Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Natural method for clearing cellular debris provides new targets for lupus treatment

24.02.2012
Cells that die naturally generate a lot of internal debris that can trigger the immune system to attack the body, leading to diseases such as lupus.
Now Georgia Health Sciences University researchers report that an enzyme known to help keep a woman's immune system from attacking a fetus also helps block development of these autoimmune diseases that target healthy tissues, such as DNA or joints.

The findings point toward new treatment strategies for autoimmune diseases, which are on the rise in light of a germ-conscious society that regularly destroys many of the previously pervasive microbes that made the immune system more tolerant.

"The basic premise of lupus is you have lost normal tolerance to yourself, your own proteins and DNA," said Dr. Tracy L. McGaha, GHSU immunologist and corresponding author of the study published in Proceedings of the National Academy of Sciences.

They found that IDO, or indoleomine 2,3-dioxegenase, helps promote tolerance to debris generated by natural cell death and that when IDO is removed from the mix, the debris spurs an immune response that can trigger autoimmune disease. In mice genetically programmed to develop lupus, blocking IDO resulted in earlier, more aggressive disease.

"This connects IDO and macrophages. It's a newly described role for IDO in regulation of tolerance toward self," McGaha said. Consequently, increasing IDO production or its downstream effects might be a way to regain lost tolerance, he said.

They studied activity in the spleen, a hard-working immune organ, that constantly filters blood. In a perfectly orchestrated defense, the entrance to the spleen is surrounded by immune cells that scour blood for viruses, bacteria, even fat and cholesterol floating by.

A nearby subset of macrophages, which are essentially scavengers, then capture and consume the undesirables, McGaha said. Interestingly, a lot of what macrophages consume is dead immune cells.

Macrophages also appear to help keep the peace by preventing the immune system from joining the fray. McGaha earlier found that if he destroyed macrophages, then fed the spleen dead cells, there was inflammation instead of calm. "That tells us there is something inherent in this subset of macrophages that is important for the suppressive process," McGaha said referencing the paper published in 2011 in the journal Blood.

The new paper shows IDO is part of that "something." Efficient elimination of cell debris while keeping nearby immune cells quiet is important because some debris is known to grab the attention of the immune system, McGaha said. He noted that it's normal – and healthy – for damaged cells to become targets.

"We are really interested in this process of normal cell debris removal because in lupus, it's thought to be one of the main drivers of inflammation," he said.

The immune system has points of expansion and regulation where it decides whether or not to act. Knowing key points, such as IDO's regulatory role, provides treatment targets that can interrupt a destructive cascade of immune activity, McGaha said. Previous studies have shown evidence of self-attack is present many years before disease symptoms appear, he said.

Environmental assaults, such as a bad sunburn, can be the initial trigger of the abnormal immune response in diseases like lupus. In healthy individuals, the immune system rises to the occasion of an infection then goes back to baseline. In autoimmune disease, patients tend not to return to normal levels.

GHSU's 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 it and that it could help transplanted organs escape rejection. They suggested that McGaha look at IDO as a regulatory mechanism used by macrophages.

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

Further reports about: DNA Health Sciences IDO autoimmune disease immune cell immune response immune system

More articles from Life Sciences:

nachricht Biochemical 'fingerprints' reveal diabetes progression
22.08.2017 | Umea University

nachricht When fish swim in the holodeck
22.08.2017 | University of Vienna

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

Molecular volume control

22.08.2017 | Life Sciences

When fish swim in the holodeck

22.08.2017 | Life Sciences

Biochemical 'fingerprints' reveal diabetes progression

22.08.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>