# Project 2. cGMP manufacture of HIV-1 Env trimer sortase A-conjugated nanoparticles

> **NIH NIH U19** · DUKE UNIVERSITY · 2024 · $3,682,416

## Abstract

ABSTRACT-PROJECT 2
A key goal of HIV-1 vaccine development is to induce long-lasting protective broadly neutralizing antibody
(bnAb) responses that can inhibit HIV-1 infection. However, such protective immune responses have been
difficult to induce in the setting of vaccination. One strategy to induce these protective responses is to present
to the immune system the target for neutralizing antibodies, HIV-1 envelope (Env) trimers in their native form.
Multimerizing Env trimers on nanoparticles (NPs) enhances their immunogenicity, thus a goal for immunogen
design is to present multiple copies of well-folded Env trimers. Env is a metastable protein that adopts multiple
conformations. The primary obstacle facing Env trimer NP vaccines is that Env fusion nanoparticles,
recombinantly expressed as a single polypeptide chain, can adopt a mixture of well-folded and misfolded
conformations. The misfolded Env trimers may induce non-neutralizing antibody responses that change Env
conformation upon binding or compete with bnAb precursors for binding to HIV-1 Env. For HIV-1 Env trimer
NPs to become a rapid and widely-used platform for HIV-1 vaccine design, a nanoparticle platform that easily
incorporates well-folded Env trimers without the need for costly, year-long protein engineering experiments is
needed. To overcome the hurdles of HIV-1 Env nanoparticle vaccines, we have innovated a rapid system for
generating well-folded HIV-1 Env trimer nanoparticles using a sortase A conjugation method. The HIV-1 Env
trimers and ferritin are produced separately and to a high purity, allowing for elimination of misfolded protein.
By mixing HIV-1 Env trimer, ferritin and sortase A enzyme, the HIV-1 Env trimer is covalently linked to the
ferritin nanoparticle. The resulting sortase A-conjugated nanoparticles (scNPs) display the Env trimer in the
desired conformation. The overall goals of Project 2 are to translate sortase A-conjugated nanoparticles into a
cGMP-capable process for generation of viral vaccines against numerous pathogens and to manufacture two
HIV-1 bnAb-targeting immunogens for evaluation in a Phase I trial conducted by the HIV Vaccine Trials
Network (HVTN). To accomplish this goal, we will first determine optimal expression system for ferritin and
sortase A and establish target product profiles for platform production (Aim 1). Then, we will develop,
manufacture, and quality release recombinant sortase A and ferritin platform molecules for the conjugation of
Env stabilized trimer to ferritin nanoparticles (Aim 2). Next, we will cGMP produce and quality release >1 g of
two different stabilized Env trimer scNP drug substances and drug products for toxicology studies and clinical
testing in a Phase I clinical trial (Aim 3). The first Env trimer scNP, CH505 TF Env trimer scNP, will be used as
the first boosting immunogen in a CH505 Env NP sequential vaccine targeting CD4 binding site bnAbs. Finally,
we will produce an additional sequential Env trimer scNP to se...

## Key facts

- **NIH application ID:** 10738742
- **Project number:** 5U19AI160546-03
- **Recipient organization:** DUKE UNIVERSITY
- **Principal Investigator:** Jason Dickens
- **Activity code:** U19 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $3,682,416
- **Award type:** 5
- **Project period:** 2021-12-17 → 2026-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10738742

## Citation

> US National Institutes of Health, RePORTER application 10738742, Project 2. cGMP manufacture of HIV-1 Env trimer sortase A-conjugated nanoparticles (5U19AI160546-03). Retrieved via AI Analytics 2026-06-01 from https://api.ai-analytics.org/grant/nih/10738742. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*