Regulatory T cells take the spotlight

ﾩ STEVE GSCHMEISSNER/PHOTO RESEARCHERS, INC

It?s a constant nagging problem, how cancers loaded with mutant proteins escape immune response. In 2004, Weiping Zou, now at the University of Michigan School of Medicine in Ann Arbor, and his colleagues showed that human ovarian tumors can recruit regulatory T cells to suppress other T cells. ¹ They do this by generating large amounts of the chemokine CCL22. Their findings pointed to a significant link between regulatory T-cell levels and patient mortality.

The paper remains "the best study of regulatory T cells in a human tumor system," Yang-Xin Fu at the University of Chicago says. In addition to revealing a novel and important mechanism tumors use to suppress the immune system, Ping Yu at the University of Chicago says it revealed a new cancer therapy strategy. In mice bearing human tumors, Zou and his colleagues found that antibodies targeting CCL22 blocked migration of transplanted human regulatory T cells.

"Inhibiting the inhibitors is a novel way to treat cancer," Zou says. "Several groups, including ours, started clinical trials in manipulating regulatory T cells in patients with cancer. The results are too preliminary, but interesting."