Targeting troublesome T cells
The T cells of the immune system play an important role in defending the body against invading microorganisms. However, sometimes subsets of these cells fail to distinguish friend from foe, wrecking havoc with the body's own tissues and leading to allergies or autoimmune diseases such as rheumatoid arthritis and multiple sclerosis. One strategy for treatment would be to suppress the activity of all T cells, but this can seriously compromise an individual's immunity. Now, Teodor-D Brumeneanu and colleagues have devised a way to selectively eliminate only those T cells that are causing the problem (Nature Biotechnology, Vol. 19, Issue 2, 01 Feb 2001, p. 142-147).
T cells express protein structures (receptors) on their cell surface that permit them to spot and then bind other protein "flags"-called antigens-on a foreign target. Groups of T cells express different receptors that allow them to recognize various intruders. Using a model system that reflects what might occur in the body, the researchers exploited this property by engineering a molecule that could bind to a specific subset of T cells, delivering a toxic drug called doxorubicin to those cells.
In the test tube, the engineered molecule selectively killed the cells. When tested in mice, it also reduced the concentration of the targeted T cells compared with the free drug. Although preliminary, the results suggest that targeted drug of this type could be useful in treating autoimmune diseases by eliminating specific T cell populations.
Dr. Teodor-D. Brumeanu
Mount Sinai School of Medicine
Department of Microbiology
New York, NY 10029
(C) Nature Biotechnology press release.
Message posted by: Trevor M. D'Souza