A team of researchers from Utrecht University, the Erasmus Medical Center and Harbour BioMed has identified a human monoclonal antibody that neutralizes SARS-CoV-2 and SARS-CoV-1 coronaviruses in cell culture. Named 47D11, this cross-neutralizing antibody targets a communal epitope (antigenic determinant) on these viruses and may offer potential for prevention and treatment of COVID-19.
Colorized scanning electron micrograph of a VERO E6 cell (blue) heavily infected with SARS-COV-2 virus particles (orange), isolated from a patient sample. Image credit: NIAID.
This research builds on the work our groups have done in the past on antibodies targeting SARS-CoV-1 that emerged in 2002-2003, said senior co-author Dr. Berend-Jan Bosch, a scientist in the Department of Biomolecular Health Sciences at Utrecht University.
Using this collection of SARS-CoV-1 antibodies, we identified an antibody that also neutralizes infection of SARS-CoV-2 in cultured cells.
Such a neutralizing antibody has potential to alter the course of infection in the infected host, support virus clearance or protect an uninfected individual that is exposed to the virus.
The human 47D11 antibody binds to a domain that is conserved in both SARS-CoV-1 and SARS-CoV-2, explaining its ability to neutralize both viruses.
This cross-neutralizing feature of the antibody is very interesting and suggests it may have potential in mitigation of diseases caused by future-emerging related coronaviruses, Dr. Bosch said.
This discovery provides a strong foundation for additional research to characterize this antibody and begin development as a potential COVID-19 treatment, added senior co-author Dr. Frank Grosveld, a researcher in the Department of Cell Biology at the Erasmus Medical Center and founding chief scientific officer at Harbour BioMed.
The 47D11 antibody is fully human, allowing development to proceed more rapidly and reducing the potential for immune-related side effects.
Binding of 47D11 to HEK-293T cells expressing GFP-tagged spike proteins of SARS-CoV-1 and SARS-CoV-2 detected by immunofluorescence assay. The human mAb 7.7G6 targeting the MERS-CoV S1B spike domain was taken along as a negative control, cell nuclei in the overlay images are visualized with DAPI. Image credit: Wang et al, doi: 10.1038/s41467-020-16256-y.
Conventional therapeutic antibodies are first developed in other species and then must undergo additional work to humanize them.
The 47D11 antibody was generated using Harbour BioMeds H2L2 transgenic mouse technology.
This is groundbreaking research, said Jingsong Wang, Founder, Chairman & Chief Executive Officer of Harbour BioMed.
Much more work is needed to assess whether this antibody can protect or reduce the severity of disease in humans.
We expect to advance development of the antibody with partners.
We believe our technology can contribute to addressing this most urgent public health need and we are pursuing several other research avenues.
The teams paper was published in the journal Nature Communications.
C. Wang et al. 2020. A human monoclonal antibody blocking SARS-CoV-2 infection. Nat Commun 11, 2251; doi: 10.1038/s41467-020-16256-y