• Since the inhibition of phosphinositide-3-kinase ? (PI3K?) is known to result in the overall increase of cell surface expression of L-selectin in CTLs and other types of leucocytes (1, 2), we propose to study the potential pathways linking PI3K? inhibition and L-selectin expression in host immune responses against viral infections.
  • The leucocyte restricted homing molecule L-selectin has not been considered an important molecule on influenza-specific CTLs since expression is downregulated following T cell activation and is low on CTLs harvested from infected lungs.Ê
  • However, Dr Ager has shown that L-selectin is re-expressed on influenza-specific CTLs before lymph node egress and L-selectin is essential for virus clearance since L-selectin null CTLs cannot control influenza infection despite being activated in lymph nodes.Ê
  • Moreover, L-selectin enhanced CTLs expressing a shedding-resistant mutant of L-selectin, which do not downregulate L-selectin following activation (L?P) are superior in controlling influenza infection.