Christalyn Rhodes

Normal airway epithelial cells do not move much when cultured in a lab plate. In fact, they become jammed, forming a solid-looking layer of cells. Surprisingly, the same cells from asthma patients behave differently. They are unjammed, moving around the plate in a coordinated fashion. This form of cellular movement is known as collective cell migration and is believed to play an important role in the pathophysiology of asthma.

A number of genetic and environmental risk factors are associated with the development of asthma: allergies, a parent with asthma, smoking. One factor that stood out for Christalyn Rhodes, a PhD candidate in the Biological Sciences in Public Health program at the Harvard T. H. Chan School of Public Health, was frequent viral respiratory tract infections. “There is all this epidemiological data that shows that if you have recurring cold infections before the age of three, your odds of developing asthma are much higher.”

Rhodes wondered if infection with a rhinovirus, the virus responsible for common colds, could push jammed epithelial cells to behave like unjammed asthmatic cells in culture. As she predicted, following rhinovirus infection, epithelial cells from non-asthmatic patients became unjammed and began to move in the same collective fashion as asthmatic cells.

The results from these experiments are fascinating for scientists in a number of fields. “They represent the first time we have seen viral infections push jammed epithelial cells to collectively migrate,” Rhodes explains. Collective cell migration was known to occur during cancer invasion, morphogenesis and wound healing. Rhodes results suggest that it might also occur during certain viral infections. “These results also indicate that all the epidemiology association studies that found a connection between colds and asthma are right,” Rhodes adds. For Rhodes, the next steps involve uncovering the mechanism by which rhinoviruses induce collective cell migration, and this could lead to the development of a preventive therapy for asthma.