New antibodies offer hope for preventing Epstein-Barr virus infection

15:00

By: Azzat Manal

New antibodies offer hope for preventing Epstein-Barr virus infection

Scientists in the United States have developed a new group of antibodies that could eventually help prevent infection by Epstein-Barr virus (EBV), one of the most widespread viruses affecting humans.

EBV is estimated to have infected the vast majority of adults worldwide. In many cases, the initial infection causes few or no noticeable symptoms, allowing the virus to remain undetected. Once acquired, however, EBV remains in the body for life, usually in a dormant state and under the control of the immune system.

The virus has long attracted scientific attention because of its links to several health conditions. It is best known as the main cause of infectious mononucleosis, but it has also been associated with certain cancers and with multiple sclerosis. The risk of serious complications can be considerably higher in people whose immune systems are weakened, including some organ and bone-marrow transplant recipients.

In a recent study, researchers from Fred Hutchinson Cancer Center and the University of Washington focused on two proteins found on the surface of EBV: gp350 and gp42. These proteins play important roles in allowing the virus to attach to and enter B cells, a type of white blood cell that is central to the body's immune response.

The researchers developed 10 previously identified antibody candidates capable of targeting these viral proteins. Two were directed against gp350, while eight targeted gp42. The objective was to determine whether blocking these proteins could prevent the virus from entering susceptible cells and establishing an infection.

One of the antibodies showed particularly promising protective effects when tested in laboratory mice with immune systems designed to reproduce important characteristics of the human immune response. The findings suggest that antibodies targeting specific entry mechanisms could potentially provide a way to interfere with EBV before it becomes established in the body.

Developing effective antibodies against EBV has been challenging because of the virus's complex interaction with B cells. Researchers have therefore been looking for precise points of vulnerability that could be targeted without interfering excessively with normal immune function.

To improve the relevance of their experiments, the team used genetically engineered mice capable of producing antibodies with human-like characteristics. Such models can help researchers evaluate potential antibody therapies before moving to human studies, although promising animal results do not necessarily guarantee that a treatment will be safe or effective in people.

The potential medical applications could be particularly important for patients undergoing organ or bone-marrow transplantation. These patients often receive immunosuppressive medications to prevent rejection, but the resulting weakened immune response can allow EBV to become active and cause serious complications.

One concern is post-transplant lymphoproliferative disorder, or PTLD, in which lymphocytes begin multiplying uncontrollably. In some cases, the condition can develop into an aggressive form of cancer. Preventing EBV infection or limiting its ability to reactivate could therefore become an important strategy for protecting vulnerable patients.

The approach could also be relevant to children receiving organ transplants who have never previously been exposed to EBV. Preventing infection in such high-risk patients could potentially reduce the likelihood of severe virus-related complications later.

Despite the encouraging findings, the research remains at an early stage. The antibodies have not yet been tested in human clinical trials, and researchers will need to establish their safety, dosage, effectiveness and potential side effects before considering them for medical use.

The findings are part of a broader effort to develop new ways of controlling EBV. Researchers around the world are also investigating vaccine strategies designed to prevent infection before the virus can establish its lifelong presence in the body.

If future studies confirm the effectiveness of these antibodies in humans, they could eventually become part of a preventive strategy for people at particularly high risk of EBV-related complications. For now, however, the results represent an important experimental step rather than an available treatment.