Figure 2

Isolation of single B cells and generation of mAbs against CSFV. A Anti-CSFV antibodies were detected using a CSFV antibody test kit (positive blocking rate ≥ 40% and negative blocking rate ≤ 30%). PI values of serum samples isolated from unvaccinated mice. B PI values of serum samples isolated from individual mice immunized with the E2 subunit vaccine. The results were obtained from at least three biological replicates (mean ± SD) and analysed using a t test with GraphPad Prism software; ns, not statistically significant; *p < 0.05, **p < 0.005 and ****p < 0.0001 (versus the negative control, NC). C Isolation of single B cells from vaccinated mice via FACS. Single B cells from the splenocyte population of mouse no. 4 were used to isolate single B cells stained with biotin-E2-APC and rat anti-mouse IgM-FITC. CSFV E2-specific plasmablasts isolated from splenocytes in P4 constituted approximately 0.1% of the cell population. D The mAbs 3A9 and 4F7 were successfully expressed in HEK293 cells, as shown by nonreducing and reducing SDS-PAGE. E mAb isotyping was performed according to the manufacturer’s instructions. The result was based on measurement of the OD at 450 nm.