cell culture
Norovirus
© igor/Dollar Photo Club
cultured in the lab
Forty-eight years after noroviruses were first identified, US scientists have found a way to grow them in the lab. Their study, published in the journal Science, will allow researchers to explore and develop procedures to prevent and treat infection and to better understand norovirus biology.
N
in patients with chronic norovirus infections, the virus could be detected in intestinal cells called enterocytes, but normal human enterocyte cells orovirus, also known as winter
rapidly died when put into culture.
vomiting bug or the cruise ship virus, is the leading
“A breakthrough came when we learned
cause of illness and outbreaks from contaminated
that Dr Hans Clevers’ team in the Netherlands
food. Unfortunately, the virus does not grow in
had developed a method to make a new type of
laboratory cultures that traditionally support
human intestinal epithelial cell culture system
the growth of other viruses, such as transformed
including enterocytes,” Dr Estes said. “These novel,
cells that are derived from cancerous tissues.
multicellular human cultures, called enteroids, are
In addition, noroviruses are species specific —
made from adult intestinal stem cells from patient
human noroviruses only infect and cause disease in
tissues. We anticipated that putting the virus in
humans, and mouse noroviruses only do so in mice.
these non-transformed human cell cultures would
Human noroviruses do not grow in mice or other
let the virus grow.”
small animal models typically used for research.
It took Dr Estes and colleagues about one
“People have been trying to grow norovirus in
year to get the human intestinal epithelial cultures
the lab for a very long time. We tried for the last
growing well in the lab. After successfully testing
20 years,” said senior author Dr Mary Estes from
the cultures with another human gastrointestinal
the Baylor College of Medicine. “Despite all the
virus — rotavirus — they tried with the human
attempts and the success of growing other viruses,
norovirus.
it remained a mystery why noroviruses were so hard to work with.” Dr Estes theorised that scientists had not
“[We] found that some strains would grow, but others wouldn’t,” said Dr Estes. “We suspected that still something was missing.”
succeeded at growing noroviruses because they
The researchers tried to improve the growth of
didn’t have the right cell type. She showed that
the viruses by adding to the cultures substances that
www.LabOnline.com.au | www.LifeScientist.com.au
LAB+LIFE SCIENTIST - Oct/Nov 2016 | 23