Tag Archives: Fred Hutchinson Cancer Research Center

Hit and run gene therapy?

The approach looks promising but there’s a still long way to go before this ‘simpler, gentler’ approach to gene therapy will make its way into any treatments. From an August 30, 2017 news item on Nanowerk,

A new biomedical tool using nanoparticles that deliver transient gene changes to targeted cells could make therapies for a variety of diseases — including cancer, diabetes and HIV — faster and cheaper to develop, and more customizable.

The tool, developed by researchers at Fred Hutchinson Cancer Research Center and tested in preclinical models, is described in a paper published August 30 [2017] in Nature Communications.

This animation demonstrates the approach,

Biodegradable nanoparticles (orange) carry short-lived gene therapy to specific cells (light teal). Animation by Kimberly Carney / Fred Hutch News Service

An August 30, 2017 Fred Hutchinson Cancer Research Center (Fred Hutch) news release (from news release received via email; also on EurekAlert) by Sabrina Richards, which originated the news item, elucidates further (Note: Some links and notes have been removed),

“Our goal is to streamline the manufacture of cell-based therapies,” said lead author DR. MATTHIAS STEPHAN [6], a faculty member in the Fred Hutch Clinical Research Division and an expert in developing biomaterials. “In this study, we created a product where you just add it to cultured cells and that’s it — no additional manufacturing steps.”

Stephan and his colleagues developed a nanoparticle delivery system to extend the therapeutic potential of messenger RNA, which delivers molecular instructions from DNA to cells in the body, directing them to make proteins to prevent or fight disease.

The researchers’ approach was designed to zero in on specific cell types — T cells of the immune system and blood stem cells — and deliver mRNA directly to the cells, triggering short-term gene expression. It’s called “hit-and-run” genetic programming because the transient effect of mRNA does not change the DNA, but it is enough to make a permanent impact on the cells’ therapeutic potential.

Stephan and colleagues used three examples in the Nature Communications paper to demonstrate their technology:

* Nanoparticles carried a gene-editing tool to T cells of the immune system that snipped out their natural T-cell receptors, and then was paired with genes encoding a “chimeric antigen receptor” or CAR, a synthetic molecule designed to attack cancer.
* Targeted to blood stem cells, nanoparticles were equipped with mRNA that enabled the stem cells to multiply and replace blood cancer cells with healthy cells when used in bone marrow transplants.
* Nanoparticles targeted to CAR-T cells and containing foxo1 mRNA, which signals the anti-cancer T cells to develop into a type of “memory” cell that is more aggressive and destroys tumor cells more effectively and maintains anti-tumor activity longer.

Other attempts to engineer mRNA into disease-fighting cells have been tricky. The large messenger molecule degrades quickly before it can have an effect, and the body’s immune system recognizes it as foreign — not coming from DNA in the nucleus of the cell — and destroys it.

Stephan and his Fred Hutch collaborators devised a workaround to those hurdles.

“We developed a nanocarrier that binds and condenses synthetic mRNA and protects it from degradation,” Stephan said. The researchers surrounded the nanoparticle with a negatively charged envelope with a targeting ligand attached to the surface so that the particle selectively homes in and binds to a particular cell type.

The cells swallow up the tiny carrier, which can be loaded with different types of manmade mRNA. “If you know from the scientific literature that a signaling pathway works in synergy, you could co-deliver mRNA in a single nanoparticle,” Stephan said. “Every cell that takes up the nanoparticle can express both.”

The approach involves mixing the freeze-dried nanoparticles with water and a sample of cells. Within four hours, cells start showing signs that the editing has taken effect. Boosters can be given if needed. Made from a dissolving biomaterial, the nanoparticles are removed from the body like other cell waste.

“Just add water to our freeze-dried product,” Stephan said. Since it’s built on existing technologies and doesn’t require knowledge of nanotechnology, he intends for it to be an off-the-shelf way for cell-therapy engineers to develop new approaches to treating a variety of diseases.

The approach could replace labor-intensive electroporation, a multistep cell-manufacturing technique that requires specialized equipment and clean rooms. All the handling ends up destroying many of the cells, which limits the amount that can be used in treatments for patients.

Gentler to cells, the nanoparticle system developed by the Fred Hutch team showed that up to 60 times more cells survive the process compared with electroporation. This is a critical feature for ensuring enough cells are viable when transferred to patients.

“You can imagine taking the nanoparticles, injecting them into a patient and then you don’t have to culture cells at all anymore,” he said.

Stephan has tested the technology is cultured cells in the lab, and it’s not yet available as a treatment. Stephan is looking for commercial partners to move the technology toward additional applications and into clinical trials where it could be developed into a therapy.

Here’s a link to and a citation for the paper,

Hit-and-run programming of therapeutic cytoreagents using mRNA nanocarriers by H. F. Moffett, M. E. Coon, S. Radtke, S. B. Stephan, L. McKnight, A. Lambert, B. L. Stoddard, H. P. Kiem, & M. T. Stephan. Nature Communications 8, Article number: 389 (2017) doi:10.1038/s41467-017-00505-8 Published online: 30 August 2017

This paper is open access.

Biodegradable nanoparticles to program immune cells for cancer treatments

The Fred Hutchinson Cancer Research Centre in Seattle, Washington has announced a proposed cancer treatment using nanoparticle-programmed T cells according to an April 12, 2017 news release (received via email; also on EurekAlert), Note: A link has been removed,

Researchers at Fred Hutchinson Cancer Research Center have developed biodegradable nanoparticles that can be used to genetically program immune cells to recognize and destroy cancer cells — while the immune cells are still inside the body.

In a proof-of-principle study to be published April 17 [2017] in Nature Nanotechnology, the team showed that nanoparticle-programmed immune cells, known as T cells, can rapidly clear or slow the progression of leukemia in a mouse model.

“Our technology is the first that we know of to quickly program tumor-recognizing capabilities into T cells without extracting them for laboratory manipulation,” said Fred Hutch’s Dr. Matthias Stephan, the study’s senior author. “The reprogrammed cells begin to work within 24 to 48 hours and continue to produce these receptors for weeks. This suggests that our technology has the potential to allow the immune system to quickly mount a strong enough response to destroy cancerous cells before the disease becomes fatal.”

Cellular immunotherapies have shown promise in clinical trials, but challenges remain to making them more widely available and to being able to deploy them quickly. At present, it typically takes a couple of weeks to prepare these treatments: the T cells must be removed from the patient and genetically engineered and grown in special cell processing facilities before they are infused back into the patient. These new nanoparticles could eliminate the need for such expensive and time consuming steps.

Although his T-cell programming method is still several steps away from the clinic, Stephan imagines a future in which nanoparticles transform cell-based immunotherapies — whether for cancer or infectious disease — into an easily administered, off-the-shelf treatment that’s available anywhere.

“I’ve never had cancer, but if I did get a cancer diagnosis I would want to start treatment right away,” Stephan said. “I want to make cellular immunotherapy a treatment option the day of diagnosis and have it able to be done in an outpatient setting near where people live.”

The body as a genetic engineering lab

Stephan created his T-cell homing nanoparticles as a way to bring the power of cellular cancer immunotherapy to more people.

In his method, the laborious, time-consuming T-cell programming steps all take place within the body, creating a potential army of “serial killers” within days.

As reported in the new study, Stephan and his team developed biodegradable nanoparticles that turned T cells into CAR T cells, a particular type of cellular immunotherapy that has delivered promising results against leukemia in clinical trials.

The researchers designed the nanoparticles to carry genes that encode for chimeric antigen receptors, or CARs, that target and eliminate cancer. They also tagged the nanoparticles with molecules that make them stick like burrs to T cells, which engulf the nanoparticles. The cell’s internal traffic system then directs the nanoparticle to the nucleus, and it dissolves.

The study provides proof-of-principle that the nanoparticles can educate the immune system to target cancer cells. Stephan and his team designed the new CAR genes to integrate into chromosomes housed in the nucleus, making it possible for T cells to begin decoding the new genes and producing CARs within just one or two days.

Once the team determined that their CAR-carrying nanoparticles reprogrammed a noticeable percent of T cells, they tested their efficacy. Using a preclinical mouse model of leukemia, Stephan and his colleagues compared their nanoparticle-programming strategy against chemotherapy followed by an infusion of T cells programmed in the lab to express CARs, which mimics current CAR-T-cell therapy.

The nanoparticle-programmed CAR-T cells held their own against the infused CAR-T cells. Treatment with nanoparticles or infused CAR-T cells improved survival 58 days on average, up from a median survival of about two weeks.

The study was funded by Fred Hutch’s Immunotherapy Initiative, the Leukemia & Lymphoma Society, the Phi Beta Psi Sorority, the National Science Foundation and the National Cancer Institute.

Next steps and other applications

Stephan’s nanoparticles still have to clear several hurdles before they get close to human trials. He’s pursuing new strategies to make the gene-delivery-and-expression system safe in people and working with companies that have the capacity to produce clinical-grade nanoparticles. Additionally, Stephan has turned his sights to treating solid tumors and is collaborating to this end with several research groups at Fred Hutch.

And, he said, immunotherapy may be just the beginning. In theory, nanoparticles could be modified to serve the needs of patients whose immune systems need a boost, but who cannot wait for several months for a conventional vaccine to kick in.

“We hope that this can be used for infectious diseases like hepatitis or HIV,” Stephan said. This method may be a way to “provide patients with receptors they don’t have in their own body,” he explained. “You just need a tiny number of programmed T cells to protect against a virus.”

Here’s a link to and a citation for the paper,

In situ programming of leukaemia-specific T cells using synthetic DNA nanocarriers by Tyrel T. Smith, Sirkka B. Stephan, Howell F. Moffett, Laura E. McKnight, Weihang Ji, Diana Reiman, Emmy Bonagofski, Martin E. Wohlfahrt, Smitha P. S. Pillai, & Matthias T. Stephan. Nature Nanotechnology (2017) doi:10.1038/nnano.2017.57 Published online 17 April 2017

This paper is behind a paywall.