A rapid method for detection of antigen-specific B cells

The global pandemic of SARS-CoV-2 has united efforts of many scientists all over the world to develop wet-lab techniques and computational approaches aimed at the identification of antigen-specific T and B cells. The latter provide specific humoral immunity that is essential for the survival of COVID-19 patients, and vaccine development has been essentially based on these cells.Here, we implemented an approach that integrates sorting of antigen-specific B cells and B-cell receptor mRNA sequencing (BCR-seq) followed by computational analysis. This rapid and cost-efficient method allowed us to identify antigen-specific B cells in peripheral blood of patients with severe COVID-19 disease. Subsequently, specific BCRs were extracted, cloned, and produced as full antibodies. We confirmed their reactivity toward the spike RBD domain. Such an approach can be effective for monitoring and identification of B cells participating in an individual immune response.