Human adenovirus serotype 5 is sensitive to IgM-independent neutralization in vitro and in vivo

Doszpoly, A., de la Cuesta, F., Lopez-Gordo, E., Bénézech, C., Nicklin, S. A. and Baker, A. H. (2019) Human adenovirus serotype 5 is sensitive to IgM-independent neutralization in vitro and in vivo. Viruses, 11(7), 616. (doi: 10.3390/v11070616) (PMID:31284434) (PMCID:PMC6669743)

189622.pdf - Published Version
Available under License Creative Commons Attribution.



Human adenovirus 5 (HAdV-5) is used as a vector in gene therapy clinical trials, hence its interactions with the host immune system have been widely studied. Previous studies have demonstrated that HAdV-5 binds specifically to murine coagulation factor X (mFX), inhibiting IgM and complement-mediated neutralization. Here, we examined the physical binding of immune components to HAdV-5 by nanoparticle tracking analysis, neutralization assays, mass spectrometry analysis and in vivo experiments. We observed that purified mouse Immunoglobulin M (IgM) antibodies bound to HAdV-5 only in the presence of complement components. Active serum components were demonstrated to bind to HAdV-5 in the presence or absence of mFX, indicating that immune molecules and mFX might bind to different sites. Since binding of mFX to HAdV-5 blocks the neutralization cascade, these findings suggested that not all complement-binding sites may be involved in virion neutralization. Furthermore, the data obtained from serum neutralization experiments suggested that immune molecules other than IgM and IgG may trigger activation of the complement cascade in vitro. In vivo experiments were conducted in immunocompetent C57BL/6 or immuno-deficient Rag2-/- mice. HAdV-5T* (a mutant HAdV-5 unable to bind to human or mFX) was neutralized to some extent in both mouse models, suggesting that murine immunoglobulins were not required for neutralization of HAdV-5 in vivo. Liquid Chromatography-Mass Spectrometry (LC-MS/MS) analysis of HAdV-5 and HAdV-5T* after exposure to murine sera showed stable binding of C3 and C4b in the absence of mFX. In summary, these results suggest that HAdV-5 neutralization can be mediated by both the classical and alternative pathways and that, in the absence of immunoglobulins, the complement cascade can be activated by direct binding of C3 to the virion.

Item Type:Articles
Additional Information:Also funded by a Biotechnology and Biological Sciences Research Council 532 Grant (BB/L027933/1) and the European Commission (FP7 IAPP 324325).
Glasgow Author(s) Enlighten ID:Baker, Professor Andrew and Lopez Gordo, Miss Estrella and Nicklin, Professor Stuart and Doszpoly, Dr Andor
Authors: Doszpoly, A., de la Cuesta, F., Lopez-Gordo, E., Bénézech, C., Nicklin, S. A., and Baker, A. H.
College/School:College of Medical Veterinary and Life Sciences > School of Cardiovascular & Metabolic Health
Journal Name:Viruses
ISSN (Online):1999-4915
Published Online:05 July 2019
Copyright Holders:Copyright © 2019 The Authors
First Published:First published in Viruses 11(7):616
Publisher Policy:Reproduced under a Creative Commons License

University Staff: Request a correction | Enlighten Editors: Update this record

Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
583362BHF Chair of Translational Cardiovascular SciencesAndrew BakerBritish Heart Foundation (BHF)SS/CH/11/2/28733RI CARDIOVASCULAR & MEDICAL SCIENCES