Navigation Links
Rare hybrid cell key to regulating the immune system
Date:5/24/2010

AUGUSTA, Ga. - A cell small in number but powerful in its ability to switch the immune system on or off is a unique hybrid of two well-known immune cell types, Medical College of Georgia researchers report.

"This is actually the first cell we know of that has this type of appearance in nature," Dr. Andrew Mellor, molecular geneticist and immunologist who co-directs MCG's Immunotherapy Discovery Institute, said of the cell that looks like a dendritic cell and a B cell but isn't really either.

The discovery of this rare hybrid could have implications for the efficacy of new therapies that manipulate these two cell types to treat diseases such as cancer and rheumatoid arthritis.

When MCG scientists first reported the human equivalent of this cell in Science in 2002, they called it a subset of the dendritic cell that clusters in high exposure areas such as the gut but also roams the body, looking for invaders like a virus or cancer. Dendritic cells show their find to T cells, telling them to ignore or attack by bringing trash-eating macrophages, natural killer cells and the like into the fight.

What seemed most unique about the subset is its ability to express indoleamine 2,3 dioxygenase, or IDO, to turn off T cells. IDO is an enzyme used by fetuses and tumors alike to escape the immune response.

The new studies show that is only part of the cells' distinctiveness. The cells also have the identifying markings of B cells, known for their ability to make antibodies against invaders. In fact, they found the IDO-presenting cells came from the same precursor cell as B cells. But, when the scientists looked at mice missing B cells, they still found the IDO-producing cells. Hence, the cell didn't need to produce antibodies to turn off T cells.

In reality, IDO-expressing cells have properties of both cells, said Burles A. Johnson III, an MCG M.D.-Ph.D. student and first author of the paper published online this week in PNAS. "It looks like a B cell and it's not. It looks like a dendritic cell and it is and it isn't," Johnson said.

While their studies are in mice, the cells also are in humans, showing up in some unfortunate places such as the drainage system for tumors, melanoma or even HIV where they likely help the diseases survive.

They also may be showing up in new dendritic cell therapies designed to strengthen the immune response to cancer. If the therapies happen to include some IDO-expressing cells, those could end up helping the cancer, said Mellor, the paper's corresponding author. "All you need is a few of these cells in your dendritic cell vaccine and you don't get stimulation any more, you get suppression," Mellor said.

Their confusing face could also cause hybrids to be lost in B cell-depleting therapies designed to lessen the immune system's attack on joints in rheumatoid arthritis. "These therapies may also deplete IDO-expressing cells and decrease therapy effectiveness because you are eliminating cells that are there to help you," Johnson said.

"This gives us new insight into why these therapies might not be working as well as we think they might," Mellor added. Long-term goals include figuring out how to manipulate the hybrid's activity to benefit patients.


'/>"/>

Contact: Toni Baker
tbaker@mcg.edu
706-721-4421
Medical College of Georgia
Source:Eurekalert  

Related medicine news :

1. Phybridge Named "Cool Vendor" by Leading Analyst Firm
2. TCT for Surgeons course will highlight hybrid surgical and interventional techniques
3. Phybridge Inc. Joins the Cisco Developer Network and Completes Cisco Interoperability Verification Testing
4. Howard Leights New Pilot Push-in Ear Plug Delivers Occupational Hearing Protection with Innovative, Hybrid Design
5. Mount Sinai discovers bone marrow plays critical role in enhancing immune response to viruses
6. New Blue Ocean Load & Go™ CR Series Immune Monitoring Systems Debut at ISAC CYTO 2010
7. ASCO data highlight novel anti-cancer approach that exposes tumors to immune attack
8. New Clues to Treating Immune System Disorders
9. PET scanning probes reveal different cell function within the immune system
10. Immunetics Wins $2.8 Million Contract for New Type of HIV Test
11. New Diagnostic Testing Company, Blue Ocean Biomedical, Specializes In Automated, Load & Go Cell Analysis Systems For Immune Monitoring
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Rare hybrid cell key to regulating the immune system
(Date:6/27/2017)... CT (PRWEB) , ... June 27, 2017 , ... Dr. ... the recent renovation of his practice, Advanced Periodontics and Dental Implant Center of Connecticut. ... increased the administrative and waiting areas. The renovations are intended to improve patient comfort ...
(Date:6/27/2017)... ... 27, 2017 , ... Children’s National Health System received top honors in the ... ranking #1 out of more than 1500 neonatal intensive care units coast to ... a distinction given to the top performing children’s hospitals in the country. , ...
(Date:6/26/2017)... SALISBURY, MD. (PRWEB) , ... June 26, 2017 ... ... their crop, according to a recent review of government data released by the ... continuous improvement in management practices, Maryland’s soybean farmers have increased their productivity on ...
(Date:6/26/2017)... ... June 26, 2017 , ... New patients with missing ... Cotey, with or without a referral. Dr. Cotey is a trusted dentist who has ... tooth replacement option. , Patients with missing teeth in Fitchburg, WI, are encouraged to ...
(Date:6/25/2017)... ... , ... CareSet Labs released the Root NPI Graph today at the 2017 ... improved version of the Doctor Referral teaming dataset commonly available from Medicare. , Originally ... the the “Doctor Referral Dataset” as released by Medicare and “DocGraph” as released by ...
Breaking Medicine News(10 mins):
(Date:6/10/2017)... , June 9, 2017  Shane K. Burchfield, DPM, is recognized ... excellence as a Podiatrist in Alabama . ... Family First Foot Care. He brings over 20 years of experience, ... management and healthcare, to his role. ... Care, PC is pleased to welcome you to his ...
(Date:6/8/2017)...   Responding to Heath Ledger,s father,s recent ... singer Chris Cornell in May, the mental health ... free online psychiatric drug side effects search ... psychotropic drug risks. The father of the ... accidental overdose, has called for tighter rules on prescription drugs. ...
(Date:6/7/2017)... 6, 2017  Diplomat Specialty Infusion Group, a brand of Diplomat ... its Iowa location. The ... now features an ISO 7 cleanroom—the standard needed to compound intravenous ... low level of pollutants. "Our ... and better serve our Iowa patients," said ...
Breaking Medicine Technology: