# In vivo gene editing of CCR5 in bone marrow using improved lentiviral vectors

> **NIH NIH F30** · UNIVERSITY OF CALIFORNIA, SAN DIEGO · 2020 · $50,520

## Abstract

Project Summary/Abstract:
While research efforts to develop highly-active antiretroviral therapy have greatly extended healthy lifespan for
HIV-1 infected individuals receiving treatment, the virus poses unique challenges for the development of a
long-sought after cure. Part of the viral lifecycle involves the permanent insertion of the HIV genome into a host
cell's genetic material, establishing a long term population of HIV infected cells. New strategies to prevent
spread from these cells must be developed. Unlike currently available antiviral drugs, anti-HIV gene therapy
holds the potential for the treatment and even cure of HIV-1 infection. The gene therapy-mediated knockout of
the HIV co-receptor CCR5 in HIV susceptible cells has shown potential in greatly reducing HIV viral loads in
both mouse models of HIV disease and early phase human clinical trials. Surprisingly, in rare trial participants,
this drop in viral load is sustained even when antiretroviral drug therapy is halted. However, all current anti-HIV
gene therapy strategies rely on the separation and ex vivo manipulation of HIV susceptible cells, followed by
re-infusion of these newly HIV-resistant cells back into patients. This approach requires access to advanced
cell culture and bone marrow transplant facilities and is currently prohibitively expensive for the majority of HIV
infected individuals living where the HIV epidemic continues to worsen.
To address these technical, economic, and biological challenges, new approaches to inexpensive gene
therapy must be developed. CD34+ hematopoietic stem and progenitor cells (HSPCs) are an attractive target
for gene therapy, given their status as predecessors to all cells susceptible to HIV. However, these cells have
shown resistance to genetic modification by currently available lentiviral vectors. In new data introduced in this
application, I demonstrate previously unforeseen levels of gene delivery to CD34+ HSPCs in vitro, achieved by
pseudotyping lentiviral vectors with the measles virus hemagglutinin and fusion glycoproteins. Mechanistic
insights from this work has guided mutagenesis of vesicular-stomatitis virus glycoproteins which will be used to
identify restriction factors in CD34+ HSPCs. In this application, I propose using these novel lentiviral vectors to
evaluate the potential of in vivo transduction as a potential anti-HIV strategy, using a humanized mouse model
of HIV infection. By direct intrafemoral injection of lentiviral vectors carrying the CRISPR/Cas9 system targeting
CCR5, I will evaluate if this approach can achieve sufficiently high levels of gene knockout to protect from HIV
challenge. If successful, this approach holds the potential to radically reduce the cost and technical difficulty of
anti-HIV gene therapy.

## Key facts

- **NIH application ID:** 10029620
- **Project number:** 7F30HL137563-04
- **Recipient organization:** UNIVERSITY OF CALIFORNIA, SAN DIEGO
- **Principal Investigator:** Stosh Ozog
- **Activity code:** F30 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $50,520
- **Award type:** 7
- **Project period:** 2019-10-11 → 2021-04-14

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10029620

## Citation

> US National Institutes of Health, RePORTER application 10029620, In vivo gene editing of CCR5 in bone marrow using improved lentiviral vectors (7F30HL137563-04). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/10029620. Licensed CC0.

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