Researchers discover how cancer 'invisibility cloak' works

Researchers discover how cancer 'invisibility cloak' works

Researchers at National Jewish Health have discovered how a lipid secreted by cancer tumors prevents the immune system from mounting an immune response against it. When lysophosphatidic acid (LPA) binds to killer T cells, it acts almost like an "invisibility cloak," preventing T cells from recognizing and attacking nascent tumors.

"In recent years, several therapeutic medicines have been developed that spur a person's own immune system to fight ," said Raul Torres, PhD, professor of immunology at National Jewish Health, and senior author on the paper, published in the October issue of Cancer Immunology Research. "Our findings suggest new targets and strategies for enlisting the immune system's help in fighting cancer."

Scientists believe the human immune system recognizes and destroys many cancerous before they develop into dangerous tumors. However, tumors also employ strategies to evade detection by the immune system.

Scientists have known that LPA is secreted by many types of cancer cells, appears to promote the growth and spread of cells, and that immune cells known as CD-8 "killer" T cells have several receptors for LPA. Killer T cells can destroy when activated against them.

In the new paper, researchers led by Dr. Torres showed that LPA keeps T cells inactivated even after they have "seen" a target, or antigen, on a cancer cell that would normally trigger an immune response. They identified the LPA5 receptor as the specific receptor responsible for inhibiting the immune response. In cell cultures and in mice LPA prevented signaling within cells, the appearance of molecules associated with T-cell activation, and proliferation of the T cells. When they transferred T cells lacking the LPA5 receptor into mice with cancer, tumor growth essentially halted.

"Knowing specifically how LPA inhibits the suggests several strategies for harnessing the immune system's natural ability to fight cancer," said Dr. Torres.

Related Stories

Modulating the immune system to combat metastatic cancer

May 24, 2013

Cancer cells spread and grow by avoiding detection and destruction by the immune system. Stimulation of the immune system can help to eliminate cancer cells; however, there are many factors that cause the immune system to ...

Study reveals that chemotherapy works in an unexpected way

Apr 04, 2013

It's generally thought that anticancer chemotherapies work like antibiotics do, by directly killing off what's harmful. But new research published online on April 4 in the Cell Press journal Immunity shows that effective chemot ...

Study shows how Staph toxin disarms the immune system

Oct 16, 2013

Researchers at NYU Langone Medical Center have discovered a new mechanism by which the deadly Staphylococcus aureus bacteria attack and kill off immune cells. Their findings, published today in the journal Cell Host & Mi ...

Recommended for you

Putting the brakes on cancer

Dec 19, 2014

A study led by the University of Dundee, in collaboration with researchers at our University, has uncovered an important role played by a tumour suppressor gene, helping scientists to better understand how ...

Peanut component linked to cancer spread

Dec 19, 2014

Scientists at the University of Liverpool have found that a component of peanuts could encourage the spread and survival of cancer cells in the body.

User comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.