Abstract (EN):
In the present study we have compared the immunophenotypic characteristics of the CD56(+10) and CD56(+hi) NK-cell subsets in a group of normal healthy adults. Our results show that CD56(+hi) NK-cells display greater light-scatter properties than CD56(+10) NK-cells at the same time they have higher levels of CD25 and CD122 IL-2 chains, together with a higher reactivity for HLA-DR and CD45RO and lower levels of CD45RA, supporting that, as opposed to the majority of the CD56(+10) population, CD56(+hi) NK-cells might correspond to a subset of activated circulating NK-lymphocytes. Higher expression of the CD2 and CD7 costimulatory molecules found for the CD56(+hi) NK-cells would support their greater ability to respond to various stimuli. In addition, CD56(+hi) NK-cells expressed higher levels of several adhesion molecules such as CD2, CD11c, CD44, CD56, and CD62L compared to CD56(+10) NK-cells, supporting a particular ability of these cells to migrate from blood to tissues and/or a potential advantage to form conjugates with target cells. Interestingly, CD56(+10) and CD56(+hi) NK-cells showed a different pattern of expression of killer receptors that might determine different activation requirements for each of these NK-cell subsets. For instance, absence or low levels of CD16 expression might explain the lower antibody-dependent cytotoxicity activity of CD56(+hi) NK-cells. On the other hand, the virtual absence of expression of the CD158a and NKB1 immunoglobulin-like and the greater reactivity for the CD94 lectin-like killer receptors on CD56(+hi) in comparison to CD56(+10) NK-cells might determine different MHC-class I specificities for both NK-cell subsets, a possibility that deserves further studies to be confirmed. (C) 2001 Academic Press.
Language:
English
Type (Professor's evaluation):
Scientific
No. of pages:
13