A Recombinant Sialidase Fusion Protein Effectively Inhibits Human Parainfluenza Viral Infection In Vitro and In Vivo

Anne Moscona,Lori Aschenbrenner,Fang Fang,David Wurtman,Gallen Triana‐Baltzer,Qi‐Xiang Li,Matteo Porotto,Stefan Niewiesk,Samantha Palmer,Caroline Tai

doi:10.1086/653621

Anne Moscona, Lori Aschenbrenner + Show 8 more

Open Access

https://doi.org/10.1086/653621

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Abstract

The first step in infection by human parainfluenza viruses (HPIVs) is binding to the surface of respiratory epithelial cells via interaction between viral receptor-binding molecules and sialic acid-containing receptors. DAS181, a recombinant sialidase protein containing the catalytic domain of Actinomyces viscosus sialidase, removes cell surface sialic acid, and we proposed that it would inhibit HPIV infection. Depletion of sialic acid receptors by DAS181 was evaluated by lectin-binding assays. Anti-HPIV activity in cultured cell lines and in human airway epithelium was assessed by the reduction in viral genomes and/or plaque forming units on treatment. In vivo efficacy of intranasally administered DAS181 was assessed using a cotton rat model. DAS181-mediated desialylation led to anti-HPIV activity in cell lines and human airway epithelium. Intranasal DAS181 in cotton rats, a model for human disease, significantly curtailed infection. Enzymatic removal of the sialic acid moiety of HPIV receptors inhibits infection with all tested HPIV strains, both in vitro and in cotton rats. Enzyme-mediated removal of sialic acid receptors represents a novel antiviral strategy for HPIV. The results of this study raise the possibility of a broad spectrum antiviral agent for influenza virus and HPIVs.

Highlights

The first step in infection by human parainfluenza viruses (HPIVs) is binding to the surface of respiratory epithelial cells via interaction between viral receptor-binding molecules and sialic acid–containing receptors
DAS181-mediated desialylation led to anti-HPIV activity in cell lines and human airway epithelium
The results of this study raise the possibility of a broad spectrum antiviral agent for influenza virus and HPIVs

Summary

Methods

Anti-HPIV activity in cultured cell lines and in human airway epithelium was assessed by the reduction in viral genomes and/ or plaque forming units on treatment. In vivo efficacy of intranasally administered DAS181 was assessed using a cotton rat model. LLC-MK and CV-1 cell lines were obtained from American Type Culture Collection (ATCC) and maintained in MEM/EBSS media supplemented with 10% fetal bovine serum, 1ϫ Glutamax (Invitrogen), and 1ϫ Antibiotic/ Antimycotic solution (Sigma) at 37ЊC in a humidified atmosphere of 5% CO2. Virus stocks of HPIV-1 (C-35), HPIV-2 (Greer), HPIV-3 (C243; “HPIV3C”), and Sendai (murine PIV1, strain 52) were obtained from ATCC and propagated on LLC-MK cells. IFV A/PortChalmers/1/73 (H3N2) was obtained from ATCC, propagated on MDCK cells, and tested for drug sensitivity in HAE cells as described elsewhere [20]

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