The new work by Albert and his co-authors, Postdoctoral Associate Birthe Sauter, M.D., and Assistant Professor Nina Bhardwaj, M.D., Ph.D., provides an avenue for using the cell's natural machinery to bypass this requirement, allowing the individual's own dendritic cell to determine the correct part of the tumor antigen that fits their MHC molecules. In a model system, the researchers collected human tissue and infected it with influenza. These cells were triggered to undergo apoptosis (pronounced a-puh-TOE-sis), a type of cell suicide or programmed death. The dying cells were cultured with dendritic cells, making the dendritic cells capable of activating killer T cells that specifically target influenza antigen.
"In other words, the dendritic cells have the ability to acquire antigens from other cells and make them recognizable by T cells," says Bhardwaj, senior author of the paper. "The T cells, in particular the CD8+ killer cells, can then proceed to kill any other cell that contains tumor or viral antigens. It appears that only dendritic cells--and not cells like monocytes--have this ability."
One possible use for this technique is tumor immunotherapy, in which an individual's own tumors--or tumor cell lines containing antigens similar to the person's tumor--could be used a "apoptotic food," says Albert.
"The advantage of this technique is that we could use a person's immune system to choose the appropriate pieces of protein to be presented to the MHC, overcoming the need for designer immunotherapy," continues Albert. "In this way, an individual's own immune system is revved up to attack the tumor based on the expression of tumor-specific antigens."
The diversity of tu
'"/>
Contact: Joseph Bonner
runews@rockvax.rockefeller.edu
212-327-7900
Rockefeller University
10-Mar-1998