Researchers use light to coax cells to move

Mar 30, 2010

(PhysOrg.com) -- Suppose you could get immune cells to move just where you wanted them to in the body - to fight infection or kill a tumor? It may sound like science fiction or magic, but it's not.

Researchers at the University of Wisconsin-Madison have shown that they can make immune cells in living fish embryos move the way they want them to, simply by shining a focused on them from their microscope.

Published recently in Developmental Cell, the study was done to visualize the dynamics of cell movement. The experiments also showed that a signaling protein called PI(3)K is essential in two ways for cells to move.

Though no one can say for sure yet, some scientists can imagine astonishing future clinical possibilities for the remotely activated cell-moving ability.

"Could you move immune cells to wounds to help fight infections?" says lead author Dr. Anna Huttenlocher of the UW School of Medicine and Public Health. "Could you control the movement of to kill tumors? Could you remove inflammation-causing cells from arthritic hands?"

It's pie in the sky, but very intriguing, says Huttenlocher, a professor of medical microbiology and immunology and of pediatrics.

The goal of the study was to understand how called leukocytes travel to inflammation sites, and what signaling mechanisms are involved.

Huttenlocher, a physician investigator who sees patients with at American Family Children's Hospital, uses zebrafish embryos in her studies on . Individual cells inside the transparent embryos are visible with a high-powered confocal microscope.

The UW-Madison team concentrated on PI(3)K because it is a critical regulator of many cellular processes, including cell migration. It's thought to activate another protein called Rac, which then causes the front edge of some cells to protrude before the back end of the cell inches forward. However, there have been conflicting reports on PI(3)K's exact role in the process.

Huttenlocher and her team used a tool developed by a University of North Carolina collaborator, who showed in test tube studies that he could induce cell movement. The tool uses a light beam to activate cells that have been tagged with a substance that responds to light by becoming fluorescent.

With a spotlight on them, cells containing Rac not only glowed, they also moved.

"The light turned on the Rac, which activated the leading edge of the cell to protrude," Huttenlocher says.

Using the light beam, Sa Kan Yoo, a graduate student in the lab, controlled exactly where the cells would go, even guiding them to align themselves to spell out the letters RAC.

"If you activate Rac at the leading edge of a cell, you can control where it goes," Huttenlocher says.

The researchers found that PI(3)-K was active in the process in two different ways. It first signaled Rac to move the front of the immune cell forward and then signaled the back side to follow, like a crawling inch worm.

"We've shown that PI3-K is probably even more important in this migration process than scientists had suspected," says Huttenlocher.

Knowing how and where the protein works may help in the development of therapeutic drugs.

"Since we now know movement begins with activity at the front edge of the cell, we can look deeper into the signaling pathways involved there and search for targets that could enhance or inhibit the process," she says.

Explore further: US scientists make embryonic stem cells from adult skin

Related Stories

Chopping off protein puts immune cells into high gear

Jan 24, 2007

The complex task of launching a well-organized, effective immune system attack on specific targets is thrown into high gear when either of two specific enzymes chop a protein called LAG-3 off the immune cells leading that ...

Breakthrough uses light to manipulate cell movement

Aug 19, 2009

One of the biggest challenges in scientists' quest to develop new and better treatments for cancer is gaining a better understanding of how and why cancer spreads. Recent breakthroughs have uncovered how ...

Now playing -- Cell migration LIVE!

Jun 08, 2007

Johns Hopkins researchers have found a way to directly observe cell migration -- in real time and in living tissue. In a report in the June 5 issue of Developmental Cell, the scientists say their advance could lead to str ...

Recommended for you

Leeches help save woman's ear after pit bull mauling

18 hours ago

(HealthDay)—A pit bull attack in July 2013 left a 19-year-old woman with her left ear ripped from her head, leaving an open wound. After preserving the ear, the surgical team started with a reconnection ...

New pain relief targets discovered

Apr 17, 2014

Scientists have identified new pain relief targets that could be used to provide relief from chemotherapy-induced pain. BBSRC-funded researchers at King's College London made the discovery when researching ...

User comments : 0

More news stories

Impact glass stores biodata for millions of years

(Phys.org) —Bits of plant life encapsulated in molten glass by asteroid and comet impacts millions of years ago give geologists information about climate and life forms on the ancient Earth. Scientists ...