Antibodies Isolated from Ebola Survivors Recognize Wide Range of Ebolavirus Species

By LabMedica International staff writers
Posted on 01 Feb 2016

Image: Under very-high magnification, this digitally-colorized scanning electron micrograph (SEM) depicts a number of filamentous Ebolavirus particles (red) that had budded from the surface of a VERO cell (brown) of the African green monkey kidney epithelial cell line (Photo courtesy of the [US] National Institute of Allergy and Infectious Diseases).

A team of molecular virologists has isolated human monoclonal antibodies from Ebola survivors that were able to neutralize multiple species of the virus and protect guinea pigs from challenge with the live virus.

Recent studies had suggested that antibody-mediated protection against the Ebolaviruses might be achievable, but little was known about whether or not antibodies could confer cross-reactive protection against viruses belonging to diverse Ebolavirus (EBOV) species, such as Sudan ebolavirus (SUDV) and Bundibugyo ebolavirus (BDBV).

To clarify this point investigators at Vanderbilt University (Nashville, TN, USA) and the University of Texas Medical Branch (Galveston, USA) isolated a large panel of human monoclonal antibodies (mAbs) against BDBV glycoprotein (GP) using peripheral blood B cells from survivors of the 2007 BDBV outbreak in Uganda.

The investigators reported in the January 21, 2016, online edition of the journal Cell that a large proportion of mAbs with potent neutralizing activity against BDBV bound to the viral glycan cap and recognized diverse epitopes within this major antigenic site. They identified several glycan cap-specific mAbs that neutralized multiple ebolaviruses, including SUDV, and a cross-reactive mAb that completely protected guinea pigs from lethal challenge with heterologous EBOV.

"We thought we would need five different sets of vaccines or five different (drugs)," said senior author Dr. James Crowe Jr., professor of pediatrics, pathology, microbiology, and immunology at Vanderbilt University. "This work suggests there are common elements across different groups of Ebola viruses. Maybe we can come up with one therapeutic or one vaccine that would solve all of them. This work points the way to using fully human antibodies as the next generation of antibody therapeutics. From the human antibody work [...] and the vaccine work that is being done, it is clear we can find a protective strategy for Ebola. That is a big step forward."

Related Links:
Vanderbilt University
University of Texas Medical Branch