Circadian rhythms go both ways: in and from retina

Removal of Bmal1 accelerates the deterioration of vision that comes with Read more

Genomics plus human intelligence

The power of gene sequencing to solve puzzles when combined with human Read more

'Master key' microRNA has links to both ASD and schizophrenia

Recent studies of complex brain disorders such as schizophrenia and autism spectrum disorder (ASD) have identified a few "master keys," risk genes that sit at the center of a network of genes important for brain function. Researchers at Emory and the Chinese Academy of Sciences have created mice partially lacking one of those master keys, called MIR-137, and have used them to identify an angle on potential treatments for ASD. The results were published this Read more

Andrew Gewirtz

Breaking the rules: flagellin vs rotavirus

Flagellin is a bacterial protein that activates the innate immune system. Its name comes from flagella, the whips many bacteria use to propel themselves.

On Thursday, a team of researchers led by immunologist Andrew Gewirtz reported in Science that treatment with flagellin can prevent or cure rotavirus infection in animals. Rotavirus infection is one of the most common causes of severe diarrhea and is a major cause of death for children in developing countries.

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Andrew Gewirtz, PhD

Gewirtz’s lab is now at Georgia State, but he and his colleagues initiated this research while at Emory and several co-authors are affliliated with Emory, including immunologist Ifor Williams.

These findings are remarkable for several reasons. One is: give the immune system something from bacteria, and it’s better at fighting a virus? As Gewirtz says in a GSU news release: “It’s analogous to equipping an NFL defense with baseball bats. Blatant violation of all the rules but yet, at least in this case, very effective.”

For me, what was most surprising about this paper was that treatment with flagellin, or immune signaling proteins activated by flagellin, can get mice with severely impaired immune systems – no T cells or B cells at all — to evict rotavirus. These are mice that have to be reared under special conditions because they are vulnerable to other infections. Interferons, well-known antiviral signaling molecules, are also not involved in resisting or evicting rotavirus infection, the researchers found. Read more

Posted on by Quinn Eastman in Immunology Leave a comment

How intestinal bacteria influence appetite, metabolism

Pathologist Andrew Gewirtz and his colleagues have been getting some welldeserved attention for their research on intestinal bacteria and obesity.

Briefly, they found that increased appetite and insulin resistance can be transferred from one mouse to another via intestinal bacteria. The results were published online by Science magazine.

Previous research indicated intestinal bacteria could modify absorption of calories, but Gewirtz and his colleagues showed that they influence appetite and metabolism (in mice)

“It has been assumed that the obesity epidemic in the developed world is driven by an increasingly sedentary lifestyle and the abundance of low-cost high-calorie foods,” Gewirtz says. “However, our results suggest that excess caloric consumption is not only a result of undisciplined eating but that intestinal bacteria contribute to changes in appetite and metabolism.”

A related report in Nature illustrates how “next generation” gene sequencing is driving large advances in our understanding of all the things the bacteria in our intestines do to us.

Gewirtz’s laboratory’s discovery grew out of their study of mice with an altered immune system. The mice were engineered to lack a gene, Toll-like receptor 5 (TLR5), which helps cells sense the presence of bacteria.

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Posted on by Quinn Eastman in Immunology Leave a comment