Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Mayo Clinic researchers discover new immune system molecule that can help or harm health

18.06.2003


Mayo Clinic researchers have identified a new member of the important B7 family of immune system "co-stimulators." Co-stimulators are molecules that are capable of turning the immune system on or off -- and in the process, profoundly affecting human health.



Mayo Clinic researchers named this newest molecule B7-H4. It inhibits the action of T cells, the immune system warriors whose basic job is to attack invaders. Turning off T cells helps transplant patients accept foreign organs. But turning off T cells harms cancer patients -- their tumors continue to grow without defensive attacks by T cells. The Mayo Clinic report appears in the June 17 issue of Immunity.

These findings may help researchers learn how to manipulate immune system co-stimulators to serve such therapeutic objectives as:


1) stopping the body from attacking itself in autoimmune diseases;
2) thwarting rejection of transplanted organs;
3) guiding the body to attack a cancer cell.

Significance of the Mayo Clinic Investigation

B7-H4 is the fourth in a line of so-called "co-stimulation" molecules discovered over five years of research led by Lieping Chen, M.D., Ph.D., professor of Immunology at Mayo Medical School. The first in the line, B7-H1, was discovered in 1999 by Dr. Chen and colleagues. And, as in so many families, the members of this molecule family bear intriguing differences. Chief among these differences: Not all B7 members serve the body the same way -- some boost the immune system, some blunt its effect and some do both, at different times, depending on the partner to which they bind and the pathways for action they create.

Says Dr. Chen, "The immune system is a double-edged sword. It can help and it can damage. It has a positive and a negative capacity -- and understanding and controlling these is the key issue for manipulation of diseases with new treatments. This molecule is very important for doing that work because it is a very potent negative regulation component of the immune system."

The Investigation

To examine the B7 group further, Mayo Clinic researchers analyzed genes in a database composed of members that were likely to be part of the B7 superfamily. Then they cloned the B7-H4 molecule, modeled it in 3-D on a computer and found the functional part of interest. Next, they engineered the molecule and tested its effects in T cells, both in cell culture and in live mice. They did this because Dr. Chen’s laboratory is probing the molecular basis of cellular communication to discover how different components of the immune system talk to each other on the cell surface. The basic exchange that occurs on the cell surface involves two parts: a receptor and its partner, which is called a "ligand." How these two parts interact determines the action the immune system takes.

Mayo Clinic’s Findings

B7-H4 is a very powerful "negative regulator," highly efficient at turning off T cells. This is important because in certain diseases, such as cancers, this regulator may be overly active. In healthy cells, there are no negative regulators. The implication: One reason healthy cells are healthy is that they don’t have B7-H4 shutting down the T cells that police the body for invaders; their T cells are working and are protecting them. "In a tumor, you may have excess B7-H4 turning off T cells all the time. In a normal healthy body, the negative regulators like B7-H4 have to be turned on," says Dr. Chen. The mechanism by which B7-H4 inhibits T cells appears to be one of arresting cell division and the cell-proliferation cycle.

At a Glance Summary
  • Some immune system molecules can go both ways: they can have the positive effect of boosting the immune system, or the negative effect of shutting it down -- or do both at different times -- depending on the nature of the partners to which they bind.
  • B7-H4, the subject of Mayo’s current investigation, powerfully shuts down the immune system response of T cells.
  • By discovering which molecules -- and which partners, or ligands -- are involved in turning the immune system on or off, Dr. Chen is confident Mayo Clinic research will help scientists devise new treatment strategies. "This new finding about B7-H4 adds excitement to the possibility of therapeutic manipulation of the immune system," he says.

Mary Lawson | EurekAlert!
Further information:
http://www.mayo.edu/

More articles from Health and Medicine:

nachricht Speed data for the brain’s navigation system
06.12.2016 | Deutsches Zentrum für Neurodegenerative Erkrankungen e.V. (DZNE)

nachricht Study suggests possible new target for treating and preventing Alzheimer's
02.12.2016 | Oregon Health & Science University

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Porous crystalline materials: TU Graz researcher shows method for controlled growth

07.12.2016 | Materials Sciences

Simple processing technique could cut cost of organic PV and wearable electronics

06.12.2016 | Materials Sciences

3-D printed kidney phantoms aid nuclear medicine dosing calibration

06.12.2016 | Medical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>