Protein-printing technique gives snapshots of immune syst...( CAMBRIDGE Mass. (Nov. 3 2008) When ...)

CAMBRIDGE, Mass. (Nov. 3, 2008) When Albrecht Durer and other Renaissance artists painstakingly etched images onto plates, swabbed ink into the fine grooves and transferred the images to paper with a press, they never could have guessed that centuries later the same technique would uncover the secrets of human cells.

Whitehead Institute and Massachusetts Institute of Technology researchers have borrowed a technique from such "intaglio" printing to create snapshots describing the behavior of immune cell populations at a moment in time.

The work may aid vaccine research and eventually lead to clinical devices that change the way physicians diagnose and treat infection and disease, suggests J. Christopher Love, a former postdoctoral associate in the lab of Whitehead Member Hidde Ploegh and now an MIT assistant professor of chemical engineering.

For the first time, the method developed by Love and his colleagues lets researchers look at single white blood cells and measure specific characteristics of the antibodies they produce when the body is under attack.

The white blood cells called B cells can offer billions of combinations of antibodies that bind to bacteria, viruses or toxins, flagging the invaders for destruction. "There are no two cells with the exact same signature," notes Hidde Ploegh.

And neither is there much information about what combination of antibodies goes with what target, Ploegh adds. But isolating and keeping B cells alive long enough to investigate them is inefficient and time-consuming, and it has been impossible to fully correlate analyses of all the antibodies.

In recent years, biologists have begun to exploit a set of techniques, collectively called soft lithography, to transfer patterns of biological materials to microarrays, much as Renaissance artists transferred images to paper.

Love came up with a new twist on this idea: individual cells could make the ink.