Differential phenotypic properties of human peripheral blood CD56(dim+) and CD56(bright+) natural killer cell subpopulations

We investigated the presence of integrins and various other cell surface markers on the surface of freshly isolated CD56(dim+) and CD56(bright+) NK cells, the latter comprising a mean of 6.5% of total peripheral 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 CD56(bright+) cells, other myeloid markers were not found. 28% of CD56(bright+) cells were positive for CD45RO. These results support the notion that CD56(bright+) NK cells, based on their different marker profile, may possess different functional and biodistributional properties and - due to the signal-transducing capabilities of several adhesion molecules - differential patterns of stimulability compared to the majority of PB-NK cells.