Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Delivery system for gene therapy may help treat arthritis

15.05.2012
A DNA-covered submicroscopic bead used to deliver genes or drugs directly into cells to treat disease appears to have therapeutic value just by showing up, researchers report.

Within a few hours of injecting empty-handed DNA nanoparticles, Georgia Health Sciences University researchers were surprised to see increased expression of an enzyme that calms the immune response.

In an animal model of rheumatoid arthritis, the enhanced expression of indoleomine 2,3 dioxygenase, or IDO, significantly reduced the hallmark limb joint swelling and inflammation of this debilitating autoimmune disease, researchers report in the study featured on the cover of The Journal of Immunology.

"It's like pouring water on a fire," said Dr. Andrew L. Mellor, Director of the GHSU's Medical College of Georgia Immunotherapy Center and the study's corresponding author. "The fire is burning down the house, which in this case is the tissue normally required for your joints to work smoothly," Mellor said of the immune system's inexplicable attack on bone-cushioning cartilage. "When IDO levels are high, there is more water to control the fire."

Several delivery systems are used for gene therapy, which is used to treat conditions including cancer, HIV infection and Parkinson's disease. The new findings suggest the DNA nanoparticle technique has value as well for autoimmune diseases such as arthritis, type 1 diabetes and lupus. "We want to induce IDO because it protects healthy tissue from destruction by the immune system," Mellor said.

The researchers were exploring IDO's autoimmune treatment potential by inserting the human IDO gene into DNA nanoparticles. They hoped to enhance IDO expression in their arthritis model when Dr. Lei Huang, Assistant Research Scientist and the paper's first author, serendipitously found that the DNA nanoparticle itself produced the desired result. Exactly how and why is still being pursued. Early evidence suggests that immune cells called phagocytes, white blood cells that gobble up undesirables like bacteria and dying cells, start making more IDO in response to the DNA nanoparticle's arrival. "Phagocytes eat it and respond quickly to it and the effect we measure is IDO," Mellor said.

Dr. Tracy L. McGaha, GHSU immunologist and a co-author on the current study, recently discovered that similar cells also prevented development of systemic lupus erythematosus in mice.

Follow-up studies include documenting all cells that respond by producing more IDO. GHSU researchers already are working with biopolymer experts at the Massachusetts Institute of Technology, the University of California, Berkeley and the Georgia Institute of Technology to identify the optimal polymer.

The polymer used in the study is not biodegradable so the researchers need one that will eventually safely degrade in the body. Ideally, they'd also like it to target specific cells, such as those near inflamed joints, to minimize any potential ill effects.

"It's like a bead and you wrap the DNA around it," Mellor said of the polymer. While the DNA does not have to carry anything to get the desired response in this case, DNA itself is essential to make cells express IDO. To ensure that IDO expression was responsible for the improvements, they also performed experiments in mice given an IDO inhibitor in their drinking water and in mice genetically altered to not express IDO. "Without access to the IDO pathway, the therapy no longer works," Mellor said.

Drs. Andrew Mellor and David Munn reported in 1998 in the journal Science that the fetus expresses IDO to help avoid rejection by the mother's immune system. Subsequent studies have shown tumors also use IDO for protection and clinical trials are studying the tumor-fighting potential of an IDO inhibitor. On the flip side, there is evidence that increasing IDO expression can protect transplanted organs and counter autoimmune disease.

Mellor is the Bradley-Turner and Georgia Research Alliance Eminent Scholar in Molecular Immunogenetics at MCG. The research was funded by the Carlos and Marguerite Mason Trust and the National Institutes of Health and a patent is pending on the findings.

Toni Baker | EurekAlert!
Further information:
http://www.georgiahealth.edu

More articles from Health and Medicine:

nachricht Usher syndrome: Gene therapy restores hearing and balance
25.09.2017 | Institut Pasteur

nachricht MRI contrast agent locates and distinguishes aggressive from slow-growing breast cancer
25.09.2017 | Case Western Reserve University

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The fastest light-driven current source

Controlling electronic current is essential to modern electronics, as data and signals are transferred by streams of electrons which are controlled at high speed. Demands on transmission speeds are also increasing as technology develops. Scientists from the Chair of Laser Physics and the Chair of Applied Physics at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) have succeeded in switching on a current with a desired direction in graphene using a single laser pulse within a femtosecond ¬¬ – a femtosecond corresponds to the millionth part of a billionth of a second. This is more than a thousand times faster compared to the most efficient transistors today.

Graphene is up to the job

Im Focus: LaserTAB: More efficient and precise contacts thanks to human-robot collaboration

At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.

Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Nerves control the body’s bacterial community

26.09.2017 | Life Sciences

Four elements make 2-D optical platform

26.09.2017 | Physics and Astronomy

Goodbye, login. Hello, heart scan

26.09.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>