Glycan and Its Role in Combating COVID-19

Newly identified beta-coronavirus i.e. the 2019 novel coronavirus is associated with a contagious transmittable respiratory disease called COVID-19. This disease has been declared as a "pandemic" by the World Health Organization (WHO). The entry of coronavirus in the human respiratory epithelial cells depends upon the interaction between host cell receptor ACE2 and viral S-glycoprotein. However, this type of molecular recognition in between cell surface receptors and envelope glycoproteins are mediated by specific glycan epitopes and attribute to viral entry through membrane fusion. Glycans are essential biomolecules made by all living organisms, have roles in serving structure, energy storage, and system regulatory purposes. The glycan shield plays a crucial role in concealing the surface S protein from molecular recognition. The immunomodulatory properties of Glycan-binding proteins (GBPs) like Lectins, build them as an attractive candidates for vaccine adjuvant. Investigations involving the complement system activation by the lectin pathway in COVID-19 and diseases are in need of the hour. The innate immune response involving complement system could have varied biological effects against an array of microbial infections. The advances in glycoprotein style methods especially immunomodulatory action of some lectins are necessary to boost the effectiveness of treatment of COVID-19 and other pandemics.