Gladstone and UCSF scientists reactivate immune

Therapy stimulates recovery of the thymus gland

SAN FRANCISCO, CA – February 21, 2008 – Scientists at the Gladstone Institute of Virology and Immunology (GIVI) and the University of California, San Francisco (UCSF) have found that therapy can be used to stimulate the production of vital immune cells, called “T- cells,” in adults with HIV infection.

HIV disease destroys T-cells, leading to collapse of the immune system and severe infection. The thymus gland, which produces T-cells, gradually loses function over time (a process called “involution”) and becomes mostly inactive during adulthood. Because the thymus gland does not function well in adults, it is difficult for HIV-infected adults to make new T-cells. Thus, therapies that stimulate the thymus to produce new T-cells could help HIV-infected patients to rebuild their embattled immune systems.

Although it has been long assumed that the thymus cannot be reactivated in humans, research published in the March issue of the Journal of Clinical Investigation, shows that the thymus can be stimulated to produce more T-cells. This study is the first to show that pharmacologic therapies can be used to enhance human thymic function.

“These results represent new proof-of-principle findings that thymic involution can be reversed in humans” said Laura Napolitano, MD, lead author of the study, an Assistant Investigator at Gladstone and Assistant Professor of Medicine at UCSF. “Improved T-cell production may be helpful for some medical conditions such as HIV disease or bone marrow transplantation. These findings contribute new information to our understanding of T-cell production and are also an important step to determine whether immune therapies might someday benefit patients who need more T-cells.”