Eva Kanso, associate professor of aerospace and mechanical engineering, was awarded a 2016 Integrated NSF Support Promoting Interdisciplinary Research and Education (INSPIRE) grant to lead an interdisciplinary team in the study of the bacteria-host interaction.
The average human body carries around three times more bacterial cells than human ones, according to the American Society for Microbiology. Many of these microbes first interact with the human body along ciliated surfaces, such as in the upper airways. Cilia are microscopic, hair-like structures, that clear harmful bacteria out of the body, while allowing beneficial ones to remain. It is the mechanics of this cilia-bacteria interaction that Kanso and her team are studying. Their results will have important implications in medicine as they provide a better understanding of the structure and function of cilia along the surfaces of tissues.
“We want to understand the interaction between bacteria and ciliated cells,” Kanso said. “How does the mechanical environment that’s created by the cilia shape the behavior of bacteria along the ciliated surface?”
The $1-million, three-year grant was established to address complicated, pressing scientific problems that require the joint effort of two distinct disciplines to solve.
Members of the Kanso-led team include Scott Fraser, provost professor of biomedical engineering and molecular and computational biology and Elizabeth Garrett Professor of Convergent Biosciences, as well as biologists from the University of Hawaii at Manoa. The Hawaii team is led by Professor Margaret McFall-Ngai, Fellow of the National Academy of Science and Director of the Pacific Bioscience Research Center, and Professor Edward Ruby of the Kewalo Marine Laboratory. Janna Nawroth, Technology Development Fellow at the Wyss Institute at Harvard and visiting scholar at the Pacific Bioscience Research Center, is also working with the group.
Dysfunction of ciliary mechanisms, whether due to a genetic disorder or acquired causes, are directly linked to infection and disease. A deeper understanding of cilia mechanics will shed light on this connection, one day impacting the development of diagnostic tools and pharmaceuticals.
“We are interested in motile cilia,” Kanso said. “They are really dense and they have an internal structure— a molecular structure formed of motor proteins and microtubules that allows them to move, to beat basically.”
Their movement is used to clear bacteria and other particles away from the cells they are protecting. “We used to think that this ciliary-mucus clearance forms a strict barrier to everything and clears it out,” Kanso said. “But now there is evidence that the upper airway system is actually host to a lot of beneficial bacteria.” Meaning cilia are able to distinguish between harmful and beneficial bacteria and filter out only the bad.
But how do cilia know which bacteria to filter out and which to allow in? Kanso and her team believe that the best place to start looking for the answer is with the mechanics of the cilia and the flows they create, and how these flows shape the interaction with bacteria.
The group, by studying the Hawaiian bobtail squid and its method of recruiting and regulating bacteria for bioluminescence using cilia, will develop predictive, physics-based computer models to determine exactly how the ciliary mechanism functions.
“Right now, it’s a basic science question,” Kanso said. “But if we understand that better, then it will have consequences in medicine and biotechnology. It could enable new designs or new ideas in the diagnostics of infectious diseases and in drug development.”