Navigation Links
New study finds how cells with damaged DNA alert the immune system

Research led by biologists at the University of California, Berkeley, has found that damage to a cell's DNA sets off a chain reaction that leads to the increased expression of a marker recognized by the body's immune system.

The new findings, to be published July 3 in an advanced online issue of Nature, shed light on a long-standing question of how the natural killer (NK) cells - which are able to attack tumors - can differentiate cells that are cancerous from those that are healthy.

"Our study is the first to show that there are mechanisms in place for the immune system to identify cancer cells," said Stephan Gasser, UC Berkeley post-doctoral researcher in molecular and cell biology and lead author of the paper. "It reveals how natural killer cells distinguish something they're supposed to get rid of versus something they're supposed to keep."

The researchers explain that the immune system is designed to detect and attack foreign invaders, but cancer cells present a special challenge because they are still the bodies own cells, albeit ones in which the genes have gone awry.

"Many scientists question the importance of the immune system in stemming the development of cancer," said David H. Raulet, professor of immunology at UC Berkeley's Department of Molecular and Cell Biology and senior investigator of the study. "Our research adds to recent evidence that the immune system plays a significant role."

The researchers put cultures of ovarian epithelial cells and fibroblasts from mice through a battery of abuse, including heat shock, pH changes, oxygen deprivation and starvation. However, the only type of stress that set off the sequence of events associated with impairment of a cell's genetic material -- the DNA damage pathway -- was exposure to radiation and chemotherapy drugs.

They found that cells in which the DNA damage pathway was triggered were the ones that exhibited an increase in the expression of special protein s on the cell surface. These "ligands" on the membrane are specific to the NKG2D receptor on natural killer cells and are used to flag damaged cells for destruction. There are several types of NKG2D ligands, but the best known is called Rae1.

Prior studies have shown that the DNA damage pathway is activated in precancerous lesions, as well as many advanced tumors. In addition, many cancer cells express Rae1. It has been known that when genetic abnormalities occur, the cell cycle is halted so that the cell has time to fix the damage before the DNA is replicated. If the damage is too severe for the cell to repair on its own, it can trigger cell death, a process known as apoptosis.

"All of this is happening autonomously within the cell," said Raulet. "What's new about our study is that we found that cells with damaged DNA can also involve other cells in the fight, triggering a mechanism that signals other cells - specifically NK cells - to attack. It could be another ingenious trick that the body uses to ward off cancerous cells."

Interestingly, the NKG2D receptor is also found on the CD8+ T cell, a type of immune cell that acts as a sentry with a long-term memory of prior invaders. These cells stand ready to find and destroy cells infected by viruses before the virus can spread.

"We don't have direct information about the role of the DNA damage pathway in regulating immune responses to infectious diseases, but given what we have shown here, it is certainly plausible that it contributes to the expression of the NKG2D ligand," said Raulet. "It may also be that the Rae1 ligand helps trigger T cell responses that contribute to long term specific immunity. It's certainly an area of research that warrants more study."

Other co-authors of the paper are Sandra Orsulic, assistant professor at the Massachusetts General Hospital Center for Cancer Research, and Eric Brown, assistant professor at the University of Pennsylvania School of Medi cine.


'"/>

Source:University of California - Berkeley


Related biology news :

1. Bioartificial kidney under study at MCG
2. W.M. Keck Foundation funds study of friendly microbes
3. Yellowstone microbes fueled by hydrogen, according to U. of Colorado study
4. Genome-wide mouse study yields link to human leukemia
5. Clam embryo study shows pollutant mixture adversely affects nerve cell development
6. New imaging method gives early indication if brain cancer therapy is effective, U-M study shows
7. Same mutation aided evolution in many fish species, Stanford study finds
8. Sequencing of marine bacterium will help study of cell communication
9. Genetically modified rice in China benefits farmers health, study finds
10. A new study examines how shared pathogens affect host populations
11. NYU study reveals how brains immune system fights viral encephalitis
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:6/14/2017)... June 15, 2017  IBM (NYSE: IBM ) is introducing ... event dedicated to developing collaboration between startups and global businesses, ... 15-17. During the event, nine startups will showcase the solutions ... various industries. France ... market, with a 30 percent increase in the number of ...
(Date:5/16/2017)... DALLAS , May 16, 2017   ... for health organizations, and MD EMR Systems ... certified development partner for GE, have established a ... Patient Portal product and the GE Centricity™ products, ... Centricity EMR. These new integrations ...
(Date:4/19/2017)... 19, 2017 The global military ... is marked by the presence of several large global ... by five major players - 3M Cogent, NEC Corporation, ... for nearly 61% of the global military biometric market ... the global military biometrics market boast global presence, which ...
Breaking Biology News(10 mins):
(Date:7/26/2017)... 26, 2017  Nurse practitioners play a crucial role in ... a Merck Manuals survey released today. The survey ... that most (88 percent) believe they spend at least half ... ... Merck Manuals survey of 210 nurse practitioners finds that ...
(Date:7/24/2017)... , July 24, 2017 Intralytix, Inc. announced ... from Lesaffre, a French family group. This investment marks ... to develop and commercialize bacteriophage-based products, for various benefits ... interest. As ... designs manufactures and markets innovative solutions for baking, food ...
(Date:7/20/2017)... ... July 20, 2017 , ... Dr. Asher Kimchi, Founder and ... of the 2017 IAC Awards at the 22nd World Congress on Heart Disease held ... four faculty to receive the Distinguished Fellowship Awards. , Dr. Asher Kimchi, together with ...
(Date:7/20/2017)... (PRWEB) , ... July 20, 2017 , ... Corporate Directors ... at its 27th annual Director of the Year Awards. , The awards will be ... Jolla. This annual event celebrates directors who have made significantly positive contributions in ...
Breaking Biology Technology: