Featured Research

from universities, journals, and other organizations

External capsule protects gum disease-causing bacteria from immune response

Date:
November 17, 2011
Source:
American Society for Microbiology
Summary:
The capsule of Porphyromonas gingivalis, the bacterium that causes gum disease, provides stealth, boosting the bacterium's virulence, according to new study. Call it a sugar coating, if you will, for in fact, the capsule is made from sugar molecules, which do not ordinarily elicit immunity. Thus it hides the bacterium's proteins within, preventing immune response.

The capsule of Porphyromonas gingivalis, the bacterium that causes gum disease, provides stealth, boosting the bacterium's virulence, according to a paper published in the November Infection and Immunity. Call it a sugar coating, if you will, for in fact, the capsule is made from sugar molecules, which do not ordinarily elicit immunity. Thus it hides the bacterium's proteins within, preventing immune response.

In the study, the researchers, led by Janina P. Lewis of Virginia Commonwealth University, Richmond, compared the ability of normal, and mutant bacteria that were missing the capsule, to activate the immune system, to enter eukaryotic cells (the kind that are present in multicellular organisms), to cause disease, and to survive in mice. "The mutant bacteria activated the host to a greater extent, and thus, were more easily killed by eukaryotic cells," says Lewis. "Thus, the capsule protects the bacteria and allows them to survive unnoticed in our bodies."

Capsules also protect both bacteria and fungi, including P. gingivalis, as per this report, from being engulfed by the immune system's phagocytes (phago=eat; cyto=cell) and from being identified by dendritic cells as dangerous, thus marking them for destruction by antibodies. Conversely, in the study, mutant, non-encapsulated P. gingivalis were rapidly engorged by immune cells, and killed.

"Thus, anything that would interfere with generation of capsule, such as drugs interfering with the action of enzymes involved in synthesis of the sugar coat, could be used in treatment of periodontal disease, and importantly, could have broader implications for prevention of more serious diseases," by other encapsulated bacteria, such as pneumonia, anthrax, meningitis, endocarditis, and gastroenteritis, says Lewis.


Story Source:

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


Journal Reference:

  1. A. Singh, T. Wyant, C. Anaya-Bergman, J. Aduse-Opoku, J. Brunner, M. L. Laine, M. A. Curtis, J. P. Lewis. The Capsule of Porphyromonas gingivalis Leads to a Reduction in the Host Inflammatory Response, Evasion of Phagocytosis, and Increase in Virulence. Infection and Immunity, 2011; 79 (11): 4533 DOI: 10.1128/IAI.05016-11

Cite This Page:

American Society for Microbiology. "External capsule protects gum disease-causing bacteria from immune response." ScienceDaily. ScienceDaily, 17 November 2011. <www.sciencedaily.com/releases/2011/11/111116192905.htm>.
American Society for Microbiology. (2011, November 17). External capsule protects gum disease-causing bacteria from immune response. ScienceDaily. Retrieved September 1, 2014 from www.sciencedaily.com/releases/2011/11/111116192905.htm
American Society for Microbiology. "External capsule protects gum disease-causing bacteria from immune response." ScienceDaily. www.sciencedaily.com/releases/2011/11/111116192905.htm (accessed September 1, 2014).

Share This




More Health & Medicine News

Monday, September 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

We've Got Mites Living In Our Faces And So Do You

We've Got Mites Living In Our Faces And So Do You

Newsy (Aug. 30, 2014) A new study suggests 100 percent of adult humans (those over 18 years of age) have Demodex mites living in their faces. Video provided by Newsy
Powered by NewsLook.com
Liberia Continues Fight Against Ebola

Liberia Continues Fight Against Ebola

AFP (Aug. 30, 2014) Authorities in Liberia try to stem the spread of the Ebola epidemic by raising awareness and setting up sanitation units for people to wash their hands. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
California Passes 'yes-Means-Yes' Campus Sexual Assault Bill

California Passes 'yes-Means-Yes' Campus Sexual Assault Bill

Reuters - US Online Video (Aug. 30, 2014) California lawmakers pass a bill requiring universities to adopt "affirmative consent" language in their definitions of consensual sex, part of a nationwide drive to curb sexual assault on campuses. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
New Drug Could Reduce Cardiovascular Deaths

New Drug Could Reduce Cardiovascular Deaths

Newsy (Aug. 30, 2014) The new drug from Novartis could reduce cardiovascular deaths by 20 percent compared to other similar drugs. Video provided by Newsy
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