Featured Research

from universities, journals, and other organizations

New mechanism of bacterial pathogenesis discovered

Date:
June 27, 2012
Source:
Suomen Akatemia (Academy of Finland)
Summary:
Scientists have identified a new mechanism of bacterial pathogenesis. Bacteria that cause chronic infections have an amazing but yet poorly known ability to subvert immune response, live and produce offspring, enter and wake up from a dormant phase to cause, in some instances, deadly complications.

Scientists have identified a new mechanism of bacterial pathogenesis. The results of the research project, partly funded by the Academy of Finland, have been published in the journal Proceedings of the National Academy of Sciences of the United States of America (PNAS).

Related Articles


Bacteria that cause chronic infections have an amazing but yet poorly known ability to subvert immune response, live and produce offspring, enter and wake up from a dormant phase to cause, in some instances, deadly complications.

Bartonella bacteria cause chronic infections in mammals (incl. humans), and are typically transmitted to new hosts mainly by arthropod vectors such as fleas, lice and ticks, but also via direct tissue trauma (e.g. cat scratches).

One very notable feature of these bacteria is their ability to cause vasoproliferative tumours that resemble Kaposi's sarcoma in patients suffering from immunodeficiency (e.g. AIDS, aggressive cancer treatments, organ transplantation). If left untreated, these foci of inflammation maintain a chronic infection and contribute to transmitting bacteria to new hosts.

In his research, biologist Arto Pulliainen (University of Turku) has demonstrated that Bartonella henselae injects a protein called BepA into vascular endothelial cells and that this protein manipulates cAMP-mediated cell signalling using a previously unknown mechanism.

BepA directly binds the host cell adenylyl cyclase, which is an enzyme responsible for the production of cAMP. However, the binding of BepA to the adenylyl cyclase does not activate cAMP production per se, but the adenylyl cyclase rather becomes more sensitive to its natural activator, stimulatory G-protein (Gαs). The cellular concentration of cAMP increases and prevents the death of the host cell. BepA significantly prolongs the lifespan of the host cell and partly contributes to the formation of vasoproliferative tumours.

Several bacterial species are known to manipulate host cell functions via cAMP-mediated cell signalling. The symptoms are typically very strong and may even be deadly. The best-known example is Vibrio cholerae and its cholera toxin, which modifies Gαs into a permanently adenylyl cyclase-stimulating form. BepA, in turn, manipulates host cell signalling in a subtle sophisticated manner, which is ideal for chronic persistence of Bartonella henselae in the infected vascular endothelium.

The research has been carried out at the Universities of Basel and Turku.


Story Source:

The above story is based on materials provided by Suomen Akatemia (Academy of Finland). Note: Materials may be edited for content and length.


Journal Reference:

  1. Pulliainen, A.T., Pieles, K., Brand, C.S., Hauert, B., B๖hm, A., Quebatte, M., Webf, A., Gstaiger, M., Aebersold, R., Dessauer, C.W. and Dehio, C. Bacterial effector binds host cell adenylyl cyclase to potentiate Gαs-dependent cAMP production. Proceedings of the National Academy of Sciences, 2012 DOI: 10.1073/pnas.1117651109

Cite This Page:

Suomen Akatemia (Academy of Finland). "New mechanism of bacterial pathogenesis discovered." ScienceDaily. ScienceDaily, 27 June 2012. <www.sciencedaily.com/releases/2012/06/120627091754.htm>.
Suomen Akatemia (Academy of Finland). (2012, June 27). New mechanism of bacterial pathogenesis discovered. ScienceDaily. Retrieved March 5, 2015 from www.sciencedaily.com/releases/2012/06/120627091754.htm
Suomen Akatemia (Academy of Finland). "New mechanism of bacterial pathogenesis discovered." ScienceDaily. www.sciencedaily.com/releases/2012/06/120627091754.htm (accessed March 5, 2015).

Share This


More From ScienceDaily



More Plants & Animals News

Thursday, March 5, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Praying Mantis Looks Long Before It Leaps

Praying Mantis Looks Long Before It Leaps

Reuters - Innovations Video Online (Mar. 5, 2015) — Slowed-down footage of the leaps of praying mantises show the insect&apos;s extraordinary precision, say researchers. Video provided by Reuters
Powered by NewsLook.com
Octopus Grabs Camera and Turns It Around On Photographer

Octopus Grabs Camera and Turns It Around On Photographer

Buzz60 (Mar. 5, 2015) — A photographer got the shot of a lifetime, or rather an octopus did, when it grabbed the camera and turned it around to take an amazing picture of the photographer. Jen Markham (@jenmarkham) has the story. Video provided by Buzz60
Powered by NewsLook.com
Ringling Bros. Eliminating Elephant Acts

Ringling Bros. Eliminating Elephant Acts

AP (Mar. 5, 2015) — The Ringling Bros. and Barnum & Bailey Circus is ending its iconic elephant acts. The circus&apos; parent company, Feld Entertainment, told the AP exclusively that the acts will be phased out by 2018 over growing public concern about the animals. (March 5) Video provided by AP
Powered by NewsLook.com
Raw: Tourists Visit Rare Grey Whales in Mexico

Raw: Tourists Visit Rare Grey Whales in Mexico

AP (Mar. 4, 2015) — Once nearly extinct, grey whales now migrate in their thousands to Mexico&apos;s Vizcaino reserve in Baja California, in search of warmer waters to mate and give birth. Tourists flock to the reserve to see the whales, measuring up to 49 feet long. (March 4) 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:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

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