Differential expression of members of the N-formylpeptide receptor gene cluster in human phagocytes.

The human genes for two N-formylpeptide phagocyte chemoattractant receptors (gene symbols FPR1 and FPRL1) cross-hybridize with each other and with FPRL2, a human gene of unknown expression and function. The FPR1 product is approximately 1000-fold more sensitive than the FPRL1 product to N-formylpeptides. We now report cloning of the first cDNA for FPRL2 and the first description of the RNA distribution in normal human phagocytes for all three genes. FPR1 and FPRL1 are expressed in neutrophils and monocytes. In contrast, FPRL2 RNA is detectable in monocytes but not in neutrophils, and its product could not be activated by N-formylpeptides. Thus, the regulation of FPRL2 gene expression in vivo differs from FPR1 and FPRL1.