Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Receptor Holds the Key to Mosquito Immune Response

20.06.2006
Researchers Identify Gene Used to Recognize Pathogens

Researchers at the Johns Hopkins Bloomberg School of Public Health have identified a gene in the Anopheles gambiae mosquito’s DNA that is central to the insect’s ability to defend against infectious pathogens, including Plasmodium, the parasite that causes malaria in humans. Potentially, a mosquito with an enhanced capacity to recognize and kill Plasmodium would be unable to transmit malaria. The researchers' findings appear in the June 20, 2006, edition of the journal PLoS Biology.

Insects do not have antibodies, which are essential for pathogen recognition in humans. Instead, insects rely on a limited number of genes coding for adhesive proteins (pattern-recognition receptors) that can adhere to molecular patterns on a pathogen’s surface.

“Each pathogen has its own unique combination of surface patterns. The immune systems of the mosquito and other insects primarily rely on recognizing the pattern of a specific pathogen to activate an immune response that kills the invader,” explained George Dimopoulos, PhD, senior author of the study and assistant professor in the Bloomberg School’s Malaria Research Institute. The AgDscam gene—short for Anopheles gambiae Down syndrome cell adhesion molecule gene—is an essential factor of the mosquito’s immune system and can produce thousands of receptors with different pathogen-binding specificities. AgDscam appears to be capable of recognizing a broad range of different pathogens, and can thereby carry out a function for which a large number of genes would have been needed. Studies previously conducted by other researchers identified an immunity-related function of the Dscam gene in fruit flies.

The researchers found that when the AgDscam gene was deactivated, or “silenced”, the mosquitoes died at a greater rate from bacterial infections. They also found that the numbers of Plasmodium increased 65 percent in the gut of mosquitoes with the silenced gene. The findings suggest that better knowledge of how the AgDscam gene is involved in killing Plasmodium could be used to develop novel ways to control malaria.

The AgDscam gene has 101 protein-coding regions, called exons, that can be spliced together in different combinations to produce over 31,000 possible splice-forms that function as receptors. When the mosquitoes were exposed to different pathogens such as bacteria, fungi and parasites, the AgDscam gene produced an array of different splice-forms with different interaction properties. When the researchers cut AgDscam protein levels in half, they could link AgDscam’s function with the immune system, as the mosquitoes became less resistant to infection. The results showed that infected mosquitoes produced AgDscam splice-forms (receptors) that were better in recognizing—and defending against—the invading pathogen.

“AgDscam is in a way similar to antibodies; different combinations of immunoglobulin domains, which are coded by spliced exons, are used to produce a broad range of receptors. Now we need to learn more about AgDscam’s association with the malaria parasite. A mosquito with an enhanced capacity to recognize and kill Plasmodium would not transmit malaria,” said Dimopoulos.

In a previous study published in the June 8, 2006, edition of PLoS Pathogens, the Hopkins researchers determined that mosquitoes employ the same immune factors to fight off bacterial pathogens as they do to kill malaria-causing Plasmodium parasites.

“AgDscam, a hyper variable immunoglobulin domain containing receptor of the Anopheles gambiae innate immune system” was written by Yuemei Dong, Harry Taylor and George Dimopoulos. Dong and Dimopoulos are with the W. Harry Feinstone Department of Molecular Microbiology and Immunology at the Johns Hopkins Bloomberg School of Public Health. Taylor is currently with Meharry Medical College.

The study was supported by grants from the National Institute of Allergy and Infectious Disease, the World Health Organization Training in Tropical Diseases program, the Ellison Medical Foundation and the Johns Hopkins Malaria Research Institute.

Public Affairs media contacts for the Johns Hopkins Bloomberg School of Public Health: Tim Parsons or Kenna Lowe at 410-955-6878 or paffairs@jhsph.edu.

Tim Parsons | EurekAlert!
Further information:
http://www.jhsph.edu

More articles from Life Sciences:

nachricht Flow of cerebrospinal fluid regulates neural stem cell division
21.05.2018 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Chemists at FAU successfully demonstrate imine hydrogenation with inexpensive main group metal
21.05.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

Im Focus: Dozens of binaries from Milky Way's globular clusters could be detectable by LISA

Next-generation gravitational wave detector in space will complement LIGO on Earth

The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...

Im Focus: Entangled atoms shine in unison

A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.

The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...

Im Focus: Computer-Designed Customized Regenerative Heart Valves

Cardiovascular tissue engineering aims to treat heart disease with prostheses that grow and regenerate. Now, researchers from the University of Zurich, the Technical University Eindhoven and the Charité Berlin have successfully implanted regenerative heart valves, designed with the aid of computer simulations, into sheep for the first time.

Producing living tissue or organs based on human cells is one of the main research fields in regenerative medicine. Tissue engineering, which involves growing...

Im Focus: Light-induced superconductivity under high pressure

A team of scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg investigated optically-induced superconductivity in the alkali-doped fulleride K3C60under high external pressures. This study allowed, on one hand, to uniquely assess the nature of the transient state as a superconducting phase. In addition, it unveiled the possibility to induce superconductivity in K3C60 at temperatures far above the -170 degrees Celsius hypothesized previously, and rather all the way to room temperature. The paper by Cantaluppi et al has been published in Nature Physics.

Unlike ordinary metals, superconductors have the unique capability of transporting electrical currents without any loss. Nowadays, their technological...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

 
Latest News

Supersonic waves may help electronics beat the heat

18.05.2018 | Power and Electrical Engineering

Keeping a Close Eye on Ice Loss

18.05.2018 | Information Technology

CrowdWater: An App for Flood Research

18.05.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>