While flu pandemics occur every 10 to 40 years, the factors that lead to the emergence of pandemic viruses are not well understood, explains study co-author Adolfo García-Sastre, PhD, Professor of Microbiology at Mount Sinai School of Medicine. "What's most threatening is the possibility of another pandemic, similar to that of 1918, which was caused by a novel influenza subtype virus capable of causing severe respiratory disease and death," says Dr. García-Sastre. "So if we can understand the molecular mechanisms behind its transmission, perhaps we can do something to block transmission and prevent illness."
To do this, Dr. García-Sastre and his team studied two key molecular structures: hemagglutinin, a protein located in of the surface of the influenza virus, and sialic acid, a cellular molecule that is recognized by hemaglutinins of both human and avian strains of influenza virus. These molecules are key to initiation of infection. There are 16 different subtypes of hemagglutinin called H1 through H16, present in influenza virus strains circulating in birds. H1 and H3 are found today in human influenza viruses.
Hemaglutinin helps open the door to the cell to allow the virus to infect. The first step is in this process is the binding of the hemagglutinin to sialic acid containing molecules in the cell surface. There are two primary ways sialic acids are associated with molecules in the cell surface—one is th
Source:The Mount Sinai Hospital / Mount Sinai School of Medicine