DIFFERENTIAL PHENOTYPIC PROPERTIES OF HUMAN PERIPHERAL-BLOOD CD56(DIM-KILLER-CELL SUBPOPULATIONS() AND CD56(BRIGHT+) NATURAL)

We investigated the presence of integrins and various other cell surfa ce markers on the surface of freshly isolated CD56(dim+) and CD56(brig ht+) NK cells, the latter comprising a mean of 6.5% of total periphera l blood (PB) CD3(-)CD56(+) NK cells. This small subpopulation stained more intensively for CD2, CD11c, CD15s, CD44, CD49e, CD55, CD62L, HLA- DR, and GZS-1, whereas there was no expression of CD49f in contrast to CD56(dim+) cells. The myeloid antigen CDw65 was present on 11% of CD5 6(bright+) cells, other myeloid markers were not found. 28% of CD56(br ight+) cells were positive for CD45RO. These results support the notio n that CD56(bright+) NK cells, based on their different marker profile , may possess different functional and biodistributional properties an d - due to the signal-transducing capabilities of several adhesion mol ecules - differential patterns of stimulability compared to the majori ty of PB-NK cells.