Navigation Links
Specialized regulatory T cell stifles antibody production centers
Date:7/25/2011

HOUSTON A regulatory T cell that expresses three specific genes shuts down the mass production of antibodies launched by the immune system to attack invaders, a team led by scientists at The University of Texas MD Anderson Cancer Center reported online in the journal Nature Medicine.

"Regulatory T cells prevent unwanted or exaggerated immune system responses, but the mechanism by which they accomplish this has been unclear," said paper senior author Chen Dong, Ph.D., professor in MD Anderson's Department of Immunology and director of the Center for Inflammation and Cancer.

"We've identified a molecular pathway that creates a specialized regulatory T cell, which suppresses the reaction of structures called germinal centers. This is where immune system T cells and B cells interact to swiftly produce large quantities of antibodies," Dong said.

The discovery of the germinal center off-switch, which comes two years after Dong and colleagues identified the mechanisms underlying a helper T cell that activates the centers, has potential implications for cancer and autoimmune diseases.

"In some types of cancer, the presence of many regulatory T cells is associated with poor prognosis," Dong said. "The theory is those cells suppress an immune system response in the tumor's microenvironment that otherwise might have attacked the cancer."

However, in B cell lymphomas, overproliferation and mutation of B cells are the problems, Dong said. Hitting the regulatory T cell off-switch might help against lymphomas and autoimmune diseases, while blocking it could permit an immune response against other cancers.

Antibody production central

Germinal centers are found in the lymph nodes and the spleen. They serve as gathering points for B and T cell lymphocytes, infection-fighting white blood cells.

When the adaptive immune system detects an invading bacterium or virus, B cells present a piece of the invader, an antigen, to T cells. The antigen converts a nave T cell to a helper T cell that secretes cytokines, which help the B cells expand and differentiate into specialized antibodies to destroy the intruder.

"Germinal centers have mostly B cells with a few helper T cells to regulate them. The B cells mutate to make high-affinity antibodies and memory B cells for long-term immunity. The cell population in the germinal center structures replicates in an average of several hours, one of the fastest rates of cell replication known in mammals," Dong said.

Tracking down specialized T cell

In the Nature Medicine paper, Dong and colleagues found that a subgroup of regulatory T cells that expresses two genes, Bcl-6 and CXCR5, moves into germinal centers in both mice and humans, where they have access to B cells.

(Bcl-6 produces a protein called a transcription factor, which moves into the cell nucleus to regulate other genes. CXCR5 is a receptor protein for a signaling molecule called CXCL13.)

They also found that the Bcl-6/CXCR5 T cells aren't produced in the thymus, with other T cells, but are generated by regulatory T cell precursor cells that express Foxp3, another transcription factor.

Knocking out the regulatory T cells that express all three proteins in mice resulted in increased germinal center production of antibodies. They named this key T cell the T follicular regulatory cell, or Tfr.

In a 2009 paper in the journal Science, the researchers found that nave T cells that expressed Bcl-6 and CXCR5 also gathered in the B cell zone of germinal centers. Expression of Bcl6 converted the T cell into a T follicular helper (Tfh) cell that launches antibody production in the germinal centers.

With Tfr turning germinal centers off and Tfh turning them on, we could potentially regulate antibody production, Dong noted. Increasing Tfr production could be a new approach to treating autoimmune inflammatory disorders, such as lupus and rheumatoid arthritis.


'/>"/>

Contact: Scott Merville
smerville@mdanderson.org
713-792-0661
University of Texas M. D. Anderson Cancer Center
Source:Eurekalert

Related medicine news :

1. Specialized blood plasma treatment does not improve rotator cuff healing, study finds
2. Clinical waste management needs specialized regulation
3. The Walden Group, a Specialized Strategic Healthcare Investment Banking Firm, Adds Key Advisory Services
4. Serving the World With Specialized Insurance for Missionaries
5. Racial disparities diminish in specialized cancer centers
6. Chateau Amber Retreat Provides Specialized Post-Cosmetic Surgery Care in Palm Springs Luxury
7. CareTech Solutions Presents Specialized Healthcare Call Center at HIMSS10
8. Short on specialized intensive care physicians, team-based approach improves ICU outcomes
9. Newly discovered regulatory mechanism essential for embryo development and may contribute to cancer
10. “Global Supply Chain Visibility and Security; Business Necessity, Regulatory Imperative”
11. RAPS Seeks Nominations for Regulatory Awards, RAPS Fellows
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/24/2017)... ... ... “Finding Christ Through Social Media: Year One #A365DayJourney to ... path toward true communion with God. “Finding Christ Through Social Media: Year One ... published author Lea Michelle Johnson, a follower of Christ, wife and mother who ...
(Date:3/24/2017)... ... March 24, 2017 , ... “The Communion of Saints: ... of God in congregations across the United States. “The Communion of Saints” ... 1964 who has served congregations in seven states throughout his long career of ...
(Date:3/23/2017)... ... ... A recent report from the National Council on Teacher Quality (NCTQ) advocates ... based on a review of GPA and SAT/ACT requirements at 221 institutions in 25 ... argues that this higher bar should be set by states, by the Council for ...
(Date:3/23/2017)... Braunfels, TX (PRWEB) , ... March 23, 2017 , ... ... new clinic, located at 960 Gruene Road in Building 2. The clinic is the ... Dr. Andrew Bennett, PT, says opening the company’s second New Braunfels location brings things ...
(Date:3/23/2017)... ... ... The MBI “Hall of Fame” recognizes the contributions of those whose careers are or were ... careers of all others involved. , On Monday, March 21st, 2017 Laurie Robert, ... Fame. The induction took place during the World of Modular – Award Gala in ...
Breaking Medicine News(10 mins):
(Date:3/24/2017)... YORK , March 24, 2017 ... and Equipment stocks, which are: Neovasc Inc. (NASDAQ: NVCN), Hologic ... Heart Inc. (NASDAQ: SSH ). These companies are ... its prior gains on Thursday, March 23 rd , 2017, ... afternoon, while shares of health care companies in the S&P ...
(Date:3/24/2017)... 2017  HealthMine surveys with 9,250 insured consumers fielded ... plan members want help from their plans in five ... their health, 2) help closing gaps in care, 3) ... and 5) relevant, real-time guidance. Meeting these needs is ... A Reason to Stay Engaged ...
(Date:3/24/2017)... The Board of Directors of Nordic Nanovector ASA (OSE: ... complete 2016 Annual Accounts with notes. The report is attached ... the section Investor Relations/Reports and presentations/Annual Reports. ... For further information, please ... Cell: +47-91-51-95-76 Email: ir@nordicnanovector.com Media enquiries: ...
Breaking Medicine Technology: