Requirements for receptor engagement during infection by adenovirus complexed with blood coagulation factor X

Bradshaw, A.C. , Parker, A.L., Duffy, M.R., Coughlan, L., van Rooijen, N., Kahari, V.M., Nicklin, S.A. and Baker, A.H. (2010) Requirements for receptor engagement during infection by adenovirus complexed with blood coagulation factor X. PLoS Pathogens, 6(10), e1001142. (doi: 10.1371/journal.ppat.1001142)

Abstract

Human adenoviruses from multiple species bind to coagulation factor X (FX), yet the importance of this interaction in adenovirus dissemination is unknown. Upon contact with blood, vectors based on adenovirus serotype 5 (Ad5) binds to FX via the hexon protein with nanomolar affinity, leading to selective uptake of the complex into the liver and spleen. The Ad5:FX complex putatively targets heparan sulfate proteoglycans (HSPGs). The aim of this study was to elucidate the specific requirements for Ad5:FX-mediated cellular uptake in this high-affinity pathway, specifically the HSPG receptor requirements as well as the role of penton base-mediated integrin engagement in subsequent internalisation. Removal of HS sidechains by enzymatic digestion or competition with highly-sulfated heparins/heparan sulfates significantly decreased FX-mediated Ad5 cell binding in vitro and ex vivo. Removal of <i>N</i>-linked and, in particular, <i>O</i>-linked sulfate groups significantly attenuated the inhibitory capabilities of heparin, while the chemical inhibition of endogenous HSPG sulfation dose-dependently reduced FX-mediated Ad5 cellular uptake. Unlike native heparin, modified heparins lacking <i>O</i>- or <i>N</i>-linked sulfate groups were unable to inhibit Ad5 accumulation in the liver 1h after intravascular administration of adenovirus. Similar results were observed <i>in vitro</i> using Ad5 vectors possessing mutations ablating CAR- and/or αv integrin binding, demonstrating that attachment of the Ad5:FX complex to the cell surface involves HSPG sulfation. Interestingly, Ad5 vectors ablated for αv integrin binding showed markedly delayed cell entry, highlighting the need for an efficient post-attachment internalisation signal for optimal Ad5 uptake and transport following surface binding mediated through FX. This study therefore integrates the established model of αv integrin-dependent adenoviral infection with the high-affinity FX-mediated pathway. This has important implications for mechanisms that define organ targeting following contact of human adenoviruses with blood.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Nicklin, Professor Stuart and Bradshaw, Dr Angela and Baker, Professor Andrew and Parker, Dr Alan and Coughlan, Dr Lynda and Duffy, Ms Margaret
• Authors: Bradshaw, A.C., Parker, A.L., Duffy, M.R., Coughlan, L., van Rooijen, N., Kahari, V.M., Nicklin, S.A., and Baker, A.H.
• Subjects: R Medicine > R Medicine (General)
• College/School: College of Medical Veterinary and Life Sciences > School of Cardiovascular & Metabolic Health
• Journal Name: PLoS Pathogens
• Publisher: Public Library of Science
• ISSN: 1553-7366
• ISSN (Online): 1553-7374
• Published Online: 07 October 2010
• Copyright Holders: Copyright © 2010 The Authors
• First Published: First published in PLoS Pathogens 6(10):e1001142
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher