# Ultrasensitive Env Detection Assay for Broadly Neutralizing Antibody Screening

> **NIH NIH R61** · GEORGE WASHINGTON UNIVERSITY · 2024 · $449,464

## Abstract

PROJECT SUMMARY
Broadly neutralizing antibodies (bNAbs) are a promising immunotherapy that can be incorporated in many
strategies for the treatment and/or cure of HIV-1. There is a clear association between the neutralization
sensitivity of virus and how effective bNAbs are in suppressing virus replication during clinical trials, but the
precise nature of this relationship is still not clear. Individual clinical trials have reached different conclusions
about the utility of pre-screening participants’ virus for in vitro neutralization sensitivity before enrollment into
clinical trials mainly due to two obstacles: length of assay time and difficulty in obtaining the correct samples to
test. The Bosque lab has recently published an ultrasensitive method to detect p24 gag protein down to the fg/ml
level, and the assay was validated in ex vivo cells from PLWH. Here we will apply this novel methodology to
address these 2 obstacles by developing an assay that gives an indirect readout of neutralization sensitivity but
in a very short amount of time and directly in cell lysates. We will achieve this ultra-sensitive Env binding assay
by developing it in three parts for the first R61 phase: Aim 1 will optimize the capture and detector antibodies by
testing a matrix of bNAbs against diverse pseudoviruses with known neutralization sensitivities, Aim 2 will
optimize biological matrices by testing Env detection in plasma and cell lysates, and Aim 3 will determine assay
precision for ratios of sensitive and resistant virus in a diverse viral quasispecies. We will validate and qualify
this ultra-sensitive Env binding assay during the second R33 phase in two parts: Aim 4 will validate the assay
through post-hoc testing of well-studied clinical trial samples. Aim 5 will implement correct quality systems for
this assay to prepare for CLIA qualification. Our multi-disciplinary team has all the expertise necessary to achieve
these aims that, when completed, result in an ultra-sensitive binding assay for Env protein to screen clinical trial
participants that is time-efficient, accurate and qualified.

## Key facts

- **NIH application ID:** 10827962
- **Project number:** 5R61AI176582-02
- **Recipient organization:** GEORGE WASHINGTON UNIVERSITY
- **Principal Investigator:** Alberto Bosque
- **Activity code:** R61 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $449,464
- **Award type:** 5
- **Project period:** 2023-04-12 → 2026-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10827962

## Citation

> US National Institutes of Health, RePORTER application 10827962, Ultrasensitive Env Detection Assay for Broadly Neutralizing Antibody Screening (5R61AI176582-02). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/10827962. Licensed CC0.

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