# Method for the isolation of antibodies with functional activity against cell surface targets

> **NIH NIH R43** · ABBRATECH, INC. · 2022 · $253,440

## Abstract

“Method for the isolation of antibodies with functional activity against cell surface targets”
ABSTRACT
We have derived a method for isolating functional mAbs against cell surface receptors that are separately
either agonists, antagonists, and partial agonists. We termed the method Directed Ligand Binding (DLB).
And in DLB’s first iteration (DLB1) we have successfully used it for peptide- and protein ligands. Using
DLB1 these ligands were genetically incorporated into the complementarity determining region (CDR) of
an appropriate phage display scFv library. At its essence DLB is a means to direct or bias the initial binding
of a subtracted (to remove non-specific- and irrelevant binding) phage displayed Ab library toward a target
cell surface receptor binding site by incorporating that receptor’s ligand or inhibitor into the Ab library itself.
And then rely on the increased binding ability, via the interaction of both an individual mAb’s CDRs plus
the covalently attached ligand to transiently stabilize the Ab::receptor complex to withstand the increasing
stringency of the phage biopanning washing cycles used to remove any weak binders. In the DLB1
method, we genetically encoded the ligand into the Ab’s CDR. But that limited us to peptide and protein
ligands. We now want to apply the DLB method for the enzymatic conjugation of ligands into an
appropriately modified CDR of a complementing library. We refer to this new method as DLB2.0. The
significant advantages of the DLB2.0 method are several fold, including: (1) the same library can be used
for many screens, and (2) the means for testing mAbs derived from DLB2.0 with and without attached
ligand is trivial; just omit the ligand attachment step before any screen. The proposed study uses several
GPCR targets as the model and functionality in a cell-based reporter assay as the application. Regarding
the commercial application, we are mainly focused on the method. It is true that the targets we have
chosen to develop the method, in some cases, do not have exceptional commercial value. When the
DLB2.0 generates appropriate IgGs we intend to partner and collaborate with strong academic, and
pharmaceutical- and biotech companies by providing them with the IgG clones and/or purified IgG proteins
so that they can perform the structural and biological studies needed to both better understand and utilize
the mAbs we develop. At Abbratech intend to provide custom services to commercial entities
(Pharmaceutical and Biotechnology companies) using the data obtained from this work, including any
collaborative results, as a demonstration of the power of DLB2.0.

## Key facts

- **NIH application ID:** 10478450
- **Project number:** 1R43AI167147-01A1
- **Recipient organization:** ABBRATECH, INC.
- **Principal Investigator:** Michael P Weiner
- **Activity code:** R43 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $253,440
- **Award type:** 1
- **Project period:** 2022-06-01 → 2023-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10478450

## Citation

> US National Institutes of Health, RePORTER application 10478450, Method for the isolation of antibodies with functional activity against cell surface targets (1R43AI167147-01A1). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10478450. Licensed CC0.

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