Characterization of a vaccine-elicited human antibody with sequence homology to VRC01-class antibodies that binds the C1C2 gp120 domain

Sci Adv. 2022 May 6;8(18):eabm3948. doi: 10.1126/sciadv.abm3948. Epub 2022 May 4.

Abstract

Broadly HIV-1-neutralizing VRC01-class antibodies bind the CD4-binding site of Env and contain VH1-2*02-derived heavy chains paired with light chains expressing five-amino acid-long CDRL3s. Their unmutated germline forms do not recognize HIV-1 Env, and their lack of elicitation in human clinical trials could be due to the absence of activation of the corresponding naïve B cells by the vaccine immunogens. To address this point, we examined Env-specific B cell receptor sequences from participants in the HVTN 100 clinical trial. Of all the sequences analyzed, only one displayed homology to VRC01-class antibodies, but the corresponding antibody (FH1) recognized the C1C2 gp120 domain. For FH1 to switch epitope recognition to the CD4-binding site, alterations in the CDRH3 and CDRL3 were necessary. Only germ line-targeting Env immunogens efficiently activated VRC01 B cells, even in the presence of FH1 B cells. Our findings support the use of these immunogens to activate VRC01 B cells in humans.

MeSH terms

  • Antibodies, Neutralizing
  • Broadly Neutralizing Antibodies
  • HIV Antibodies / chemistry
  • HIV-1*
  • Humans
  • Sequence Homology
  • Vaccines*

Substances

  • Antibodies, Neutralizing
  • Broadly Neutralizing Antibodies
  • HIV Antibodies
  • Vaccines