Roles of cytoskeleton in mouse polyomavirus trafficking

6 Roles of cytoskeleton in mouse polyomavirus trafficking ABSTRACT: Mouse polyomavirus (mPyV) is small non-enveloped DNA virus. Its endocytic pathway is studied for a potential utilisation of polyomaviral virus-like particles in gene therapy and/or immunotherapy. mPyV enter cells by internalisation into smooth monopinocytic vesicles. During it's journey through the cell, it pass through early endosomes, and at the time 3 hours post infection, it is localised in endoplasmic reticulum and recycling endosomes. Many aspects of mPyV trafficking and nuclear entry are not clear yet. Time-lapse live imaging fluorescence confocal microscopy was used to describe the mouse polyomavirus intracellular movements. For these studies, we utilised mPyV fluorophore-labeled virions and cells expressing GFP-tagged g-actin or alpha-tubulin. Some virion-loaded vesicles were seen to move with actin organised into dynamic structures. Some of these structures resembled actin comets created by Listeria or vaccinia virus. At the same time post infection (40-60 min post infection), movement of the virion loaded vesicles along mirotubules was observed suggesting the simultaneous involvement of actin and tubulin during mPyV trafficking. Dynamitin, a dominant negative inhibitor of dynein-dynactin function reduced mPyV infection. Taken..