Navigation Links
Penn study finds pro-death proteins required to regulate healthy immune function

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
University of Pennsylvania School of Medicine

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:
(Date:12/1/2015)... Middletown, PA (PRWEB) , ... December 01, 2015 ... ... separate environments; however, there are professionals who believe that with innovative technologies and ... services allows the patient to get the benefit of a dual-approach to his ...
(Date:12/1/2015)... ... 01, 2015 , ... CloudLIMS today announced that it is ... under the New Products and Services category for its innovative product offering, BioTracer. ... that helps labs organize data and track samples with storage inventories. BioTracer's ...
(Date:12/1/2015)... ... December 01, 2015 , ... The importance of volumetric ... the focus of numerous abstracts accepted for presentation here, at the 101st Annual ... abstracts highlight the use of Volpara Solutions’ quantitative breast imaging software tools for ...
(Date:12/1/2015)... ... December 01, 2015 , ... SAN ... today announced that the organization has awarded Education and Developmental Therapies (EDT), an ... Award. The award celebrates exceptional special needs providers that excel in synthesizing the ...
(Date:12/1/2015)... ... December 01, 2015 , ... ... the care management and population health arenas, is pleased to announce that VIP ... containment services, has successfully implemented the ACUITY Complete Care™ Management to back their ...
Breaking Medicine News(10 mins):
(Date:12/1/2015)...  The migration to value-based care will require ... that help patients stay healthy and reduce healthcare ... enabled, incorporate care guidelines and be reflective of ... also allow all stakeholders to collaborate across care ... That is the vision, however, research by Chilmark ...
(Date:12/1/2015)... -- --> --> ... (NKI-AVL), among the world,s largest and most prestigious ... Icon™, the company,s latest generation stereotactic radiosurgery system ... --> With the option to use ... Knife Icon offers greatly enhanced flexibility in how ...
(Date:12/1/2015)... , December 1, 2015 ... segments the concerned market with analysis and forecast of ... orthobiologics report defines and segments the concerned market with ... to the Market Research Report "North American Orthobiologics Market ... Factors & Spinal Stimulation, Stem Cell Therapy, Viscosupplementation), by ...
Breaking Medicine Technology: