Lectin from Triticum vulgaris (WGA) Inhibits Infection with SARS-CoV-2 and Its Variants of Concern Alpha and Beta.

Janina Auth,Eva Prieschl-Grassauer,Martina Morokutti-Kurz,Maria Fröba,Ulrich Schubert,Andrea Dolischka,Philipp Graf,Maximilian Große,Christian Setz,Michael Schindler,Natalia Ruetalo,Pia Rauch

doi:10.3390/ijms221910205

Abstract

Even in the face of global vaccination campaigns, there is still an urgent need for effective antivirals against SARS-CoV-2 and its rapidly spreading variants. Several natural compounds show potential as antiviral substances and have the advantages of broad availabilities and large therapeutic windows. Here, we report that lectin from Triticum vulgaris (Wheat Germ Agglutinin) displays antiviral activity against SARS-CoV-2 and its major Variants of Concern (VoC), Alpha and Beta. In Vero B4 cells, WGA potently inhibits SARS-CoV-2 infection with an IC50 of <10 ng/mL. WGA is effective upon preincubation with the virus or when added during infection. Pull-down assays demonstrate direct binding of WGA to SARS-CoV-2, further strengthening the hypothesis that inhibition of viral entry by neutralizing free virions might be the mode of action behind its antiviral effect. Furthermore, WGA exhibits antiviral activity against human coronavirus OC43, but not against other non-coronaviruses causing respiratory tract infections. Finally, WGA inhibits infection of the lung cell line Calu-3 with wild type and VoC viruses with comparable IC50 values. Altogether, our data indicate that topical administration of WGA might be effective for prophylaxis or treatment of SARS-CoV-2 infections.

Highlights

Recent WHO statistics (10 September 2021) report more than 223 million confirmed cases of COVID-19, including up to 4.6 million deaths [1], numbers that are expected to be still on the rise
In order to investigate whether Wheat Germ Agglutinin (WGA) exhibits antiviral activity against SARS-CoV-2, Vero B4 cells (African green monkey kidney cells) were infected with the patient isolate
Cell culture supernatants were harvested after 3 days and virus production was analyzed via quantitative RT-PCR and Western blot

Summary

Introduction

Recent WHO statistics (10 September 2021) report more than 223 million confirmed cases of COVID-19, including up to 4.6 million deaths [1], numbers that are expected to be still on the rise. While vaccination campaigns are ongoing, the emergence and spread of SARS-CoV-2 variants is becoming a major threat to public health. These “Variants of Concern” (VOC) are the result of viral evolution and variability and have the potential to evade vaccine- or infection-induced antiviral immune response [2,3]. In the case of the VOC Delta, recent reports describe headache, sore throat, runny nose, and fever as main symptoms, resembling a common cold and possibly leading to misinterpretations and overlooking of COVID-19 infection [7]

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