Requirements for Receptor Engagement during Infection by Adenovirus Complexed with Blood Coagulation Factor X

PLoS Pathogens

Veli-Matti Kähäri¹  Nico van Rooijen²  Angela C. Bradshaw³  Andrew H. Baker³  Alan L. Parker³  Margaret R. Duffy³  Stuart A. Nicklin³  Lynda Coughlan³ 

[1] Department of Dermatology, University of Turku and Turku University Central Hospital, Turku, Finland;Department of Molecular Cell Biology, Vrije Universiteit Medical Center (VUMC), Amsterdam, The Netherlands;Institute of Cardiovascular and Medical Sciences, British Heart Foundation Glasgow Cardiovascular Research Centre, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom

关键词: Heparin;    Sulfates;    Sulfation;    Integrins;    Adenoviruses;    Cell binding;    Gene transfer;    DAPI staining;   

DOI  :  10.1371/journal.ppat.1001142

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

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 N-linked and, in particular, O-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 O- or N-linked sulfate groups were unable to inhibit Ad5 accumulation in the liver 1h after intravascular administration of adenovirus. Similar results were observed in vitro 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.

【 授权许可】

CC BY