Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

How the gut manages bacteria

20.10.2008
A RIKEN-led international research group has puzzled out details of the intricate mechanism by which the immune system in the gut can respond rapidly to changes in its bacterial environment. Eventually, the work could lead to better treatment and control of gut infections and inflammatory bowel diseases.

A previously unknown mechanism enables the immune system in the gut to respond rapidly to changes in bacteria

A RIKEN-led international research group has puzzled out details of the intricate mechanism by which the immune system in the gut can respond rapidly to changes in its bacterial environment. Eventually, the work could lead to better treatment and control of gut infections and inflammatory bowel diseases.

The gut is in direct contact with the external environment and houses at least 400 different species of bacteria in vast numbers. It maintains a finely tuned immune system built around immunoglobulin A (IgA) antibodies produced by B cells to protect the body against pathogens and manage the growth of benign organisms. Previous research by other researchers unraveled a mechanism whereby T cells control the formation of these IgA-producing B cells in organized multi-cellular structures called Peyer’s patches, which develop in the embryo. But such a system could take weeks to respond to invasive bacteria.

The latest work reveals a second mechanism that operates without intervention of T cells, and develops only after colonization of the intestine with bacteria, hence after birth. It involves another set of cellular structures called isolated lymphoid follicles (ILFs).

In a recent paper in the journal Immunity (1), the researchers, led by Sidonia Fagarasan of the RIKEN Center for Allergy and Immunology in Yokohama, detail how these ILFs piece together, providing an understanding of the newly identified mechanism. They used strains of mice bred to lack compounds significant to the development of ILFs.

The researchers noticed that the numbers and size of ILFs in the gut paralleled the level of bacteria, increasing with bacterial colonization and decreasing with the use of antibiotics. Recently, they also discovered cells in adults similar to embryonic lymphoid tissue-inducer (LTi) cells essential to the development of immune centers, such as lymph nodes and Peyer’s patches.

Fagarasan and her colleagues showed that these adult LTi cells could interact with underlying stromal cells in the gut to recruit the cellular components of ILFs—B cells and antigen-presenting dendritic cells (Fig. 1). But the adult LTi cells only did this effectively in the presence of bacterial cells which stimulate an immune response, partly through the production of tumor necrosis factor. So ILFs are only formed when bacteria are present. The researchers also demonstrated that functioning ILFs could transform typical B cells that make immunoglobulin M into those that produce IgA.

“If we can understand more about these LTi cells and their interactions,” says Fagarasan, “it could provide us with the potential to manipulate the gut immune system.”

1. Tsuji, M., Suzuki, K., Kitamura, H., Maruya, M., Kinoshita, K., Ivanov, I.I., Itoh, K., Littman, D.R. & Fagarasan, S. Requirement for lymphoid tissue-inducer cells in isolated follicle formation and T cell-independent Immunoglobulin A generation in the gut. Immunity 29, 261–271 (2008).

The corresponding author for this highlight is based at the RIKEN Laboratory for Mucosal Immunity

Saeko Okada | researchsea
Further information:
http://www.researchsea.com
http://www.rikenresearch.riken.jp/research/555/

More articles from Life Sciences:

nachricht Seeing on the Quick: New Insights into Active Vision in the Brain
15.08.2018 | Eberhard Karls Universität Tübingen

nachricht New Approach to Treating Chronic Itch
15.08.2018 | Universität Zürich

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

Im Focus: Lining up surprising behaviors of superconductor with one of the world's strongest magnets

Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur

What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

2018 Work Research Conference

25.07.2018 | Event News

 
Latest News

Unraveling the nature of 'whistlers' from space in the lab

15.08.2018 | Physics and Astronomy

Diving robots find Antarctic winter seas exhale surprising amounts of carbon dioxide

15.08.2018 | Earth Sciences

Early opaque universe linked to galaxy scarcity

15.08.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>