Epstein-Barr virus (EBV) affects more than 90 percent of the population worldwide and was the first human virus found to be associated with cancer. Now, researchers from Beth Israel Deaconess Medical Center (BIDMC) have broadened the understanding of this widespread infection with their discovery of a second B-cell attachment receptor for EBV.
The new findings, which currently appear on-line in Cell Reports, reinforce current directions being taken in the development of a vaccine to guard against EBV, and raise important new questions regarding the virus's possible relationship to malaria and to autoimmune diseases.
"Our discovery that CD35 is an attachment receptor for EBV helps explain several previously unsolved observations," explains the study's senior author Joyce Fingeroth, MD, a member of the Division of Infectious Diseases at BIDMC and Associate Professor of Medicine at Harvard Medical School.
First discovered in the early 1960s, EBV is one of eight viruses in the human herpesvirus family. The virus affects nine out of 10 people at some point in their lifetimes. Infections in early childhood often cause no disease symptoms, but people infected during adolescence or young adulthood may develop infectious mononucleosis. EBV is also associated with several types of cancer, including Hodgkin's lymphoma, non-Hodgkin's lymphoma and nasopharyngeal carcinoma, and has been linked to certain autoimmune disorders.
"EBV was the first human virus that was discovered to be a tumor virus," explains Fingeroth. "In fact, individuals who have had infectious mononucleosis have a four times increased risk of developing Hodgkin's disease." After the initial infection, the EBV virus remains in a person's body for life.
To gain entry, viruses must first attach to their host cells. For herpesviruses, receptors on the viral envelope become connected to complementary receptors on the cell membrane. In the case of EBV, the virus gains access to the immune system by attaching to primary B cells.
Nearly 30 years ago, Fingeroth and her colleagues discovered that this attachment occurs via the CD21 protein, which until now was the only known B cell attachment receptor for EBV. The recent finding that B cells from a patient lacking CD21 can be infected and immortalized by EBV had indicated that an alternative attachment receptor must exist. The identification of this second receptor -- CD35 -- by Fingeroth's team, led by first author Javier Ogembo, PhD, of BIDMC and the University of Massachusetts Medical School, not only underscores an important finding regarding primary infection but also underscores the importance of EBVgp350/220, (the virus protein that has been found to bind to both attachment receptors) for the development of a vaccine against EBV.
"The EBV glycoprotein gp350/220 is the most abundant surface glycoprotein on the virus," notes Fingeroth, adding that these results further suggest the virus fusion apparatus is the same for both receptors. "An EBV vaccine might be able to prevent infection or, alternatively, greatly reduce a person's risk of developing infectious mononucleosis and EBV-associated cancers, without necessarily preventing the EBV infection itself."
Interestingly, she adds, whereas a human has now been identified to be lacking the CD21 receptor, no persons are known to lack CD35.
"CD35 is a latecomer in evolution and in its current form, exists only in humans," says Fingeroth. "We know that it is often targeted in autoimmune diseases and was recently identified as a malaria receptor. Our new discovery may, therefore, reveal new avenues for the exploration of unexplained links between EBV, autoimmune diseases, malaria and cancer."
In addition to Fingeroth and Ogembo, study coauthors include BIDMC investigators Lakshmi Kannan, Ionita Ghiran, Anne Nicholson-Weller and George Tsokos; and University of Massachusetts Medical School investigator Robert Finberg.
This study was supported by a grant from the National Institutes of Health (R01A10635710) as well as support from the American Heart Association, the St. Baldrick's Foundation, and the Cancer Research Institute.
Beth Israel Deaconess Medical Center is a patient care, teaching and research affiliate of Harvard Medical School and currently ranks third in National Institutes of Health funding among independent hospitals nationwide. BIDMC is clinically affiliated with the Joslin Diabetes Center and is a research partner of the Dana-Farber/Harvard Cancer Center. BIDMC is the official hospital of the Boston Red Sox. For more information, visit www.bidmc.org.
Bonnie Prescott | EurekAlert!
How brains surrender to sleep
23.06.2017 | IMP - Forschungsinstitut für Molekulare Pathologie GmbH
A new technique isolates neuronal activity during memory consolidation
22.06.2017 | Spanish National Research Council (CSIC)
An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.
Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine
Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
23.06.2017 | Physics and Astronomy
23.06.2017 | Physics and Astronomy
23.06.2017 | Information Technology