A collaborative team from The University of Texas Medical Branch at Galveston, Vanderbilt University, The Scripps Research Institute and Integral Molecular Inc. have learned that antibodies in the blood of people who have survived a strain of the Ebola virus can kill various types of Ebola. The study is currently available in Cell.
The findings are significant because it helps researchers further understand the immune response to a virus such as Ebola and could lead to treatments for Ebola as well as other related viruses.
The study involved using blood samples from people who had survived the Ebola Bundibugyo strain.
When someone has survived an Ebola infection, they have developed antibodies. The question is, can these antibodies protect against a future infection with the virus and related filoviruses?
Although several mouse antibody-based treatments have provided protection against Ebola Zaire in animal models, there are no available therapeutics based on antibodies from human survivors and no universal treatments against multiple filoviruses, including Ebola Sudan and Ebola Bundibugyo.
In the study, researchers used the blood of seven people who survived Ebola Bundibugyo virus infection during the 2007 outbreak in Uganda to isolate a large number of B cells that produce antibodies, which are the small protein molecules capable of inactivating the virus.
"The work on antibodies isolated from survivors of filovirus infections, including Marburg and Ebola, was started by James Crowe's laboratory at Vanderbilt University together with our laboratory about 3 years ago," said virologist Alex Bukreyev, professor at UTMB and co-corresponding author. "In this study, we isolated a remarkably diverse array of virus-specific antibodies, which appeared to bind to various parts of the envelope protein of the virus. Some of the antibodies neutralized not only Ebola Bundibugyo virus, but also Ebola Zaire and Sudan viruses."
"The quality of these naturally occurring human antibodies as biological drugs to treat the virus infection is remarkable, and we are doubly encouraged because they recognize multiple species of Ebola," said immunologist James Crowe, Director of the Vanderbilt Vaccine Center.
A portion of the isolated antibodies effectively protected mice and guinea pigs against a lethal Ebola Zaire infection.
"These data provide the basis for understanding the immune response to filovirus infections in humans," said Bukreyev. "Our results provide a roadmap to developing a single antibody-based treatment effective against not only infections caused by Ebola Zaire virus, but also caused by related filoviruses."
Other authors of this paper include UTMB's Xiaoli Shen, Philipp Ilinykh, Natalia Kuzmina, Curtis Klages and Thomas Ksiazek; Andrew Flyak, Rebecca Lampley, Nurgun Kose, Andre Branchizio, Hannah King, Leland Brown, James Slaughter, Gopal Sapparapu and James Crowe, Jr. from Vanderbilt University; Charles Murin, Hannah Turner, Joshua David, Marnie Fusco, Erica Ollmann Saphire and Andrew Ward from The Scripps Research Institute and Christopher Bryan, Edgar Davidson and Benjamin Doranz from Integral Molecular Inc.
This study was supported by three grants from the National Institute of Allergy and Infectious Diseases of the National Institutes of Health – grants AI109711, AI109762 and AI067927 – and by a Defense Threat Reduction Agency award, HDTRA1-13-1-0034.