Gene expression of Natural Killer cell-primed monocytes and their subsequent derived dendritic cells

Transcriptome analysis of monocytes directly exposed to cell-to-cell contact with Natural Killer (NK) cells or separated by a transwell membrane and their subsequent monocyte-derived dendritic cells. The role of Natural Killer (NK) cells in the early differentiation of monocytes into dendritic cells (DCs) is poorly understood. Their interaction is thought to be restricted to a bilateral cross talk of soluble cytokines. However, many authors have shown that NK cells effect over myeloid cells is dependent on direct cell-to-cell contact. In order to understand what determines a major effect of NK cells over monocytes and their derived DCs, total RNA samples from purified monocytes and monocyte-derived DCs, exposed to direct contact with NK cells or separated by a transwell membrane were amplified and hybridized to the Affymetrix Human GeneChip 2.0 ST array. Analyses were performed using BRB-ArrayTools version 4.5.0, developed by Dr. Richard Simon and the BRB-ArrayTools Development Team. We found that compared to untouched monocytes, cell-to-cell contact with NK cells modified the expression of 283 genes whereas contact through a transwell membrane modified the expression of 35 genes. After differentiation and compared to DCs derived from untouched monocytes, DCs derived from monocytes allowed to direct cell-to-cell contact with NK cells had the expression of 128 genes modified whereas DCs derived from monocytes primed through a transwell membrane had only 2 genes modified. Our results suggested that cell-to-cell interactions with NK cells are important to imprint a stable transcriptional program in monocytes lasting even after their further differentiation into DCs. We analyzed RNA samples extracted from purified monocytes and their subsequent derived DCs obtained from blood of 5 unrelated healthy male donors from the NIH Clinical Center Department of Transfusion Medicine, protocol No. 99-CC-0168), previously exposed to autologous NK cells. Samples were analyzed using the Affymetrix Human GeneChip 2.0 ST array and data was processed by BRB-ArrayTools developed by Dr. Richard Simon and the BRB-ArrayTools Development Team and Partek (Partek Inc.). No technical replicates were performed.