# Developing intrabody therapeutics for mitochondrial DNA heteroplasmy

> **NIH NIH R21** · UNIVERSITY OF PITTSBURGH AT PITTSBURGH · 2022 · $196,929

## Abstract

PROJECT SUMMARY
Numerous diseases arise from the presence of both normal and pathogenic mutant forms of mitochondrial DNA
(mtDNA). A modest reduction of this heteroplasmy in favor of the normal mtDNA can lead to significant patient
benefit. We intend to identify single-chain antibodies (scFvs) that recognize structures unique to some
pathogenic mtDNA sequences. Because scFvs can inhibit polymerases, we seek to identify novel antibodies
that block replication of particular pathological mtDNA variants that cause primary mitochondrial disorders. ScFvs
have been identified that recognize the general family of DNA structures being targeted, called G-quadruplexes
(G4s). Using positive and negative phage screening, we will isolate scFvs with the ability to bind a specific G4
structure. We will characterize scFvs in biophysical and biochemical experiments to identify lead candidates that
discriminate between pathogenic and normal mtDNA structures. Lead scFvs will then be functionalized with
mitochondrial-targeting sequences for targeted expression in mitochondria to test for beneficial heteroplasmy
shift. ScFvs that exhibit the highest affinity and most potent blockage of polymerase activity at the target
sequence will then be studied in cell culture, where cell uptake, localization, and phenotypic effects on
heteroplasmy and mitochondrial oxygen consumption will be determined. The advantages of this mt-scFv
expression approach are that it is selective, easily targeted to mitochondria, and can be repeated to maintain the
achieved health benefit.

## Key facts

- **NIH application ID:** 10386997
- **Project number:** 1R21HD107802-01
- **Recipient organization:** UNIVERSITY OF PITTSBURGH AT PITTSBURGH
- **Principal Investigator:** Brett A Kaufman
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $196,929
- **Award type:** 1
- **Project period:** 2022-03-08 → 2024-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10386997

## Citation

> US National Institutes of Health, RePORTER application 10386997, Developing intrabody therapeutics for mitochondrial DNA heteroplasmy (1R21HD107802-01). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10386997. Licensed CC0.

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