Distribution of leukotriene B4 receptors in human hematopoietic cells

Leukotriene B4 (LTB4), a product of arachidonic acid metabolism, plays an i mportant role in inflammatory responses. We have cloned From human erythrol eukemia cells, a G protein-coupled receptor, designated P2k(7), which was l ater identified as the receptor for LTB4 (B-LTR). We have investigated the distribution of LTB4 receptors in various hematopoietic cells. Northern blo tting and reverse transcription-coupled polymerase chain reaction (RT-PCR) analyses using radiolabeled LTB4 receptor cDNA as a probe indicated the pre sence of LTB4 receptor mRNA in peripheral blood leukocytes but not in plate lets. Flow cytometry analysis of peripheral blood cells using specific LTB4 receptor antibodies revealed that monocytes, granulocytes, and lymphocytes , but not platelets, express LTB4 receptors. RT-PCR-Southern hybridization analysis revealed that peripheral blood leukocytes and human umbilical vein endothelial cells express the LTB4 receptor. Of the hematopoietic cell lin es tested, promonocytic U937 cells, promyelocytic HL-60 cells, K562 cells, and human erythroleukemia cells express the LTB4 receptor. These results su ggest a physiological role fur the LTB4 receptor in the stimulation of mono cytes, neutrophils, and endothelial cells. (C) 2000 Elsevier Science B.V. A ll rights reserved.