Science + Technology

UCLA AIDS and Stem Cell Researchers Discover Way to Develop T-cells From Human Embryonic Stem Cells, Raising Hopes for a Gene Therapy to Combat AIDS

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Researchers from the UCLA AIDS Institute and the Institutefor Stem Cell Biology and Medicine have demonstrated for the first time thathuman embryonic stem cells can be genetically manipulated and coaxed to developinto mature T-cells, raising hopes for a gene therapy to combat AIDS.

The study, to be published the week of July 3 in the onlineedition of the Proceedings of the National Academy of Sciences, found that itis possible to convert human embryonic stem cells into blood-forming stem cellsthat in turn can differentiate into the helper T-cells that HIV specificallytargets. T-cells are one of the body's main defenses against disease.

The results mark the first time that scientists have beenable to derive T-cells out of human embryonic stem cells, said Zoran Galic, assistant researchbiologist, and lead researcher on the study.

"This tells you that you may be able to use human embryonicstem cells to treat T‑cell and other blood diseases. This could be a veryimportant weapon in the fight against AIDS," Galicsaid.

The study is available at http://www.pnas.org/papbyrecent.shtml.

In their study, the researchers cultured human embryonicstem cells, which were incubated on mouse bone marrow support cells, which inturn converted them into blood‑forming cells. Those cells were theninjected into a human thymus gland that had been implanted in a mouse, and thethymus then changed those blood-forming cells into T-cells. Located just abovethe heart in humans, the thymus is the organ where T-cells develop. Itgradually shrinks in adults, weakening the immune system over time.

These results indicate that it is possible to decipher thesignals that control the development of embryonic stem cells into matureT-cells, said study co-author Jerome Zack, associate director of the UCLA AIDS Institute, and professor of medicineand of microbiology, immunology and molecular genetics at the David GeffenSchool of Medicine at UCLA.

"That way we can eventually repopulate the immune system inpatients needing T-cells," Zack said.

This in turn could give rise to gene therapy approaches totreat other diseases involving T-cells. In addition to HIV, for instance, thetechnique could be used to treat severe combined immunodeficiency, or the "bubbleboy disease," which leaves its victims without a working immune system, forcingthem to a life in an antiseptic, germ-free environment.

Other researchers who participated in this study are ScottG. Kitchen, Amelia Kacena, AparnaSubramanian, Bryan Burke and Ruth Cortado, all withthe David Geffen School of Medicine at UCLA.

The National Institutes ofHealth funded the study.

Established in 1992, the UCLA AIDS Institute is a multidisciplinarythink tank drawing on the skills of top-flight researchers in the worldwidefight against HIV and AIDS, the first cases of which were reported in 1981 byUCLA physicians. Institute members include researchers in virology andimmunology, genetics, cancer, neurology, ophthalmology, epidemiology, socialscience, public health, nursing, and disease prevention. Their findings haveled to advances in treating HIV as well as other diseases such as hepatitis Band C, influenza, and cancer.

The Institute for Stem Cell Biology and Medicine waslaunched on March 6, 2005, with a UCLA commitment of $20 million over fiveyears. The institute brings together geneticists, engineers, ethicists,chemists, policy experts, pathologists, immunologists, oncologists, hematologistsand scientists from other disciplines to uncover the mysteries of the growthand development of adult and embryonic stem cells. The institute is acollaboration of the David Geffen School of Medicine at UCLA, UCLA's Jonsson Cancer Center,the UCLA Henry Samueli School of Engineering andApplied Science, and the UCLA College of Letters and Science.

-UCLA-

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