Tumor Cells Want No Contact With Immune Cells

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Tumor Cells Want No Contact With Immune Cells

ScienceDaily (Jun. 12, 2008) - As tumors progress they develop ways to escape

recognition and attack by cells of the immune system. However, the mechanisms by

which tumors modify the immune system have not been clearly determined.

New insight into the way in which chronic lymphocytic leukemia (CLL) cells limit

immune cell attack has now been provided by Gribben and colleagues, at

Barts and The London School of Medicine, United Kingdom.

For immune cells known as CD4+ and CD8+ T cells to become activated they must

contact other cells known as APCs. The area of contact is known as the

immunological synapse and it is highly organized. In the study, CD4+ and CD8+ T

cells from patients with CLL were found to exhibit defective immunological

synapse formation with APCs. Further, if CD4+ and CD8+ T cells from healthy

individuals were cultured with CLL APCs, they also showed defective

immunological synapse formation.

As treatment with an immune system--modifying drug improved immunological

synapse formation, the authors suggest that approaches to overcoming

immunological synapse defects might improve the efficacy of new ways to treat

cancer that are currently being developed and that are based on enhancing the

antitumor activity of CD4+ and CD8+ T cells.

Journal reference: Chronic lymphocytic leukemia T cells show impaired

immunological synapse formation that can be reversed with an immunomodulating

drug. Journal of Clinical Investigation. June 12, 2008