New research led by scientists at La Jolla Institute for Immunology (LJI) reveals the workings of a human antibody called mAb 3A6, which may prove to be an important component for Ebola virus therapeutics.
This antibody was isolated from blood samples from an Ebola survivor treated at Emory University Hospital during the 2014-2016 Ebola virus outbreak, an outbreak that began in West Africa and killed more than 11,300 people.
In their new study, the researchers showed that mAb 3A6 helps block infection by binding to an important part of Ebola’s viral structure, called the “stalk.” Study collaborators at the NIH’s National Institute of Allergy and Infectious Diseases (NIAID) found that treatment with mAb 3A6 can benefit non-human primates in advanced stages of Ebola virus disease.
“This antibody offers the best protection in primates, at the lowest dose yet seen for any single antibody,” says LJI Professor, President & CEO Erica Ollmann Saphire, Ph.D., MBA, who led the recent Nature Communications study alongside John A. G. Briggs, Ph.D., of Cambridge University and the Max Planck Institute of Biochemistry; Gabriella Worwa, D.V.M., and Jens H. Kuhn, M.D., Ph.D., of NIAID; and Carl W. Davis, Ph.D., and Rafi Ahmed, Ph.D., of the Emory Vaccine Center.
The discovery that mAb 3A6 appears effective at a very low dose is also exciting. “The lower the amount of an antibody you can deliver to someone, the easier it will be to manufacture a treatment-and the lower the cost,” says study first author Kathryn Hastie, Ph.D., LJI Instructor and Director of LJI’s Center for Antibody Discovery.
How the antibody works
The key to treating Ebola virus is to find antibodies that anchor tightly to and block essential machinery of the virus. The researchers zeroed in on mAb 3A6 because it appears to target a structure on Ebola virus called the “stalk.” The stalk is an important part of the Ebola virus structure because it anchors Ebola’s glycoprotein structure (which drives entry into a host cell) to Ebola’s viral membrane.
The team spearheaded efforts to capture images of mAb 3A6 in action. The researchers used two imaging techniques, called cryoelectron tomography and x-ray crystallography, to show how mAb 3A6 binds to Ebola virus to interrupt the infection process.
The researchers found that mAb 3A6 binds to a site normally concealed by a shifting landscape of viral proteins. “There’s a dynamic movement in these proteins,” says Hastie. “They might kind of wiggle around, move back and forth, maybe lean over a little bit or go up and down.”
Antibody mAb 3A6 takes advantage of this little protein dance. It has such a strong affinity for its viral target that it can slip between the proteins, lift them up, and latch on its target.
Hastie says mAb 3A6’s ability to bind to this target is important for several reasons. First, the site is conserved across different species of Ebola virus, making antibodies that target this region an attractive component in “pan-Ebolavirus” therapeutics. Second, the new understanding of how mAb 3A6 “lifts up” proteins in the viral stalk gives scientists a clearer view of Ebola’s weaknesses. MAb 3A6 also shows us how similar antibodies against the stalks of other viruses might work as well.
This study gives us some hints for how to design vaccines that are specifically against this region of Ebola virus.”
Kathryn Hastie, Ph.D., LJI Instructor and Director of LJI’s Center for Antibody Discovery
Additional authors of the study, “Anti-Ebola virus mAb 3A6 protects highly viremic animals from fatal outcome via binding GP(1,2) in a position elevated from the virion membrane,” include Zhe “Jen” Li Salie, who solved the X-ray structure; Zunlong Ke, who performed the cryoelectron tomography; Lisa Evans DeWald, Sara McArdle, Ariadna Grinyó, Edgar Davidson, Sharon L. Schendel, Chitra Hariharan, Michael J. Norris, Xiaoying Yu, Chakravarthy Chennareddy, Xiaoli Xiong, Megan Heinrich, Michael R. Holbrook, Benjamin Doranz, Ian Crozier, Yoshihiro Kawaoka, Luis M. Branco, Jens H. Kuhn
This study was supported in part by the National Institute of Health’s National Institute for Allergy and Infectious Diseases (grant U19 AI142790, Contract No. HHSN272201400058C, Contract No. HHSN272200700016I, Contract No. HHSN272201800013C), DARPA (contract W31P4Q-14-1-0010), and UK Medical Research Council (grant MC_UP_1201/16), the European Research Council (ERC-CoG-648432 MEMBRANEFUSION), and the Max Planck Society.
Hastie, K. M., et al. (2025). Anti-Ebola virus mAb 3A6 protects highly viremic animals from fatal outcome via binding GP(1,2) in a position elevated from the virion membrane. Nature Communications. doi.org/10.1038/s41467-025-56452-2.
News
MIT Scientists Reprogram Immune Cells Inside the Body To Destroy Cancer
Natural killer cells reprogrammed inside mice eliminated lymphoma tumors and helped damaged livers heal, though whether this approach could help people with cancer or autoimmune disease remains unknown. To make a cancer treatment from [...]
Melanoma mRNA Vaccine Shows Promise in Preventing Disease Recurrence
Key takeaways: Phase 3 trial finds personalized intismeran plus pembrolizumab may better prevent high-risk melanoma recurrence after surgery The trial enrolled 1,137 patients and builds on phase 2 results showing about half the recurrence [...]
Scientists Discover a Powerful New Weapon Against a Dangerous Gut Infection
The promise of an experimental treatment for C. difficile gut infections lies partly in the bacteria it leaves alive, according to early laboratory and mouse research. Broad-spectrum antibiotics can disrupt the gut’s microbial community, [...]
Your Bones May Hold a Hidden Clue to Blood Cancer Survival
For people with blood cancers called myelodysplastic syndromes, osteoporosis may hold an overlooked clue to survival, a three-year observational study suggests. In blood cancers that develop in the bone marrow, an important clue to [...]
Researchers Discover What Reading for Pleasure May Be Doing to Your Brain
Reading for pleasure may offer surprising benefits for the brain, with research linking the habit to better mental health, stronger cognitive abilities, and a lower risk of dementia. Reading for pleasure may do far [...]
Scientists Discover a Hidden Trigger That Keeps Inflammation Alive
Inflammation persists after proteins detach from immune receptors, revealing a potential target for autoimmune treatments. Since a Nobel Prize-winning discovery in the 1990s identified molecules called Toll-like Receptors as the guardians of the human [...]
A Virus Gives Itself Away the Moment It Attacks
Researchers have found the trigger behind a powerful bacterial defense against viruses. Viruses that prey on bacteria could become an increasingly important tool for treating bacterial infections, particularly as antibiotic resistance makes some infections [...]
Scientists Discover Aspirin May Slash Dementia Risk by 70% – but Only for Certain People
Aspirin was linked to a sharply lower dementia risk in some older adults, and their genes may hold the clue. A Monash University analysis found that older adults with a particular genetic profile had [...]
Inflammation May Awaken Dormant Cancer Cells Years After Treatment
The body’s response to inflammation may disturb cancer cells that have been lying silent for years, giving them an opportunity to grow again. Researchers at the Francis Crick Institute have found that gut inflammation [...]
Where do nanoparticles go once they enter the body?
New international best practice guidance, co-written at ANSTO, sets out how to measure where nanoparticles like titanium dioxide end up in the body and how long they remain. The guidance has been shared by [...]
Long-Acting HIV Shots Could Solve a Major Treatment Challenge for Young People
A major African trial suggests that changing how HIV treatment is delivered could significantly improve viral suppression in adolescents. Young people with HIV were more likely to keep the virus suppressed when they received [...]
WHO Factsheets – The top 10 causes of death
In 2023, the 10 leading causes of death accounted for 33 million deaths, or 54% of the total 61 million deaths worldwide. The top global causes of death, in order of total number of lives lost, [...]
Aging Cells May Be Hiding From the Immune System – Scientists Think They Know How
Your immune system is supposed to clear out damaged cells. Researchers may have found how some of them hide and linger as the body ages. Researchers led by Cedars-Sinai Health Sciences University have identified [...]
Your Voice May Reveal How Fast Your Brain Is Aging
Researchers have developed a machine-learning “speech clock” that estimates age from subtle patterns in how people speak and what they say. It is possible that people’s voices may contain certain signals of aging that [...]
Optogenetics Pioneers Win 2026 Nobel Prize in Physiology or Medicine
The 2026 Nobel Prize in Physiology or Medicine has been awarded to Peter Hegemann, Georg Nagel, and Karl Deisseroth for the development of optogenetics, a revolutionary technology that uses light to control individual neurons [...]
Molecular Manufacturing: The Future of Nanomedicine – From NanoappsMedical Inc.
This book explores the revolutionary potential of atomically precise manufacturing technologies to transform global healthcare, as well as practically every other sector across society. This forward-thinking volume examines how envisaged Factory@Home systems might enable the cost-effective [...]
