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
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 ScienceÂ 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.
Andrew Gewirtz, PhD
Gewirtzâ€™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 itâ€™s better at fighting a virus? As Gewirtz says in a GSU news release: â€œItâ€™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.â€
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 â€“ 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
Flagellin treatment protects against chemicals, bacteria, viruses and radiation
This title for a 2008 paper in Journal of Immunology, from pathologist Andrew Gewirtz’s laboratory, is astounding. Flagellin can protect against all those things (in mice, of course)? What about bullets or heartbreak? What is flagellin?
Flagellin is a structural feature many bacteria have in common — courtesy of iGEM via Creative Commons
Flagellin is the main structural component of flagella, the miniature whips bacteria use to propel themselves.Â Several Emory scientists are investigating how flagellin could be used as a protective agent to strengthen the body’s innate defenses and also as a vaccine component.
Posted on November 19, 2010
by Quinn Eastman
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.
Itâ€™s the innate immune systemâ€™s job to recognize the first signs of infectionâ€”that is, the moment a pathogen enters the body. â€œIn a sense they act as smoke detectors if you will,â€ says Pulendran. â€œLittle alarms.â€