Drosophila melanogaster - the common fruit fly - was used in this study, due to its similar human immune function qualities, sharing characteristics of cellular and humoral, or extracellular fluids, immunity and signaling pathways. The fruit fly makes such a great model, in fact, that NASA developed a new Fruit Fly Lab in 2014 to accommodate continued study of Drosophila. This facility will support longer duration studies involving multiple generations of fruit flies.
Kimbrell was one of the earliest investigators into Drosophila immunity. As senior researcher in the Department of Molecular and Cellular Biology at UC Davis, she brought Drosophila immunity into space exploration-related studies. Though fruit fly immunity had been studied on Earth, its immunity had not been studied using hypergravity or spaceflight. Kimbrell and her team of researchers wanted to test the immune response of fruit flies impacted by changes in gravity at the organismal level.
"Immune response is central to health for essentially all organisms, and, not surprisingly, in the stressful space environment there are a variety of changes to how a person or other organisms can fight an infection," explained Kimbrell. "In order to try and understand those changes, my group used the simple fruit fly, well-studied for its immune response on Earth, as a model to help sort out at a cell-based level what happens to the immune response when an organism is in space."
There are two main signaling pathways, Toll and Imd, which act as the go-betweens of immune response to fungal and bacterial infections in fruit flies. In humans, Toll counterparts are known as Toll-like receptors (TLRs), since a 2011 Nobel Prize-winning team discovered the Toll pathway response to immunity first in fruit flies. Humans and other mammals share these two
|Contact: Laura Niles|
NASA/Johnson Space Center