Abstract

Background

In outpatients, monoclonal antibodies to Spike protein reduce viral load and improve outcomes, with a greater effect in serum antibody-negative at baseline. The aim of this study was to find epitope candidates to produce neutralizing monoclonal antibodies (mAb) for COVID-19 treatment.

Methods

IgG COVID-19 patients (N=500) against SARS-CoV-2 was confirmed. Epitope mapping was performed by Luminex technology. A computational pipeline based in predictive models was designed to predict S protein epitopes most likely to be recognized by mAb from COVID-19 convalescent patients.

Results

Validation Screening: 29 epitopes of the SARS-CoV-2 S protein were predicted by our pipeline and included in the Luminex panel. 40 serum samples from convalescent COVID-19 patients and 126 pre-pandemia negative controls were included in the validation screening.

Epitope mapping: 500 serum samples were tested against the 8 epitopes selected in the validation screening. The two epitopes with the highest IgG of participants above the seropositivity cut-offs were selected. The two most immunogenic epitopes were screened in phage library containing 10^? clones of antibodies anti-SARS-CoV-2 to produce mAbs by phage display technology.

Conclusions

The two epitopes with the highest IgG reactivity validated against serum samples from 500 COVID-19 convalescent patients and phage library are good candidates for the production of new neutralizing mAbs against SARS-CoV-2 S protein.