Scientists Isolate mAbs That Neutralize GI Virus

Researchers at Vanderbilt University Medical Center have isolated the first human monoclonal antibodies (mAbs) that can neutralize norovirus, a virus that causes acute gastrointestinal (GI) illness.

The study, published in the journal Gastroenterology on Aug. 28, 2018, suggests that these isolated mAbs “have high potential” for improving diagnosis and treatment of norovirus illness as well as furthering efforts to develop the first effective norovirus vaccine, according to the research team.

Norovirus, a highly contagious virus that causes vomiting and diarrhea, infects nearly 20 million people each year in the United States. While most people recover from norovirus illness in one to three days, the infection contributes to approximately 200,000 deaths worldwide each year, mostly among young children and the elderly. Roughly 600 of those deaths occur annually in the US, the university reports.

Conducted in collaboration with researchers at Baylor College of Medicine and funded in part by the National Institutes of Health, the study isolated mAbs from patients previously infected with norovirus. The researchers tested the neutralizing capability of the antibodies against the live virus grown in a monolayer culture of human cells from the middle segment of the small intestine.

They identified a large panel of human mAbs that neutralize the pandemic GII.4 Sydneystrain of the virus, which the researchers state is the most common norovirus strain currently circulating among humans. The team identified at least three neutralizing sites on the virus that should aid efforts to develop an effective vaccine.

“In the past, no one could grow norovirus in the lab, so progress on developing treatments was slow,” said James Crowe Jr, MD, the paper’s corresponding author and professor in the Departments of Pediatrics and Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, in an Aug. 30, 2018 press release. “Here we combined brand-new technologies for growing norovirus in primary human gut tissues with our state-of-the-art antibody discovery platform to identify these exciting antibodies.”

Crowe, who directs the Vanderbilt Vaccine Center, and his colleagues have developed innovative technologies for isolating and studying antiviral antibodies; they have isolated human mAbs for many pathogenic viruses, including Zika, HIV, dengue, influenza, Ebola, respiratory syncytial virus, and rotavirus. The university says that Crowe’s lab has developed methods that can quickly isolate antibody-producing white blood cells from survivor blood samples. By fusing the white blood cells to fast-growing myeloma (cancer) cells, the researchers can produce large quantities of mAbs that target specific viruses.

Source: Vanderbilt University Medical Center