NANOSCALE IMAGING OF ANTIVIRAL INNATE IMMUNITY IN THE ZEBRAFISH, DANIO RERIO

NANOSCALE IMAGING OF ANTIVIRAL INNATE IMMUNITY IN THE ZEBRAFISH, DANIO RERIO

By Kristin A. Gabor

Thesis Advisors: Dr. Carol H. Kim and Dr. Samuel T. Hess

A Lay Abstract of the Thesis Presented in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy (in Interdisciplinary Studies in Functional Genomics) May, 2012

Keywords: Innate Immunity, Antiviral response, Caveolae, Super-Resolution microscopy, Zebrafish

Viral infections affect billions of people worldwide. Examples of common human diseases that are caused by viruses include the common cold, influenza, and chickenpox. Each year there are three to five million cases of influenza and two million instances of hepatitis C. These two viruses alone account for over a million deaths annually. Caveolae are cell membrane domains that have been shown to be associated with viral infections. An aim of my research is to investigate the role of caveolae in the immune response to virus invasion. My work provides new insights into viral abrogation of host immune responses, characterizes a new model organism for studying influenza infection, and extends a novel imaging tool to perform these studies with unprecedented resolution. This research presents novel microscopic evidence for viral disruption of caveolae, and the ultimate suppression of the host antiviral signaling response. Visualization of caveolae has previously been hampered by the inability to image with sufficient resolution. Novel imaging tools such as Fluorescence Photoactivation Localization Microscopy (FPALM) recently have overcome the limitations of conventional microscopy, thus enabling us to study the relationship between invading viruses, the host immune response, and the role of caveolae at the single molecule level. Using FPALM, we reveal a mechanism for virus evasion of host cell defenses through disruption of clusters of antiviral signaling molecules organized within caveolae. We demonstrate that a functional consequence of caveolar disruption is the dispersal of antiviral molecules and inhibition of the host antiviral response. This has broader implications for the role of caveolae in antiviral immunity. Further, we have characterized and demonstrated that Influenza A Virus can infect and replicate in zebrafish, causing a disease state. This provides us with a model to study antiviral immunity in a living organism using a pathogen relevant to human disease. To perform experiments in a physiologically relevant system with sufficient spatial resolution, we have extended FPALM to the level of a living vertebrate organism. Understanding the complex mechanisms through which viruses modulate immune function should provide insight into a range of potential targeted antiviral therapies.