Is 6-sulfo sialyl Lewis X the common receptor determinant recognized by H5 , H6 , H7 and H9 influenza viruses of terrestrial poultry?
Influenza viruses of terrestrial poultry differ from ancestral duck viruses by enhanced binding to sulfated and/or fucosylated Neu5Ac alpha 2-3Gal-terminated receptors and, occasionally, by the ability to bind to Neu5Ac alpha 2-6Gal-terminated (human-type) receptors. These findings suggest that the adaptation to receptors in poultry can enhance the potential of an avian virus for avian-to-human transmission and pandemic spread.
(i) Age-related decline in thymopoietic efficacy is not dependent on androgen presence, and (ii) androgens are involved in the maintenance of peripheral T-cell (particularly CD4+ cell) homeostasis during aging.