B-Cell Receptor Features and Database Establishment in Recovered COVID-19 Patients by Combining 5'-RACE with PacBio Sequencing

Antibodies induced by viral infection can not only prevent subsequent virus infection, but can also mediate pathological injury following infection. Therefore, understanding the B-cell receptor (BCR) repertoire of either specific neutralizing or pathological antibodies from patients convalescing from Coronavirus disease 2019 (COVID-19) infection is of benefit for the preparation of therapeutic or preventive antibodies, and may provide insight into the mechanisms of COVID-19 pathological injury. In this study, we used a molecular approach of combining 5' Rapid Amplification of cDNA Ends (5'-RACE) with PacBio sequencing to analyze the BCR repertoire of all 5 and 2 genes in B-cells harvested from 35 convalescent patients after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We observed numerous BCR clonotypes within most COVID-19 patients, but not in healthy controls, which validates the association of the disease with a prototypical immune response. In addition, many clonotypes were found to be frequently shared between different patients or different classes of antibodies. These convergent clonotypes provide a resource to identify potential therapeutic/prophylactic antibodies, or identify antibodies associated with pathological effects following infection with SARS-CoV-2.