Researchers at Fred Hutch Cancer Center have engineered new antibodies that completely blocked Epstein Barr virus infection in laboratory mice, marking a potential breakthrough in preventing a pathogen that silently infects nearly everyone on Earth.
The virus, known as EBV, lurks in the bodies of approximately 95% of people worldwide. While most carriers never develop symptoms, the infection is linked to several cancers, neurodegenerative diseases, and other chronic conditions. For transplant patients on immunosuppressive medications, EBV can become life-threatening.
The team created monoclonal antibodies designed to stop EBV from attaching to and entering human immune cells. Using mice engineered to produce human antibodies, they identified ten promising candidates targeting two critical viral proteins: gp350, which helps the virus stick to cells, and gp42, which allows it to penetrate them. One antibody targeting gp42 completely prevented infection in humanized mice, while another targeting gp350 provided partial protection.
"Finding human antibodies that block Epstein Barr virus from infecting our immune cells has been particularly challenging because EBV finds a way to bind to nearly every one of our B cells," said Andrew McGuire, a biochemist at Fred Hutch. "We decided to use new technologies to try to fill this knowledge gap and we ended up taking a critical step toward blocking one of the world's most common viruses."
A major technical hurdle has always been developing antibodies that work without triggering the immune system to attack the therapy itself, a problem that arises when antibodies come from non-human sources. The Fred Hutch approach solved this by focusing on antibodies that naturally occur in humans.
Immediate need in transplant medicine
More than 128,000 people in the United States receive solid organ or bone marrow transplants annually. These patients take medications that suppress their immune system to prevent rejection, but that same suppression can allow EBV to reactivate and multiply unchecked. The virus can then trigger post-transplant lymphoproliferative disorders, a serious form of lymphoma that develops in transplant recipients.
"Preventing EBV viremia has strong potential to reduce the incidence of PTLD and limit the need to reduce immunosuppression, thereby helping preserve graft function while improving overall patient outcomes," said Rachel Bender Ignacio, an infectious disease physician at Fred Hutch and the University of Washington School of Medicine. "Effective prevention of EBV viremia remains a significant unmet need in transplant medicine."
Children undergoing transplants face particular risk since many have never encountered EBV before. Others may be exposed through donor organs carrying latent virus. Currently, there are no targeted therapies to prevent this complication.
The team envisions administering these antibodies as an infusion to high-risk patients before or shortly after transplantation. By blocking the virus early, the therapy could prevent both initial infection and reactivation of dormant virus.
Fred Hutch has filed intellectual property claims for the antibodies. McGuire and graduate student Crystal Chhan are collaborating with an industry partner to advance the research toward human testing. Safety studies in healthy adults would likely follow, then trials in transplant patients most vulnerable to EBV complications.
The research was published in Cell Reports Medicine in February 2026.
Author Jessica Williams: "This is exactly the kind of unglamorous, painstaking work that solves real clinical problems for patients with few other options."
Comments