Amino acid variation at VP1-145 of enterovirus A71 determines the viral infectivity and receptor usage in a primary human intestinal model

Ikrame Aknouch; Inés García-Rodríguez; Francesca Paola Giugliano; Carlemi Calitz; Gerrit Koen; Hetty van Eijk; Nina Johannessson; Sjoerd Rebers; Lieke Brouwer; Vanesa Muncan; Koert J Stittelaar; Dasja Pajkrt; Katja C Wolthers; Adithya Sridhar

doi:10.3389/fmicb.2023.1045587

Amino acid variation at VP1-145 of enterovirus A71 determines the viral infectivity and receptor usage in a primary human intestinal model

Front Microbiol. 2023 Apr 17:14:1045587. doi: 10.3389/fmicb.2023.1045587. eCollection 2023.

Authors

Ikrame Aknouch^{1

2

3}, Inés García-Rodríguez^{1

2}, Francesca Paola Giugliano⁴, Carlemi Calitz^{1

2}, Gerrit Koen¹, Hetty van Eijk¹, Nina Johannessson^{1

2}, Sjoerd Rebers¹, Lieke Brouwer^{1

2}, Vanesa Muncan⁴, Koert J Stittelaar⁵, Dasja Pajkrt², Katja C Wolthers¹, Adithya Sridhar^{1

2}

Affiliations

¹ Department of Medical Microbiology, OrganoVIR Labs, Amsterdam UMC, Location Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands.
² Department of Pediatric Infectious Diseases, Emma Children's Hospital, Amsterdam UMC, Location Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands.
³ Viroclinics Xplore, Schaijk, Netherlands.
⁴ Tytgat Institute for Intestinal and Liver Research, Amsterdam Gastroenterology Endocrinology and Metabolism, Amsterdam UMC, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands.
⁵ Department of Epidemiology, Bioinformatics and Animal Models, Wageningen Bioveterinary Research, Wageningen University, Wageningen, Netherlands.

Abstract

Enterovirus A71 (EV-A71) can elicit a wide variety of human diseases such as hand, foot, and mouth disease and severe or fatal neurological complications. It is not clearly understood what determines the virulence and fitness of EV-A71. It has been observed that amino acid changes in the receptor binding protein, VP1, resulting in viral binding to heparan sulfate proteoglycans (HSPGs) may be important for the ability of EV-A71 to infect neuronal tissue. In this study, we identified that the presence of glutamine, as opposed to glutamic acid, at VP1-145 is key for viral infection in a 2D human fetal intestinal model, consistent with previous findings in an airway organoid model. Moreover, pre-treatment of EV-A71 particles with low molecular weight heparin to block HSPG-binding significantly reduced the infectivity of two clinical EV-A71 isolates and viral mutants carrying glutamine at VP1-145. Our data indicates that mutations in VP1 leading to HSPG-binding enhances viral replication in the human gut. These mutations resulting in increased production of viral particles at the primary replication site could lead to a higher risk of subsequent neuroinfection.

Importance: With the near eradication of polio worldwide, polio-like illness (as is increasingly caused by EV-A71 infections) is of emerging concern. EV-A71 is indeed the most neurotropic enterovirus that poses a major threat globally to public health and specifically in infants and young children. Our findings will contribute to the understanding of the virulence and the pathogenicity of this virus. Further, our data also supports the identification of potential therapeutic targets against severe EV-A71 infection especially among infants and young children. Furthermore, our work highlights the key role of HSPG-binding mutations in the disease outcome of EV-A71. Additionally, EV-A71 is not able to infect the gut (the primary replication site in humans) in traditionally used animal models. Thus, our research highlights the need for human-based models to study human viral infections.Graphical Abstract.

Keywords: EV-A71; Transwell; VP1-145; heparin sulfate proteoglycan; human inestinal organoids; polarized epithelium.