# bNAb induction by antigenically diverse V1V2 lineage specific SHIVs and SOSIPs

> **NIH NIH R01** · UNIVERSITY OF PENNSYLVANIA · 2020 · $796,855

## Abstract

PROJECT SUMMARY
Despite decades of HIV-1 vaccine research, there are still no examples of vaccines or immunogens that
consistently elicit potent broadly neutralizing antibodies (bNAbs) in animal models or in human subjects. This
includes recent preclinical trials of soluble Env trimers (SOSIPs) and structure-based, scaffolded Env outer
domain immunogens. To overcome this critical roadblock in vaccine design, we propose a novel strategy
based on the scientific premise that since most examples of successful bNAb elicitation come from natural
human infection by primary HIV-1 strains, the most likely means for eliciting bNAbs in RMs is by productive
infection with SHIVs bearing primary HIV-1 Envs in their native configurations. Then, by characterizing the co-
evolutionary pathways of bNAbs and the cognate SHIV Envs (“immunotypes”) that elicit them through repeated
rounds of B cell receptor (BCR) engagement and affinity maturation, a “molecular guide” for rational vaccine
design can be developed and tested by both “B lineage design” and “reverse vaccinology” approaches. This
application proposes an innovative research plan – supported by recent discoveries in our laboratory regarding
novel SHIV designs – that advances these concepts. We propose to target the development of V1V2 epitope
specific bNAbs because of unique features of their ontogeny that make them attractive for vaccine
development, and because of the recent identification of Env immunotypes that bind germline and intermediate
ancestor V1V2 lineage BCRs, leading to affinity maturation and neutralization breadth. Building on these
promising findings, we hypothesize that co-infection of rhesus macaques with antigenically-diverse SHIVs
whose Envs have been preselected to bind germline and intermediate ancestor V1V2 bNAb lineage specific
BCRs, and co-immunization of RMs with homologous Env SOSIPs, will enhance BCR engagement and
maturation and accelerate the development of HIV-1 V1V2 targeted bNAbs. To test this hypothesis, we
propose to: (i) analyze NAb potency, breadth and epitope specificity, together with molecular patterns of Env-
Ab coevolution, in 8 RMs infected by a mixture of six SHIVs bearing subtype A, B and C Envs preselected to
bind germline and intermediate ancestor V1V2 bNAb lineage BCRs, compared with RMs infected by individual
SHIVs bearing the same Envs; (ii) analyze NAb potency, breadth and epitope specificity, together with
molecular patterns of Env-Ab coevolution, in 8 RMs infected by a mixture of six SHIVs bearing the Env from
CAP256SU, which binds the germline V1V2 bNAb BCR, and its evolved variants that led to bNAb maturation in
the human subject CAP256, compared with animals infected by SHIV CAP256SU only; (iii) corroborate the
identification of Env immunotypes in Aims 1 and 2 responsible for bNAb induction by re-engineering selected
Envs into SHIVs, followed by infection of 8 RMs and analysis of NAb potency, breadth and specificity; and (iv)
construct novel Env SOSIPs...

## Key facts

- **NIH application ID:** 9975687
- **Project number:** 5R01AI131331-04
- **Recipient organization:** UNIVERSITY OF PENNSYLVANIA
- **Principal Investigator:** GEORGE M SHAW
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $796,855
- **Award type:** 5
- **Project period:** 2017-08-17 → 2022-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9975687

## Citation

> US National Institutes of Health, RePORTER application 9975687, bNAb induction by antigenically diverse V1V2 lineage specific SHIVs and SOSIPs (5R01AI131331-04). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/9975687. Licensed CC0.

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