Navigation Links
Host or foreign -- the body's frontline defense mechanism understood
Date:2/4/2011

This week, the highly-respected US Academy of Sciences journal (PNAS) published an article describing how the first line of defence of the human immune system distinguishes between microbes and the body's own structures. The basis of this recognition mechanism has been unclear since the key protein components were discovered over 30 years ago and has now finally been cracked by a collaboration between high-level research groups at the University of Helsinki, Finland.

When a microbe has infected us, the first defence mechanism that attacks it is a protein-based marking and destruction system called complement. It usually suffices that foreign targets are marked as enemy while our own targets are left untouched, so that white blood cells attack only foreign targets like bacteria, viruses and parasites.

Researchers at the Haartman Institute and the Institute of Biotechnology at the University of Helsinki have, as a result of years of dedicated work, been able to show how complement dis-tinguishes foreign structures from our own structures all days before antibodies have a chance to develop. The key to unlocking the problem was when the groups of Sakari Jokiranta and Adrian Goldman in Helsinki, along with David Isenman's group in Canada, were able to solve the structure of two components of the system at atomic resolution. The structure revealed a stunning unexpected arrangement: factor H bound two of the C3bs, which mark foreign targets, in two different ways. Laboratory tests showed that this actually happened: to recognise our own cells, factor H binds not only C3b but also the cell surface at the same. Thus, the system mark only foreign structures for destruction by the white blood cells.

This new understanding of how host and foreign structures are distinguished by the front-line defence mechanism also explains how the severe and often fatal form of disease "Hemolytic Uremic Syndrome" (HUS) starts. This rare disease often occurs in children and can be caused by genetic defects in factor H or in C3b, or else by the disruption of factor H activity by antibod-ies. In Finland, too, some of these patients have had to have complete liver-kidney transplants because of the severity of the disease. Consequently, the research's surprising and wide-reaching result will be important not only in terms of advancing basic immunological research but also in the diagnosis and treatment of very sick children.


'/>"/>

Contact: Dr. Sakari Jokiranta
sakari.jokiranta@helsinki.fi
358-505-471-184
University of Helsinki
Source:Eurekalert

Related biology news :

1. Advice to the new administration: UM foreign and domestic policy guide
2. US tax breaks subsidize foreign oil production
3. Researchers: EPA should recognize environmental impact of protecting foreign oil
4. Ravenous foreign pests threaten national treasures
5. What causes cell defenses to crumble?
6. Researchers recreate SARS virus, open door for potential defenses against future strains
7. New dummy design and development wins US Department of Defense award
8. Lockheed Martin Team Wins Role on Key Department of Defense Biometrics Contract Vehicle
9. Raytheon Chosen to Help Provide Department of Defense Biometrics Operations and Support Services
10. ASM biodefense and emerging diseases research meeting
11. SectorWatch.biz Issues Commentary for Investors of Homeland Defense Companies FOUR, MAGS, NSSC, PNTR, BCO, and CKP
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/5/2017)... , April 4, 2017 KEY FINDINGS ... anticipated to expand at a CAGR of 25.76% during ... diseases is the primary factor for the growth of ... report: https://www.reportbuyer.com/product/4807905/ MARKET INSIGHTS The global ... product, technology, application, and geography. The stem cell market ...
(Date:3/30/2017)... The research team of The Hong Kong Polytechnic University (PolyU) ... ground breaking 3D fingerprint minutiae recovery and matching technology, pushing contactless ... use in identification, crime investigation, immigration control, security of access and ... ... A research team led by Dr Ajay Kumar ...
(Date:3/27/2017)... , March 27, 2017  Catholic Health Services ... Management Systems Society (HIMSS) Analytics for achieving Stage ... Model sm . In addition, CHS previously earned ... hospitals using an electronic medical record (EMR). ... high level of EMR usage in an outpatient ...
Breaking Biology News(10 mins):
(Date:10/10/2017)... , Oct. 10, 2017 SomaGenics announced the ... NIH to develop RealSeq®-SC (Single Cell), expected to be ... small RNAs (including microRNAs) from single cells using NGS ... the need to accelerate development of approaches to analyze ... "New techniques for measuring levels of mRNAs ...
(Date:10/10/2017)... ... October 10, 2017 , ... The Pittcon Program ... honoring scientists who have made outstanding contributions to analytical chemistry and ... 2018, the world’s leading conference and exposition for laboratory science, which will be ...
(Date:10/9/2017)... ... , ... The award-winning American Farmer television series will feature 3 Bar Biologics ... at 8:30aET on RFD-TV. , With global population estimates nearing ten billion people ... to feed a growing nation. At the same time, many of our valuable resources ...
(Date:10/9/2017)... ... October 09, 2017 , ... The ... medical marijuana products targeting the needs of consumers who are incorporating medical marijuana ... place in Phoenix, Arizona. , As operators of two successful Valley dispensaries, The ...
Breaking Biology Technology: