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:6/22/2016)... BETHESDA, Md. , June 22, 2016  The American ... by Trade Show Executive Magazine as one of ... Summit on May 25-27 at the Bellagio in ... based on the highest percentage of growth in each of ... number of exhibiting companies and number of attendees. The 2015 ...
(Date:6/16/2016)... June 16, 2016 The ... expected to reach USD 1.83 billion by 2024, ... Research, Inc. Technological proliferation and increasing demand in ... expected to drive the market growth. ... The development of advanced multimodal techniques for ...
(Date:6/3/2016)... 3, 2016 Das ... Nepal hat ein 44 ... geprägter Kennzeichen, einschließlich Personalisierung, Registrierung und IT-Infrastruktur, ... Produktion und Implementierung von Identitätsmanagementlösungen. Zahlreiche renommierte ... Januar teilgenommen, aber Decatur wurde als konformste ...
Breaking Biology News(10 mins):
(Date:6/24/2016)... June 24, 2016 Epic Sciences unveiled ... cancers susceptible to PARP inhibitors by targeting homologous ... (CTCs). The new test has already been incorporated ... multiple cancer types. Over 230 clinical ... response pathways, including PARP, ATM, ATR, DNA-PK and ...
(Date:6/23/2016)... ... June 23, 2016 , ... UAS LifeSciences, one ... of their brand, UP4™ Probiotics, into Target stores nationwide. The company, which has ... add Target to its list of well-respected retailers. This list includes such fine ...
(Date:6/23/2016)... , June 23, 2016 Houston Methodist ... the Cy-Fair Sports Association to serve as their ... agreement, Houston Methodist Willowbrook will provide sponsorship support, ... connectivity with association coaches, volunteers, athletes and families. ... the Cy-Fair Sports Association and to bring Houston ...
(Date:6/23/2016)... June 23, 2016   EpiBiome , a precision ... million in debt financing from Silicon Valley Bank (SVB). ... and to advance its drug development efforts, as well ... "SVB has been an incredible strategic partner ... a traditional bank would provide," said Dr. Aeron ...
Breaking Biology Technology: