Receptor Specificity in Surveillance of Natural Sequence Evolution of Influenza A Virus Hemagglutinin
Rahul Raman, Kannan Tharakaraman, Zachary Shriver, Akila Jayaraman, V. Sasisekharan and Ram Sasisekharan
from: Influenza: Current Research (Edited by: Qinghua Wang and Yizhi Jane Tao). Caister Academic Press, U.K. (2016) Pages: 101-120.
Influenza A viruses are rapidly evolving pathogens with potential for novel strains to emerge and cause human pandemics. H1N1, H2N2 and H3N2 influenza A virus (known as human viruses) hemagglutinin (HA) binds to glycan receptors in the human upper respiratory epithelia that are terminated by α2,6-linked sialic acid (also known as human receptors), a critical feature that permits the virus to efficiently infect and transmit via aerosol in humans. The avian-adapted H5N1, H9N1, H7N7, H7N2 and H7N9 have shown binding to human receptors, cause severe infections in humans and are rapidly evolving in various species but are yet to adapt to the human host to establish sustained circulation. There is a need to better understand and differentiate glycan receptor binding properties between these avian-adapted and human viruses. This chapter offers perspectives on structural and biochemical analyses of HA-glycan receptor interactions from standpoint of distinguishing receptor specificity of human and avian viruses and also in the context of their natural evolution. The perspectives offered in this chapter are intended to expand the current thinking and hence understanding of HA-glycan specificity to facilitate improved surveillance and preparedness in the event of an emergence of a novel strain with pandemic potential read more ...