The effects of modified sialic acids on mucus and erythrocytes on influenza A virus HA and NA functions

Karen N. Barnard; Brynn K. Alford-Lawrence; David W. Buchholz; Brian R. Wasik; Justin R. LaClair; Hai Yu; Rebekah Honce; Stefan Ruhl; Petar Pajic; Erin K. Daugherity; Xi Chen; Stacey L. Schultz-Cherry; Hector C. Aguilar; Ajit Varki; Colin R. Parrish

The copyright holder for this preprint (which was not peer-reviewed) is the author/funder. The difference between Neu5Gc and Neu5Ac has been found to influence the tropism of several different viruses, as well as some bacterial toxins (3, 5). Indeed, it has been proposed that the loss of the CMAH gene in humans was an adaptive response to pathogen pressures (40). Neu5Gc is highly expressed in some tissues of IAV natural host species, including pigs 140 and horses, and is also present in the tissues of mice and guinea pigs, which are frequently used as animals models (9, 12, 41) . Neu5Gc has been seen to prevent binding of the HAs of some IAV, particularly in human-adapted strains (39, 42) , but the effects on NA have not been well characterized. Nevertheless, examination of swine IAV isolates found distinct strain differences in their ability to cleave Neu5Gc by sialidase activity which were generally lower 145 than against Neu5Ac (43) .