A Long Noncoding RNA Mediates Both Activation and Repression of Immune Response Genes

A New Linc in Innate Immunity Long noncoding RNAs (lncRNAs) have recently emerged as important regulators of gene expression in a wide variety of biological processes, although specific roles for these molecules in the immune system have not been described. Carpenter et al. (p. 789 , published online 1 August) now define the function of one such lncRNA in the immune system, lincRNA-Cox2. Whole-transcriptome profiling revealed that lincRNA-Cox2 was induced in mouse macrophages in response to activation of Toll-like receptors—molecules that detect microbes and alert the immune system to respond. LincRNA-Cox2 both positively and negatively regulated the expression of distinct groups of inflammatory genes. Negative regulation of gene expression was mediated by lincRNA-Cox interaction with heterogeneous nuclear ribonucleoprotein A/B and A2/B1.