Non-human primate LIBRA-Seq accelerates neutralizing antibody discovery in RM vaccinated against HIV-1

Area of Science:

• Immunology
• Vaccinology
• Molecular Biology

Background:

• Broadly neutralizing antibodies (bNAbs) are crucial for effective HIV-1 vaccine design.
• Current vaccine candidates struggle to elicit responses against diverse HIV-1 strains.
• Stabilized envelope (Env) trimers like BG505 SOSIP show promise in inducing neutralizing antibodies (NAbs).

Purpose of the Study:

• To understand the development of NAbs after Env trimer immunization in rhesus macaques (RM).
• To develop a high-throughput method for analyzing B cell responses to HIV-1 Env trimers.
• To identify novel bNAbs with potential for HIV-1 vaccine development.

Main Methods:

• Conjugation of biotinylated BG505 SOSIP to streptavidin-linked DNA oligonucleotides and fluorophores.
• Development of probes for single-cell RNA sequencing (sc-RNA-Seq) and flow cytometry.
• Isolation and sequencing of BG505 SOSIP-specific memory B cells from vaccinated RM PBMCs.

Main Results:

• The developed probes accurately recovered previously identified NAbs (100% accuracy).
• Ten novel antibodies with autologous neutralizing activity were identified from five vaccinated RM.
• The technology enabled high-throughput recovery of paired clonotype identity, antigen specificity, and gene expression.

Conclusions:

• The novel probe technology is effective for high-throughput analysis of bNAb responses.
• This advancement facilitates the discovery of potent NAbs for HIV-1 vaccine candidates.
• Understanding NAb development in RM is critical for designing effective HIV vaccines.