Experimental monoclonal antibodies show promise against Epstein-Barr virus

A panel of investigational monoclonal antibodies (mAbs) targeting different sites of the Epstein-Barr virus (EBV) blocked the infection when tested in human cells in the laboratory. Moreover, one of the experimental mAbs provided almost complete protection against EBV infection and lymphoma when tested in mice.

The results appear online today in the journal Immunity. Scientists from the National Institute of Allergy and Infectious Diseases (NIAID), which is part of the National Institutes of Health, in collaboration with researchers from the Walter Reed Army Institute of Research, led the study.

EBV is one of the most common human viruses. After infection with EBV, the virus lies dormant in the body, but in some cases it can reactivate. It is the main cause of infectious mononucleosis and is associated with some cancers, including Hodgkin’s lymphoma and autoimmune diseasessuch as multiple sclerosis.

People with weakened immune systems such as transplant recipients, are more likely than immunocompetent individuals to develop severe symptoms and complications from EBV infection. There is no licensed vaccine to protect against the virus.

Researchers have developed several experimental mAbs that target two key proteins—gH and gL—found on the surface of EBV. These two proteins are known to promote EBV fusion human cells and cause infection. When tested in the laboratory, the investigational mAbs prevented EBV infection of human B cells and epithelial cells lining the throat at the initial site of EBV infection.

By analyzing the structure of mAbs and their two surface proteins using X-ray crystallography and extended microscopy, the researchers identified several sites of vulnerability on virus to aim When tested in mice, one of the experimental mAbs, called mAb 769B10, provided almost complete protection against EBV infection when administered. The mAb also protected all mice tested against EBV lymphoma.

According to the researchers, the findings highlight viable EBV vaccine targets and the potential for using experimental mAbs alone or in combination to prevent or treat EBV infection in immunocompromised patients most susceptible to severe EBV-related disease. Additional studies with mAb 769B10 are planned, the authors note.