Featured Research

from universities, journals, and other organizations

Micro-organisms are 'invisible' to the immune system

Date:
August 19, 2011
Source:
Lund University
Summary:
That micro-organisms have a great capacity to vary their surface structure is well known. It is one of the reasons why it is so difficult to develop vaccines against HIV and malaria, and why new influenza vaccines have to be produced every year. But it seems that these micro-organisms are also able to completely avoid activating a strong immune response in the person attacked.

That micro-organisms have a great capacity to vary their surface structure is well known. It is one of the reasons why it is so difficult to develop vaccines against HIV and malaria, and why new influenza vaccines have to be produced every year. But it seems that these micro-organisms are also able to completely avoid activating a strong immune response in the person attacked.

This is what Professor Gunnar Lindahl from Lund University and his research group show in an article in Cell Host & Microbe.

"If we get a serious streptococcus infection, we want our immune defences to create antibodies aimed at certain parts of the micro-organisms' surface protein. But that mechanism does not work particularly well, which is a disadvantage for us and an advantage for the bacteria," he says.

Gunnar Lindahl's group has studied group A streptococci. These are one of the world's most important disease bacteria, causing ordinary tonsillitis, fatal toxic shock syndrome and a very serious autoimmune disease.

The part of the bacteria that has been studied is a surface protein called the M protein, more precisely the part of this protein (the "hypervariable region") which has the ability to vary extensively, in order to escape attack. The research showed that the relevant part of the protein was not just variable, but also managed to avoid eliciting any strong antibody response from the immune system.

"This may be what actually constitutes the micro-organisms' primary weapon: that they avoid antagonizing the immune system. In the case of a long-lasting infection, the immune system does indeed start to produce antibodies eventually, but by then the micro-organisms can have established a firm footing," says Gunnar Lindahl.

The micro-organisms' ability to sneak under the immune system's radar, as it were, was already suggested in certain scientific articles in the 1950s. But this ability was then overshadowed by their other defensive mechanism, i.e. the ability to vary their surface structure. And since a strong variation was considered to be obviously connected to strong antibody pressure -- that the micro-organisms were simply forced to vary in order to elude the antibodies -- no one has paid any attention to investigating whether there really was any strong antibody pressure.

The findings of the Lund researchers are part of basic research in molecular biology, but have consequences for the development of new vaccines. The vaccine developers must in future take account not only of the capacity for variation in bacteria, viruses and other micro-organisms, but also of their ability to avoid activating the immune defence system.


Story Source:

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


Journal Reference:

  1. Jonas Lannergεrd, Mattias C.U. Gustafsson, Johan Waldemarsson, Anna Norrby-Teglund, Margaretha Stεlhammar-Carlemalm, Gunnar Lindahl. The Hypervariable Region of Streptococcus pyogenes M Protein Escapes Antibody Attack by Antigenic Variation and Weak Immunogenicity. Cell Host & Microbe, 2011; 10 (2): 147-157 DOI: 10.1016/j.chom.2011.06.011

Cite This Page:

Lund University. "Micro-organisms are 'invisible' to the immune system." ScienceDaily. ScienceDaily, 19 August 2011. <www.sciencedaily.com/releases/2011/08/110819081914.htm>.
Lund University. (2011, August 19). Micro-organisms are 'invisible' to the immune system. ScienceDaily. Retrieved July 23, 2014 from www.sciencedaily.com/releases/2011/08/110819081914.htm
Lund University. "Micro-organisms are 'invisible' to the immune system." ScienceDaily. www.sciencedaily.com/releases/2011/08/110819081914.htm (accessed July 23, 2014).

Share This




More Health & Medicine News

Wednesday, July 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Courts Conflicted Over Healthcare Law

Courts Conflicted Over Healthcare Law

AP (July 22, 2014) — Two federal appeals courts issued conflicting rulings Tuesday on the legality of the federally-run healthcare exchange that operates in 36 states. (July 22) Video provided by AP
Powered by NewsLook.com
Why Do People Believe We Only Use 10 Percent Of Our Brains?

Why Do People Believe We Only Use 10 Percent Of Our Brains?

Newsy (July 22, 2014) — The new sci-fi thriller "Lucy" is making people question whether we really use all our brainpower. But, as scientists have insisted for years, we do. Video provided by Newsy
Powered by NewsLook.com
Scientists Find New Way To Make Human Platelets

Scientists Find New Way To Make Human Platelets

Newsy (July 22, 2014) — Boston scientists have discovered a new way to create fully functioning human platelets using a bioreactor and human stem cells. Video provided by Newsy
Powered by NewsLook.com
Gilead's $1000-a-Pill Drug Could Cure Hep C in HIV-Positive People

Gilead's $1000-a-Pill Drug Could Cure Hep C in HIV-Positive People

TheStreet (July 21, 2014) — New research shows Gilead Science's drug Sovaldi helps in curing hepatitis C in those who suffer from HIV. In a medical study, the combination of Gilead's Hep C drug with anti-viral drug Ribavirin cured 76% of HIV-positive patients suffering from the most common hepatitis C strain. Hepatitis C and related complications have been a top cause of death in HIV-positive patients. Typical medication used to treat the disease, including interferon proteins, tended to react badly with HIV drugs. However, Sovaldi's %1,000-a-pill price tag could limit the number of patients able to access the treatment. TheStreet's Keris Lahiff reports from New York. Video provided by TheStreet
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