# Development of novel HIV Env vaccines to augment B lymphocyte responses via delivery of stabilized well-ordered Env spikes for comparative evaluation in preclinical immunogenicity and efficacy studies

> **NIH NIH P01** · INTERNATIONAL AIDS VACCINE INITIATIVE · 2020 · $14,125

## Abstract

PROJECT SUMMARY 
The overall goal of this project is to develop and compare three new HIV envelope (Env) trimer delivery 
vaccines that are designed to mimic the natural presentation of the transmembrane glycoprotein complex (the 
spike) that occurs during HIV infection. Our vaccine design approach emphasizes delivery of authentic Env 
trimer primarily because antibodies (Abs) with broad HIV-neutralizing activity (bNAbs) have been elicited only 
in patients infected with HIV. Recently, several new Env glycoprotein designs have been developed that should 
enable improved presentation of the native trimeric Env. These new immunogens assemble into correctly 
folded trimeric complexes that are significantly more stable, which should make it possible to stimulate B cells 
with a more uniform well-ordered mimic of the functional Env trimer. An additional challenge to realizing the 
potential benefits of the improved immunogen will be identification and development of vaccine delivery 
platforms that can present the correctly-configured glycoprotein complex in vivo and also stimulate immune 
system functions required to drive the B cell response beyond development of antibodies with limited 
neutralization breadth. Accordingly, the goal of this research project is to apply this promising Env trimer 
stabilization technology to the development of three novel vaccines that will present nearly identical stable, 
well-ordered viral spikes, but use substantially different delivery mechanisms that will stimulate distinctive 
profiles of immune system functions. This will make it possible to conduct comparative studies to specifically 
analyze how vaccine platforms and their unique immunostimulatory properties affect the qualities of the Env 
antibody response. Each vaccine will deliver a stabilized HIV clade C strain 1086 (C.1086) Env immunogen 
that will be developed using the new native flexibly-linked (NFL) Env trimer technology (EnvNFL), which will be 
adapted for expression of transmembrane glycoproteins. The three Specific Aims for the project are focused 
on development and evaluation of the new vaccines and production of vaccine material needed to support 
preclinical testing in animal models, which will be conducted in collaboration with the Research Project Teams 
and Technical Cores that are members of this HIVRAD Program. This Project Team will develop novel 
stabilized spike delivery vaccines based on three immunogenic vaccine platforms, including: 1) an innovative 
mRNA vector and adjuvant delivery system called RNActive®; 2) EnvNFL trimers arrayed on inactivated 
vesicular stomatitis virus (VSV) particles formulated with adjuvant; and 3) EnvNFL delivered with a live 
replication-competent VSV vector that incorporates Env in its viral envelope. The Project Team will generate 
and optimize the three novel vaccine candidates, ensure that they effectively deliver stabilized transmembrane 
spikes with the expected antigenicity profiles, and provide ...

## Key facts

- **NIH application ID:** 9970396
- **Project number:** 5P01AI124337-05
- **Recipient organization:** INTERNATIONAL AIDS VACCINE INITIATIVE
- **Principal Investigator:** Christopher Parks
- **Activity code:** P01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $14,125
- **Award type:** 5
- **Project period:** 2016-07-19 → 2022-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9970396

## Citation

> US National Institutes of Health, RePORTER application 9970396, Development of novel HIV Env vaccines to augment B lymphocyte responses via delivery of stabilized well-ordered Env spikes for comparative evaluation in preclinical immunogenicity and efficacy studies (5P01AI124337-05). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/9970396. Licensed CC0.

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