Apopto/RepleniSENS at University of Arizona

Rejuvenating the Immune System

Principal Investigator: Janko Nikolich-Zugich

Research Team: Megan Smithey

Immune cell function declines with age, as the thymus loses the cells that "educate" the precursors of immune cells called killer T-cells, and as defective killer T-cells accumulate and suppress the full diversity of youthful, functional killer Ts that target newly-encountered threats. At the University of Arizona, SENS Research Foundation is funding research to restore the production of new killer T-cells while making room for them by purging the defective cells from the system.
The decline immune function with age is driven by two causes. First, biological aging causes the limited pool of immunological killer T-cells to be slowly taken over by defective ("anergic") subpopulations that are no longer able to carry out their specialized work, and suppress the effectiveness of the rest of the system. Second, the aging thymus gland, where precursor stem cells are transformed into effective T-cells, slowly shrinks with age, losing the cells that are responsible for educating emerging immunological warriors.
SRF is funding work in the Department of Immunobiology at the University of Arizona to rejuvenate the immune system of aging mice by repairing this age-related damage. Research associate Dr. Megan Smithey, working in the lab of Dr. Janko Nikolich-Zugich (co-director of the Arizona Center on Aging), will be testing a two-pronged strategy. First, as a proof-of-principle for the effectiveness of eventual tissue engineering of a new, youthful thymus, she will use growth factors to replenish the specialized thymus cells critical to killer T-cell education. Simultaneously, she will be purging old mice of anergic T-cells, to make room for newly-educated cells to repopulate the immunological "space" and restore their adaptive immunity.