(Press-News.org) In a study published today in the Open Access journal PLOS Pathogens, researchers at Emory University have discovered a potentially important mechanism by which the Ebola virus alters and evades the immune response of its infected host.
Ebola virus is the causative agent of Ebola Hemorrhagic Fever (EHF), a disease with up to 90 percent mortality. While human outbreaks of Ebola hemorrhagic fever have been confined to Africa, Ebola virus infections in bats, the presumed natural reservoir of the virus, have also been detected in Europe and Asia.
The high lethality of the disease, combined with its short incubation period and the lack of vaccines or effective treatments, makes Ebola virus a significant public health threat as well as a potentially devastating biological weapon. Efforts to develop a vaccine against Ebola virus have been met with limited success, and it is likely that the virus employs complex immune evasion mechanisms that present unique challenges for vaccine design. Understanding these evasion mechanisms is a critical first step in developing an effective vaccine.
In this study, the authors examined the role of a protein secreted in large quantities by Ebola virus-infected cells. The protein shares regions with a membrane protein that the virus expresses on its surface and uses to initiate the infection process. The authors studied antibodies generated by immunizing mice with the viral surface protein and/or the secreted protein. They determined that the secreted protein can selectively drive induction of antibody responses to itself and also compete for antibodies to the viral surface protein that would otherwise bind to and inactivate the virus.
"Our findings provide an explanation for the lack of protective antibodies against the viral surface protein in patients who have survived Ebola virus infection," says Dr. Chinglai Yang, assistant professor of microbiology and immunology at the Emory University School of Medicine. "We hypothesize that the secreted protein allows the virus to subvert the host antibody response in vivo, and that this may enable the virus to cause repeated or sustained infection in its natural reservoir."
The results suggest that immunity induced by a vaccine may need to reach a sufficient threshold to effectively neutralize the incoming virus to protect against Ebola virus infection. These findings raise new challenges for Ebola vaccine design, as vaccines will most likely have to be tailored to overcome or avoid the ability of the secreted decoy protein to interfere with host immune responses. Such approaches could enable the development of more efficacious vaccines to prevent Ebola virus infection.
INFORMATION:
FINANCIAL DISCLOSURE: This study is supported by Public Health Service grants 1R01AI093406 and 1R01AI069148 from the National Institute of Health. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
COMPETING INTERESTS: The authors have declared that no competing interests exist.
PLEASE ADD THIS LINK TO THE PUBLISHED ARTICLE IN ONLINE VERSIONS OF YOUR REPORT:
http://dx.plos.org/10.1371/journal.ppat.1003065
(link will go live upon embargo lift)
CITATION: Mohan GS, Li W, Ye L, Compans RW, Yang C (2012) Antigenic Subversion: A Novel Mechanism of Host Immune Evasion by Ebola Virus. PLoS Pathog 8(12): e1003065. doi:10.1371/journal.ppat.1003065
Institutional Media Contact:
Holly Korschun
404-727-3990
hkorsch@emory.edu
PLOS Media Contact:
Gina Alvino
(415) 568-3173
plospathogens@plos.org
Disclaimer
This press release refers to an upcoming article in PLOS Pathogens. The release is provided by the article authors. Any opinions expressed in these releases or articles are the personal views of the journal staff and/or article contributors, and do not necessarily represent the views or policies of PLOS. PLOS expressly disclaims any and all warranties and liability in connection with the information found in the releases and articles and your use of such information.
Media Permissions
PLOS Journals publish under a Creative Commons Attribution License, which permits free reuse of all materials published with the article, so long as the work is cited (e.g., Kaltenbach LS et al. (2007) Huntingtin Interacting Proteins Are Genetic Modifiers of Neurodegeneration. PLoS Genet 3(5): e82. doi:10.1371/journal.pgen.0030082). No prior permission is required from the authors or publisher. For queries about the license, please contact the relative journal contact indicated here: http://www.plos.org/about/media-inquiries/.
About PLOS Pathogens
PLOS Pathogens publishes outstanding original articles that significantly advance the understanding of pathogens and how they interact with their host organisms. All works published in PLOS Pathogens are open access. Everything is immediately available subject only to the condition that the original authorship and source are properly attributed. Copyright is retained by the authors. The Public Library of Science uses the Creative Commons Attribution License.
About the Public Library of Science
The Public Library of Science (PLOS) is a non-profit organization of scientists and physicians committed to making the world's scientific and medical literature a freely available public resource. For more information, visit http://www.plos.org.
END
ANN ARBOR — A new genetic analysis has revealed that many Amazon tree species are likely to survive human-caused climate warming in the coming century, contrary to previous findings that temperature increases would cause them to die out.
However, the authors of the new study warn that extreme drought and forest fires will impact Amazonia as temperatures rise, and the over-exploitation of the region's resources continues to be a major threat to its future. Conservation policy for the Amazon should remain focused on reducing global greenhouse-gas emissions and preventing ...
In a study published today in the Open Access journal PLOS Pathogens, scientists at McMaster University in Hamilton, Ontario have determined that a specialized class of immune cells, known as T cells, retains its functionality with age and can respond to virus infections with the same vigor as T cells from a young person. This is a valuable finding as it is generally believed that elderly individuals are at increased risk of infection because immunity deteriorates with age.
T cells play an important role in defending the body from virus infections. For a long time, ...
New genetic analysis has revealed that many Amazon tree species are likely to survive man-made climate warming in the coming century, contrary to previous findings that temperature increases would cause them to die out.
A study, published in the latest edition of Ecology and Evolution, reveals the surprising age of some Amazonian tree species – more than 8 million years – and therefore shows that they have survived previous periods as warm as many of the global warming scenarios forecast for the year 2100.
The authors write that, having survived warm periods in the ...
Multiple myeloma is a type of leukaemia which affects B lymphocytes. There have been some indications that exposure to pesticides or chlorinated solvents increases the risk of developing this cancer. New research published in Biomed Central's open access journal Journal of Occupational Medicine and Toxicology provides a large (from 22 centres across Europe), matched control study into lifetime risk of multiple myeloma. They find that risk of Multiple myeloma is related to farm work, printing and cleaning. But although exposure to pesticides seemed to be a risk, exposure ...
Wearable technology is not only for sports and fashion enthusiasts it can also be used to monitor and aid clinical rehabilitation according to new research published in BioMed Central's open access journal BioMedical Engineering OnLine.
Neurorehabilitation researchers from Italy have developed a low cost, wearable system, consisting of strain sensors made of conductive elastomers printed onto fabric. A low voltage battery powers the sensors, which are then able to send data to a computer via Bluetooth.
In this case study a wireless inertial sensor (MEMS) containing ...
The origins of congenital heart defects could be traced right back to the first stages of embryonic development - according to University of East Anglia (UEA) research.
Findings published today in the journal PLOS ONE show that the beginnings of important parts of the heart can be traced to very early stages of embryo development. The research has been funded by the British Heart Foundation.
Biologists investigated chicken eggs at the gastrulation stage - between 12 and 14 hours after fertilisation.
They found that some cells would go on to create the anterior ...
Survival of the fittest: longevity of Olympic medallists in the modern era
Mortality in former Olympic athletes: retrospective cohort analysis
Editorial: Everyone could enjoy the "survival advantage" of elite athletes
Olympic medallists live longer than the general population, regardless of country of origin, medal won, or type of sport played, finds a study in the Christmas issue published on bmj.com today.
A second study comparing athletes who trained at different physical intensities, found that those from high or moderate intensity sports have no added survival ...
A detection dog to identify Clostridium difficile in stool samples and infected patients: proof of principle study
Dogs can sniff out Clostridium difficile (the infective agent that is responsible for many of the dreaded "hospital acquired infections") in stool samples and even in the air surrounding patients in hospital with a very high degree of accuracy, finds a study in the Christmas issue published on bmj.com today.
The findings support previous studies of dogs detecting various types of cancer and could have great potential for screening hospital wards to help ...
Researchers in Belgium also show how dogs can help patients with severe sleep problems.
They describe a 35 year old patient with severe excessive daytime sleepiness. She suffered sleep attacks up to six times a day and sometimes slept up to 16 hours a day.
Until recently, this severe sleepiness considerably hampered her social life and limited her use of public transport, as she usually fell asleep within a few minutes of sitting down.
She'd then wake up at the end of the line and have to fight sleepiness on the way back. Sometimes she'd forget where she started ...
The tooth fairy and malpractice
Opinions of the tooth fairy as kind and giving may need to be revised following "mounting reports of less child-friendly activity", says a paper published in the BMJ Christmas edition and appearing online today.
Researchers from across London became concerned following misdemeanours of the mythical character and a worrying trend in malpractice. One boy in particular became extremely distressed because the tooth fairy "had put a tooth in his left ear" after he left it under his pillow. Further investigation turned out he was right.
Further ...
