Oral Presentation 8th Australasian Virology Society Meeting and 11th Annual Meeting of the Australian Centre for Hepatitis & HIV Virology Meeting 2015

The basic domain of HSV-1 pUS9 recruits kinesin-1 to facilitate spread from neurones (#14)

Russell Diefenbach 1 , April Davis 1 , Monica Miranda Saksena 1 , Marian Fernandez 2 , Barbara Kelly 1 , Cheryl Jones 2 , Jennifer LaVail 3 , Jing Xue 4 , Anthony Cunningham 1
  1. Centre for Virus Research, Westmead Millennium Institute for Medical Research, The University of Sydney, Westmead, NSW, Australia
  2. Centre for Perinatal Infection Research, The Children′s Hospital at Westmead, Westmead, NSW, Australia
  3. Departments of Anatomy and Ophthalmology, University of California San Francisco, San Francisco, California, USA
  4. Cell Signalling Unit, Children’s Medical Research Institute, The University of Sydney, Westmead, NSW, Australia

The alphaherpesviral envelope protein pUS9 has been shown to play a role in anterograde axonal transport of HSV-1 yet the molecular mechanism is unknown. To address this, we used an in vitro pulldown assay to define a series of five arginine residues within the conserved pUS9 basic domain that were essential for binding the molecular motor kinesin-1. Mutation of these pUS9 arginine residues to asparagine blocked the binding of both recombinant and native kinesin-1. We next generated HSV-1 with the same pUS9 arginine residues mutated to asparagine (HSV-1pUS9KBDM) and then restored them back to arginine (HSV-1pUS9KBDR). The two mutated viruses were analysed initially in a zosteriform model of recurrent cutaneous infection. The primary skin lesion scores were identical in severity and kinetics and there were no differences in viral load at dorsal root ganglionic (DRG) neurons at day 4 pi for both viruses. In contrast, HSV-1pUS9KBDM showed a partial reduction in secondary skin lesions at day 8 pi compared to HSV-1pUS9KBDR. The use of rat DRG neuronal cultures in a microfluidic chamber system showed both a reduction in anterograde axonal transport and spread from axons to non-neuronal cells for HSV-1pUS9KBDM. Therefore the basic domain of pUS9 contributes to anterograde axonal transport and spread of HSV-1 from neurones to the skin through recruitment of kinesin-1.