Featured Research

from universities, journals, and other organizations

New type of bacterial protection found within cells: Novel immune system response to infections discovered

Date:
November 13, 2012
Source:
University of California - Irvine
Summary:
Biologists have discovered that fats within cells store a class of proteins with potent antibacterial activity, revealing a previously unknown type of immune system response that targets and kills bacterial infections.

UC Irvine biologists have discovered that fats within cells store a class of proteins with potent antibacterial activity, revealing a previously unknown type of immune system response that targets and kills bacterial infections.

Steven Gross, UCI professor of developmental & cell biology, and colleagues identified this novel intercellular role of histone proteins in fruit flies, and it could herald a new approach to fighting bacterial growth within cells. The study appeared November 13 in eLife, a new peer-reviewed, open-access journal supported by the Howard Hughes Medical Institute, the Max Planck Society and the Wellcome Trust.

"We found that these histone proteins have pan-antibacterial abilities and can have a wide-ranging effect," Gross said. "If we can discover how to manipulate the system to increase histone levels, we may one day have a new way to treat patients with bad bacterial infections."

Histones exist in large numbers in most animal cells; their primary job is to help DNA strands fold into compact and robust structures inside the nucleus. Gross said there is some evidence that histones secreted from cells protect against bacteria living outside cells. However, many bacteria enter cells, where they can avoid the immune system and continue replicating.

In principle, Gross said, histones could protect cells against such bacteria from the inside, but for many years this was thought unlikely because most histones are bound to DNA strands in the cell nucleus, whereas bacteria multiply in the cellular fluid outside the nucleus, called cytosol. Additionally, free histones can be extremely damaging to cells, so most species have developed mechanisms to detect and degrade free histones in the cytosol.

In their study, Gross and colleagues demonstrate that histones bound to lipid (fat) droplets can protect cells against bacteria without causing any of the harm normally associated with the presence of free histones. In experiments with lipid droplets purified from Drosophila fruit fly embryos, they show that lipid-bound histones can be released to kill bacteria.

The researchers injected similar numbers of bacteria into Drosophila embryos that contained lipid-bound histones and into embryos genetically modified to not contain them. They discovered that the histone-deficient flies were 14 times more likely to die of bacterial infections. Similar results were found in experiments on adult flies. Additional evidence suggested that histones might also protect mice against bacteria.

"Because numerous studies have now identified histones on lipid droplets in many different cells -- from humans as well as mice and flies -- it seems likely that this system may be quite general," Gross said.


Story Source:

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


Journal Reference:

  1. Preetha Anand, Silvia Cermelli, Zhihuan Li, Adam Kassan, Marta Bosch, Robilyn Sigua, Lan Huang, Andre J Ouellette, Albert Pol, Michael A Welte, Steven P Gross. A novel role for lipid droplets in the organismal antibacterial response. eLife, 2012; 1 DOI: 10.7554/eLife.00003

Cite This Page:

University of California - Irvine. "New type of bacterial protection found within cells: Novel immune system response to infections discovered." ScienceDaily. ScienceDaily, 13 November 2012. <www.sciencedaily.com/releases/2012/11/121113143656.htm>.
University of California - Irvine. (2012, November 13). New type of bacterial protection found within cells: Novel immune system response to infections discovered. ScienceDaily. Retrieved September 19, 2014 from www.sciencedaily.com/releases/2012/11/121113143656.htm
University of California - Irvine. "New type of bacterial protection found within cells: Novel immune system response to infections discovered." ScienceDaily. www.sciencedaily.com/releases/2012/11/121113143656.htm (accessed September 19, 2014).

Share This



More Plants & Animals News

Friday, September 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Elephant Undergoes Surgery in Tbilisi Zoo

Raw: Elephant Undergoes Surgery in Tbilisi Zoo

AP (Sep. 18, 2014) Grand the elephant has successfully undergone surgery to remove a portion of infected tusk at Tbilisi Zoo in Georgia. British veterinary surgeons used an electric drill to extract the infected piece. (Sept. 18) Video provided by AP
Powered by NewsLook.com
Chimp Violence Study Renews Debate On Why They Kill

Chimp Violence Study Renews Debate On Why They Kill

Newsy (Sep. 17, 2014) The study weighs in on a debate over whether chimps are naturally violent or become that way due to human interference in the environment. Video provided by Newsy
Powered by NewsLook.com
Some Tobacco Farmers Thrive Amid Challenges

Some Tobacco Farmers Thrive Amid Challenges

AP (Sep. 16, 2014) The South's tobacco country is surviving, and even thriving in some cases, as demand overseas keeps growers in the fields of one of America's oldest cash crops. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

AFP (Sep. 16, 2014) Scientists say a female colossal squid weighing an estimated 350 kilograms (770 lbs) and thought to be only the second intact specimen ever found was carrying eggs when discovered in the Antarctic. Duration: 00:47 Video provided by AFP
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