Corporate Banner
Satellite Banner
Stem Cells, Cellular Therapy & Biobanking
>
Scientific Community
 
Become a Member | Sign in
Home>News>This Article
  News
Return

Biologists Discover Solution to Problem Limiting Development of Human Stem Cell Therapies

Published: Tuesday, January 07, 2014
Last Updated: Tuesday, January 07, 2014
Bookmark and Share
An effective strategy that could prevent the human immune system from rejecting the hESCs derived grafts.

Biologists at UC San Diego have discovered an effective strategy that could prevent the human immune system from rejecting the grafts derived from human embryonic stem cells, a major problem now limiting the development of human stem cell therapies.

Their discovery may also provide scientists with a better understanding of how tumors evade the human immune system when they spread throughout the body.

The achievement, published in a paper in this week’s early online edition of the journal Cell Stem Cell by a collaboration that included scientists from China, was enabled by the development of “humanized” laboratory mice that contained a functional human immune system capable of mounting a vigorous immune rejection of foreign cells derived from human embryonic stem cells.

Because human embryonic stem cells are different from our own body’s cells, or “allogenic,” a normally functioning human immune system will attack these foreign cells. One way to reduce the body’s “allogenic immune response” is to suppress the immune system with immunosuppressant drugs.

“For organ transplantation to save patients with terminal diseases that has been quite successful,” says Yang Xu, a professor of biology who headed the team of researchers that included Ananda Goldrath, an associate biology professor at UC San Diego. “But for stem cell therapies, the long term use of toxic immunosuppressant drugs for patients who are being treated for chronic diseases like Parkinson’s disease or diabetes pose serious health problems.”

Researchers had long been searching for a human immunity relevant model that would allow them to develop strategies to implant allogenic cells derived from embryonic stem cells safely. “The problem is that we only had data from mouse immune system and those are not usually translatable in humans, because human and mouse immune systems are quite different,” explains Xu. “So what we decided to do was to optimize the humanized mouse that carries a functional human immune system.”

To do that, the biologists took immune deficient laboratory mice and grafted into their bodies human fetal thymus tissues and hematopoietic stem cells derived from fetal liver of the same human donor. “That reconstituted in these mice a normally functioning human immune system that effectively rejects cells derived human embryonic stem cells,” says Xu. With these “humanized” mouse models, the biologists then tested a variety of immune suppressing molecules alone or in combination and discovered one combination that worked perfectly to protect cells derived from human embryonic stem cells from immune rejection.

That combination was CTLA4-lg, an FDA-approved drug for treating rheumatoid arthritis that suppresses T-cells responsible for immune rejection, and a protein called PD-L1 known to be important for inducing immune tolerance in tumors. The researchers discovered that the combination of these two molecules allowed the allogeneic cells to survive in humanized mice without triggering an immune rejection.

“If we express both molecules in cells derived from human embryonic cells, we can protect these cells from the allogenic immune rejection,” says Xu. “If you have only one such molecule expressed, there is absolutely no impact. We still don’t know exactly how these pathways work together to suppress immune rejection, but now we’ve got an ideal system to study this.”

He and his team of researchers also believe their discovery and the development of their humanized mouse models may offer the much needed tools to develop ways to activate immune response to tumors, because these molecules are known to be important in allowing tumors to evade the human immune system.

“You’re dealing with the same exact pathways that protect tumors from our immune system,” says Xu. “If we can develop strategies to disrupt or silence these pathways in tumors, we might be able to activate immunity to tumors. The humanized mouse system is really a powerful model with which to study human tumor immunity.”


Further Information
Access to this exclusive content is for Technology Networks Premium members only.

Join Technology Networks Premium for free access to:

  • Exclusive articles
  • Presentations from international conferences
  • Over 2,500+ scientific posters on ePosters
  • More than 3,700+ scientific videos on LabTube
  • 35 community eNewsletters


Sign In



Forgotten your details? Click Here
If you are not a member you can join here

*Please note: By logging into TechnologyNetworks.com you agree to accept the use of cookies. To find out more about the cookies we use and how to delete them, see our privacy policy.

Related Content

Anti-Leukemia Drug May Also Work Against Ovarian Cancer
An antibody therapy already in clinical trials to treat chronic lymphocytic leukemia (CLL) may also prove effective against ovarian cancer – and likely other cancers as well.
Wednesday, November 19, 2014
New Blood: Tracing the Beginnings of Hematopoietic Stem Cells
Researchers uncover earliest clues yet to development of cells that produce all adult blood cells.
Monday, August 18, 2014
New Reprogramming Method Makes Better Stem Cells
Researchers have shown for the first time that stem cells created using different methods produce differing cells.
Friday, July 04, 2014
Researchers Develop Efficient Model for Generating Human Stem Cells
Approach has potential to simplify generation of iPSCs for use in human stem cell therapies.
Wednesday, August 07, 2013
Scientific News
The Mending Tissue - Cellular Instructions for Tissue Repair
NUS-led collaborative study identifies universal mechanism that explains how tissue shape regulates physiological processes such as wound healing and embryo development.
Tissue Bank Pays Dividends for Brain Cancer Research
Checking what’s in the bank – the Brisbane Breast Bank, that is – has paid dividends for UQ cancer researchers.
iPS Cells Discover Drug Target for Muscle Disease
Researchers have designed a model that reprograms fibroblasts to the early stages of their differentiation into intact muscle cells in a step towards a therapeutic for Duchenne muscular dystrophy.
Engineered Hot Fat Implants Reduce Weight Gain
Scientists at UC Berkeley have developed a novel way to engineer the growth and expansion of energy-burning “good” fat, and then found that this fat helped reduce weight gain and lower blood glucose levels in mice.
Transplanted Stem Cells Can Benefit Retinal Disease Sufferers
Tests on animal models show that MSCs secrete growth factors that suppress causes of diabetic retinopathy and macular degeneration.
MRI Scanners Can Steer Therapeutics to Specific Target Sites
Scientists from the University of Sheffield have discovered MRI scanners, normally used to produce images, can steer cell-based, tumour busting therapies to specific target sites in the body.
Team Finds Early Inflammatory Response Paralyzes T Cells
Findings could have enormous implications for immunotherapy, autoimmune disorders, transplants and other aspects of immunity.
Early Detection of Lung Cancer
The University of Manchester has signed a collaboration agreement with Abcodia to perform proteomics studies on a cohort of non-small cell lung cancer cases from the UKCTOCS biobank, with the aim of discovering new blood-based biomarkers for earlier detection of the disease.
Researchers Identify Drug Candidate for Skin, Hair Regeneration
Formerly undiscovered role of protein may lead to the development of new medications that stimulate hair and skin regeneration in trauma or burn victims.
Basis for New Treatment Options for a Fatal Leukemia in Children Revealed
Detailed molecular analyses allow new insights into the function of tumour cells and options for new treatments.
Skyscraper Banner

Skyscraper Banner
Go to LabTube
Go to eposters
 
Access to the latest scientific news
Exclusive articles
Upload and share your posters on ePosters
Latest presentations and webinars
View a library of 1,800+ scientific and medical posters
2,500+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
3,700+ scientific videos
Close
Premium CrownJOIN TECHNOLOGY NETWORKS PREMIUM FREE!