Turbocharging Antibody Response to Cancer etc

The human immune system is a powerful deterrent to a wide range of diseases, including cancer. But it takes time to build an immunity to new diseases. Researchers at Scripps Research Institute have devised a synthetic adaptor that can generate an almost instant immune response to the protein target of one's choice.

Most vaccines - like those for measles or smallpox - prompt the immune system to build a standing army of antibodies against a virus or bacterium by injecting a deactivated version of the bug into the body.

But it can take weeks or months to build up immunity, and you have to catch people before they get infected. What's more, the approach doesn't always work - cancer and HIV vaccines have proved elusive.

So instead, Carlos Barbas and colleagues at the Scripps Research Institute in La Jolla, California, have developed dumb-bell shaped "adaptor" molecules that bind mouse antibodies to proteins on the surface of disease-causing agents, redirecting the antibodies' killing focus. In an earlier experiment they attached these molecules to a single kind of antibody in the lab, and injected these "retrofitted" antibodies into the mouse to kill tumour cells.

Now they have demonstrated that these synthetic molecules can bind many kinds of antibodies to cancer cells inside mice and reduce the size of implanted human tumours.

Four weeks after the molecules were injected, the colon tumours had shrunk by up to 90 per cent, and melanomas by 78 per cent (Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.0900147106). _NS

Even if this new immune therapy does not completely eradicate a tumour, by shrinking its size it gives the patient's medical team more time to chance upon the magic bullet treatment for that particular patient. Each person is different, so it is natural that a person's response to disease and therapy will be unique.