Features Partner Sites Information LinkXpress
Sign In
Advertise with Us
Micromedic Technologies

T-cells Derived from Human Embryonic Stem Cells May Prevent Graft Rejection

By BiotechDaily International staff writers
Posted on 29 May 2013
Print article
Image: Senior author Dr. Matthias Hebrok (Photo courtesy of the University of California, San Francisco).
Image: Senior author Dr. Matthias Hebrok (Photo courtesy of the University of California, San Francisco).
Image: Contributing author Dr. Mark Anderson (Photo courtesy of the University of California, San Francisco).
Image: Contributing author Dr. Mark Anderson (Photo courtesy of the University of California, San Francisco).
A recent paper described the development of a method for using human embryonic stem cells (hESCs) to generate fully functional thymus tissue capable of supporting T-cell development and proliferation.

Inducing immune tolerance to prevent rejection is a key step toward successful engraftment of stem-cell-derived tissue in a clinical setting. Using human pluripotent stem cells to generate thymic epithelial cells (TECs) capable of supporting T-cell development represents a promising approach to reach this goal; however, progress toward generating functional TECs has been limited.

Investigators at the University of California, San Francisco (USA) developed a new method for directing differentiation of hESCs into thymic epithelial progenitors (TEPs), cells that mature into TECs. The in vitro method was based on the precise chronological regulation of several signaling factors including TGF-beta (transforming growth factor-beta), BMP4 (bone morphogenetic protein 4), Wnt (wingless-type MMTV integration site family), Shh (sonic hedgehog), and FGF (fibroblast growth factor).

Timing the activation of these signaling factors was critical. "If we used one factor for a day longer or shorter it would not work," said senior author Dr. Matthias Hebrok, professor of diabetes research at the University of California, San Francisco. "It would be like driving down the highway and missing your exit."

Results published in the May 16, 2013, online edition of the journal Cell Stem Cell revealed that the hESC-derived TEPs matured into functional TECs that supported T-cell development upon transplantation into thymus-deficient mice. Furthermore, the engrafted TEPs produced T-cells capable of in vitro proliferation as well as in vivo immune responses.

"The thymus is an environment in which T-cells mature, and where they also are instructed on the difference between self and nonself," said contributing author Dr. Mark Anderson, professor of medicine at the University of California, San Francisco. "Some T cells are prepared by the thymus to attack foreign invaders—including transplants, while T cells that would attack our own tissues normally are eliminated in the thymus."

The protocol described in this study prompted only about 15% of hESCs to differentiate into functional thymus tissue. Even so, Dr. Anderson said, "We now have developed a tool that allows us to modulate the immune system in a manner that we never had before."

Related Links:
University of California, San Francisco



Print article

Channels

Drug Discovery

view channel
Image: Naturally occurring clay from Kisameet Bay, Canada, exhibits potent antibacterial activity against multidrug-resistant pathogens (Photo courtesy of Kisameet Glacial Clay Inc.).

Antibiotic Resistant Bacteria Succumb to Treatment with Unique Natural Clay

A team of Canadian medical microbiologists has demonstrated the potential use of a unique type of natural clay for treating pathogenic bacteria that have become resistant to the commonly used antibiotics.... Read more

Business

view channel

Purchase Agreement to Boost Ebola Vaccine Development

A deal to help boost development of a vaccine to protect against Ebolavirus infection was finalized at the recent Davos Conference in Switzerland. Gavi (Geneva, Switzerland), the global alliance for vaccines and immunizations, announced that it would spend five million USD to purchase the Ebola vaccine under development... Read more
Copyright © 2000-2016 Globetech Media. All rights reserved.