Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Notch protein signaling directs early T-cell development

07.07.2005


A better grasp of immune cell lineages may improve outcomes for transplant, other immunosuppressed patients



Researchers at the University of Pennsylvania School of Medicine have recently clarified the role of the Notch protein in T-cell development. T cells are required for many aspects of immunity, including fighting viral infections, providing cancer surveillance, and regulating multiple aspects of the immune response.

T cells are made in the thymus, a small organ situated under the breastbone near the heart, whose primary function is T-cell production. However, T cells ultimately come from hematopoietic (blood-producing) stem cells in the bone marrow, from which all blood-cell types begin. A progenitor cell leaves the bone marrow to seed the thymus, eventually giving rise to T cells. In the absence of instructions by the Notch protein, T-cell development does not occur, even in the presence of a normal thymus.


In this study–published in the most recent issue of Nature Immunology–the investigators found that Notch, a protein that regulates diverse cell-fate decisions in multi-cellular organisms, is active in very early T-cell progenitors in the thymus of mice. Notch contributes to the subsequent differentiation of these early T-cell progenitors into T cells.

"Notch signaling instructs multi-potent progenitor cell types to enter the T-cell developmental pathway," says senior author Avinash Bhandoola, MD, PhD, Assistant Professor of Pathology and Laboratory Medicine. "However, we don’t yet understand in which tissue these instructions are being delivered, and which cell type is the recipient."

Co-author Warren Pear, MD, PhD, Associate Professor of Pathology and Lab Medicine and member of Penn’s Abramson Family Cancer Research Institute and Institute for Medicine and Engineering, was one of the original discoverers of the role of Notch in T-cell development. His lab developed tools to block Notch signaling, which were key to identifying its function in T-cell progenitors. Findings from this current study suggest that Notch acts very early after progenitor cells enter the thymus, among other probable points in T-cell development.

Notch activates gene transcription in the nucleus of cells, and depending on the biochemical context, it turns certain pathways on, and others off. "To the extent that we know where, and in which cells Notch is acting, we may be able to figure out how Notch works in the thymus," says co-lead author Arivazhagan Sambandam, PhD, Research Associate, also in the Department of Pathology and Laboratory Medicine.

"Studying events in the thymus is important because intrathymic events may be a bottleneck in T-cell reconstitution, which is deficient in post-transplant patients," says co-lead author Ivan Maillard, MD, PhD, Research Associate in the Division of Hematology-Oncology and the Abramson Family Cancer Research Institute. "What the study allows us to do is begin to define exactly where intrathymic Notch signaling happens and where to look for problems and for the relevant molecular interactions."

In many clinical situations, early T-cell progenitors are likely to be deficient–especially in patients undergoing bone marrow or hematopoietic stem cell transplantation, in whom new T cells fail to be produced for long periods of time. In some, especially elderly patients, there is never true recovery of T cells, and such non-recovery is associated with problems such as infections. To improve the outcome of transplant patients, the process of T-cell development needs to be better understood. This may also be important in cancer patients who get profound immunosuppression from treatments and in AIDS patients when T cells are not made at a sufficient rate to replenish the T-cell pool.

The Pear and Bhandoola labs plan to apply the knowledge gained in their basic scientific studies to the clinic. According to Maillard, "In humans, it’s more difficult to look inside the thymus, but we plan to use our unique Notch reagents in model systems to generate hypotheses about the exact nature of Notch control of T-cell development, eventually moving that knowledge to relevant clinical situations."

Karen Kreeger | EurekAlert!
Further information:
http://www.uphs.upenn.edu

More articles from Life Sciences:

nachricht Repairing damaged hearts with self-healing heart cells
22.08.2017 | National University Health System

nachricht Biochemical 'fingerprints' reveal diabetes progression
22.08.2017 | Umea University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

Cholesterol-lowering drugs may fight infectious disease

22.08.2017 | Health and Medicine

Meter-sized single-crystal graphene growth becomes possible

22.08.2017 | Materials Sciences

Repairing damaged hearts with self-healing heart cells

22.08.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>