Pneumonia Due to Human Coronavirus OC43 in an Immunocompetent Adult Detected by Multiplex Polymerase Chain Reaction

Montelukast Inhibits HCoV-OC43 Infection as a Viral Inactivator

Coronaviruses (CoVs) consist of a large group of RNA viruses causing various diseases in humans and in lots of animals. Human coronavirus (HCoV) OC43, the prototype of beta-coronavirus discovered in the 1960s, has been circulating in humans for long time, and infection with other emerging strains of beta-coronavirus (SARS-CoV, SARS-CoV-2, and MERS-CoV) can lead to severe illness and death. In this study, we found that montelukast, a leukotriene receptor antagonist, potently inhibited the infection of HCoV-OC43 in distinct cells in a dose- and time- dependent manner. Additionally, the results showed that montelukast induced release of HCoV-OC43 genomic RNA by disrupting the integrity of the viral lipid membrane, and irreversibly inhibited viral infection. Considering the similarity among HCoV-OC43, MERS-CoV, and SARS-CoV-2, it suggests that montelukast may be a potential candidate for the treatment of human beta-coronavirus infection.

Roles of Sialyl Glycans in HCoV-OC43, HCoV-HKU1, MERS-CoV and SARS-CoV-2 Infections

Ongoing seasonal HCoV-OC43 and HCoV-HKU1 (common cold), an ongoing zoonotic infection of highly lethal MERS-CoV in humans (MERS disease), and an ongoing pandemic SARS-CoV-2 (COVID-19) with high mutability giving some variants causing severe illness and death have been reported to attach to sialyl receptors via their spike (S) glycoproteins and via additional short spikes, hemagglutinin-esterase (HE) glycoproteins, for HCoV-OC43 and HCoV-HKU1. There is lack of zoonotic viruses that are origins of HCoV-HKU1 and the first recorded pandemic CoV (SARS-CoV-2) for studies. In this chapter, we review current knowledge of the roles of sialyl glycans in infections with these viruses in distinct infection stages. Determination of the similarities and differences in roles of sialyl glycans in infections with these viruses could lead to a better understanding of the pathogenesis and transmission that is essential for combating infections with CoVs that recognize sialyl glycans.