Oncolytic H-1 parvovirus binds to sialic acid on laminins for cell attachment and entry

Amit Kulkarni,Tiago Ferreira,Lars A R Ystaas,Hrvoje Miletic,Laurent Brino,Valérie Palissot,Serena Bonifati,Antonio Marchini,Anna Golebiewska,Ralf Roeth,Tiina Marttila,Clemens Bretscher,Amélie Weiss,Annabel Grewenig,Beate Niesler,Francisco Azuaje,Simone P Niclou,Jubayer A Hossain,Nazim El-Andaloussi

doi:10.1038/s41467-021-24034-7

Abstract

H-1 parvovirus (H-1PV) is a promising anticancer therapy. However, in-depth understanding of its life cycle, including the host cell factors needed for infectivity and oncolysis, is lacking. This understanding may guide the rational design of combination strategies, aid development of more effective viruses, and help identify biomarkers of susceptibility to H-1PV treatment. To identify the host cell factors involved, we carry out siRNA library screening using a druggable genome library. We identify one crucial modulator of H-1PV infection: laminin γ1 (LAMC1). Using loss- and gain-of-function studies, competition experiments, and ELISA, we validate LAMC1 and laminin family members as being essential to H-1PV cell attachment and entry. H-1PV binding to laminins is dependent on their sialic acid moieties and is inhibited by heparin. We show that laminins are differentially expressed in various tumour entities, including glioblastoma. We confirm the expression pattern of laminin γ1 in glioblastoma biopsies by immunohistochemistry. We also provide evidence of a direct correlation between LAMC1 expression levels and H-1PV oncolytic activity in 59 cancer cell lines and in 3D organotypic spheroid cultures with different sensitivities to H-1PV infection. These results support the idea that tumours with elevated levels of γ1 containing laminins are more susceptible to H-1PV-based therapies.

Highlights

H-1 parvovirus (H-1PV) is a promising anticancer therapy
One set of cells was left untreated to control the intrinsic cytotoxicity of every transfected small interfering RNA (siRNA) pool, while the other set of cells was infected with recH-1PV-EGFP to analyse H-1PV transduction
Based on the EGFP transduction values, the genes were classified into three groups: (i) putative H-1PV activator genes, whose silencing decreases the EGFP signal, with 151 genes considered as top activators because their silencing reduced EGFP signalling intensity by >70% in comparison with control siRNA; (ii) putative H-1PV repressor genes, whose silencing enhances the EGFP signal, with 89 genes considered as top repressors because their silencing increased EGFP signalling intensity by >160%; and (iii) unrelated genes, whose silencing did not affect EGFP signal significantly, so they are less likely to be implicated in the H-1PV life cycle

Summary

Introduction

H-1 parvovirus (H-1PV) is a promising anticancer therapy. in-depth understanding of its life cycle, including the host cell factors needed for infectivity and oncolysis, is lacking. We provide evidence of a direct correlation between LAMC1 expression levels and H-1PV oncolytic activity in 59 cancer cell lines and in 3D organotypic spheroid cultures with different sensitivities to H-1PV infection These results support the idea that tumours with elevated levels of γ1 containing laminins are more susceptible to H-1PV-based therapies. One promising avenue is the combination of OVs with other forms of immunotherapy (e.g., checkpoint blockade)[3,7,8,9,10,11] Another is to identify patients with tumours whose genetic characteristics are favourable to the virus life cycle and who are most likely to benefit from OV treatment. NS1 activity is modulated by post-translational modifications such as phosphorylation and acetylation[17,19,20]

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