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 Potential seen for tailoring treatment for acute myeloid leukemia
10.12.2018 | University of Washington Health Sciences/UW Medicine

nachricht UC San Diego researchers develop sensors to detect and measure cancer's ability to spread
06.12.2018 | University of California - San Diego

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: Researchers develop method to transfer entire 2D circuits to any smooth surface

What if a sensor sensing a thing could be part of the thing itself? Rice University engineers believe they have a two-dimensional solution to do just that.

Rice engineers led by materials scientists Pulickel Ajayan and Jun Lou have developed a method to make atom-flat sensors that seamlessly integrate with devices...

Im Focus: Three components on one chip

Scientists at the University of Stuttgart and the Karlsruhe Institute of Technology (KIT) succeed in important further development on the way to quantum Computers.

Quantum computers one day should be able to solve certain computing problems much faster than a classical computer. One of the most promising approaches is...

Im Focus: Substitute for rare earth metal oxides

New Project SNAPSTER: Novel luminescent materials by encapsulating phosphorescent metal clusters with organic liquid crystals

Nowadays energy conversion in lighting and optoelectronic devices requires the use of rare earth oxides.

Im Focus: A bit of a stretch... material that thickens as it's pulled

Scientists have discovered the first synthetic material that becomes thicker - at the molecular level - as it is stretched.

Researchers led by Dr Devesh Mistry from the University of Leeds discovered a new non-porous material that has unique and inherent "auxetic" stretching...

Im Focus: The force of the vacuum

Scientists from the Theory Department of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science (CFEL) in Hamburg have shown through theoretical calculations and computer simulations that the force between electrons and lattice distortions in an atomically thin two-dimensional superconductor can be controlled with virtual photons. This could aid the development of new superconductors for energy-saving devices and many other technical applications.

The vacuum is not empty. It may sound like magic to laypeople but it has occupied physicists since the birth of quantum mechanics.

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

New Plastics Economy Investor Forum - Meeting Point for Innovations

10.12.2018 | Event News

EGU 2019 meeting: Media registration now open

06.12.2018 | Event News

Expert Panel on the Future of HPC in Engineering

03.12.2018 | Event News

 
Latest News

Small but ver­sat­ile; key play­ers in the mar­ine ni­tro­gen cycle can util­ize cy­anate and urea

10.12.2018 | Life Sciences

New method gives microscope a boost in resolution

10.12.2018 | Physics and Astronomy

Carnegie Mellon researchers probe hydrogen bonds using new technique

10.12.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>