Featured Research

from universities, journals, and other organizations

Waiting for the right moment: Bacterial pathogens delay their entry into cells

Date:
August 26, 2010
Source:
Max-Planck-Gesellschaft
Summary:
Pathogens make themselves feel at home in the human body, invading cells and living off the plentiful amenities on offer. However, researchers reveal an opposite strategy used to ensure infection success. Pathogens can actually delay their entry into cells to ensure their survival. Upon cell contact, bacteria trigger a local strengthening of the cellular skeleton with the aid of signalling molecules, allowing them to remain outside the cell. The researchers also show that this strategy, unknown until now, is used by certain intestinal pathogens as well.

Neisseria gonorrhoeae bacteria, forming micro-colonies on the surface of a human cell, stimulate signals to stabilize their extracellular life style.
Credit: Max Planck Institute for Infection Biology

Pathogens make themselves feel at home in the human body, invading cells and living off the plentiful amenities on offer. However, researchers at the Max Planck Institute for Infection Biology, Berlin, together with colleagues at Harvard University, reveal an opposite strategy used to ensure infection success. Pathogens can actually delay their entry into cells to ensure their survival. Upon cell contact, bacteria trigger a local strengthening of the cellular skeleton with the aid of signalling molecules, allowing them to remain outside the cell. The researchers also show that this strategy, unknown until now, is used by certain intestinal pathogens as well.

The research appears in PLoS Biology, published by the Public Library of Science (Aug. 24, 2010).

Infection with the sexually transmitted bacterium Neisseria gonorrhoeae can lead to an inflammation of the urogenital tract, the uterus and ovaries. By means of thread-shaped proteins on its surface called pili, the bacterium attaches itself to the cell membrane. Once attached, the bacteria undergo rapid changes of their surface structure to avoid recognition by the host's immune system. Only during the later stages of infection will the pathogens penetrate cells and occasionally advance into deeper tissues to find further breeding ground.

Until now scientists were firmly focused on understanding the tricks used by these pathogens to enter cells. The results of the Berlin-based researchers suggest, however, that bacteria may spend as much effort in resisting cell entry. Host cells tend to generate tiny vesicles by which they transport bacteria inadvertently into the interior. The researchers have now shed some light on the signals which prevent the bacteria from being 'swallowed'. Upon fastening themselves to the cell surface, the bacteria induce a sequence of events that results in the strengthening of the cell skeleton directly beneath the point of attachment. The structural protein Actin is transported to attachment sites, where it forms a strong, supportive chain. In tandem, another structural protein Caveolin-1 and the signalling proteins VAV2 and RhoA are recruited to the cell membrane where they play a central role in effectively maintaining N. gonorrhoeae in the extracellular milieu.

Better outside than inside

These results have opened up new perspectives in understanding the course of infections: "For a long time it was thought that most pathogens strive to enter cells quickly. However, the opposite may be the case. It seems the bacteria prolong their extracellular existence in order to survive," declares Thomas F. Meyer of the Max Planck Institute of Infection Biology. By anchoring to the cell via pili proteins and assembling an underlying support skeleton, the pathogen is buffered against the often inhospitable conditions of the extracellular environment.

By extrapolating their findings to the intestinal bacteria Escherichia coli, the scientists have indicated that the strategy of delaying entry into cells to ensure survival may be widespread among pathogens, possibly even the bacterial agents of meningitis and pneumonia. These newly discovered signalling pathways may therefore have exciting implications for the prevention of infection.


Story Source:

The above story is based on materials provided by Max-Planck-Gesellschaft. Note: Materials may be edited for content and length.


Journal Reference:

  1. Jan Peter Boettcher, Marieluise Kirchner, Yuri Churin, Alexis Kaushansky, Malvika Pompaiah, Hans Thorn, Volker Brinkmann, Gavin MacBeath, Thomas F. Meyer, Gary E. Ward. Tyrosine-Phosphorylated Caveolin-1 Blocks Bacterial Uptake by Inducing Vav2-RhoA-Mediated Cytoskeletal Rearrangements. PLoS Biology, 2010; 8 (8): e1000457 DOI: 10.1371/journal.pbio.1000457

Cite This Page:

Max-Planck-Gesellschaft. "Waiting for the right moment: Bacterial pathogens delay their entry into cells." ScienceDaily. ScienceDaily, 26 August 2010. <www.sciencedaily.com/releases/2010/08/100825093255.htm>.
Max-Planck-Gesellschaft. (2010, August 26). Waiting for the right moment: Bacterial pathogens delay their entry into cells. ScienceDaily. Retrieved September 21, 2014 from www.sciencedaily.com/releases/2010/08/100825093255.htm
Max-Planck-Gesellschaft. "Waiting for the right moment: Bacterial pathogens delay their entry into cells." ScienceDaily. www.sciencedaily.com/releases/2010/08/100825093255.htm (accessed September 21, 2014).

Share This



More Plants & Animals News

Sunday, September 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: San Diego Zoo Welcomes Cheetah Cubs

Raw: San Diego Zoo Welcomes Cheetah Cubs

AP (Sep. 20, 2014) The San Diego Zoo has welcomed two Cheetah cubs to its Safari Park. The nearly three-week-old female cubs are being hand fed and are receiving around the clock care. (Sept. 20) Video provided by AP
Powered by NewsLook.com
Chocolate Museum Opens in Brussels

Chocolate Museum Opens in Brussels

AFP (Sep. 19, 2014) Considered a "national heritage" in Belgium, chocolate now has a new museum in Brussels. In a former chocolate factory, visitors to the permanent exhibition spaces, workshops and tastings can discover derivatives of the cocoa bean. Duration: 01:00 Video provided by AFP
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