Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

How does the immune system isolate and destroy intruders?

26.07.2006
Dendritic cells are the body’s “watchdogs”. They recognize and then degrade pathogens, isolating characteristic fragments that are recognized by the immune system thus triggering targeted responses. At the Institut Curie, CNRS and Inserm researchers have now discovered how dendritic cells produce these fragments.

They have revealed the hitherto unknown role of the NADPH oxidase NOX2 in immune recognition, thus shedding light on how the immune system works and so enhancing our capacity to manipulate and use it therapeutically. This discovery, published in the July 14, 2006 issue of Cell, should help us to fine-tune the immune response in the treatment of certain diseases like cancer.

The body is constantly under attack from outside forces (viruses and bacteria) and sometimes from forces within (cellular abnormalities leading to cancer). Its defensive response is to activate the immune system. There are two types of defense. First, there is innate immunity, which has no memory and so is constantly on the lookout for infectious agents to destroy. Second, there is adaptive immunity, which over time acquires memories of particular pathogens.

This requires a “learning” phase in which the dendritic cells degrade pathogenic agents into characteristic fragments, the epitopes, and then present these epitopes to the T and B lymphocytes, thereby initiating immune responses. The pathogen’s profile is memorized through this learning process and the next time the same pathogen is encountered the body immediately recognizes it and so is able to respond rapidly.

NOX2, immunity’s double agent

In innate immune responses, the invader is totally destroyed, a process in which the NADPH oxidase NOX2 plays a central role. In neutrophils, the cells at the heart of innate immune responses, NOX2 ensures the complete destruction of invading pathogens so they are no longer harmful to the body.

In adaptive immune responses, the dendritic cells’ challenge is to degrade the pathogen just partially, thus preserving sufficiently representative fragments that can be presented to the T and B lymphocytes. Ariel Savina at the Institut Curie, in the Inserm team of Sebastian Amigorena(1), has been studying how dendritic cells, the body’s “watchdogs”, achieve this controlled degradation of pathogens into epitopes. What they have found is that NOX2 is also implicated in adaptive immune responses. Its role in this case contrasts with that in neutrophils. NOX2 regulates the pH in the compartments (phagosomes) of the dendritic cells where pathogens are degraded, thus ensuring suitable acidity.

This pH regulation slows the degradation of the pathogens thus avoiding their complete destruction, which allows the dendritic cells to trigger a specific and efficient adaptive immune response.

These new findings shed light on how the immune system works and should help us to optimize one of the most promising approaches to cancer treatment: immunotherapy, in which the immune system is used to destroy tumor cells. The Institut Curie has for many years been participating actively in the development of innovative immunotherapeutic strategies. Two clinical trials are currently under way at the Institut Curie, one in patients with choroidal melanoma and another in cervical cancer patients. The results are expected some time in 2007.

(1) Sebastian Amigorena is CNRS Director of Research and Head of Inserm/Institut Curie Unit 653 “Immunity and cancer”.

Catherine Goupillon | alfa
Further information:
http://www.cell.com/

More articles from Life Sciences:

nachricht Warming ponds could accelerate climate change
21.02.2017 | University of Exeter

nachricht An alternative to opioids? Compound from marine snail is potent pain reliever
21.02.2017 | University of Utah

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Impacts of mass coral die-off on Indian Ocean reefs revealed

21.02.2017 | Earth Sciences

Novel breast tomosynthesis technique reduces screening recall rate

21.02.2017 | Medical Engineering

Use your Voice – and Smart Homes will “LISTEN”

21.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>