ImmGen Report: Molecular definition of Natural Killer cell identity and activation

Using whole-genome microarray datasets of the Immunological Genome Project, we demonstrate a closer transcriptional relationship between NK and T cells than any other leukocytes, distinguished by their expression of similar signaling functions. While resting NK cells were known to share expression of a few genes with cytotoxic CD8(+) T cells, transcriptome-wide analysis demonstrates that the commonalities extend to hundreds of genes, many with unknown functions. The NK cell response to viral infection is dampened relative to cytotoxic CD8(+) T cells, in part due to their “pre-primed” state. Collectively, the data provide global context for known and novel molecular aspects of NK cell identity and function by delineating the genome-wide repertoire of gene expression of NK cells in various states.