Hidden Lineage Complexity of Glycan-Dependent HIV-1 Broadly Neutralizing Antibodies Uncovered by Digital Panning and Native-Like gp140 Trimer.
Germline precursors and intermediates of broadly neutralizing antibodies (bNAbs) are essential to the understanding of humoral response to HIV-1 infection and B-cell lineage vaccine design. Using a native-like gp140 trimer probe, we examined antibody libraries constructed from donor-17, the source of glycan-dependent PGT121-class bNAbs recognizing the N332 supersite on the HIV-1 envelope glycoprotein. To facilitate this analysis, a digital panning method was devised that combines biopanning of phage-displayed antibody libraries, 900 bp long-read next-generation sequencing, and heavy/light (H/L)-paired antibodyomics. In addition to single-chain variable fragments resembling the wild-type bNAbs, digital panning identified variants of PGT124 (a member of the PGT121 class) with a unique insertion in the heavy chain complementarity-determining region 1, as well as intermediates of PGT124 exhibiting notable affinity for the native-like trimer and broad HIV-1 neutralization. In a competition assay, these bNAb intermediates could effectively compete with mouse sera induced by a scaffolded BG505 gp140.681 trimer for the N332 supersite. Our study thus reveals previously unrecognized lineage complexity of the PGT121-class bNAbs and provides an array of library-derived bNAb intermediates for evaluation of immunogens containing the N332 supersite. Digital panning may prove to be a valuable tool in future studies of bNAb diversity and lineage development.
['He|Linling|L|', 'Lin|Xiaohe|X|', 'de Val|Natalia|N|', 'Saye-Francisco|Karen L|KL|', 'Mann|Colin J|CJ|', 'Augst|Ryan|R|', 'Morris|Charles D|CD|', 'Azadnia|Parisa|P|', 'Zhou|Bin|B|', 'Sok|Devin|D|', 'Ozorowski|Gabriel|G|', 'Ward|Andrew B|AB|', 'Burton|Dennis R|DR|', 'Zhu|Jiang|J|']
broadly neutralizing antibodies next-generation sequencing native-like trimer B-cell lineage development HIV-1 vaccine design antibody phage display