Technology Briefing Tumor counterattack

Tumor cells have well-described strategies - using both a stealthy defense and a killing offense - for circumventing the immune system. New work now shows that highly metastatic cancer cells have yet another offensive strategy for killing lymphocytes.

On the defensive front, major histocompatibility complex (MHC) glycoproteins are involved in presenting antigens to cytotoxic T cells, and distinguishing self from non-self. Cancer cells evade surveillance by the immune system by reducing expression of MHC glycoproteins, also known as human leukocyte antigens (HLA), on their cell surface. The tumor cells thus passively avoid destruction by T cells because the T lymphocytes do not recognize them as foreign. ...