Fig. 1
From: Broadly neutralizing human antibodies against Omicron subvariants of SARS-CoV-2
Isolation of memory B cells targeting SARS-CoV-2 BA.5-RBD from convalescent donors. A Overview of experimental design. CD19+CD27+ BA.5-RBD+ B cells from convalescent donors were sorted by flow cytometry. The VH and VL fragments in single B cells were amplified and sequenced, and the resulting constructs were transfected to Expi293F cells for antibody production. B Determination of the binding activity of donor plasma by ELISA. The plasma was incubated in ELISA plates coated with 1 µg/mL recombinant BA.5-RBD protein, followed by detection with HRP-conjugated anti-human antibody. The table below shows the types and orders of vaccinations received by the convalescent donors and the day of blood sample collection after breakthrough infection. AZ: AstraZeneca COVID-19 vaccine. M: Moderna COVID-19 (mRNA-1273) vaccine. C Neutralization assay of SARS-CoV-2 BA.5 pseudovirus with the three convalescent donors. The neutralizing titer 50 (NT50), indicating the plasma dilution resulting in half-maximal inhibition was calculated. D The gating strategy for BA.5-RBD-specific memory B cell from donor 3. From left to right, the panels show gatings used to isolate lymphocytes, live cells, BV-510-CD19+PE-Cy7-CD27+ cells (Q2 population), and CD19+CD27+ cells, which were further gated for BV421-BA.5-RBD