Navigation Links
Penn study finds pro-death proteins required to regulate healthy immune function
Date:8/13/2007

PHILADELPHIA Researchers at the University of Pennsylvania School of Medicine have found that proteins known to promote cell death are also necessary for the maturation and proliferation of immune cells. Activation of T-cell receptors on the surface of lymphocytes by foreign antigens initiate a calcium-mediated signaling pathway that ends in cell differentiation and growth. The Penn scientists discovered that in the cells that lack the pro-death proteins Bax and Bak, calcium signaling is disrupted and energy production is reduced. Restoration of Bax corrects the signaling problems, increases energy production, and stimulates cell division.

The results, published online in the journal Immunity, bolster the teams hypothesis that metabolic cell activity directly controls life and death decisions in cells. This issue also includes a related commentary by the studys lead author, Russell Jones, PhD, and senior author Craig B. Thompson, MD.

It is well known that cells that lack Bax (Bcl-2-associated X protein) and Bak (Bcl-2-antagonist/killer) continue living under conditions that would cause normal cells to undergo programmed cell death or apoptosis. What is less well understood, is why lymphocytes missing these key proteins are unable to trigger a strong immune response and do not proliferate as normal in response to stimulation.

We simply say they are the same thing, says Thompson, Director of the Abramson Cancer Center and Chairman and Professor of Cancer Biology and Medicine. The molecular basis of both findings is based on how Bax and Bak work on intracellular membranes.

Specifically, the team found that when the T-cell receptor was stimulated on mutant cells lacking both proteins, proliferation was severely reduced relative to normal cells. Closer investigation showed that the amount and rate of calcium release from intracellular stores was altered in the mutant cells.

The inadequate calcium signals were unable to stimulate the mitochondria, which are the energy factories in the cell. Without mitochondrial activation, a key by-product of energy production, called reactive oxygen species or ROS, were not produced. And because ROS tell the cell to divide, cell proliferation is compromised.

Although Thompsons group investigated the function of Bax and Bak in T cells, the team thinks their findings will likely apply to many different cell types. When a cell receives signals to increase metabolism, it increases mitochondrial activity and energy production. That leads to the production of more energy than the cell can deal with, and consequently, the release of ROS. It is the release of reactive oxygen species by the mitochondria that actually generate the proliferation. We think that is the basis of all cell proliferation, says Thompson.


'/>"/>
Contact: Karen Kreeger
karen.kreeger@uphs.upenn.edu
215-349-5658
University of Pennsylvania School of Medicine
Source:Eurekalert

Related medicine news :

1. Gene study links endometriosis, infertility
2. Study reveals how stress can make you sick
3. Study points out that HIV vaccine may not be accepted easily
4. A new study surpasses Gene Therapy Hurdle
5. Tomato Sauce reduces Cancer Risk- Study
6. A question on study of Adult Stem Cell
7. Study on obesity and heart failure
8. National Lung Study in the process
9. Marijuana gateway theory strengthened by study of twins
10. Old theory of adaptation confirmed by new study
11. Study casts doubt on keyboard ills
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/27/2016)... ... June 27, 2016 , ... TopConsumerReviews.com recently awarded their highest ... . , Millions of individuals in the United States and Canada wear eyeglasses. Once ... to both correct vision and make a fashion statement. Even celebrities use glasses as ...
(Date:6/26/2016)... ... ... blind and certified personal trainer is helping to develop a weight loss fitness plan that ... the two major problems leading the fitness industry today:, , All ... They don’t eliminate all the reasons people quit their exercise program , ...
(Date:6/25/2016)... ... June 25, 2016 , ... "With 30 hand-drawn hand ... project," said Christina Austin - CEO of Pixel Film Studios. , ProHand Cartoon’s ... within Final Cut Pro X . Simply select a ProHand generator and drag ...
(Date:6/25/2016)... (PRWEB) , ... June 25, 2016 , ... Conventional wisdom ... of success. In terms of the latter, setting the bar too high can result ... more than just slow progress toward their goal. , Research from PsychTests.com ...
(Date:6/24/2016)... ... 24, 2016 , ... The Pulmonary Hypertension Association (PHA) learned ... receive two significant new grants to support its work to advance research and ... by recognizing patients, medical professionals and scientists for their work in fighting pulmonary ...
Breaking Medicine News(10 mins):
(Date:6/24/2016)... , June 24, 2016  Global Blood ... biopharmaceutical company developing novel therapeutics for the treatment ... today announced the closing of its previously announced ... stock, at the public offering price of $18.75 ... offering were offered by GBT. GBT estimates net ...
(Date:6/24/2016)... 2016 Dublin ... addition of the " Global Markets for Spectroscopy ... This report focuses on the ... review, including its applications in various applications. The report ... includes three main industries: pharmaceutical and biotechnology, food and ...
(Date:6/24/2016)... The Academy of Managed Care Pharmacy (AMCP) ... would allow biopharmaceutical companies to more easily share health ... and coverage decisions, a move that addresses the growing ... The recommendations address restrictions in the sharing of ... label, a prohibition that hinders decision makers from accessing ...
Breaking Medicine Technology: