Seasonal Coronaviruses: Receptor Binding, Immune Evasion and Cross-species Transmission

Four seasonal coronaviruses are responsible for 15-30% of the human common cold. As with all coronaviruses, the S-proteins of the seasonal coronaviruses are responsible for entry into the cells of the respiratory tract. To mediate this process, the S-proteins must first bind to molecules on the surface of these cells known as "receptors". Among the seasonal coronaviruses, different host proteins and carbohydrates serve as receptors. At the same time, the human immune system produces "neutralizing antibodies" that bind to the S-protein to block its ability to bind its receptors. In this way, antibodies protect us from viral infection and disease. Vast animal coronavirus reservoirs exist in bats, rodents and other animals and the emergence of new viral threats is deemed to be high. The goal of this work is to study the varied ways that the seasonal coronaviruses have evolved to infect humans and evade the immune system. The knowledge gained will serve in the development of therapeutics and vaccines should new coronaviruses cross species barriers to infect humans.