Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Major breakthrough in transplantation immunity

08.04.2009
Australian scientists have made a discovery that may one day remove the need for a lifetime of toxic immunosuppressive drugs after organ transplants.

Professor Jonathan Sprent and Dr Kylie Webster from Sydney's Garvan Institute of Medical Research, in collaboration with colleagues, Dr Shane Grey and Stacey Walters, have successfully tested a method, in experimental mice, of adjusting the immune system for just long enough to receive a tissue transplant and accept it as 'self'. At no stage, during or after the procedure, is there any need for immunosuppressive drugs.

The results are now online in the current edition of the prestigious Journal of Experimental Medicine.

"Under normal circumstances, the body would attack a transplanted organ unless immunosuppressive drugs such as cyclosporin were given," said Sprent. "In this project, mice were given a substance, or 'complex', that altered their immune systems, so that they accepted transplanted cells as their own."

Sprent developed the 'complex' with Professor Charles Surh from California's Scripps Research Institute and Dr Onur Boyman, physician and Head of the Basic Immunology Unit at the University Hospital of Lausanne in Switzerland.

The complex combines a molecule, interleukin-2 (IL-2), with an antibody in order to stimulate immune cells known as T regulatory cells.

"In broad terms, IL-2 is a growth factor for T cells," explained Sprent. "My colleague Onur Boyman discovered that by combining IL-2 with different antibodies you can control its action, boosting specific populations of T cells, while subduing others. For this project we needed to boost the numbers of T regulatory cells."

"T regulatory cells quiet the immune system, subduing the body's killer T cells when it's time to stop fighting an infection."

"The other side of the coin is that a superabundance of T regulatory cells prevents killer T cells from functioning. And you wouldn't want to be without killer T cells for long because they fight infections and cancers."

"For this project, we boosted T regulatory cells temporarily, in a procedure that we believe might be very useful clinically, particularly for preventing rejection."

It was the task of postdoctoral researcher Kylie Webster, working with Stacey Walters, to see if she could make the T regulatory cell response work in a clinically realistic setting.

"We took normal, healthy mice, injected them for three consecutive days with the complex, then transplanted insulin-producing cells on the fourth day," said Kylie. "By the time of transplant there were huge numbers of T regulatory cells in their systems, making graft-destroying T cells ineffective."

"The numbers of T regulatory cells dropped over time, and the immune systems returned to normal in about two weeks. By that time 80% of the mice had accepted the grafts of insulin producing cells as their own."

"This acceptance rate is very high for transplantation, with mice normally rejecting grafts within 2-3 weeks."

"A graft is considered accepted if it's tolerated after 100 days. We took some mice out to 200-300 days, and not one of them rejected."

While cautious, Professor Sprent is very encouraged by the results.

"We have yet to determine exactly how the complex works. Once we do, I believe a clinical trial of this very non-toxic agent would be worthwhile."

"Our approach works well with pancreatic islets, or insulin-producing cells, but we have yet to try other clinically-relevant grafts such as kidneys and hearts, which are technically very difficult in mice," he said.

"I am also aware that effective approaches in mice do not necessarily give good results in humans because of subtle differences in the immune systems of mouse and man."

"Those provisos given, if we were able to duplicate this experiment in humans, it would fulfil the dream of everyone in the transplant field."

ABOUT GARVAN

The Garvan Institute of Medical Research was founded in 1963. Initially a research department of St Vincent's Hospital in Sydney, it is now one of Australia's largest medical research institutions with nearly 500 scientists, students and support staff. Garvan's main research programs are: Cancer, Diabetes & Obesity, Immunology and Inflammation, Osteoporosis and Bone Biology, and Neuroscience. The Garvan's mission is to make significant contributions to medical science that will change the directions of science and medicine and have major impacts on human health. The outcome of Garvan's discoveries is the development of better methods of diagnosis, treatment, and ultimately, prevention of disease.

Alison Heather | EurekAlert!
Further information:
http://www.garvan.org.au

More articles from Health and Medicine:

nachricht Scientists learn more about how gene linked to autism affects brain
19.06.2018 | Cincinnati Children's Hospital Medical Center

nachricht Overdosing on Calcium
19.06.2018 | Albert-Ludwigs-Universität Freiburg im Breisgau

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: Overdosing on Calcium

Nano crystals impact stem cell fate during bone formation

Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

Im Focus: Photoexcited graphene puzzle solved

A boost for graphene-based light detectors

Light detection and control lies at the heart of many modern device applications, such as smartphone cameras. Using graphene as a light-sensitive material for...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Carbon nanotube optics provide optical-based quantum cryptography and quantum computing

19.06.2018 | Physics and Astronomy

How to track and trace a protein: Nanosensors monitor intracellular deliveries

19.06.2018 | Life Sciences

New material for splitting water

19.06.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>