Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Interspecies Transplant Works in First Step for New Diabetes Therapy

15.07.2013
Animal-to-human transplant of insulin-producing cells without use of drugs is ultimate goal

In the first step toward animal-to-human transplants of insulin-producing cells for people with type 1 diabetes, Northwestern Medicine® scientists have successfully transplanted islets, the cells that produce insulin, from one species to another. And the islets survived without immunosuppressive drugs.

Northwestern scientists developed a new method that prevented rejection of the islets, a huge problem in transplants between species, called xenotransplantation.

“This is the first time that an interspecies transplant of islet cells has been achieved for an indefinite period of time without the use of immunosuppressive drugs,” said study co-senior author Stephen Miller. “It’s a big step forward.”

“Our ultimate goal is to be able to transplant pig islets into humans, but we have to take baby steps,” said Xunrong Luo, M.D., also co-senior author of the study that will be published online July 12 in the journal Diabetes. “Pig islets produce insulin that controls blood sugar in humans.”

Luo is an associate professor of nephrology at Northwestern University Feinberg School of Medicine and medical director of the Human Islet Cell Transplantation Program at Northwestern Memorial Hospital. Miller is the Judy Gugenheim Research Professor of Microbiology-Immunology at Feinberg.

For people with hard-to-control type 1 diabetes, a transplant of insulin-producing islets from a deceased donor is one important way to control their chronic disease, in which their bodies do not produce insulin. However, there is a severe shortage of islet cells from deceased donors. Many patients on waiting lists don’t receive the transplant or suffer damage to their heart, nerves, eyes and kidneys while they wait.

Using islets from another species would provide wider access to transplants for humans and solve the problem. But concerns about controlling rejection of transplants from a different species have made that approach seem insurmountable until now.

In the new study, scientists persuaded the immune systems of mice to recognize rat islets as their own and not reject them. Notably, the method did not require the long-term use of drugs to suppress the immune system, which have serious side effects. The islets lived and produced insulin in the mice for at least 300 days, which is as long as scientists followed the mice.

While the barrier from rats to mice is probably lower than from pigs to humans, the study showed interspecies islet transplants are possible and without immunosuppressive drugs, Luo said.

In the study, the rat splenocytes, a type of white blood cell located in the spleen, were removed and treated with a chemical that caused their deaths. Next, the dead splenocytes were injected into the mice. The cells entered the spleen and liver and were mopped up by scavenger cells. The scavengers processed the splenocytes and presented fragments of them on their cell surface, triggering a reaction that told the T cells to accept the subsequently transplanted rat islets and not attack them.

But rejection was still a threat. A unique challenge of an interspecies transplant is controlling the B cells, immune cells that are major producers of antibodies. Initially, when scientists transplanted the rat islets into the mice, the mouse immune system started producing antibodies against the rat cells causing rejection.

To solve the problem, Luo realized she needed to kill off the B-cells at the same time she injected the donor islets into the mice. Thus, she gave the mice B-cell depleting antibodies -- already used in a clinical setting in human transplants. When the B-cells naturally returned after the transplant, they no longer attacked the rat islets.

“With this method, 100 percent of the islets survived indefinitely,” Luo said. “Now we’re trying to figure out why the B-cells are different when they come back.”

The study lead author is Shusen Wang, formerly a postdoctoral student in Luo’s lab.

The research was supported by the JDRF and National Institutes of Health Directors New Innovator Award DP2 DK083099.

Erin White | EurekAlert!
Further information:
http://www.northwestern.edu

More articles from Life Sciences:

nachricht Rainbow colors reveal cell history: Uncovering β-cell heterogeneity
22.09.2017 | DFG-Forschungszentrum für Regenerative Therapien TU Dresden

nachricht The pyrenoid is a carbon-fixing liquid droplet
22.09.2017 | Max-Planck-Institut für Biochemie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>