lectin-antibody sandwich immunoassay. In this study, we supplied recombinant WFA(+)-hM2BP as the standard glycoprotein and the overlaid antibody to enhance the robustness of WFA(+)-hM2BP quantification. The optimum conditions for producing recombinant WFA(+)-hM2BP were selected by cell glycome analysis based on a lectin microarray. Interlot variability of recombinant WFA(+)-hM2BP was determined using an antibody-overlay lectin microarray. Screening of anti-M2BP mAb was completed by incorporating a WFA-antibody sandwich ELISA and an antibody-overlay lectin microarray. The lectin microarray analysis revealed that human embryonic kidney 293 cells efficiently and stably produced WFA(+)-hM2BP in DMEM containing 10% FCS without any variation in the M2BP glycosylation level. A spiking experiment with recombinant WFA(+)-hM2BP was mostly effective for antibody screening. The reconstituted sandwich immunoassay was useful for the continuous quantification and cutoff index expression of serum WFA(+)-hM2BP. The multiple use of lectin-assisted glycan profiling enabled us to construct a reliable sandwich assay kit for monitoring liver fibrosis in patients with viral hepatitis. This will assist in the development pipeline for other glycodiagnostic agents.