Description
Research in human immunobiology is mainly based on working with peripheral blood mononuclear cells (PBMC). However, recent investigations have shown that circulating CD4+ T cells are less sensitive to several T-cell activating monoclonal antibodies (mAb) and to recall antigens as compared to tissue-resident cells or cells that were in-vitro cultured at a high cell density of 10^7 cells/mL for 2 days at 37C and 5% CO2 (RESTORE protocol, Rmer et al., Blood 2011, PMID: 21931118). To explain the increase in sensitivity of CD4+ T-cells to mAbs and recall antigens on a molecular level, we performed microarray hybridizations of total RNA from T-cells isolated from PBMC that were cultured at a low or high cell density. To avoid the detection of genes that are up- or down-regulated by the culture process itself, we used low cell density cultured PBMC, instead of freshly prepared PBMC.