| |
|
|
|
|
|
|
|||
|
Blood, 1 November 2007, Vol. 110, No. 9, pp. 3263-3270. Prepublished online as a Blood First Edition Paper on August 10, 2007; DOI 10.1182/blood-2007-07-100453.
Submitted July 10, 2007
Department of Medicine, Harvard Medical School, Boston, MA, United States * Corresponding author; email: jboyce{at}rics.bwh.harvard.edu.
Cysteinyl leukotrienes (cys-LTs) induce inflammation through two G protein-coupled receptors (GPCRs), CysLT1 and CysLT2, which are co-expressed by most myeloid cells. Cys-LTs induce proliferation of mast cells (MCs), transactivate c-Kit, and phosphorylate extracellular signal-regulated kinase (ERK). Although MCs express CysLT2, their responses to cys-LTs are blocked by antagonists of CysLT1. We demonstrate that CysLT2 interacts with CysLT1, and that knock-down of CysLT2 increases CysLT1 surface expression and CysLT1-dependent proliferation of cord blood-derived human MCs (hMCs). Cys-LT-mediated responses were absent in MCs from mice lacking CysLT1 receptors, but enhanced by the absence of CysLT2 receptors. CysLT1 and CysLT2 receptors co-localized to the plasma membranes and nuclei of a human MC line, LAD2. Antibody-based fluorescent lifetime imaging microscopy confirmed complexes containing both receptors based on fluorescence energy transfer. Negative regulation of CysLT1-induced mitogenic signaling responses of MCs by CysLT2 demonstrates physiologically relevant functions for GPCR heterodimers on primary cells central to inflammation.
This article has been cited by other articles:
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Copyright © 2007 by American Society of Hematology Online ISSN: 1528-0020 | |||||||||