Highly potent multivalent VHH antibodies against Chikungunya isolated from an alpaca naïve phage display library

J Nanobiotechnology. 2022 May 14;20(1):231. doi: 10.1186/s12951-022-01417-6.

Abstract

Background: Chikungunya virus (CHIKV) is a re-emerged mosquito-borne alphavirus that can cause musculoskeletal diseases, imposing a substantial threat to public health globally. High-affinity antibodies are need for diagnosis and treatment of CHIKV infections. As a potential diagnostic and therapeutic agent, the multivalent VHH antibodies is a promising tookit in nanomedicine. Here, we developed potent multivalent VHH antibodies from an alpaca naïve phage display library targeting the E2 glycoprotein of the CHIKV virus.

Results: In the present study, we generated 20 VHH antibodies using a naïve phage display library for binders to the CHIKV E2 glycoprotein. Of these, multivalent VHH antibodies Nb-2E8 and Nb-3C5 had specific high-affinity binding to E2 protein within the nanomolar range. The equilibrium dissociation constant (KD) was between 2.59-20.7 nM, which was 100-fold stronger than the monovalent antibodies' affinity. Moreover, epitope mapping showed that Nb-2E8 and Nb-3C5 recognized different linear epitopes located on the E2 glycoprotein domain C and A, respectively. A facile protocol of sandwich ELISA was established using BiNb-2E8 as a capture antibody and HRP-conjugated BiNb-3C5 as a detection antibody. A good linear correlation was achieved between the OD450 value and the E2 protein concentration in the 5-1000 ng/mL range (r = 0.9864, P < 0.0001), indicating its potential for quantitative detection of the E2 protein.

Conclusions: Compared to monovalent antibodies, multivalent VHH antibodies Nb-2E8 and Nb-3C5 showed high affinity and are potential candidates for diagnostic applications to better detect CHIKV virions in sera.

Keywords: Chikungunya; E2 glycoprotein; Epitope; Naïve phage display library; VHH antibody.

MeSH terms

  • Animals
  • Antibodies, Viral
  • Bacteriophages*
  • Camelids, New World*
  • Chikungunya Fever*
  • Chikungunya virus*
  • Glycoproteins
  • Single-Domain Antibodies*

Substances

  • Antibodies, Viral
  • Glycoproteins
  • Single-Domain Antibodies