Featured Research

from universities, journals, and other organizations

Scientists guide immune cells with light and microparticles

Date:
November 16, 2009
Source:
Yale University
Summary:
Scientists have developed a new approach to studying how immune cells chase down bacteria in our bodies. They used holographic optical tweezers to guide "artificial bacteria" -- microparticles that mimic bacteria by giving off a chemical "scent," stimulating immune cells to respond. By controlling the chemical patterns produced, they were able to study how immune cells respond to and interact with these chemical signals.

Yale engineers created microparticles that mimic bacteria and can be manipulated with holographic optical tweezers. Those pictured emit a repulsive chemical “scent,” which the approaching cell tries to avoid as it squeezes past.
Credit: Eric Dufresne and Holger Kress

A team led by Yale University scientists has developed a new approach to studying how immune cells chase down bacteria in our bodies. Their findings are described in the November 15 issue of Nature Methods Advanced Online Publication.

When bacteria enter our bodies they secrete molecules, leaving behind chemical trails as they move through our system. It has been known for some time that immune cells follow these trails in order to hunt the bacteria. However, studying exactly how immune cells process these chemical signals has been challenging.

Now a team of scientists -- led by Eric Dufresne, the John J. Lee Assistant Professor of Mechanical Engineering, and Holger Kress, a postdoctoral associate in the Yale School of Engineering & Applied Science -- has developed a way to create artificial chemical trails that can be shaped in three dimensions over time. By controlling the chemical trails, the team was able to control the movements of neutrophils -- immune cells in the blood -- and study how they are able to respond to these signals.

The team used sponge-like microparticles, designed by the laboratory of Tarek Fahmy, associate professor of biomedical engineering at Yale, that mimicked bacteria by slowly releasing a characteristic bacterial "scent." They then moved these microparticles using focused beams of light to control the pattern of released chemicals over space and time, stimulating the immune cells to respond. The neutrophils can be seen following the microparticles on videos produced by the researchers.

"By fusing recent advances in optical and materials science, we've developed a new approach to control chemical microenvironments with light," said Dufresne, who developed holographic optical tweezers -- the underlying technology used to manipulate the microparticles -- in the late 1990s. "Until now, people have used optical tweezers to move physical objects. We've demonstrated that they can also be used to manipulate chemical gradients."

The team used two different chemicals, one of which attracted the cells and another that repelled them, to demonstrate how they could direct the neutrophils into moving along a path, either toward or away from the microparticles. They could also examine how the cells responded when there were conflicting signals sent by several of the artificial bacteria.

Chemotaxis -- the migration of cells based on chemical signals in their environment -- plays an important role in a number of biological processes and diseases beyond the immune system. "Understanding how cells move in response to chemical stimuli can help us better understand how a single egg develops into a complex organism or how brain cells grow into a network of neurons in a growing embryo, or how cancer cells spread through the body," Kress said. "This technique could give biologists insight into the ways many different types of cells respond to environmental stimuli in a wide range of situations."

Authors of the paper include Holger Kress, Jin-Gyu Park, Cecile Mejean, Jason Forster, Jason Park, Yong Zhang, Dianqing Wu, Tarek Fahmy and Eric Dufresne (all of Yale University); Spencer Walse (U.S. Department of Agriculture); Orion D Weiner (University of California, San Francisco).

The research was funded by the German Academy of Sciences Leopoldina, the National Institutes of Health and the National Science Foundation.


Story Source:

The above story is based on materials provided by Yale University. Note: Materials may be edited for content and length.


Cite This Page:

Yale University. "Scientists guide immune cells with light and microparticles." ScienceDaily. ScienceDaily, 16 November 2009. <www.sciencedaily.com/releases/2009/11/091116131828.htm>.
Yale University. (2009, November 16). Scientists guide immune cells with light and microparticles. ScienceDaily. Retrieved September 21, 2014 from www.sciencedaily.com/releases/2009/11/091116131828.htm
Yale University. "Scientists guide immune cells with light and microparticles." ScienceDaily. www.sciencedaily.com/releases/2009/11/091116131828.htm (accessed September 21, 2014).

Share This



More Health & Medicine News

Sunday, September 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Sierra Leone's Nationwide Ebola Curfew Underway

Sierra Leone's Nationwide Ebola Curfew Underway

Newsy (Sep. 20, 2014) Sierra Leone is locked down as aid workers and volunteers look for new cases of Ebola. Video provided by Newsy
Powered by NewsLook.com
Changes Found In Brain After One Dose Of Antidepressants

Changes Found In Brain After One Dose Of Antidepressants

Newsy (Sep. 19, 2014) A study suggest antidepressants can kick in much sooner than previously thought. Video provided by Newsy
Powered by NewsLook.com
Could Grief Affect The Immune Systems Of Senior Citizens?

Could Grief Affect The Immune Systems Of Senior Citizens?

Newsy (Sep. 19, 2014) The study found elderly people are much more likely to become susceptible to infection than younger adults going though a similar situation. Video provided by Newsy
Powered by NewsLook.com
Jury Delivers Verdict in Salmonella Trial

Jury Delivers Verdict in Salmonella Trial

AP (Sep. 19, 2014) A federal jury has convicted three people in connection with an outbreak of salmonella poisoning five years ago that sickened hundreds of people and was linked to a number of deaths. (Sept. 19) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins