How immune cells 'sniff out' bacteria

Mar 29, 2010
Biophysicists at Yale created a method to stimulate single living cells with light and microparticles. Left side: The five particles pictured are trapped with laser tweezers and release a chemical which attracts the cell. Right side: The cell encounters a larger chemical concentration close to the particles (white-yellow region) than further away from the particles (red-black region). Credit: Holger Kress and Eric Dufresne

Scientists are learning how our immune system senses and tracks down infection in the body by responding to chemical "scents" emitted by bacteria. Studying how immune cells manipulate their movement in response to external signals could shed light not only on how our immune system functions but also how cancer cells spread through the body and even how the brain wires itself.

Speaking at the Society for General Microbiology's spring meeting in Edinburgh, Dr Holger Kress describes a new technique pioneered by himself and Professor Eric Dufresne at Yale University in the US that uses sponge-like micro-particles to mimic bacteria.

The micro-particles slowly release a characteristic bacterial "scent" that is picked up by , causing them to actively move towards the source of the chemical in an attempt to hunt down the model microbes. These micro-particles can be trapped and manipulated three-dimensionally using 'optical tweezers' - highly focussed laser beams that are able to precisely control the movement of the particles to within a millionth of a millimetre. "By controlling the shape of the chemical signals, we were able to control the movements of immune cells and study how they respond to the signals," said Dr Kress.

The scientists found that a single chemical-releasing micro-particle was enough to encourage (a type of immune cell) to migrate towards it. Within less than one minute's exposure to the micro-particle, the neutrophils were able to polarize the growth of their internal 'skeleton' in the direction of the chemical.

Dr Kress explained that although researchers had successfully identified the types of that stimulate immune cells, it is still a challenge to work out the exact details of the immune . "This new technique allows us to measure systematically how cells respond to various stimuli over minute gradients in time and space."

Dr Kress believes his technique could be applied across a wide range of research fields. "Cell migration along chemical gradients of this kind plays a key role in wound healing and the wiring of the brain. It is also an essential feature of many diseases - particularly metastatic cancers," he said.

Explore further: Mice study shows efficacy of new gene therapy approach for toxin exposures

Provided by Society for General Microbiology

5 /5 (2 votes)
add to favorites email to friend print save as pdf

Related Stories

Researchers discover internal compass of immune cell

Dec 14, 2006

Researchers at the University of California, San Diego (UCSD) School of Medicine have discovered how neutrophils – specialized white blood cells that play key roles in inflammation and in the body's immune ...

Brain structure assists in immune response (Video)

Jan 28, 2009

For the first time, a team of researchers at the University of Pennsylvania School of Veterinary Medicine have imaged in real time the body's immune response to a parasitic infection in the brain.

Study: Tumors inhibit immune system

May 29, 2006

Seattle scientists have shown that tumors can manipulate the immune system to stop it from attacking cancer cells, said a study published in Nature Immunology.

New origin found for a critical immune response

Mar 01, 2009

An immune system response that is critical to the first stages of fighting off viruses and harmful bacteria comes from an entirely different direction than most scientists had thought, according to a finding by researchers ...

Recommended for you

How Alzheimer's peptides shut down cellular powerhouses

Aug 29, 2014

The failing in the work of nerve cells: An international team of researchers led by Prof. Dr. Chris Meisinger from the Institute of Biochemistry and Molecular Biology of the University of Freiburg has discovered ...

User comments : 0