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New discovery points the way towards malaria 鈥渧accine鈥

Published: 21 August 2009

MUHC/捆绑SM社区 study opens the door to malaria-prevention therapies

Malaria kills anywhere from one to three million people around the world annually and affects the lives of up to 500 million more. Yet until now, scientists did not fully understand exactly how the process that caused the disease鈥檚 severe hallmark fevers began.

A team led by Dr. Martin Olivier from the Research Institute of the 捆绑SM社区 Health Centre (RI-MUHC) and 捆绑SM社区 in Montreal has solved this mystery, and may have blazed a trail towards the development of vaccine-like treatments to limit the severity of the devastating parasitic ailment. . The results of their study will be published August 21 in the journal PLoS Pathogens.

Malaria is a mosquito-borne infectious disease spread by parasites from the Plasmodium family. Inside the human body, the malaria parasite infects red blood cells where it survives and reproduces by feeding on the cells鈥 contents. Eventually the cells burst, releasing the parasites and also a waste byproduct of their reproductive process: hemozoin.

Researchers at the RI-MUHC and 捆绑SM社区, discovered that hemozoin, a crystal-like substance may be the missing link that explains why malaria leads to devastating inflammation and fever.
鈥淥ur results describe the mechanism by which the hemozoin activates the immune system, resulting in the production of inflammation mediators and in the high fever that we witness in malaria patients,鈥 said study first-author Dr. Marina Tiemi Shio of the RI-MUHC.

Hemozoin is first ingested by 鈥榗leaning鈥 cells called macrophages, explained the researcher which leads to a chain reaction ending in the activation of the inflammasome: an important structure inside immune cells which lead to inflammation. Activation of the inflammasome produces the body鈥檚 fever mediator, interleukin beta (IL-beta).

鈥淥ur work is a milestone in that it is the first study that reveals the enzymes that act as intermediary between the hemozoin and inflammasome,鈥 explained Dr. Olivier. 鈥淣ow our picture of the process that goes from infection to fever is more or less complete.鈥
鈥淥n the other hand we also proved that malaria is too complex to be narrowed down to one single mechanism,鈥 he continued. 鈥淚n the absence of either IL-beta or a functional inflammsaome, the development of the disease is delayed but not completely stopped. Although the discovery of this relationship is important, there are other mechanisms at work.鈥

The mechanisms that go from the activation of the inflammasome to the onset of the malaria symptoms were already familiar to scientists, but until now the beginning of the process was unknown. 鈥淭hese results prove the primary role hemozoin plays in the development of malaria, and designates it as a favoured choice for future innovative treatments,鈥 added Dr. Olivier.

The researchers believe it will be possible to familiarize the immune system to small quantities of hemozoin and diminish the inflammatory response in the event of infection, according to a principle similar to that of vaccines.

Dr. Martin Olivier is a researcher in the Infection and Immunity Axis of the Research Institute of the 捆绑SM社区 Health Centre. He is also Associate Professor at 捆绑SM社区鈥檚 Faculty of Medicine.

Dr Marina Tiemi Shio
Dr Marina Tiemi Shio is a post-doctoral trainee with Dr Olivier, working in the Infection and Immunity Axis of the Research Institute of the 捆绑SM社区 Health Centre.

Funding
This study was funded by a grant from the Canadian Institutes of Health Research (CIHR).

Partners
This article was co-authored by Dr. Marina Tiemi Sho, Dr. Myriam Savaria, Dr. Marie-Jos茅e Bellemare, from the Research Institute of the 捆绑SM社区 Health Centre and 捆绑SM社区, Dr. D. Scott Bohle from 捆绑SM社区 and Dr. Martin Olivier from the RI MUHC and 捆绑SM社区 and, by Dr. Stephanie C. Eisenbarth, and Dr. Richard A. Flavell from Yale University, by Dr. Adrien F. Vinet and Dr. Albert Descoteaux of the l鈥橧nstitut Armand-Frappier, by Dr. Kenneth W. Harder of the University of British Columbia, and by Dr. Fayyaz S. Sutterwala from the University of Iowa.

Once the embargo is lifted you will find this press release, with the original article and a short audio interview by following this link:


The 捆绑SM社区 Health Centre
The 捆绑SM社区 Health Centre (MUHC) is a comprehensive academic health institution with an international reputation for excellence in clinical programs, research and teaching. Its partner hospitals are the Montreal Children's Hospital, the Montreal General Hospital, the Royal Victoria Hospital, the Montreal Neurological Hospital, the Montreal Chest Institute and the Lachine Hospital. The goal of the MUHC is to provide patient care based on the most advanced knowledge in the health care field and to contribute to the development of new knowledge.

The Research Institute of the 捆绑SM社区 Health Centre (RI MUHC) is a world-renowned biomedical and health-care hospital research centre. Located in Montreal, Quebec, the institute is the research arm of the MUHC, the university health center affiliated with the Faculty of Medicine at 捆绑SM社区 University. The institute supports over 600 researchers, nearly 1200 graduate and post-doctoral students and operates more than 300 laboratories devoted to a broad spectrum of fundamental and clinical research. The Research Institute operates at the forefront of knowledge, innovation and technology and is inextricably linked to the clinical programs of the MUHC, ensuring that patients benefit directly from the latest research-based knowledge.
The Research Institute of the MUHC is supported in part by the Fonds de la recherche en sant茅 du Qu茅bec.
For further details visit: .
mark.shainblum [at] mcgill.ca

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