Featured Research

from universities, journals, and other organizations

Antibody orientation matters

Date:
December 10, 2012
Source:
Rockefeller University Press
Summary:
The orientation of antibody binding to bacteria can mean life or death to the bug, according to a new study. These findings may help explain why these bacteria cause millions of localized infections, but more serious, systemic blood infections are rare.

The orientation of antibody binding to bacteria can mean life or death to the bug, according to a study published in The Journal of Experimental Medicine on December 10th. These findings may help explain why these bacteria cause millions of localized infections, but more serious, systemic blood infections are rare.

Related Articles


Streptococcus pyogenes -- the causative agent of strep throat -- typically invades the body's mucosal surfaces, including the throat and skin. These invasions are kept in check by Y-shaped immune proteins called antibodies, which attach to the bug via their arm (or "Fab") regions. This exposes the stalk ("Fc") portion of the antibody, which is then recognized by immune cells, allowing them to ingest and kill the bacteria. Certain bacteria, including S. pyogenes, fight back by expressing surface proteins that bind the Fc region of antibodies, rendering them invisible to patrolling immune cells.

The new study by Pontus Nordenfelt of Harvard University and his colleagues at Lund University in Sweden suggests that the bacteria have the upper hand in the mucosa, but the immune system wins out in the blood. The scientists found that antibodies in saliva attached to bacteria primarily via their Fc regions, but in blood the orientation was reversed, resulting in swift killing of the bug by immune cells.

The orientation of binding was dictated by the local antibody concentration -- low antibody levels (as in saliva) favored Fc-mediated binding; high antibody levels (as in blood) favored Fab-mediated binding. How this works is not entirely clear, but it's possible that the Fc binding proteins on the bacteria become saturated in the high-antibody environment of the blood, permitting free antibody to bind in the opposite orientation.


Story Source:

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


Journal Reference:

  1. Pontus Nordenfelt, Sofia Waldemarson, Adam Linder, Matthias Mörgelin, Christofer Karlsson, Johan Malmström, and Lars Björck. Antibody orientation at bacterial surfaces is related to invasive infection. The Journal of Experimental Medicine, 2012 DOI: 10.1084/jem.20120325

Cite This Page:

Rockefeller University Press. "Antibody orientation matters." ScienceDaily. ScienceDaily, 10 December 2012. <www.sciencedaily.com/releases/2012/12/121210124206.htm>.
Rockefeller University Press. (2012, December 10). Antibody orientation matters. ScienceDaily. Retrieved November 26, 2014 from www.sciencedaily.com/releases/2012/12/121210124206.htm
Rockefeller University Press. "Antibody orientation matters." ScienceDaily. www.sciencedaily.com/releases/2012/12/121210124206.htm (accessed November 26, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Wednesday, November 26, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

Newsy (Nov. 25, 2014) — The US FDA is announcing new calorie rules on Tuesday that will require everywhere from theaters to vending machines to include calorie counts. Video provided by Newsy
Powered by NewsLook.com
Daily Serving Of Yogurt Could Reduce Risk Of Type 2 Diabetes

Daily Serving Of Yogurt Could Reduce Risk Of Type 2 Diabetes

Newsy (Nov. 25, 2014) — Need another reason to eat yogurt every day? Researchers now say it could reduce a person's risk of developing type 2 diabetes. Video provided by Newsy
Powered by NewsLook.com
Madagascar Working to Contain Plague Outbreak

Madagascar Working to Contain Plague Outbreak

AFP (Nov. 24, 2014) — Madagascar said Monday it is trying to contain an outbreak of plague -- similar to the Black Death that swept Medieval Europe -- that has killed 40 people and is spreading to the capital Antananarivo. Duration: 00:42 Video provided by AFP
Powered by NewsLook.com
Are Female Bosses More Likely To Be Depressed?

Are Female Bosses More Likely To Be Depressed?

Newsy (Nov. 24, 2014) — A new study links greater authority with increased depressive symptoms among women in the workplace. 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:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

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