Gene and protein characteristics reflect functional diversity of

Abstract: Recent findings underline the role of NK cell subsets in regulating adaptive immunity. To define characteristics of NK cell subpopula-tions, purified CD56dim and CD56bright NK cells were analyzed by using gene chip arrays covering more than 39,000 transcripts. Gene profiling re-vealed resting NK cells to differ in respect to 473 transcripts with 176 exclusively expressed in CD56dim and 130 solely in CD56bright NK cells. Results were compared with array analyses using mRNA obtained from activated CD56dim and CD56bright NK cells. In this approach, NK cell receptors, cytolytic molecules, adhesion struc-tures, and chemokine ligands showed differential expression patterns in the two subpopulations. These data were validated using FACS, RT-qPCR, or cytokine bead array (CBA) techniques. Cyto-kines produced by CD56dim and CD56bright NK cells were determined using a protein array cover-ing 79 different bioactive mediators. GDNF, IGFBP-1, EGF, and TIMP-2 were detected in both subsets. In contrast, IGFBP-3 and IGF-1 were mainly produced by CD56dim, while GM-CSF