Navigation Links
Protein helps immune cells to divide and conquer
Date:3/8/2009

Researchers at the University of California, San Diego School of Medicine have identified a key protein that is required for immune cells called B lymphocytes to divide and replicate themselves. The rapid generation of large numbers of these immune cells is critical to the body's antibody defense mechanism. However, when B cells grow unchecked, it can lead to immune cell cancers such as multiple myeloma or, when they grow to attack the wrong targets, to autoimmune disease. By discovering the role of the CD98hc protein, scientists may find new therapy targets for such diseases.

The study from the laboratory of Mark H. Ginsberg, MD., professor of medicine, will be published online March 8 in advance of print in Nature Immunology. It describes why CD98hc is essential in order for B lymphocytes to transition into antibody-secreting cells. It also describes how this relates to the protein's role in the signaling ability of integrins a large family of adhesion molecules that transfer information between the inside and outside of a cell.

According to first author Joseph Cantor, PhD, UC San Diego School of Medicine, scientists have known for nearly 25 years that CD98hc, common to all vertebrates, probably played a role in their adaptive immune system, but it wasn't known how this protein functioned.

"This protein was used as a marker of activation because it was found in low levels on resting lymphocytes," said Cantor. "But when B or T lymphocytes were stimulated by antigens for instance, to protect the body against bacteria levels of CD98hc went up 20 fold."

The scientists generated a mouse model lacking the CD98hc protein in B lymphocytes. When vaccinated, these mice were unable to mount a normal antibody response to the pathogen. Cantor says this was the first clue to the researchers of the protein's importance.

"In purifying B lymphocytes without the CD98hc protein, we discovered that the lymphocytes couldn't divide rapidly," Cantor said, adding that this proved the protein was essential to expanding the number of immune cells, a necessary step in the immune response. While deletion of the protein didn't impair early B cell activation, it did inhibit later activation of elements along the signaling pathway that push the cell forward to divide.

"Since B cells can't rapidly divide and replicate without CD98hc, perhaps by blocking this protein we could stop the unchecked growth of B lymphocyte cells that can result in cancer or block misdirected B cell attacks that can cause certain autoimmune diseases," said Ginsberg.

The CD98hc protein functions in cells by helping to transmit integrin signals, as well as transporting amino acids the building blocks of proteins into the cell. But the scientists didn't know which, if either, of these functions was related to the protein's role in the rapid division of immune cells. By replacing normal CD98hc in B cells with a version that lacked one or the other of these two functions, they discovered that the integrin-binding domain of this protein is required, but the amino acid transport function is dispensable for B cell proliferation.

"CD98hc interacts with certain integrin subunits to prompt signaling events that control cell migration, survival and proliferation. Our study shows that the rapid proliferation of B cells, necessary for the body to fight infection, is aided by the CD98hc protein's support of integrin signaling," Cantor said.


'/>"/>

Contact: Debra Kain
ddkain@ucsd.edu
619-543-6163
University of California - San Diego
Source:Eurekalert

Related medicine news :

1. Therapure Biopharma Inc. and LFB Biotechnologies Announce Development Services Contract for New Therapeutic Protein
2. Stem Cell Innovations C3A Human Liver Cell Line is Capable of Producing Biosimilar Serum Proteins for Follow-On Biologics
3. Metastasis-promoting protein identified; could provide a prognostic test or target for breast cancer
4. Scientists identify lab-made proteins that neutralize multiple strains of seasonal and pandemic flu
5. Team learns how cellular protein detects viruses and sparks immune response
6. Precautionary Allergy Alert on Undeclared Milk Protein in Expired Codes of Broughton Foods Pints of Orange Juice, Citrus Punch, Fruit Punch and Iced Tea Products
7. Blocking protein leads to fewer, smaller skin cancer tumors
8. Targeting the protein AEG1 impairs human liver cancer growth in mice
9. New technique boosts protein NMR imaging speeds
10. Brain Protein May Have Potential Against Alzheimers
11. Effects of smoking linked to accelerated aging protein
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:9/20/2017)... ... September 20, 2017 , ... “Psalms of Humidity”: is a ... mind and move the readers one step closer to God. “Psalms of Humidity” is ... his mistakes that have been made within his life are the very same things ...
(Date:9/20/2017)... ... September 20, 2017 , ... “Monique”: is the story of Monique, whose ... creation of published author, Colleen Crispi, has owned four beauty salons and written a ... in real estate and cooking. , “The doctor’s office was only three blocks ...
(Date:9/19/2017)... Birmingham, Alabama (PRWEB) , ... September 19, 2017 ... ... a customer success story on St. Vincent’s Infusion Services called, “PAPA Healthcare helps ... how St. Vincent’s Infusion Services enhanced service delivery and operations by leveraging PAPA ...
(Date:9/19/2017)... ... September 19, 2017 , ... The Lymphoma Research ... lymphoma research and serving the lymphoma community through a comprehensive series of education ... part of its national Swirl: A Wine Tasting Event series on Thursday, October ...
(Date:9/19/2017)... ... September 19, 2017 , ... The American Board ... to watch for the discomforts and hidden dangers of foot fungus, particularly in ... is at risk for developing fungal infections on the feet or toenails, the ...
Breaking Medicine News(10 mins):
(Date:9/7/2017)... nearly two decades, New Life Agency has been committed to providing the ... Life Agency announces a powerful three-way partnership designed to deliver substantial savings ... ... http://www.schrafts2.com/ (PRNewsfoto/PharmaCareCard) ... http://pharmacarecard.com/ (PRNewsfoto/PharmaCareCard) ...
(Date:9/6/2017)... SAN ANTONIO , Sept. 6, 2017  Robert ... as a Pinnacle Professional Member in recognition of his ... Dr. Szewc serves as a Nephrologist at the practice ... services, emergency medicine, kidney care and hypertension solutions. He ... over 20 years of career experience, as well as ...
(Date:9/5/2017)... -- Sapheneia and Scannerside received FDA 510(k) clearance to ... third-party Vendor neutral CT product that makes it affordable ... current MITA standards. ... specifically designed to provide CT operators, prior to a ... a predefined threshold. Scannerside Dose Check is intended to ...
Breaking Medicine Technology: