Biointron established a single-B cell antibody discovery platform based on microfluidic technology. Combined with our proprietary fast antibody expression platform, it has been proven to be fast and efficient in many projects. This case study uses our high-speed single B cell sorting platform to`screen for PD-1 antibodies. Since our platform retains hundreds of sequences, we selected 62 hits to carry out further antibody expression and validation. From an ELISA binding assay, we see that most hits had excellent binding against PD-1, with 59 out of 62 antibodies showing positive binding against PD-1. In addition, most of the antibodies demonstrated high-affinity binding in the low nanomolar range (10-9). The project objective was to obtain specific antibodies against PD-1 at different epitopes.
Figure a. 59 antibodies specifically bind PD-1 were screened by our platform is nivolumab.
Figure b. We ranked the affinity of 59 antibodies by SPR, and the affinity of almost all antibodies ranges from 0.1-1 nM. BMK is positive control (Nivolumab biosimilar).
Figure c.We analyzed the diversity of CDR sequences of the light and heavy chains of 59 Antibodies and showed good diversity.Figure d.We performed epitope binning of all antibodies and found these hits can mainly be divided into 4 epitope groups. B6924 (nivolumab biosimilar) and B2014 (pembrolizumab biosimilar) are our positive controls in this section. The result showed that we have identified many antibodies binding to distinct epitopes on PD-1 compared to controls.
