Navigation Links
Natural method for clearing cellular debris provides new targets for lupus treatment
Date:2/24/2012

Augusta, Ga. 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.


'/>"/>

Contact: Toni Baker
tbaker@georgiahealth.edu
706-721-4421
Georgia Health Sciences University
Source:Eurekalert

Related medicine news :

1. Natural enzyme provides potential new approach for treating graft-vs.-host disease
2. A natural dye obtained from lichens may combat Alzheimers disease
3. Natural killer cells could be key to anthrax defense
4. New scarless surgery takes out tumors through natural skull opening
5. BU presents approach to access biorelevant structures by remodeling natural products
6. Natural processes can limit spread of arsenic in water, says study
7. Soy-based natural S-equol supplements improve crows feet skin wrinkles in menopausal women
8. For Kids, Natural Disasters Can Whip Up Worries
9. Bodys natural marijuana-like chemicals make fatty foods hard to resist
10. Study shows pine bark naturally improves heart function
11. Cooling system may build eggs natural defenses against salmonella
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:9/20/2017)... ... ... to Moorwick”: the adventures of a young Scottish girl yearning to see the world. ... mother of five who used her time waiting for children to finish their extracurricular activities ... It was a way to give some meaning to the hours I waited for ...
(Date:9/20/2017)... ... 2017 , ... “Monique”: is the story of Monique, whose mother’s deteriorating ... published author, Colleen Crispi, has owned four beauty salons and written a book regarding ... estate and cooking. , “The doctor’s office was only three blocks away, and ...
(Date:9/19/2017)... ... September 19, 2017 , ... DeSola Group, a leading strategy, ... Flannery, to its strategic advisory and client development team. , In her ... clients across different industries to develop and implement market-justified strategies, modernize and transform ...
(Date:9/19/2017)... ... September 19, 2017 , ... Peter ... the President’s Malaria Initiative (PMI) Africa Indoor Residual Spraying (AIRS) Project , ... , The Innovation to Action Award, a USAID Catalyst Award, recognizes USAID ...
(Date:9/19/2017)... ... September 19, 2017 , ... CTNext , ... Innovation Awards (EIA), held this past Thursday night at The Space in Hamden. ... presented their innovative project ideas to a panel of judges for an opportunity ...
Breaking Medicine News(10 mins):
(Date:9/7/2017)... Ind. , Sept. 7, 2017  Zimmer Biomet ... in musculoskeletal healthcare, today announced that it will be ... Global Healthcare Conference at the Grand Hyatt hotel in ... 11, 2017 at 11:40 a.m. Eastern Time. ... via Zimmer Biomet,s Investor Relations website at http://investor.zimmerbiomet.com ...
(Date:9/6/2017)... , Sept. 6, 2017 NeuroRx, a clinical ... Suicidal Ideation and Behavior (ASIB), has been granted Fast Track ... sequential therapy of NRX-100 (ketamine HCl) followed by NRX-101 (D-cycloserine ... a pivotal trial of this sequential therapy targeting patients who ... 1 ...
(Date:9/5/2017)... 5, 2017  Just 18 months after its February ... to announce the appointment of three new senior people ... Dominic Jones-Phillips and James Wright ... Tammy Wynne joins ... access writers. She has over ten years, experience in ...
Breaking Medicine Technology: