A murine platelet-activating factor receptor gene: cloning, chromosomal localization and up-regulation of expression by lipopolysaccharide in peritoneal resident macrophages.

A murine gene encoding a platelet-activating factor receptor (PAFR) was cloned. The gene was mapped to a region of the D2.2 band of chromosome 4 both by fluorescence in situ hybridization and by molecular linkage analysis. Northern blot analysis showed a high expression of the PAFR message in peritoneal macrophages. When C3H/HeN macrophages were treated with bacterial lipopolysaccharide (LPS) or synthetic lipid A, the PAFR gene expression was induced. Bacterial LPS, but not lipid A, induced the level of PAFR mRNA in LPS unresponsive C3H/HeJ macrophages. These induction patterns were parallel to those of tumor necrosis factor-alpha mRNA. Thus the PAFR in macrophages is important in LPS-induced pathologies.