Implication of Broadly Neutralizing Bovine Monoclonal Antibodies in the Development of an Enzyme-Linked Immunosorbent Assay for Detecting Neutralizing Antibodies against Foot-and-Mouth Disease Virus Serotype O

Abstract

Vaccination with inactivated vaccines is still the main measure to control foot-and-mouth disease (FMD) in areas where the disease is endemic, and the level of neutralizing antibody in vaccinated animals is directly related to their protection against virus challenge. Currently, neutralizing antibody is mainly detected using the virus neutralization test (VNT) based on cell culture, which is laborious and time-consuming and requires restrictive biocontainment facilities. In this study, two broadly neutralizing antibodies (bnAbs), E46 and F128, were successfully produced using techniques for the isolation of single B cells from peripheral blood mononuclear cells (PBMCs) from bovines sequentially immunized with three topotypes of foot-and-mouth disease virus (FMDV) serotype O. Based on these bnAbs, a blocking enzyme-linked immunosorbent assay (ELISA) for detecting neutralizing antibodies (NA-ELISA) against FMDV serotype O was developed. The specificity and sensitivity of the test were estimated to be 99.21% and 100%, respectively. A significant correlation (P < 0.01) was observed between the NA-ELISA titers and the VNT titers for all sera from vaccinated animals and for all tested strains, suggesting that the NA-ELISA could detect neutralizing antibodies against FMDV serotype O strains of wide antigenic and molecular diversity and could be used for the evaluation of protective immunity.

Establishment of a rapid ELISPOT assay for influenza virus titration and neutralizing antibody detection

“…Recently, it was reported a blocking Enzyme‐Linked Immunosorbent Assay for detecting neutralizing antibodies against foot‐and‐mouth disease virus 8 . As the neutralization epitopes weren't unique, thus the result of this method did not reflect the actual neutralization titer.…”

Peptide enzyme‐linked immunosorbent assay (pELISA) as a possible alternative to the neutralization test for evaluating the immune response to IBV vaccine

“…The neutralizing antibody titer is primarily determined by neutralizing assays [ 2 , 39 ]. Although neutralization tests accurately reflect the neutralizing antibody titers in the serum, the technique is time consuming and laborious, which are inevitable weaknesses [ 40 , 41 ]. In the present study, pELISA with a broad-spectrum epitope not only react with different genotype IBVs sera but also indirectly reflect the neutralizing antibody levels of immune sera against IBV.…”

Selection of Vaccine Candidate for Foot-and-Mouth Disease Virus Serotype O Using a Blocking Enzyme-Linked Immunosorbent Assay

“…Sera from vaccinated animals were also assayed with above four representative strains by using NA-ELISA as previously described [ 14 ]. Briefly, serum samples were tested in 96-well plates in 2-fold dilutions.…”

“…Serum with a titer of ≥1.35 and a titer of <1.35 was considered positive and negative, respectively. Both F128 and E46 were bovine bnAbs against FMDV serotype O produced previously in our lab using a combination of fluorescence-activated cell sorter (FACS) and techniques for the isolation of single B cells [ 14 ].…”

“…A blocking ELISA for detecting neutralizing antibodies (NA-ELISA) against FMDV serotype O based on bovine broadly neutralizing monoclonal antibodies (bnAbs) was developed previously in our lab [ 14 ], it has high sensitivity and specificity, and could detect neutralizing antibodies against FMDV serotype O strains of three topotypes with a wide antigenic and molecular diversity [ 14 ]. In this study, the inactivated vaccines prepared from four representative circulating strains (FMDV O/Mya/98, SCGH/CHA/2016, O/Tibet/99 and O/XJ/CHA/2017) were used to vaccinate cattle, sheep, and pigs.…”