Featured Research

from universities, journals, and other organizations

Invertebrate Immune Systems Are Anything But Simple

Date:
June 22, 2007
Source:
European Science Foundation
Summary:
A hundred years since microbiologists first discovered the invertebrate immune system, they are just beginning to understand its complexity. Scientists recently discovered that invertebrates have evolved elaborate ways to fight disease.

The invertebrate immune system is anything but simple.
Credit: Image courtesy of European Science Foundation

A hundred years since Russian microbiologist Elie Metschnikow first discovered the invertebrate immune system, scientists are only just beginning to understand its complexity.  Presenting their findings at a recent European Science Foundation (ESF) conference, scientists showed that invertebrates have evolved elaborate ways to fight disease.

By studying starfish, Metschnikow was the first to see cells digesting bacteria, a process he called phagocytosis (the eating of cells by other cells).  Phagocytosis, it turns out, is an important immune defence in all living things.  Since Metschnikow’s work, scientists have studied the immune systems of simpler organisms (such as invertebrates) in the hope of understanding the immune systems of more complex organisms, like us.

However, invertebrates’ immune systems are more elaborate than we expected.  “We have underestimated the complexity of invertebrate immunity,” says Dr. Paul Schmid-Hempel, an evolutionary ecologist at the ETH Zurich in Switzerland.  By studying the immune systems of fruit flies, mosquitoes and other invertebrates (including bed bugs, moths, crustaceans, worms, sponges and bees), scientists are finding new molecules involved in defences against pathogens (microbes that cause disease).

One molecule found in fruit flies, Dscam, is capable of folding itself in 18,000 different ways.  Computer models that predict the structure of this molecule have led scientists to suggest that this folding creates different shapes, each capable of binding to different structures on the pathogen’s surface.  “These molecules can be used very flexibly by assembling their components in many ways,” says Schmid-Hempel.  Until now, this ability to recognize specific pathogens was thought to be limited to vertebrates.

In another exciting area of research, scientists showed the sophisticated ways that invertebrates manage their immune systems.  “Insects recognise peptidoglycan [a component of bacterial cell wall] and this triggers a rapid immune response” explains Schmid-Hempel.  However, once the bacteria have been killed, molecules digest peptidoglycans and therefore dampen down the immune response.  Regulating the immune response in this way is important because immune systems, if left unchecked, can harm an individual by mistakenly attacking cells in the body.  

In humans, the failure of the body to recognise itself results in autoimmune diseases.  For example, Crohn’s disease is the failure of the body to recognize intestinal cells, resulting in an immune response against these cells. Understanding these autoimmune processes in invertebrates might help us to better engineer drugs to tackle these debilitating diseases in humans.

Insects can also boost their immune systems ready for a pathogen invasion.  Female bedbugs, which are often wounded during mating, enhance their immune system prior to mating in anticipation of pathogen invasion.   Similarly, bumblebees maintain their immune systems in an enhanced state following a pathogen attack to counter future infections. “This can even cross generations, with mothers transferring immunity to their offspring” says Schmid-Hempel. This delicate management of immune responses has until now been regarded as a characteristic of vertebrates.

Schmid-Hempel thinks that the molecular mechanisms found in invertebrate immune systems may rival those seen in the vertebrate world.  He says: “Insects use different cells and molecules, but follow very similar principles for detecting pathogens as vertebrates.” 

And scientists are only beginning to understand the elaborate ways that invertebrates respond to pathogens.  As they discover new molecules, the invertebrate immune system could turn out to be much more like that of vertebrates — making it an even better model for the study of our own immune system.


Story Source:

The above story is based on materials provided by European Science Foundation. Note: Materials may be edited for content and length.


Cite This Page:

European Science Foundation. "Invertebrate Immune Systems Are Anything But Simple." ScienceDaily. ScienceDaily, 22 June 2007. <www.sciencedaily.com/releases/2007/06/070621102626.htm>.
European Science Foundation. (2007, June 22). Invertebrate Immune Systems Are Anything But Simple. ScienceDaily. Retrieved October 2, 2014 from www.sciencedaily.com/releases/2007/06/070621102626.htm
European Science Foundation. "Invertebrate Immune Systems Are Anything But Simple." ScienceDaily. www.sciencedaily.com/releases/2007/06/070621102626.htm (accessed October 2, 2014).

Share This



More Plants & Animals News

Thursday, October 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Dolphins and Turtles Under Threat in Pakistan

Dolphins and Turtles Under Threat in Pakistan

AFP (Oct. 2, 2014) — The turtles and Dolphins of Pakistan's Indus river - both protected by law - are in a fight for their survival as man's activities threatens their futures. Duration: 02:29 Video provided by AFP
Powered by NewsLook.com
'Harvest Break' Endures in Maine Potato Fields

'Harvest Break' Endures in Maine Potato Fields

AP (Oct. 2, 2014) — Educators and farmers are clinging to a tradition aimed at giving farmers much-needed help in getting potatoes out of the fields and into storage before the ground freezes in the nation's northeast corner. (Oct. 2) Video provided by AP
Powered by NewsLook.com
Attacking Superbugs

Attacking Superbugs

Ivanhoe (Oct. 1, 2014) — Two weapons hospitals can use to attack superbugs. Scientists in Ireland created a new gel resistant to superbugs, and a robot that can disinfect a room in minutes. Video provided by Ivanhoe
Powered by NewsLook.com
Cultural Learning In Wild Chimps Observed For The First Time

Cultural Learning In Wild Chimps Observed For The First Time

Newsy (Oct. 1, 2014) — Cultural transmission — the passing of knowledge from one animal to another — has been caught on camera with chimps teaching other chimps. Video provided by Newsy
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