Repurposing a transplant drug for bone growth

The transplant immunosuppressant drug FK506, also known as tacrolimus or Prograf, can stimulate bone formation in both cell culture and animal Read more

Beyond the amyloid hypothesis: proteins that indicate cognitive stability

If you’re wondering where Alzheimer’s research might be headed after the latest large-scale failure of a clinical trial based on the “amyloid hypothesis,” check this Read more

Mother's milk is OK, even for the in-between babies

“Stop feeding him milk right away – just to be safe” was not what a new mother wanted to hear. The call came several days after Tamara Caspary gave birth to fraternal twins, a boy and a girl. She and husband David Katz were in the period of wonder and panic, both recovering and figuring out how to care for them. “A nurse called to ask how my son was doing,” says Caspary, a developmental Read more

innate immunity

Shape-shifting RNA regulates viral sensor

Congratulations to Emory biochemists Brenda Calderon and Graeme Conn. Their recent Journal of Biological Chemistry paper on a shape-shfting RNA was selected as an Editor’s Pick and cited as a “joy to read… Technically, the work is first class, and the writing is clear.”

Calderon, a former BCDB graduate student and now postdoc, was profiled by JBC in August.

Brenda Calderon, PhD

Calderon and Conn’s JBC paper examines regulation of the enzyme OAS (oligoadenylate synthetase). OAS senses double-stranded RNA: the form that viral genetic material often takes. When activated, OAS makes a messenger molecule that drives internal innate immunity enzymes to degrade the viral material (see below).

OAS is in turn regulated by a non-coding RNA, called nc886. Non-coding means this RNA molecule is not carrying instructions for building a protein. Calderon and Conn show that nc886 takes two different shapes and only one of them activates OAS.

Conn says in a press release prepared by JBC that although nc886 is present in all human cells, it’s unknown how abundance of its two forms might change in response to infection. Read more

Posted on by Quinn Eastman in Uncategorized Leave a comment

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

When your immune system calls the shots

Bali Pulendran, PhD

A tiny invader, perhaps a virus or a microbe, enters the body, and our ancient immune system responds. But how does it know what kind of invader has landed? And once it knows, how does it decide what kind of immune response it should launch?

In humans, the immune system consists of two parallel systems working with one another to fend off invaders. One is the innate immune system, the other the adaptive immune system.

Immunologist Bali Pulendran studies how those two systems work together to identify and respond to all kinds of intruders including pathogens, viruses and microbes.

It’s the innate immune system’s job to recognize the first signs of infection—that is, the moment a pathogen enters the body. “In a sense they act as smoke detectors if you will,” says Pulendran. “Little alarms.”

Read more

Posted on by Robin Tricoles in Immunology Leave a comment