Importance of LXR-alpha transcriptome in the modulation of innate immunity.

Liver-X-Receptor alpha (LXR-alpha) that belongs to nuclear receptor/transcriptional factor family has been recognized to play crucial role in the regulation of lipid metabolism and inflammation. Consequently, the present study was addressed to explore the functional genomics of LXR-alpha within human blood immunomodulatory cells. The results of such a study, which involved LXR-alpha gene silencing through siRNA approach, revealed that: (a) the mRNA expression of genes coding for IL-8, IL-4, CX3CR1, LDLR, hTERT and c-myc was significantly elevated in response to LXR-alpha gene silencing whereas mRNA expression of genes coding for PPARs(alpha, gamma), CD36 and Dicer could not be detected; (b) the expression of Receptor C( k ) protein remained unaffected; (c) the mRNA expression of IFN-gamma gene was down regulated in LXR-alpha knockdown cells. Based upon these results we propose that LXR-alpha gene plays a crucial role in the regulation of innate immunity at the genomic level.