Two technologies, one goal: Developing and evaluating anti-Zika virus NS1 antibodies using phage display and hybridoma technologies for diagnostic applications

Currently, the phage display technology is probably one of the most mature animal-free alternatives to the hybridoma technology for developing antibodies. However, the performances of these two technologies have been rarely compared. To address this question, hybridoma and phage display approaches were used to generate antibodies against Zika virus (ZIKV) non-structural protein 1 (NS1), a biomarker of the acute phase of flavivirus infection that displays high sequence homology among flaviviruses. Phage display-derived antibodies showed enhanced specificity towards ZIKV recombinant NS1 (rNS1). Conversely, hybridoma-derived antibodies cross-reacted with other flavivirus rNS1. This likely reflects differences in selection strategies rather than in the intrinsic properties of the technologies. Despite the moderate binding affinity of paired antibodies obtained by phage display, a limit of detection of 25 ng/mL was achieved in human serum spiked with ZIKV rNS1. This sensitivity dropped to 1 ng/mL with antibodies obtained by mice immunization. Then, the high specificity of phage display-derived antibodies and sensitivity of hybridoma-derived antibodies were combined in a hybrid antibody format immunoassay. In this assay, a very specific phage display-derived antibody was used for capture and a hybridoma-derived antibody with a low dissociation rate constant (k_off) was used for detection, maintaining sensitivity as low as 1 ng/mL. This hybrid assay format also preserved high specificity when tested using serum samples from patients with acute Dengue fever that contain high levels of Dengue virus NS1. Our findings highlight the complementary strengths of both antibody generation strategies for the sensitive and specific detection of ZIKV NS1.