# In vivo engineering of chimeric antibody reprogrammed (CAR) B cells with fully tunable antibody response

> **NIH NIH R21** · UNIV OF NORTH CAROLINA CHAPEL HILL · 2024 · $233,250

## Abstract

The longstanding paradigm in vaccine development has been the introduction of immunogens that
culminates in generation of pathogen-binding antibodies (Ab). While the precise format of the antigen
presentation differs, all vaccines rely on somatic hypermutation of immunoglobulin genes in B cells to generate
Ab with greater affinity, avidity or anti-pathogen activity. Unfortunately, the natural variations in our immune
system leads to highly variable Ab responses, both in magnitude of the induced Ab response and the
breadth/potencies of the specific Ab clones generated, resulting in variable efficacy. Here, we seek to
overcome these shortcomings by directly reprogramming circulating B cells to secrete specific potent Ab of
interest, including stable integration of Ab-encoding transgenes into circulating B-cells. The resulting chimeric
antibody reprogrammed (CAR) B cells can produce Ab with magnitude, affinity and effector functions that
can all be controlled with molecular/genetic specificity. We refer to this as in vivo engineering of CAR-B cells.
 The key to realizing this vision is a delivery platform that can facilitate highly specific transduction of B-
cells in vivo. We have engineered lentivirus (LV) vectors that effectively transduce circulating immune cells.
Our first-generation system achieved highly specific transduction of circulating T-cells even at very low
virus:cell ratio, and generated substantial CAR-T cells in the circulation and in tumor of immune-deficient NSG
mice with highly aggressive BV173 lymphoma, leading to effective suppression of the tumor and prolonged
survival. We have since improved upon our first-generation system with a second-generation LV system
incorporating the Nipah virus fusion protein. Nipah LV (NLV), coupled with a proprietary combo of
transduction enhancers (TE), efficiently and specifically transduced non-activated B-cells in human PBMCs.
In pilot studies, a single injection of NLV+TE into NSG mice with circulating human PBMCs lead to effective
transduction of >0.5% of all circulating B-cells. We have also demonstrated we can harness CRISPR/Cas9 to
insert Ab transgene into a well conserved site in B cells, leading to functional B cells that can react to antigens.
 In this proposal, we seek to perform key enabling studies that substantiate our proposed CAR-B
strategy. In Aim 1, we will engineer NLV that targets different B-cell populations, and identify the combination
of NLV and TE that maximizes transduction of key human B-cells. We will then assess delivery of transgene
encoding for a potent RSV neutralizing Ab (nAb) either by non-specific integration or site-specific integration.
We will then advance into animal studies in Aim 2, where we will assess transduction efficiency and specificity
in NSG mice infused with circulating human PBMCs. We will quantify for the levels of the nAb in serum over
time, and assess protection against infection by respiratory syncytial virus (RSV). If successful, our work
...

## Key facts

- **NIH application ID:** 10791157
- **Project number:** 1R21AI180822-01
- **Recipient organization:** UNIV OF NORTH CAROLINA CHAPEL HILL
- **Principal Investigator:** Samuel Lai
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $233,250
- **Award type:** 1
- **Project period:** 2024-01-19 → 2025-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10791157

## Citation

> US National Institutes of Health, RePORTER application 10791157, In vivo engineering of chimeric antibody reprogrammed (CAR) B cells with fully tunable antibody response (1R21AI180822-01). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10791157. Licensed CC0.

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