Broad immunocytochemical localization of the formylpeptide receptor in human organs, tissues, and cells

Abstract

The formylpeptide receptor (FPR), previously found only on polymorphonuclear leukocytes and monocytes/macrophages, responds to both synthetic N-formyl oligopeptides and those produced by bacteria. The cDNA for human FPR has been cloned and a rabbit polyclonal antiserum directed against a synthetic 11-amino-acid peptide corresponding to the deduced carboxy-terminus has been produced. We have now extensively characterized and used the antibody to detect FPR on normal human tissues and cell types. The receptor antigen is present on some epithelial cells, especially those with a secretory function, and on some endocrine cells, e.g., follicular cells of the thyroid and cortical cells of the adrenal. Liver hepatocytes and Kupffer cells are positive. Smooth muscle and endothelial cells are also generally positive. In the brain and spinal cord, the neurons of the motor, sensory, and cerebellar systems, and those of the parasympathetic and sympathetic systems stain positively. These data suggest that the putative endogenous agonist for FPR or an antigenically similar receptor reacts with cellular targets in the neuromuscular, vascular, endocrine, and immune systems.

Expression and Function of Formyl Peptide Receptors on Human Fibroblast Cells

“…We were surprised at the abundance of ESTs for FPR and FPRL1 in these nonlymphoid tissues. This nonleukocyte expression was observed by Becker et al (10) who show staining of multiple tissues and cell types with rabbit polyclonal antisera against the C terminus of FPR.…”

“…To the top of 6.5-mm-diameter cell culture inserts of 8 m pore size, 10 5 cells in 200 l were added. In studies with matrixcoated cell culture inserts, inserts were incubated on the top and bottom surfaces with fibronectin (20 g/ml) or collagen IV (20 g/ml) overnight at 4°C, removed, washed with PBS, and allowed to dry before cells were added.…”

The Leukocyte Chemotactic Receptor FPR1 Is Functionally Expressed on Human Lens Epithelial Cells

“…In the past several years some evidence for non-hematopoietic FPR1 expression has accumulated, including ileum, hepatocytes, and thyroid follicular cells (7). Moreover, FPR1 is functionally expressed by fibroblasts and may support migration of these cells to sites of tissue injury (8).…”

Annexin I Regulates SKCO-15 Cell Invasion by Signaling through Formyl Peptide Receptors

“…Immunohistochemical studies using rabbit polyclonal anti-FPR-1 antibodies suggest that it is also expressed in small intestinal epithelial cells (84). Expression of FPRL-1 has also been detected in intestinal epithelial cells, whereas FPRL-2 expression seems restricted to macrophages and dendritic cells (56,(85)(86)(87).…”